[Federal Register Volume 62, Number 223 (Wednesday, November 19, 1997)]
[Rules and Regulations]
[Pages 61649-61692]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-29925]


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FEDERAL COMMUNICATIONS COMMISSION

47 CFR Part 68

[CC Docket No. 96-28; FCC 97-270]


Connection of Customer-Provided Terminal Equipment to the 
Telephone Network

AGENCY: Federal Communications Commission.

ACTION: Final rule.

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SUMMARY: On August 22, 1997, the Commission released a report and order 
adopting final rules to amend the Commissions rules, which govern the 
terms and conditions under which customer-provided terminal equipment 
may be connected to the telephone network without causing harm to the 
public switched network. As a result of the amendments, manufacturers 
will be able to test terminal equipment for compliance with a single, 
consistent set of technical standards accepted in both the United 
States and Canada. The harmonization of terminal attachment rules in 
the United States and Canada will be a model for our harmonization 
efforts with other countries.

EFFECTIVE DATE: April 20, 1998.

FOR FURTHER INFORMATION CONTACT:

    Technical Information: William VonAlven, (202) 418-2342 or email at 
[email protected].
    Legal Information: Marian Gordon, (202) 418-2320 or email at 
[email protected]. The address for both is: Network Services Division, 
Common Carrier Bureau, Federal Communications Commission, 2000 M 
Street, NW, Suite 235, Washington, DC 20054. The fax number is: (202) 
418-2345. The TTY number is: (202) 418-0484.

SUPPLEMENTARY INFORMATION:

I. Introduction

    1. In this Report and Order (``Order''), we adopt final rules to 
amend part 68 of the Commission's rules, which governs the terms and 
conditions under which customer-provided terminal equipment may be 
connected to the telephone network without causing harm to the 
network.\1\ The amendments we adopt herein are designed to harmonize 
United States and Canadian requirements governing connection of 
terminal equipment to the public switched network (``PSN'') and to 
promote barrier-free trade between Canada and the United States, in 
keeping with the spirit of the North American Free Trade Agreement

[[Page 61650]]

(``NAFTA'').\2\ As a result of these amendments to part 68, 
manufacturers in one country will be able to design and test terminal 
equipment to comply with a single, consistent set of technical 
standards accepted in both the United States and Canada.
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    \1\ See 47 CFR part 68. For a history of part 68, see Proposals 
for New or Revised Classes of Interstate and Foreign Message Toll 
Telephone Service (``MTS'') and Wide Area Telephone Service 
(``WATS''); Revision of part 68 of the Commission's rules to Specify 
Standard Plugs and Jacks for the Connection of Telephone Equipment 
to the Nationwide Telephone Network; and Amendment of Part 68 of the 
Commission's rules (Telephone Equipment Registration) to Specify 
Standards for and Means of Connection of Telephone Equipment to Lamp 
and/or Annunciator Functions of Systems, Memorandum Opinion and 
Order, 70 FCC 2d 1800 (1979), 45 FR 20841, Mar. 31, 1980.
    \2\ In Canada, certification means the right to attach terminal 
equipment to the PSN. Certification requires submission of an 
application that includes a technical description of the equipment 
and a measurement report showing compliance with CS-03, the Canadian 
terminal attachment standard. Canadian requirements for terminal 
attachment are issued by Industry Canada (``IC''). Under the 
direction of IC, the Terminal Attachment Program Advisory Committee 
(``TAPAC''), a government and industry advisory committee, reviews 
and recommends changes to equipment certification programs. Canada 
amended its terminal attachment rules (CS-03 standards) to harmonize 
Canadian standards for terminal equipment with those set forth in 
part 68 on August 14, 1996. Canada Gazette, part I, June 15, 1996, 
Notice No. SMSE-003-96.
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II. Background

    1. On March 9, 1995, the Telecommunications Industry Association 
(``TIA'') filed a Petition for Rulemaking (``Petition'') to amend 
Secs. 68.300-68.318 and portions of Sec. 68.2 of the Commission's rules 
to harmonize United States network protection standards and 
corresponding Canadian CS-03 certification regulations. Subpart D of 
part 68, which includes Secs. 68.300 through 68.318, addresses 
``Conditions for Registration,'' including requirements for 
environmental simulation (simulation ``mimics'' stresses that terminal 
equipment undergoes in shipment and handling that could potentially 
damage it), leakage current limitations, hazardous voltage limitation, 
signal power limitations, longitudinal balance limitations, on hook 
impedance limitations, billing protection, and hearing aid 
compatibility. Section 68.2 addresses the scope of the Commission's 
rules for terminal attachment.
    2. TIA is a national trade association with more than 570 member 
companies engaged in the manufacture, sale and distribution of 
telecommunications equipment including terminal equipment. TIA's 
Petition is the culmination of four years of technical effort by United 
States and Canadian industry. In September, 1990, TIA's Engineering 
Subcommittee TR-41, sponsored by its User Premises Equipment Division, 
proposed a project to ``address differences'' between Canadian and 
United States terminal attachment rules.\3\ The Subcommittee created a 
joint working group co-chaired by representatives from the United 
States and Canada to develop a harmonized set of rules to comply with 
both countries' requirements for terminal attachment.\4\
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    \3\ TIA's technical work is conducted through its Engineering 
Committees, which develop, maintain, and publish voluntary standards 
and technical reports. TIA encourages these committees to work 
cooperatively with members of the American National Standards 
Institute (``ANSI''), as well as international standards bodies 
outside the United States, to harmonize telecommunications equipment 
standards to avoid duplicating standardization work already 
successfully completed. TIA's stated trade policy goals include 
``removal of barriers to market access, full participation of United 
States government and industry in the standards-setting process 
worldwide, and achievement of a minimum level of standards required 
to ensure interoperability and proper function of the international 
network.'' See TIA Petition at 2.
    \4\ According to TIA, a wide range of interest groups in the 
United States and Canada were represented including carriers, 
manufacturers, laboratories, consultants and government personnel.
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    3. In February 1996, in response to TIA's Petition and comments 
received on the petition, the Commission issued a Notice of Proposed 
Rulemaking (NPRM) proposing to amend Part 68 to harmonize United States 
and Canadian requirements for connection to the PSN.\5\ In the NPRM, 
the Commission tentatively concluded that the amended rules would 
promote barrier-free trade between the United States and Canada by 
eliminating unnecessary differences in terminal attachment 
requirements.\6\ We tentatively concluded that the amended rules would 
be consistent with the spirit of NAFTA, and might become a guide for 
harmonization efforts with other countries.\7\ Furthermore, we 
tentatively concluded that the amended rules would create a more 
competitive equipment marketplace, resulting in lower costs for 
equipment, thereby benefitting United States and Canadian consumers. We 
also stated that the proposed rules were consistent with our commitment 
to ensure that customers and manufacturers can connect terminal 
equipment to the telephone network without causing harm to the 
network.\8\ Finally, we tentatively concluded that the Commission must 
retain ultimate responsibility for part 68 functions, but should rely 
on standards bodies whenever possible to resolve complex technical 
matters. We sought comment on these tentative conclusions.\9\
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    \5\ See Public Notice, ``Pleading Cycle Established for Comments 
on TIA's Petition for Rulemaking to Amend part 68, Subpart D'', 10 
FCC Rcd 4548 (March 27, 1995); Amendment of Part 68 of the 
Commission's Rules, Notice of Proposed Rulemaking, 11 FCC Rcd 13282 
(1996), 61 FR 15441, Apr. 8, 1996, Erratum, (Mar. 29, 1996) 
(``NPRM''). Seven parties filed comments in response to the NPRM. On 
April 16, 1996, one party filed reply comments.
    \6\ NPRM 11 FCC Rcd at 13295.
    \7\ Id. The rules are consistent with the aims of the World 
Trade Organization, which like NAFTA, seek to reduce trade barriers 
in order to promote competition.
    \8\ Id.
    \9\ Id.
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III. Discussion

A. Technical Amendments

    4. Positions of the Parties. There is unanimity of opinion among 
commenters that harmonization of part 68 and CS-03 will benefit 
terminal equipment manufacturers as well as the telecommunications 
industry. There were no oppositions to any of the proposed rules. 
Northern Telecom (``Nortel''), for example, supports the Commission's 
proposal and suggests that harmonization of technical requirements for 
attachment of terminal equipment to the PSN will facilitate trade 
between the United States and Canada because manufacturers will need to 
design and test to only one set of common standards.\10\ Lucent agrees 
that the amendment of part 68 will result in commercial advantages.\11\ 
NYNEX argues that, under the proposed rules, a de facto barrier to 
trade that was inconsistent with NAFTA will be eliminated.\12\ 
Ameritech says that the proposed rules are an example of how ``the 
government and industry can achieve agreement without the need for 
additional regulation.'' \13\
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    \10\ Nortel Comments at 1; see also VeriFone Comments at 1.
    \11\ Lucent Comments at 2.
    \12\ NYNEX Comments at 2.
    \13\ Ameritech Comments at 1; see also Verifone Comments at 1.
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    5. TIA and Sprint propose editorial corrections to the part 68 
rules in attachments to each of their comments.\14\ Additionally, 
Sprint argues that the Commission should add any tariffed data rates, 
i.e., all speeds of data communications that telephone companies agree 
to provide to the public for a requested service, to the amendments to 
part 68.\15\ More specifically, Sprint states that 38.4 kbps is an 
existing T1 subrate service and as such ``qualifies for protection in 
accordance with the purpose of the part 68 rules.'' \16\
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    \14\ Sprint Comments at 1; TIA Comments at 2.
    \15\ Sprint Comments at 3.
    \16\ Sprint requests that the valid tariffed data rate of 38.4 
kbps be included in Sec. 68.308(h)(1)(i), Table 68.308(c), and Table 
68.310(b). NPRM, 11 FCC Rcd at 13241-42, 13431, 61 FR 15441, Apr. 8, 
1996.
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    6. Discussion. Based on the record, we amend part 68 to harmonize 
it with Canada's CS-03 and summarize our amendments as follows. Section 
68.302 is designed to protect the network from harm by ensuring that, 
despite being subject to environmental stresses, terminal equipment 
will continue to comply with part 68 and not harm the

[[Page 61651]]

network. Amended Sec. 68.302 deletes vibration, temperature, and 
humidity stresses from part 68, and applies mechanical shock stresses 
only to equipment that might be affected by such stress. We delete 
these stresses because experience has shown, and the record supports, 
that they are unnecessary given the technological evolution in telecom 
equipment from an arrangement of discrete electronic components to 
solid state circuitry. Over the past ten years, failures during part 68 
registration testing involving these stresses is negligible. The 
benefits of streamlining our regulations in this regard far outweigh 
any possible harm to the network created by these stresses. In 
addition, as the result of industry coordination, we are including a 
new Type B surge test to better assure operability of customer premises 
equipment during lightning storms.
    7. Section 68.304 leakage current limitations ensure that telephone 
connections are adequately insulated against hazards to telephone 
company personnel caused by voltages within the equipment itself or as 
a result of accidental contact with commercial power sources. 
Previously, Sec. 68.304 required testing using a 60 Hertz test voltage. 
Amended Sec. 68.304 changes the 60 Hertz standard to either 50 or 60 
Hertz to harmonize with international frequencies used for this purpose 
and with Underwriters Laboratories and Canadian Standards Association 
insulation standards.
    8. Section 68.306 imposes ``fail safe'' requirements on hazardous 
voltage. These limits are generally used throughout the telephone 
industry as voltage limitations below which special protection of 
telephone craft personnel is not required. Equipment must be designed 
to avoid creating voltages exceeding these limits under normal 
operation. We amend this section to delete hazardous voltage 
requirements for Message Registration (``MR'') and Automatic 
Identification of Outward Dialing (``AIOD'') because these types of 
technology are no longer in use.\17\ In addition, this Order changes 
the current voltage limitation from 80 to 60 volts to harmonize it with 
international safety standards.
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    \17\ Message Registration (``MR'') was a specific traffic 
recording system provided by certain older types of telephone 
systems. Automatic Identification of Outward Dialing (``AIOD'') was 
a private branch exchange (PBX) service feature that identified the 
calling line on calls directed to a public switched telephone 
network for automatic message accounting recording purposes.
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    9. The signal power limitations of Sec. 68.308 are designed to 
protect the network from interference caused by excessive signal power. 
We update this section by revising the ``Through Gain'' Table to 
reflect services such as Integrated Services Digital Network (``ISDN'') 
and to delete references to the 4-wire Conventional Termination Set 
interface.\18\ We also expand subrate digital channel rates to include 
all rates presently used by industry, and adopt the ANSI T1 standard to 
replace the standard in the previous rules.\19\ Section 68.308 also 
protects the network from harm by addressing crosstalk interference. We 
reword this section for clarity and rename this section ``Transverse 
Balance Limitations'' to harmonize it with internationally recognized 
Institute of Electrical and Electronic Engineers' (``IEEE'') 
terminology.
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    \18\ The Through Gain Table shows the maximum net amplification 
permitted in multiport systems between ports. The 4-wire 
Conventional Terminating Set interface was an older technology used 
for connection of customer provided equipment to analog voiceband 
private line services.
    \19\ Subrate digital channel rates previously used by the 
industry ranged from 2.4 to 64 kilobits/second (kbps).
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    10. Section 68.312 addresses the impedance (i.e., the resistance a 
circuit offers to alternating current) that must be maintained on a 
telephone line. The amended rules reorganize and reword this section 
for clarity. Specifically, the amended rules reduce the categories of 
ringer types. We also delete those sections addressing message 
registration because this technology is no longer in use.
    11. Section 68.314 ensures that transmission of signals in the 
network does not interfere with proper operation of network billing 
equipment. The amendments to this section include rewording the section 
for clarity and deleting operating requirements for AIOD because the 
technology has been replaced. We also add a new section to clarify 
reverse battery billing (a type of loop signaling) requirements. 
Section 68.316 Hearing Aid Compatibility requirements are not amended 
by this Order. Furthermore, we delete reference to 1.544 Mbps digital 
``keep-alive'' requirements from Sec. 68.318 because they are no longer 
in effect.\20\ Finally, we amend definitions in Sec. 68.3. For example, 
we delete references to MR and AIOD equipment, but clarify that any MR 
and AIOD equipment that remains connected to the network may continue 
to be used under the provisions of Sec. 68.2.
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    \20\ Keep-alive refers to constantly present direct current 
voltage formally provided from the central office. Section 68.318 
previously stated that ``(u)ntil December 18, 1989, terminal 
equipment connecting to 1.544 Mbps services shall contain circuitry 
that assures continuity of output signal.''
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    12. The record supports our tentative conclusion that amendment of 
part 68 as described above should lower the price consumers pay for 
terminal equipment by facilitating greater efficiencies in the 
manufacturing and testing of terminal equipment. Under the amended 
rules, the technical requirements of part 68 and CS-03 would be 
harmonized so that a manufacturer in one country can design and test 
terminal equipment to a single, consistent set of technical standards 
accepted in both the United States or Canada. We conclude that these 
efficiencies will lead to an even more competitive market for terminal 
equipment than currently exists, resulting in lower costs for 
equipment, thus benefitting United States and Canadian consumers.
    13. Moreover, as commenters recognize, the amendments to part 68 
reconcile differences in standards and testing consistent with NAFTA. 
Currently, terminal equipment manufactured for use in the United States 
must meet the technical requirements of part 68. Similarly, terminal 
equipment manufactured for use in Canada must comply with the technical 
requirements contained in CS-03. Each country's respective technical 
requirements have differed sufficiently that terminal equipment 
complying with one set of regulations would not necessarily comply with 
the technical requirements of the other country. These differences, as 
NYNEX correctly states, have created unreasonable burdens on 
manufacturers and are a de facto barrier to trade inconsistent with the 
goals of NAFTA. By reconciling differences in standards and testing, 
harmonization promotes the goals of NAFTA.\21\ Furthermore, the record 
supports our tentative conclusion that, as amended, the rules remain 
consistent with the Commission's longstanding commitment to ensure that 
no public harm results from attachment of private equipment to the PSN. 
The record is unanimous that the amended

[[Page 61652]]

rules in no way diminish network protection.
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    \21\ At a February 1997 meeting of the Telecommunications 
Standards Subcommittee (``TSSC''), Mexico agreed to a ``Minimal'' 
set of network protection standards pursuant to NAFTA Article 1304-1 
(with minor exceptions to accommodate national deviations in 
networks) consistent with our initiative here to harmonize United 
States and Canadian network protection standards. The TSSC was 
established under NAFTA (Article 913) to creat a work plan for 
``making compatible the standards-related measures for authorized 
equipment.'' It is comprised of officials from NAFTA member 
countries.
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    14. Finally, we have reviewed the editorial corrections proposed by 
TIA and Sprint and find that they clarify our rules. For this reason, 
our final rules incorporate these suggested changes. In addition, we 
have added the tariffed data rate that Sprint suggests to our rules. 
While we decline to require that all tariffed rates be included, we 
agree that the specific tariffed rate Sprint suggests should be 
included to cover its currently available service.

B. Grandfathering Provision

    15. Positions of the Parties. Lucent argues that the Commission 
should amend Sec. 68.2(j) to ``provide grandfathering for existing 
equipment, in order to avoid any requirement to re-register all the 
equipment that has already been registered under current rules.'' \22\ 
Lucent argues that a grandfathering provision is necessary to avoid re-
registration of products that are already registered under current 
rules, are in use, and do not cause harm to the network. Several of the 
commenters add that re-registration of these products would impose 
substantial expense without yielding any benefits. We note that no 
party has objected to a grandfathering provision.
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    \22\ Lucent Comments at 2; see also TIA Comments at 2-3.
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    16. Discussion. We are persuaded by commenters that there would be 
no benefit to requiring the re-registration of equipment already in use 
and shown not to cause harm to the network. We therefore adopt a 
grandfathering provision.\23\ The new rule 68.2(j) reads as follows:

    \23\ We note, however, that based on past experience, the vast 
majority of equipment covered by the grandfathering rule will be 
phased out of production and replaced by models that will be subject 
to the new rules.
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    Terminal equipment and systems registered prior to April 20, 
1998, do not have to be re-registered unless subsequently modified. 
All new equipment and systems manufactured after May 19, 1999, must 
conform to the requirements.

C. Regulatory Process

    17. Background. In the NPRM, we stated that although harmonization 
of technical requirements for attachment of terminal equipment 
satisfies NAFTA requirements in a manner consistent with the interests 
of United States industry in facilitating greater efficiencies in 
manufacturing terminal equipment, we recognized that the usefulness of 
a harmonized standard is jeopardized if our regulatory process does not 
allow the standard to evolve at the same pace as technology.\24\ 
Consequently, we tentatively concluded that the Commission should rely, 
whenever possible, on standards bodies to resolve complex technical 
issues. We stated our reluctance, however, to substitute industry 
consensus for our part 68 rulemaking function as such consensus may not 
always promote the public interest.\25\ We noted that standards bodies 
often lack the Commission's authority to ensure compliance with fair 
rules supporting safe and direct electrical connection of subscriber's 
terminal equipment to the PSN.\26\
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    \24\ NPRM, 11 FCC Rcd at 13294.
    \25\ Id. at 13295.
    \26\ Id.
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    18. Positions of the Parties. TIA and NYNEX urge the Commission to 
adopt a rule requiring manufacturers to comply with the technical 
recommendations of industry standards bodies with appropriate 
Commission oversight. NYNEX states that ``(i)nstead of specifying 
technical interfaces and requirements for terminal equipment in the 
rules, the Commission should simply adopt a rule that requires 
manufacturers of such equipment to comply with the technical 
requirements and technical recommendations developed by appropriate 
industry standards bodies under the Commission's auspices * * * .'' 
\27\ NYNEX contends that through its oversight of industry standards 
bodies, the Commission should be satisfied as to the ``reasonableness'' 
of any resulting technical recommendations. TIA argues that the current 
regulatory rulemaking process lags behind changes in technology and 
supports NYNEX's proposal.\28\ Moreover, TIA states that NYNEX's 
suggested approach would be consistent with recent congressional 
directives.\29\ VeriFone contends that industry standards bodies should 
remain responsible for technical issues, but concurs with the 
Commission's decision to retain ultimate responsibility in matters 
pertaining to part 68 rulemaking authority.
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    \27\ NYNEX Comments at 3.
    \28\ TIA Comments at 3; TIA Reply Comments at     3-5.
    \29\ See, e.g., National Technology Transfer and Advancement Act 
of 1995, Pub. L. 104-113, sec. 12, 110 Stat. 775, 782-83 (1996).
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    19. Discussion. We acknowledge that efforts to harmonize our 
terminal attachment rules with those of other countries will be impeded 
if the regulatory rulemaking process fails to keep pace with 
technological changes. Therefore, we conclude that the Commission 
should rely, whenever possible, on standards bodies composed of 
industry experts to resolve complex technical matters. As we stated in 
the NPRM, the Consultative Committee on Telecommunications (``CCT'') 
has substantially assisted various harmonization activities.\30\ 
Additionally, we recently sought comment on whether standards for 
enhanced wire quality and for determining gold equivalence should be 
permanent standards and, if so, what industry body or bodies shall 
determine an appropriate voluntary standard.\31\ We decline, however, 
to substitute industry consensus completely for our part 68 rulemaking 
function. While they often may most expeditiously resolve complex 
technical matters, standards bodies lack the Commission's authority to 
ensure compliance with fair rules supporting safe and direct electrical 
connection of subscribers' telephone terminal equipment to the PSN. We 
note, for example, that new section 273(d)(4) of the Communications Act 
of 1934, as amended, seeks to ensure that voluntary standards do not 
become de facto standards that operate to exclude legitimate parties. 
Similarly, while it in this proceeding has strived to incorporate the 
advice and assistance of standards bodies to resolve complex technical 
matters, the Commission must continue to ensure through its rulemaking 
function that fair rules are developed.
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    \30\ NPRM, 11 FCC Rcd at 13294.
    \31\ Review of Secs. 68.104 and 68.213 of the Commission's Rules 
Concerning Connection of Simple Inside Wiring to the Telephone 
Network, Order on Reconsideration, Second Report and Order and 
Second Further Notice of Proposed Rulemaking, CC Docket No. 88-57, 
FCC 97-209 (June 17, 1997), at paras. 54-55, 62 FR 36463, Jul. 8, 
1997.
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IV. Conclusion

    20. We conclude that the rules we adopt herein will eliminate 
unnecessary differences in terminal attachment requirements, and 
thereby promote barrier-free trade, between the United States and 
Canada. We find this to be consistent with the spirit and letter of 
NAFTA, which mandates elimination of trade barriers through 
reconciliation of differences in standards and testing procedures. 
These rules may become a model for our harmonization efforts with 
countries around the world and should benefit consumers by creating a 
more competitive equipment marketplace, thereby lowering the prices 
they pay for equipment. We conclude that these rules are consistent 
with the Commission's long-standing commitment to ensure that no public 
harm results from attachment of private

[[Page 61653]]

equipment to the public switched network.

V. Regulatory Flexibility Analysis

    21. Final Regulatory Analysis: As required by the Regulatory 
Flexibility Act (``RFA''),\32\ an Initial Regulatory Flexibility 
Analysis (``IRFA'') was incorporated in the Notice of Proposed 
Rulemaking in this proceeding, 11 FCC Rcd 13282 (1996); Erratum, 
(released March 29, 1996) (``NPRM''). The Commission sought written 
public comments on the proposals in the NPRM, including comment on the 
IRFA. This present Final Regulatory Flexibility Analysis (``FRFA'') in 
this Report and Order (``Order'') conforms to the RFA.
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    \32\ See 5 U.S.C. 603. The RFA, see 5 U.S.C. 601 et seq., has 
been amended by the Contract With America Advancement Act of 1996, 
Pub. L. 104-121, 110 Stat. 847 (1996) (CWAAA). Title II of the CWAA 
is the Small Business Regulatory Enforcement Fairness Act of 1996 
(SBREFA).
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Need for, and Objectives of, This Order and the Rules Adopted Herein
    22. Consistent with the intent of the North American Free Trade 
Agreement (``NAFTA''), this Order amends part 68 of the Commission's 
rules to promote barrier-free trade between the United States and 
Canada. Part 68 governs the terms and conditions under which customer 
provided terminal equipment may be connected to the telephone network. 
As a result of the amendments to part 68, manufacturers will be able to 
test terminal equipment for compliance with a single, consistent set of 
technical standards accepted in both the United States and Canada. The 
harmonization of terminal attachment rules in the United States and 
Canada will be a model for our harmonization efforts with other 
countries. We adopt a grandfathering provision to cover equipment 
already registered under current rules.
Summary of Significant Issues Raised by Public Comments in Response to 
the IRFA
    23. No comments were submitted specifically in response to the 
IRFA. We have reviewed the general comments to identify issues that may 
have a significant economic impact on small businesses. All commenters 
addressing the proposed amendments to part 68 of our Rules supported 
the amendments.
Description and Estimate of the Number of Small Entities To Which Rules 
Will Apply
    24. The RFA directs the Commission to provide a description of and, 
where feasible, an estimate of the number of small entities that will 
be affected by the proposed rules. The RFA defines the term ``small 
entity'' as having the same meaning as the terms ``small business,'' 
``small organization,'' and ``small business concern'' under section 3 
of the Small Business Act.\33\ A small business concern is one which: 
(1) Is independently owned and operated; (2) is not dominant in its 
field of operation; and (3) satisfies any additional criteria 
established by the SBA.\34\ SBA has defined a small business for 
Standard Industrial Classification (``SIC'') category 4813 (Telephone 
Communications), Except Radiotelephone) to be a small entity when it 
has no more than 1,500 employees.\35\
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    \33\ See 5 U.S.C. 601(3) (incorporating by reference the 
definition of ``small business concern'' in 5 U.S.C. 632).
    \34\ 15 U.S.C. 632.
    \35\ See 13 CFR 121.201.
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    25. Consistent with our prior practice, we here exclude small 
incumbent local exchange carriers (LECs) from the definition of small 
entity and small business concern. While such a company may have 1500 
or fewer employees and thus fall within the SBA's definition of a small 
telecommunications entity, such companies are either dominant in their 
field of operations or are not independently owned and operated. Out of 
an abundance of caution, however, for regulatory flexibility analysis 
purposes, we will consider small incumbent LECs within this present 
analysis and use the term ``small incumbent LECs'' to refer to any 
incumbent LEC that arguably might be defined by SBA as a small business 
concern.
    26. Manufacturers of Telecommunications Equipment: The Commission 
has not developed a definition of small manufacturers of terminal 
equipment. The closest applicable definition under SBA rules is for 
manufacturers of telephone and telegraph apparatus (SIC 3661), which 
defines a small manufacturer as one having 1000 or fewer employees.\36\ 
According to 1992 Census Bureau data, there were 479 such 
manufacturers, and of those, 436 had 999 or fewer employees, and 7 had 
between 1000 and 1499 employees.\37\ Consequently, we estimate that 
there are fewer than 443 small manufacturers of terminal equipment that 
may be affected by the decision and rules adopted in this Order.
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    \36\ 13 CFR 121.201, SIC 3661.
    \37\ 1992 Economic Census, Industry and Employment Size of Firm, 
Table 1D (data prepared by U.S. Census Bureau under contract to the 
U.S. Small Business Administration).
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Description of Projected Reporting, Recordkeeping and Other Compliance 
Requirements
    27. There are no reporting or recordkeeping requirements. 
Manufacturers will be required to test terminal equipment to a single, 
consistent set of technical standards accepted in both the United 
States and Canada.
Steps Taken to Minimize Significant Economic Impact on Small Entities, 
and Significant Alternatives Considered
    28. We are adopting Sec. 68.2(j), which states that equipment 
already registered under the current rules does not need to be re-
registered under the new rules. We believe that such a provision will 
save manufacturers, some of which may be small businesses, the expenses 
incurred in re-registering equipment that is already in use and has 
been shown not to cause harm to the network.\38\ No alternative to this 
beneficial action was suggested.
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    \38\ The rule changes ameliorate potential technical barriers to 
entry in both the U.S. and Canada markets, thereby allowing 
manufacturers and suppliers, including small manufacturers and 
suppliers, a reasonable opportunity to conduct business in both 
markets. This result in consistent with the general purposes of 
section 257 of the 1996 Telecommunications Act, 47 U.S.C. 257. That 
section requires, among other things, that the Commission eliminate 
market entry barriers for small businesses who may provide parts or 
services to providers of telecommunications services and information 
services. Id. at section 257(a). The Commission recently issued a 
report in GN Docket No. 96-113 regarding its implementation of 
Section 257. See Section 257 Proceeding to Identify and Eliminate 
Market Entry Barriers for Small Businesses, Report No. 97-8, 1997 WL 
232120 (1997).
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Report to Congress
    29. The Commission will send a copy of the Order, including this 
FRFA, in a report to be sent to Congress pursuant to the Small Business 
Regulatory Enforcement Fairness Act of 1996, see 5 U.S.C. 801(a)(1)(A). 
A copy of the Order and this FRFA (or summary thereof) will also be 
published in the Federal Register, see 5 U.S.C. 604(b), and will be 
sent to the Chief Counsel for Advocacy of the Small Business 
Administration.

VI. Ordering Clauses

    30. Accordingly, it is ordered that, pursuant to sections 1, 4, 
201-205, 218, 220, 226, 227, 255, and 710 of the Communications Act of 
1934, as amended, 47 U.S.C. 151, 154, 201-205, 218, 220, 226, 227, 255, 
and 610, and 5 U.S.C. 552 and 553, this Report and Order is adopted, 
and part 68 of the

[[Page 61654]]

Commission's rules are amended as set forth below.
    31. It is further ordered, that the rule amendments set forth below 
shall be effective April 20, 1997.
    32. It is further ordered, that the Commission shall send a copy of 
this Order, including the Final Regulatory Flexibility Analysis, to the 
Chief Counsel for Advocacy of the Small Business Administration.

List of Subjects in 47 CFR Part 68

    Administrative practice and procedure, Communications common 
carriers, Communications equipment, Telephone.

Federal Communications Commission.
William F. Caton,
Acting Secretary.

    47 CFR part 68 is amended as follows:

PART 68--CONNECTION OF TERMINAL EQUIPMENT TO THE TELEPHONE NETWORK

    1. The authority citation for part 68 continues to read as follows:

    Authority: Sec. 1, 4, 5, 201-5, 208, 215, 218, 226, 227, 303, 
313, 314, 403, 404, 410, 522 of the Communications Act of 1934, as 
amended, 47 U.S.C. 151, 154, 155, 201-5, 208, 215, 218, 226, 227, 
303, 313, 314, 403, 404, 410, 522.

    2. Section 68.2 is amended by revising paragraphs (a)(3); (d), 
introductory text, and paragraph (j) and adding new paragraph (d)(4) to 
read as follows:


Sec. 68.2  Scope.

    (a) * * *
    (3) Of all PBX (or similar) systems to private line services for 
tie trunk type interfaces and off premises station lines. Services may 
only be added to this section as a result of rulemaking proceedings and 
equipment connected to such added services is afforded a reasonable 
transition period.
* * * * *
    (d) Grandfathered private branch exchange (or similar) systems for 
connection to private line type services (tie trunk type services, off-
premises station lines automatic identified outward dialing, and 
message registration):
* * * * *
    (4) PBX (or similar) systems connected with automatic identified 
outward dialing or message registration private line services of a type 
that complies with paragraphs (d)(l) and (d)(2) of this section may 
remain connected for life without registration unless subsequently 
modified.
* * * * *
    (j) Terminal equipment including premises wiring and protective 
apparatus (if any) directly connected to the network on April 20, 1997, 
may remain connected and be reconnected for life without registration, 
unless subsequently modified. New installations of terminal equipment, 
including premises wiring and protective apparatus (if any) may be 
installed (including additions to existing systems) up to May 19, 1999, 
without registration of any terminal equipment involved, provided that 
the terminal equipment is of a type directly connected to the network 
as of April 20, 1998. This terminal equipment may remain connected and 
be reconnected to the network for life without registration, unless 
subsequently modified.
* * * * *
    3. Section 68.3 is amended by adding the following definitions for 
Capture Level, Dual Tone Multi Frequency (DTMF), Overload Point, and 
Voiceband in alphabetical order; by revising the definition for ``Zero 
Level Decoder''; removing the definitions for AOID Data Channel 
Simulator, AIOD Leads, Message Register Leads, Message Register 
Signaling Channel Simulator; in the definition for Tie Trunk 
Transmission Interfaces, by removing paragraph (c) 4-wire Conventional 
Terminating Set (CTS); removing figures 68.3(a), 68.3(f), 68.3(g), 
68.3(h), 68.3(i), 68.3(j), 68.3(k), 68.3(l) and 68.3(m) and adding in 
their place Figures 68.3(a), 68.3(f), 68.3(g), 68.3(h), 68.3(i), 
68.3(j) and 68.3(k). Figure references are corrected in the following 
definitions: In Local Area Data Channel Simulator, Figure 68.3(k) is 
revised to read Figure 68.3(i), and in Loop Simulator Circuit, Figure 
68.3(i) is revised to read Figure 68.3(g) and Figure 68.3(j) is revised 
to read Figure 68.3(h).


Sec. 68.3  Definitions.

* * * * *
    Capture Level: Equipment with AGC (Automatic Gain Control) signal 
power limiting has virtually no output signal for input levels below a 
certain value. At some input signal power, the output level will become 
significant (usually corresponding to the expected output level) for 
the service application. The input level at which this occurs is 
defined as the ``capture level.''
* * * * *
    Dual Tone Multi Frequency (DTMF) network control signalling is a 
method of signalling using the voice transmission path. The method 
employs sixteen (16) distinct signals each composed of two (2) 
voiceband frequencies, one from each of two (2) geometrically spaced 
groups designated ``low group'' and ``high group.'' The selected 
spacing assures that no two frequencies of any group combination are 
harmonically related.
* * * * *
    Overload Point: (1) For signal power limiting circuits 
incorporating automatic gain control method, the ``overload point'' is 
the value of the input signal that is 15 dB greater than the capture 
level.
    (2) For signal power limiting circuits incorporating peak limiting 
method, the ``overload point'' is defined as the input level at which 
the equipment's through gain decreases by 0.4 dB from its nominal 
constant gain.
* * * * *
    Voiceband: The voiceband for analog interfaces is the frequency 
band from 200 Hz to 3995 Hz.
* * * * *
    Zero Level Decoder: The zero level decoder shall comply with the 
u=255 PCM encoding law as specified in ITU-TSS (CCITT) Rec. G.711 for 
voiceband encoding and decoding. See also Fig. 68.3(j).
* * * * *
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[[Page 61664]]

Sec. 68.222  [Removed]

    4. Section 68.222 is removed.
    5. Section 68.300 is revised to read as follows:


Sec. 68.300  Labeling requirements.

    (a) Registered terminal equipment and registered protective 
circuitry shall have prominently displayed on an outside surface the 
following information in the following format:
Complies With Part 68, FCC Rules
FCC Registration Number: __________

Ringer Equivalence: ________________

    (b) Registered terminal equipment and registered protective 
circuitry shall also have the following identifying information 
permanently affixed to it.
    (1) Grantee's name.
    (2) Model number, as specified in the registration application.
    (3) Serial number or date of manufacture.
    (4) Country of origin of the equipment: ``Made in __________.'' 
Required if the equipment is not manufactured in the United States. 
(Country of origin shall be determined in accordance with 19 U.S.C. 
1304 and regulations promulgated thereunder.)
    (5) As used herein, permanently affixed means that the required 
nameplate data is etched, engraved, stamped, indelibly printed or 
otherwise permanently marked. Alternatively, the required information 
may be permanently marked on a nameplate of metal, plastic, or other 
material fastened to the enclosure by welding, riveting, or with a 
permanent adhesive. Such a nameplate must be able to last for the 
expected lifetime of the equipment and must not be readily detachable.
    (6) When the device is so small or for such use that it is not 
practical to place the statements specified in this section on it, the 
information required by paragraphs (a) and (b) of this section shall be 
placed in a prominent location in the instruction manual or pamphlet 
supplied to the user. The FCC Registration Number and the Model Number 
shall be displayed on the device.
    6. Section 68.302 is revised to read as follows:


Sec. 68.302  Environmental simulation.

    Unpackaged Registered Terminal Equipment and Registered Protective 
Circuitry shall comply with all the rules specified in this subpart, 
both prior to and after the application of the mechanical and 
electrical stresses specified in this section, notwithstanding that 
certain of these stresses may result in partial or total destruction of 
the equipment. Both telephone line surges, Type A and Type B, shall be 
applied as specified in paragraphs (b) and (c) of this section. 
Different failure criteria apply for each surge type.
    (a) Mechanical shock. (1) Hand-Held Items Normally Used at Head 
Height: 18 random drops from a height of 1.5 meters onto concrete 
covered with 3 millimeters asphalt tile or similar surface.
    (2) Table (Desk) Top Equipment 0-5 kilograms: Six random drops from 
a height of 750 millimeters onto concrete covered with 3 millimeters 
asphalt tile or similar surface.
    (3) The drop tests specified in the mechanical shock conditioning 
stresses shall be performed as follows: The unit should be positioned 
prior to release to ensure as nearly as possible that for every six 
drops there is one impact on each of the major surfaces and that the 
surface to be struck is approximately parallel to the impact surface.
    (b) Telephone Line Surge--Type A.--(1) Metallic. Apply two metallic 
voltage surges (one of each polarity) between any pair of connections 
on which lightning surges may occur; this includes:
    (i) Tip to ring;
    (ii) Tip 1 to ring 1; and
    (iii) For a 4-wire connection that uses simplexed pairs for 
signalling, tip to ring 1 and ring to tip 1.

    Note to paragraph (b)(1). The surge shall have an open circuit 
voltage waveform in accordance with Figure 68.302(b) having a front 
time (tf)) of 10 s maximum and a decay time 
(td) of 560 s minimum, and shall have a short 
circuit current waveshape in accordance with Figure 68.302(c) having 
a front time (tf) of 10 ms maximum and a decay time 
(td) of 560 s minimum. The peak voltage shall be 
at least 800 volts and the peak short circuit current shall be at 
least 100 amperes. Surges are applied:

    (A) With the equipment in all states that can affect compliance 
with the requirements of this part 68. If an equipment state cannot 
be achieved by normal means of power, it may be achieved 
artificially;
    (B) With equipment leads not being surged (including telephone 
connections, auxiliary leads, and terminals for connection to non-
registered equipment) terminated in a manner that occurs in normal 
use;
    (C) Under reasonably foreseeable disconnection of primary power 
sources, with primary power cords plugged and unplugged, if so 
configured.

    (2) Longitudinal. Apply two longitudinal voltage surges (one of 
each polarity) from any pair of connections on which lightning surges 
may occur. This includes the tip-ring pair and the tip 1--ring 1 pair, 
to earth grounding connections, and to all leads intended for 
connection to non-registered equipment, connected together. Surges are 
applied as follows:
    (i) With the equipment in all states that can affect compliance 
with the requirements of this part 68. If an equipment state cannot be 
achieved by normal means of power, it may be achieved artificially;
    (ii) With equipment leads not being surged (including telephone 
connections, auxiliary leads, and terminals for connection to non-
registered equipment) terminated in a manner that occurs in normal use;
    (iii) Under reasonably foreseeable disconnection of primary power 
sources, as for example, with primary power cords plugged and 
unplugged.

    Note to paragraph (b)(2): The surge shall have an open circuit 
voltage waveform in accordance with Figure 68.302(b) with a front 
time (tf) of 10 ms (seconds) maximum 
and a decay time (td) of 160 ms minimum, and shall have a 
short circuit current waveshape in accordance with Figure 68.302(c) 
having a front time (tf) of 10 ms maximum and a decay 
time (td) of 160 ms minimum. The peak voltage shall be at 
least 1500 volts and the peak short circuit current shall be at 
least 200 amperes.

    (3) Failure Modes resulting from application of Type A telephone 
line surges. Regardless of operating state, equipment and circuitry are 
allowed to be in violation of the longitudinal balance requirements of 
Sec. 68.310(b) and (c) and, for terminal equipment connected to Local 
Area Data Channels, the longitudinal signal power requirements of Sec.  
68.308(f)(3), if:
    (i) Such failure results from an intentional, designed failure mode 
that has the effect of connecting telephone or auxiliary connections 
with earth ground; and,
    (ii) If such a failure mode state is reached, the equipment is 
designed so that it would become substantially and noticeably unusable 
by the user, or an indication is given (e.g., an alarm), in order that 
such equipment can be immediately disconnected or repaired.

    Note to paragraph (b)(3)(ii): The objective of paragraph 
(b)(3)(ii) is to allow for safety circuitry to either open-circuit, 
which would cause a permanent on-hook condition, or to short-circuit 
to ground, as a result of an energetic lightning surge. Off-hook 
tests would be unwarranted if the off-hook state cannot be achieved. 
A short to ground has the potential for causing interference 
resulting from longitudinal imbalance, and therefore designs must be 
adopted which will cause the equipment either to be disconnected or 
repaired rapidly after such a state is reached, should it occur in 
service.

    (c) Telephone Line Surge--Type B.--(1) Metallic. Apply two metallic 
voltage surges (one of each polarity) to equipment between any pair of

[[Page 61665]]

connections on which lightning surges may occur; this includes:
    (i) Tip to ring;
    (ii) Tip 1 to ring 1; and
    (iii) For a 4-wire connection that uses simplexed pairs for 
signalling, tip to ring 1 and ring to tip 1.

    Note to paragraph (c)(1): The surge shall have an open circuit 
voltage waveform in accordance with Figure 68.302(b) having a front 
time (tf) of 9 ms (30%) and a decay time 
(td) of 720 s (20%) and shall have a 
short circuit current waveshape in accordance with Figure 68.302(c) 
having a front time (tf) of 5 ms (30%) and a 
decay time (td) of 320 s (20%). The 
peak voltage shall be at least 1000 volts and the peak short circuit 
current shall be at least 25 amperes. The wave shapes are based on 
the use of ideal components in Figure 68.302(a) with S2 
in Position M. Surges are applied:

    (A) With the equipment in all states that can affect compliance 
with the requirements of this part 68. If an equipment state cannot 
be achieved by normal means of power, it may be achieved 
artificially.
    (B) With equipment leads not being surged (including telephone 
connections, auxiliary leads, and terminals for connection to non-
registered equipment) terminated in a manner that occurs in normal 
use.
    (C) Under reasonably foreseeable disconnection of primary power 
sources, as for example, with primary power cords plugged and 
unplugged.

    (2) Longitudinal. Apply two longitudinal voltage surges (one of 
each polarity) from any pair of connections on which lightning surges 
may occur. This includes the tip-ring pair and the tip 1--ring 1 pair 
to earth grounding connections and to all leads intended for connection 
to non-registered equipment, connected together. Surges are applied as 
follows:
    (i) With the equipment in all states that can affect compliance 
with the requirements of this part 68. If an equipment state cannot be 
achieved by normal means of power, it may be achieved artificially.
    (ii) With equipment leads not being surged (including telephone 
connections, auxiliary leads, and terminals for connection to non-
registered equipment) terminated in a manner that occurs in normal use.
    (iii) Under reasonably foreseeable disconnection of primary power 
sources, with primary power cords plugged and unplugged, if so 
configured.

    Note to paragraph (c)(2): For each output lead of the surge 
generator, with the other lead open, the surge shall have an open 
circuit voltage waveform in accordance with Figure 68.302(b) having 
a front time (tf) of 9 s (30%) and a 
decay time (td) of 720 s ( 20%) and 
shall have a short circuit current waveshape in accordance with 
Figure 68.302(c) having a front time (tf) of 5 s 
(30%) and a decay time (td) of 320 s 
(20%). The peak voltage shall be at least 1500 volts and 
the peak short circuit current shall be at least 37.5 amperes. The 
wave shapes are based on the use of ideal components in Figure 
68.302)(a) with S2 in Position L.

    (3) Failure Modes resulting from application of Type B telephone 
line surges. Registered terminal equipment and registered protective 
circuitry shall be capable of withstanding the energy of Surge Type B 
without causing permanent opening or shorting of the interface circuit 
and without sustaining damage that will affect compliance with these 
rules.

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    (d) Power Line Surge. (1) Apply six power line surges (three of 
each polarity) between the phase and neutral terminals of the ac power 
line while the equipment is being powered. The surge shall have an open 
circuit voltage waveform in accordance with Figure 68.302(b) having a 
front time (tf) of 2 s maximum and a decay time 
(td) of 10 s minimum and shall have a short circuit 
current waveshape in accordance with Figure 68.302(c) with a front time 
(tf) of 2 s maximum and a decay time 
(td) of 10 s minimum. The peak voltage shall be at 
least 2500 volts and the peak short circuit current shall be at least 
1000 amperes. Surges are applied:
    (i) With the equipment in all states that can affect compliance 
with the requirements of this part 68. If an equipment state cannot be 
achieved by normal means of power, it may be achieved artificially;
    (ii) With equipment leads not being surged (including telephone 
connections, auxiliary leads, and terminals for connection to non-
registered/non-certified equipment) terminated in a manner which occurs 
in normal use.
    (2) Failure Modes resulting from application of power line surge. 
Registered terminal equipment and registered protective circuitry shall 
comply with all the criteria contained in the rules and regulations in 
this subpart, both prior to and after the application of the power line 
surge specified in paragraph (d )of this section, not withstanding that 
this surge may result in partial or total destruction of the equipment 
under test.
    8. Section 68.304 is revised to read as follows:


Sec. 68.304  Leakage current limitations.

    Registered terminal equipment and registered protective circuitry 
shall have a voltage applied to the combination of points listed in the 
table below. The test voltage shall be ac of 50 or 60 Hz rms.
    (a) All telephone connections;
    (b) All power connections;
    (c) All possible combinations of exposed conductive surfaces on the 
exterior of such equipment or circuitry including grounding connection 
points, but excluding terminals for connection to other terminal 
equipment;
    (d) All terminals for connection to registered protective circuitry 
or non-registered equipment;
    (e) All auxiliary lead terminals;
    (f) All E&M lead terminals, and
    (g) All PR, PC, CY1 and CY2 leads.

Table 68.304(a).--Voltage Applied for Various Combinations of Electrical
                               Connections                              
------------------------------------------------------------------------
                                                                   ac   
               Voltage source connected between:                value\1\
------------------------------------------------------------------------
(a) and (b) (see NOTES 1, 2, 3)...............................      1500
(a) and (c) (see NOTES 1, 2)..................................      1000
(a) and (d) (see NOTES 1, 2)..................................      1000
(a) and (e) (see NOTES 1, 2)..................................      1000
(a) and (f) (see NOTES 1, 2)..................................      1000
(a) and (g) (see NOTES 1, 2)..................................      1000
(b) and (c) (see NOTE 3)......................................      1500
(b) and (d) (see NOTE 3)......................................      1500
(b) and (e) (see NOTE 3)......................................      1500
(b) and (f) (see NOTE 3)......................................      1500
(b) and (g) (see NOTE 3)......................................      1500
(c) and (e) (see NOTES 1, 2)..................................      1000
(c) and (f) (see NOTES 1, 2)..................................      1000
(d) and (e) (see NOTE 2)......................................      1000
(d) and (f) (see NOTE 2)......................................      1000
(e) and (f) (see NOTE 2)......................................     1000 
------------------------------------------------------------------------
\1\ Value to which test voltage is gradually increased.                 

    Notes to Table 68.304(a):
    (1) Gradually increase the voltage from zero to the values 
listed in Table 68.304(a) over a 30-second time period, then 
maintain the voltage for one minute. The current in the mesh formed 
by the voltage source and these points shall not exceed 10 mA peak 
at any time during this 90-second interval.
    (2) Equipment states necessary for compliance with the 
requirements of this section that cannot be achieved by normal means 
of power shall be achieved artificially by appropriate means.
    (3) A telephone connection, auxiliary lead, or E&M lead that has 
an intentional dc conducting path to earth ground at operational 
voltages (such as a ground start lead), may be excluded from the 
leakage current test in that operational state. Leads or connections 
excluded for this reason shall comply with the requirements of 
Sec. 68.306(e)(1).
    (4) A telephone connection, auxiliary lead, or E&M lead that has 
an intentional dc conducting path to earth ground for protection 
purposes at the leakage current test voltage (such as through a 
surge suppressor), may have the component providing the conducting 
path removed from the equipment for the leakage current test in that 
operational state. Components removed for this reason shall comply 
with the requirements of Sec. 68.306(e)(2).
    (5) Filter paths, such as capacitors used in EMI filters, are 
left in place during leakage current testing, since these components 
can be a path for excessive leakage.
    (6) For multi-unit equipment interconnected by cables, that is 
evaluated and registered as an interconnected combination or 
assembly, the specified 10 mA peak maximum leakage current 
limitation other than between power connection points and other 
points, may be increased as described here to accommodate cable 
capacitance. The leakage current limitation may be increased to 
(10N+0.13L) mA peak where L is the length of interconnecting cable 
in the leakage path in meters and N is the number of equipment units 
that the combination or assembly will place in parallel across a 
telephone connection.
    (7) RF filters and surge protectors on the line side of power 
supplies may be disconnected before making Sec. 68.304 leakage 
measurements. As an alternative to disconnecting these filters and 
surge protectors, this measurement may be made using a dc voltage 
equal to the peak ac test voltage.

    9. Section 68.306 is revised to read as follows:


Sec. 68.306  Hazardous voltage limitations.

    (a) General. Under no condition of failure of registered terminal 
equipment or registered protective circuitry that can be conceived to 
occur in the handling, operation or repair of such equipment or 
circuitry, shall the open circuit voltage on telephone connections 
exceed 70 volts peak after one second, except for voltages for network 
control signalling, alerting and supervision.
    (1) Type I E&M Leads. Registered terminal equipment shall comply 
with the following requirements for terminal equipment on the ``A'' or 
``B'' side of the interface as shown in Figures 68.3(e)(i):
    (i) The dc current on the E lead shall not exceed 100 mA.
    (ii) The maximum dc potentials to ground shall not exceed the 
following when measured across a resistor of 20 kohms 10%:

               Table 68.306(a).--Type I E&M, DC Potentials              
------------------------------------------------------------------------
                                     E lead                M lead       
------------------------------------------------------------------------
TE on ``B'' side originates   5 V.....  5 V.    
 signals to network on E                                                
 lead.                                                                  
TE on ``A'' side originates   -56.5 V; no positive  -56.5 V; no positive
 signals to network on M       potential with        potential with     
 lead.                         respect to ground.    respect to ground. 
------------------------------------------------------------------------

    (iii) The maximum ac potential between E&M leads and ground 
reference shall not exceed 5V peak.
    (iv) M lead protection shall be provided so that voltages to ground 
do not exceed 60 volts. For relay contact implementation, a power 
dissipation capability of 0.5 watt shall be provided in the shunt path.

[[Page 61668]]

    (v) If the registered terminal equipment contains an inductive 
component in the E lead, it must assure that the transient voltage 
across the contact as a result of a relay contact opening does not 
exceed the following voltage and duration limitations:
    (A) 300 volts peak,
    (B) A rate of change of one volt per microsecond, and
    (C) A 60-volt level after 20 milliseconds.
    (2) Type II E&M Leads. Registered terminal equipment shall comply 
with the following requirements:
    (i) For terminal equipment on the ``A'' side of the interface, the 
dc current in the E lead shall not exceed 100 mA. The maximum ac 
potential between the E lead and ground shall not exceed 5 V peak.
    (ii) For terminal equipment on the ``B'' side of the interface, the 
dc current in the SB lead shall not exceed 100 mA. The maximum ac 
potential between the SB lead and ground shall not exceed 5 V peak.
    (iii) The maximum dc potentials to ground shall not exceed the 
following when measured across a resistor of 20 kohms 10%:

                                  Table 68.306(b).--Type II E&M, DC Potentials                                  
----------------------------------------------------------------------------------------------------------------
                                        E lead                M lead              SB lead             SG lead   
----------------------------------------------------------------------------------------------------------------
TE on ``B'' side of the         5 V.......  5 V    -56.5 V; no positive   5 
 interface originates signals                                               potential with         V.           
 to network on E lead.                                                      respect to ground.                  
TE on ``A'' side of the         -56.5 V; no positive    5 V    5 V......  5 
 interface originates signals    potential with                                                    V.           
 to network on M lead.           respect to ground.                                                             
----------------------------------------------------------------------------------------------------------------

    (iv) The maximum ac potential to ground shall not exceed 5V peak on 
the following leads, from sources in the terminal equipment:
    (A) M, SG and SB leads for terminal equipment on the ``A'' side of 
the interface.
    (B) E, SG and M leads for terminal equipment on the ``B'' side of 
the interface.
    (v) If the registered terminal equipment contains an inductive 
component in the (E) or (M) lead, it must assure that the transient 
voltage across the contact as a result of a relay contact opening does 
not exceed the following voltage and duration limitations:
    (A) 300 volts peak,
    (B) A rate of change of one volt per microsecond, and
    (C) A 60-volt level after 20 milliseconds.
    (3) Off premises station voltages. (i) Talking battery or voltages 
applied by the PBX (or similar systems) to all classes of OPS interface 
leads for supervisory purposes must be negative with respect to ground, 
shall not be more than -56.5 volts dc with respect to ground, and shall 
not have a significant ac component.\1\
---------------------------------------------------------------------------

    \1\ The ac component should not exceed 5 volts peak, when not 
otherwise controlled by Sec. 68.308.
---------------------------------------------------------------------------

    (ii) Ringing signals applied by the PBX (or similar systems) to all 
classes of OPS interface leads shall comply with requirements in 
paragraph (d) of this section. Ringing voltages shall be applied 
between the ring conductor and ground.
    (4) Direct Inward Dialing (DID). Voltages applied by the PBX (or 
similar systems) to DID interface leads for supervisory purposes must 
be negative with respect to ground, shall not be more than -56.5 volts 
dc with respect to ground, and shall not have a significant ac 
component.\2\
---------------------------------------------------------------------------

    \2\ The ac component shall not exceed 5 volts peak, where not 
otherwise controlled by Sec. 68.308.
---------------------------------------------------------------------------

    (5) Local Area Data Channel Interfaces. For Local Area Data Channel 
interfaces, during normal operating modes including terminal equipment 
initiated maintenance signals, registered terminal equipment shall 
ensure, except during the application of ringing (limitations specified 
in paragraph (d) of this section), with respect to telephone 
connections (tip, ring, tip 1, ring 1) that:
    (i) Under normal operating conditions, the rms current per 
conductor between short-circuit conductors, including dc and ac 
components, does not exceed 350 milliamperes. For other than normal 
operating conditions, the rms current between any conductor and ground 
or between short-circuited conductors, including dc and ac components, 
may exceed 350 milliamperes for no more than 1.5 minutes;
    (ii) The dc voltage between any conductor and ground does not 
exceed 60 volts. Under normal operating conditions it shall not be 
positive with respect to ground (though positive voltages up to 60 
volts may be allowed during brief maintenance states);
    (iii) AC voltages are less than 42.4 volts peak between any 
conductor and ground, (terminal equipment shall comply while other 
interface leads are both):
    (A) Unterminated, and
    (B) Individually terminated to ground); and,
    (iv) Combined ac and dc voltages between any conductor and ground 
are less than 42.4 volt peak when the absolute value of the dc 
component is less than 21.2 volts, and less than (32.8 + 0.454  x  Vdc) 
when the absolute value of the dc component is between 21.2 and 60 
volts.
    (6) Ringdown Voiceband Private Line and Voiceband Metallic Channel 
Interface. During normal operation, registered terminal equipment for 
connection to ringdown voiceband private line interfaces or voiceband 
metallic channel interfaces shall ensure that:
    (i) Ringing voltage does not exceed the voltage and current limits 
specified in paragraph (d) of this section, and is:
    (A) Applied to the ring conductor with the tip conductor grounded 
for 2-wire interfaces, or
    (B) Simplexed on the tip and ring conductors with ground simplexed 
on the tip 1 and ring 1 conductors for 4-wire interfaces.
    (ii) Except during the signaling mode or for monitoring voltage, 
there is no significant positive dc voltage (not over +5 volts) with 
respect to ground:
    (A) For 2-wire ports between the tip lead and ground and the ring 
lead and ground and
    (B) For 4-wire ports between the tip lead and ground, the ring lead 
and ground, the tip 1 lead and ground, and the ring 1 lead and ground.
    (iii) The dc current per lead, under short circuit conditions shall 
not exceed 140 milliamperes.
    (b) Connection of non-registered equipment to registered terminal 
equipment or registered protective circuitry.--General. Leads to, or 
any elements having a conducting path to

[[Page 61669]]

telephone connections, auxiliary leads or E&M leads shall:
    (1) Be reasonably physically separated and restrained from and be 
neither routed in the same cable as nor use the same connector as leads 
or metallic paths connecting power connections;
    (2) Be reasonably physically separated and restrained from and be 
neither routed in the same cable as nor use adjacent pins on the same 
connector as metallic paths to lead to nonregistered equipment, when 
specification details provided to the Commission, pursuant to, 
Sec. 68.200(g), do not show that interface voltages are less than non-
hazardous voltage source limits in paragraph (c) of this section.
    (c) Non-Hazardous Voltage Source. A voltage source is considered a 
non-hazardous voltage source if it conforms with the requirements of 
Sec. 68.302, Sec. 68.304 and paragraph (b) of this section, with all 
connections to the source other than primary power connections treated 
as ``telephone connections,'' and if such source supplies voltages no 
greater than the following under all modes of operation and of failure:
    (1) AC voltages less than 42.4 volts peak;
    (2) DC voltages less than 60 volts; and
    (3) Combined ac and dc voltages less than 42.4 volts peak when the 
absolute value of the dc component is less than 21.2 volts and less 
than (32.8 + 0.454  x  V dc) when the absolute value of the dc 
component is between 21.2 and 60 volts.
    (d) Ringing Sources. Except for class A OPS interfaces, ringing 
sources shall meet all of the following restrictions:
    (1) Ringing Signal Frequency. The ringing signal shall use only 
frequencies whose fundamental component is equal to or below 70 Hz.
    (2) Ringing Signal Voltage. The ringing voltage shall be less than 
300 V peak-to-peak and less than 200 V peak-to-ground across a 
resistive termination of at least 1 megohm.
    (3) Ringing Signal Interruption Rate. The ringing voltage shall be 
interrupted to create quiet intervals of at least one second 
(continuous) duration each separated by no more than 5 seconds. During 
the quiet intervals, the voltage to ground shall not exceed the voltage 
limits given in paragraph (a)(3)(i) of this section.
    (4) Ringing Signal Sources. Ringing voltage sources shall comply 
with the following requirements:
    (i) If the ringing current through a 500 ohm(s) (and greater) 
resistor does not exceed 100 mA peak-to-peak, neither a ring trip 
device nor a monitoring voltage are required.
    (ii) If the ringing current through a 1500 ohm (and greater) 
resistor exceeds 100 mA peak-to-peak, the ringing source shall include 
a current-sensitive ring trip device in series with the ring lead that 
will trip ringing as specified in Figure 68.306(a) in accordance with 
the following conditions:
    (A) If the ring trip device operates as specified in Figure 
68.306(a) with R=500 ohm (and greater) no monitoring voltage is 
required;
    (B) If, however, the ring trip device only operates as specified in 
Figure 68.306(a) with R=1500 ohm (and greater) then the ringing voltage 
source shall also provide a monitoring voltage between 19 V dc and 56.5 
V dc, negative with respect to ground, on the tip or ring conductor.
    (iii) If the ringing current through a 500-ohm (and greater) 
resistor exceeds 100 mA (peak-to-peak) but does not exceed 100 mA peak-
to-peak with 1500-ohm (and greater) termination, the ringing voltage 
source shall include either a ring trip device that meets the operating 
characteristics specified in Figure 68.306(a) with 500-ohm (and 
greater) resistor, or a monitoring voltage as specified in paragraph 
(d)(4)(ii)(B) of this section.

    Note to paragraph (d)(4)(iii): If the operating characteristics 
specified in Figure 68.306(a) are not met with both the 500-ohm and 
1500-ohm terminations, then the terminal equipment under test fails 
(See Table 68.306(c)).

BILLING CODE 6712-01-P

[[Page 61670]]

[GRAPHIC] [TIFF OMITTED] TR19NO97.010



BILLING CODE 6712-01-C

[[Page 61671]]



                                                   Table 68.306(C).--Summary of Ring Trip Requirements                                                  
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                      Ringing current (mA p.p)                       Function required                                                  
                                     --------------------------------------------------------------------------------------   Ring trip device operates 
       Section 68.306 (d)(4).          R=500 ohms  R=1500 ohms                                                                  per figure 68.306(a)    
                                      and greater  and greater            Ring trip                  Monitor voltage                                    
--------------------------------------------------------------------------------------------------------------------------------------------------------
(i).................................         <100         <100  Optional....................  Optional....................  Optional.                   
(ii)(A).............................          N/A         >100  Yes.........................  Optional....................  Yes for both resistances.   
(ii)(B).............................          N/A         >100  Yes.........................  Yes.........................  Yes for R=1500 ohms and     
                                                                                                                             greater.                   
                                                                                                                            No for R=500 ohms and       
                                                                                                                             greater.                   
(iii)...............................         >100         <100                                                                                          
(1)Either Ring-Trip device or             Yes for                                                                                                       
 Monitor Voltage required              R=500 ohms                                                                                                       
                                              and                                                                                                       
                                      greater, if                                                                                                       
                                        Ring Trip                                                                                                       
                                        Device is                                                                                                       
                                            used.                                                                                                       
--------------------------------------------------------------------------------------------------------------------------------------------------------

    (e) Intentional paths to ground (as required by Sec. 68.304). (1) 
Connections with operational paths to ground. Registered terminal 
equipment and registered protective circuitry having an intentional dc 
conducting path to earth ground at operational voltages that was 
excluded during the leakage current test of Sec. 68.304 shall have a dc 
current source applied between the following points:
    (i) Telephone connections, including tip, ring, tip 1, ring 1, E&M 
leads and auxiliary leads, and
    (ii) Earth grounding connections.

    Note to paragraphs (e)(1)(i) and (e)(1)(ii): For each test 
point, gradually increase the current from zero to 1 ampere, then 
maintain the current for one minute. The voltage between (e)(2)(i) 
and (e)(2)(ii) of this section shall not exceed 0.1 volt at any 
time.
    Note to paragraphs (e)(2)(i) and (e)(2)(ii): 
    (1) In the event there is a component or circuit in the path to 
ground, the requirement shall be met between the grounded side of 
the component or circuit and the earth grounding connection.
    (2) Connections with protection paths to ground. Registered 
terminal equipment and protective circuitry having an intentional dc 
conducting path to earth ground for protection purposes at the 
leakage current test voltage that was removed \1\ during the leakage 
current test of Sec. 68.304 shall, upon its replacement, have a 50 
or 60 Hz voltage source applied between the following points:
---------------------------------------------------------------------------

    \1\ The path to ground is reestablished when the leads are 
replaced.
---------------------------------------------------------------------------

    (i) Simplexed telephone connections, including tip and ring, tip 
1 and ring 1, E&M leads and auxiliary leads, and
    (ii) Earth grounding connections.
    (3) Gradually increase the voltage from zero to 120 volts rms 
for registered terminal equipment, or 300 volts rms for protective 
circuitry, then maintain the voltage for one minute. The current 
between Secs. 68.306(d)(4)(i) and 68.306(d)(4)(ii) shall not exceed 
10 mA peak at any time. As an alternative to carrying out this test 
on the complete equipment or device, the test may be carried out 
separately on components, subassemblies, and simulated circuits, 
outside the unit, provided that the test results would be 
representative of the results of testing the complete unit.

    10. Section 68.308 is revised to read as follows:


Sec. 68.308  Signal power limitations.

    (a) General. Limits on signal power shall be met at the interface 
for all 2-wire network ports and, where applicable to offered services, 
both transmit and receive pairs of all 4-wire network ports. Signal 
power measurements shall be made using terminations as specified in 
each of the following limitations. The transmit and receive pairs for 
4-wire network ports shall be measured with the pair not under test 
connected to a termination equivalent to that specified for the pair 
under test. Through gain limitations apply only in the direction of 
transmission toward the network.
    (b) Voiceband metallic signal power. (1) Limitations at the 
interface on internal signal sources not intended for network control 
signaling:
    (i) The power of all signal energy, in the 200-3995 Hz voiceband, 
delivered by registered terminal equipment or registered protective 
circuitry to the appropriate loop simulator--other than non-permissive 
data equipment or data protective circuitry shall not exceed -9 dBm 
when averaged over any 3 second interval.
    (ii) For 2-wire and 4-wire lossless tie trunk type interfaces, the 
maximum power of other than live voice signals delivered to a 600-ohm 
termination shall not exceed -15 dBm when averaged over any three 
second interval.
    (iii) For OPS lines, the maximum power of other than live voice 
delivered to an OPS line simulator circuit shall not exceed -9 dB with 
respect to one milliwatt, when averaged over any 3-second interval.
    (iv) For registered test equipment or registered test circuitry the 
maximum signal power delivered to a loop simulator circuit shall not 
exceed 0 dBm when averaged over any 3-second interval.
    (v) For voiceband private lines using ringdown or inband signaling 
the maximum power of other than live voice signals delivered to a 600 
ohm termination shall not exceed -13 dBm when averaged over any 3-
second interval.
    (vi) For voiceband private lines using inband signaling in the band 
2600  150 Hz, the maximum power delivered to a 600 ohm 
termination shall not exceed -8 dBm during the signaling mode. The 
maximum power delivered to a 600 ohm termination in the on-hook steady 
state supervisory condition shall not exceed -20 dBm. The maximum power 
of other than live voice signals delivered to a 600 ohm termination 
during the non-signaling mode and for other inband systems shall not 
exceed -13 dBm when averaged over any 3-second interval.
    (2) Limitations on internal signal sources primarily intended for 
network control signaling, contained in voice and data equipment.
    (i) For all operating conditions of registered terminal equipment 
and registered protective circuitry, the maximum power in the frequency 
band below 3995 Hz delivered to a loop simulator circuit shall not 
exceed the following when averaged over any 3-second interval:
    (A) 0 dBm when used for network control (DTMF);
    (B) 0 dBm when DTMF is used for manual entry end-to-end signaling. 
When the device is used for this purpose it shall not generate more 
than 40 DTMF digits per manual key stroke.
    (C) -9 dBm in all other cases.
    (ii) For tie trunk applications, the maximum power delivered to a 
600 ohm termination for registered terminal equipment and registered 
protective circuitry under all operating conditions shall not exceed -4 
dBm over any 3 second interval.
    (3) Registered one port and multiport terminal equipment and 
protective circuitry with provision for through transmission from other 
terminal equipment, excluding data equipment and data protective 
circuitry that are registered in accordance with Sec. 68.308(b)(4).

[[Page 61672]]

    (i) Where through-transmission equipment provides a dc electrical 
signal to equipment connected therewith (e.g., for powering of electro-
acoustic transducers), dc conditions shall be provided which fall 
within the range of conditions provided by a loop simulator circuit 
unless the combination of the through-transmission equipment and 
equipment connected therewith is registered as a combination which 
conforms to paragraphs (b)(1) and (b)(2) of this section.
    (ii) Through-transmission equipment to which remotely connected 
data terminal equipment may be connected shall not be equipped with or 
connected to either a Universal or Programmed Data Jack used in data 
configurations. (See paragraph (b)(4) of this section and 
Sec. 68.502(e)).
    (4) Registered data circuit terminal equipment shall be capable of 
operation in at least one of the states discussed in paragraphs 
(b)(1)(i), (b)(1)(ii) or (b)(1)(iii) of this section. The output power 
level of the data circuit terminal equipment shall not be alterable, by 
the customer, to levels which exceed the signal power limits specified 
herein.
    (i) Data circuit terminal equipment intended to operate with a 
programming resistor for signal level control shall not exceed the 
programmed levels given in Table 68.308(a).
    (ii) Data circuit terminal equipment intended to operate in the 
fixed loss loop (FLL) state shall not transmit signal power that 
exceeds -4 dBm, in the 200--3995 Hz voiceband, when averaged over any 
and all 3 second intervals.
    (iii) Data circuit terminal equipment shall not transmit signals 
from 200 to 3995 Hz that exceed -9 dBm, when averaged over any and all 
3 second intervals.

                             Table 68.308(a)                            
------------------------------------------------------------------------
                                              Programmed data equipment 
     Programming resistor (Rp)* (ohms)           signal power output    
------------------------------------------------------------------------
Short......................................  0 dBm.                     
150........................................  -1 dBm.                    
336........................................  -2 dBm.                    
569........................................  -3 dBm.                    
866........................................  -4 dBm.                    
1240.......................................  -5 dBm.                    
1780.......................................  -6 dBm.                    
2520.......................................  -7 dBm.                    
3610.......................................  -8 dBm.                    
5490.......................................  -9 dBm.                    
------------------------------------------------------------------------
*Tolerance ) 1%.                                                        

    (5) Registered one-port and multiport terminal equipment and 
protective circuitry with provision for through-transmission from ports 
to other equipment which is separately registered for the public 
switched network, or ports to other network interfaces.
    (i) Registered terminal equipment and registered protective 
circuitry shall have no adjustments that will allow net amplification 
to occur in either direction of transmission in the through-
transmission path within the 200-3995 Hz voiceband that will exceed the 
following:

                                        Table 68.308(b).--Allowable Net Amplification Between Ports (A)(C)(D)(E)                                        
--------------------------------------------------------------------------------------------------------------------------------------------------------
               To                                Tie trunk type ports                                                                                   
-------------------------------------------------------------------------------------                                   Public switched                 
                                                     Subrate 1.544                       Integrated     OPS ports (2-    network ports   HCC digital PBX-
            From (E)                \2/4\-wire      Mbps satellite    Subrate 1.544    services trunk     wire) (B)         (2-wire)        CO 4-wire   
                                                          4W          Mbps tandem 4W                                                                    
--------------------------------------------------------------------------------------------------------------------------------------------------------
\2/4\-Wire Tie.................  0 dB              3 dB              3 dB             3 dB             6 dB                                             
Subrate 1.544 Mbps Satellite 4W  0 dB                                3 dB             3 dB             6 dB                                             
 Tie.                                                                                                                                                   
Subrate 1.544 Mbps Tandem 4W     -3 dB             0 dB              0 dB             0 dB             3 dB                                             
 Tie.                                                                                                                                                   
Integrated Services Trunk......  -3 dB             0 dB              0 dB             0 dB             3 dB                                             
RTE Digital....................  0 dB              0 dB              0 dB             0 dB             3 dB             3 dB             0 dB.          
RTE (B) PSTN/OPS...............  -3 dB             -3 dB             -3 dB            -3 dB            0 dB             0 dB             -3 dB          
OPS (B) (2-Wire)...............  -2 dB             1 dB              1 dB             1 dB             4 dB             4 dB             1 dB.          
Public Switched Network (2-                                                                            3 dB             3 dB                            
 Wire).                                                                                                                                                 
HCC Digital PBX-CO (4-Wire)....                                                                        3 dB                                             
--------------------------------------------------------------------------------------------------------------------------------------------------------

    (A) The source impedance for all measurements shall be 600 ohms. 
All ports shall be terminated in appropriate loop or private line 
channel simulator circuits or 600 ohm terminations.
    (B) These ports are for 2-wire on-premises station ports to 
separately registered terminal equipment.
    (C) These through gain limitations are applicable to multiport 
systems where channels are not derived by time or frequency compression 
methods. Terminal equipment employing such compression techniques shall 
assure that equivalent compensation for through gain parameters is 
demonstrated in the registration application.
    (D) Registered terminal equipment and registered protective 
circuitry may have net amplification exceeding the limitations of this 
subsection provided that, for each network interface type to be 
connected, the absolute signal power levels specified in this section 
are not exceeded.
    (E) The indicated gain is in the direction that results when moving 
from the horizontal entry toward the vertical entry.
    (F) Registered terminal equipment or protective circuitry with the 
capability for through transmission from voiceband private line 
channels or voiceband metallic channels to other telephone network 
interfaces shall ensure that the absolute signal power levels specified 
in this section, for each telephone network interface type to be 
connected, are not exceeded.
    (G) Registered terminal equipment or protective circuitry with the 
capability for through transmission from voiceband private line 
channels or voiceband metallic private line channels to other telephone 
network interfaces shall assure, for each telephone network interface 
type to be connected, that signals with energy in the 2450 to 2750 Hz 
band are not through transmitted unless there is at least an equal 
amount of energy in the 800 to 2450 Hz band within 20 milliseconds of 
application of signal.

[[Page 61673]]

    (ii) The insertion loss in through connection paths for any 
frequency in the 800 to 2450 Hz band shall not exceed the loss at any 
frequency in the 2450 to 2750 Hz band by more than 1 dB (maximum loss 
in the 800 to 2450 Hz band minus minimum loss in the 2450 to 2750 Hz 
band plus 1 dB).
    (6) For tie trunk interfaces--Limitation on idle circuit stability 
parameters. For idle state operating conditions of registered terminal 
equipment and registered protective circuitry, the following 
limitations shall be met:
    (i) For the two-wire interface:
    [GRAPHIC] [TIFF OMITTED] TR19NO97.018
    
    (ii) For the four-wire lossless interface:
    [GRAPHIC] [TIFF OMITTED] TR19NO97.019
    
    Note: The following definitions apply to return loss 
requirements:

RL  the return loss of 2-wire terminal equipment at the interface 
with respect to 600 ohms+2.16 F (i.e., Zref=600 
ohms+2.16 F).
[GRAPHIC] [TIFF OMITTED] TR19NO97.020

Rli  the terminal equipment input (receive) port return 
loss with respect to 600 ohms (i.e., Zref=600 ohms).
[GRAPHIC] [TIFF OMITTED] TR19NO97.021

RLo  the terminal equipment output (transmit) port return 
loss with respect to 600 ohms (i.e., Zref=600 ohms).
[GRAPHIC] [TIFF OMITTED] TR19NO97.022

tl  the transducer loss between the receive and transmit ports of 
the 4-wire PBX. tlf is the transducer loss in the forward 
direction from the receive port to the transmit port of the PBX.
[GRAPHIC] [TIFF OMITTED] TR19NO97.023

Where Ii is the current sent into the receive port and 
Ir is the current received at the transmit port 
terminated at 600 ohms.
tlr is the transducer loss in the reverse direction, from 
the transmit port to the receive port of the PBX.
[GRAPHIC] [TIFF OMITTED] TR19NO97.024

Where Ii is the current sent into the transmit port and 
Ir is the current received at the receive port terminated 
at 600 ohms. Note, the source impedance of Ii is 600 
ohms.

    (7) Registered terminal equipment and registered protective 
circuitry shall provide the following range of dc conditions to off-
premises station (OPS) lines.
    (i) DC voltages applied to the OPS interface for supervisory 
purposes and during network control signaling shall meet the limits 
specified in Sec. 68.306(a)(3)(i).
    (ii) DC voltages applied to the OPS interface during the talking 
state shall meet the following requirements:
    (A) The maximum open circuit voltage across the tip (T(OPS)) and 
ring (R(OPS)) leads for all classes shall not exceed 56.5 volts, and
    (B) Except for class A OPS interfaces, the maximum dc current into 
a short circuit across tip (T(OPS)) and ring (R(OPS)) leads shall not 
exceed 140 mA.
    (8) For connections to 1.544 Mbps digital services, the permissible 
code words for unequipped Mu-255 encoded subrate channels are limited 
to those corresponding to signals of either polarity, of magnitude 
equal to or less than X48, where code word, XN is derived by:

XN = (255 - N) base 2
-XN = (127 - N) base 2
    (c) Signal power in the 3995-4005 Hz frequency band.
    (1) Power resulting from internal signal sources contained in 
registered protective circuitry and registered terminal equipment 
(voice and data), not intended for network control signaling. For all 
operating conditions of registered terminal equipment and registered 
protective circuitry that incorporate signal sources other than sources 
intended for network control signaling, the maximum power delivered by 
such sources in the 3995-4005 Hz band to an appropriate simulator 
circuit, shall be 18 dB below maximum permitted power specified in 
paragraph (b) of this section for the voiceband.
    (2) Terminal equipment with provision of through-transmission from 
other equipment. The loss in any through-transmission path of 
registered terminal equipment and registered protective circuitry at 
any frequency in the 600 to 4000 Hz band shall not exceed, by more than 
3 dB, the loss at any frequency in the 3995 to 4005 Hz band, when 
measured into an appropriate simulator circuit from a source that 
appears as 600 ohms across tip and ring.
    (d) Longitudinal voltage at frequencies below 4 kHz. The weighted 
rms voltage \3\ averaged over 100 milliseconds that is resultant of all 
of the component longitudinal voltages in the 100 Hz to 4 kHz band 
after weighting according to the transfer

[[Page 61674]]

function of f/4000 where f is the frequency in Hertz, shall not exceed 
the maximum indicated under the conditions stated in paragraph (g) of 
this section.
---------------------------------------------------------------------------

    \3\ Average magnitudes may be used for signals that have peak-
to-rms ratios of 20 dB and less. The rms limitations must be used 
instead of average values if the peak-to-rms ratio of the 
interfering signal exceeds this value.

------------------------------------------------------------------------
                                    Maximum weighted                    
         Frequency range              rms voltage          Impedance    
------------------------------------------------------------------------
100 Hz to 4 kHz..................  -30 dBV            500 ohms.         
------------------------------------------------------------------------

    (e) Voltage in the 4 kHz to 6 MHZ frequency range-general case--2-
wire and 4-wire lossless interface (except LADC). Except as noted, rms 
voltage as averaged over 100 milliseconds at the telephone connections 
of registered terminal equipment and registered protective circuitry in 
all of the possible 8 kHz bands within the indicated frequency range 
and under the conditions specified in paragraph (g) of this section 
shall not exceed the maximum indicated below. For paragraphs(e)(1) and 
(e)(2)(i) of this section, ``f'' is the center frequency in kHz of each 
of the possible 8-kHz bands beginning at 8 kHz.
    (1) Metallic Voltage. 4 kHz to 270 kHz:

------------------------------------------------------------------------
                                                             Metallic   
 Center frequency (f) of 8 kHz    Max voltage in all 8     terminating  
              band                      kHz bands           impedance   
------------------------------------------------------------------------
8 kHz to 12 khz................  -(6.4 + 12.6 log f)     300 ohms.      
                                  dBV.                                  
12 kHz to 90 kHz...............  ......................  135 ohms.      
90 kHz to 266 kHz..............  (23-40 log f) dBV -55.  135 ohms.      
------------------------------------------------------------------------

    (2) Longitudinal voltage.
    (i) 4 kHz to 270 kHz.
    (ii) 270 kHz to 6 MHZ. The rms value of the longitudinal voltage 
components in the frequency range of 270 kHz to 6 MHZ, shall not exceed 
-30 dBV. This limitation applies with a longitudinal termination having 
an impedance of 90 ohms.

------------------------------------------------------------------------
                                                           Longitudinal 
 Center frequency (f) of 8 kHz    Max voltage in all 8     terminating  
              band                      kHz bands           impedance   
------------------------------------------------------------------------
8 kHz to 12 kHz................  -(18.4 + 20 log f) dBV  500 ohms       
12 kHz to 42 kHz...............  ......................  90 ohms        
42 kHz to 266 kHz (2-40 log f)   ......................  90 ohms        
 dBV -62 dBV.                                                           
------------------------------------------------------------------------

    (f) LADC interface. The metallic voltage shall comply with the 
general requirements in paragraph (f)(1) of this section as well as the 
additional requirements specified in paragraphs (f)(2) and (f)(3) of 
this section. The requirements apply under the conditions specified in 
paragraph (g) of this section. Terminal equipment for which the 
magnitude of the source and/or terminating impedance exceeds 300 ohms, 
at any frequency in the range of 100 kHz to 6 MHz, at which the signal 
(transmitted and/or received) has significant power, shall be deemed 
not to comply with these requirements. A signal is considered to have 
``significant power'' at a given frequency if that frequency is 
contained in a designated set of frequency bands that collectively have 
the property that the rms voltage of the signal components in those 
bands is at least 90% of the rms voltage of the total signal. The 
designated set of frequency bands must be used in testing all 
frequencies.
    (1) Metallic voltages--frequencies below 4 kHz.
    (i) Weighted rms voltage in the 10 Hz to 4 kHz frequency band. The 
weighted rms metallic voltage in the frequency band from 10 Hz to 4 
kHz, averaged over 100 milliseconds that is the resultant of all the 
component metallic voltages in the band after weighting according to 
the transfer function of f/4000 where f is the frequency in Hertz, 
shall not exceed the maximum indicated below under the conditions 
stated in paragraph (g) of this section.

------------------------------------------------------------------------
              Frequency range                      Maximum voltage      
------------------------------------------------------------------------
 10 Hz to 4 kHz............................  +3 dBV.                    
------------------------------------------------------------------------

    (ii) RMS Voltage in 100 Hz bands in the frequency range 0.7 kHz to 
4 kHz. The rms metallic voltage averaged over 100 milliseconds in the 
100-Hz bands having center frequencies between 750 Hz and 3950 Hz shall 
not exceed the maximum indicated below.

------------------------------------------------------------------------
                                              Max voltage in all 100-Hz 
      Center freq (f) of 100-Hz bands                   bands           
------------------------------------------------------------------------
750 to 3950 Hz.............................  -6 dBV.                    
------------------------------------------------------------------------

    (2) Metallic Voltages--frequencies above 4 kHz--LADC interface.
    (i) 100-Hz bands over frequency range of 4 kHz to 270 kHz. The rms 
voltage as averaged over 100 milliseconds in all possible 100-Hz bands 
between 4 kHz and 270 kHz for the indicated range of center frequencies 
and under the conditions specified in paragraph (g) of this section 
shall not exceed the maximum indicated below:

------------------------------------------------------------------------
                                              Max voltage in all 100-Hz 
    Center freq (f) of all 100-Hz bands                 bands           
------------------------------------------------------------------------
4.05 kHz to 4.6 kHz........................  0.5 dBV.                   
4.60 kHz to 5.45 kHz.......................  (59.2--90 log f) dBV.      
 5.45 kHz to 59.12 kHz.....................  (7.6--20 log f) dBV.       
59.12 kHz to 266.00 kHz....................  (43.1--40 log f) dBV.      
------------------------------------------------------------------------

Where f = center frequency in kHz of each of the possible 100 Hz 
bands.

    (ii) 8-kHz bands over frequency range of 4 kHz to 270 kHz. The rms 
voltage as averaged over 100 milliseconds in all of the possible 8-kHz 
bands between 4 kHz and 270 kHz for the indicated range of center 
frequencies and under the conditions specified in paragraph (g) of this 
section shall not exceed the maximum indicated below:

[[Page 61675]]



------------------------------------------------------------------------
   Center freq (f) of 8-kHz bands       Max voltage in all 8-kHz bands  
------------------------------------------------------------------------
8 kHz to 120 kHz....................  (17.6--20 log f) dBV.             
120 kHz to 266 kHz..................  (59.2--40 log f) dBV.             
------------------------------------------------------------------------

Where f = center frequency in kHz of each of the possible 8-kHz 
bands.

    (iii) RMS Voltage at frequencies above 270 kHz. The rms value of 
the metallic voltage components in the frequency range of 270 kHz to 6 
MHZ, averaged over 2 microseconds, shall not exceed -15 dBV. This 
limitation applies with a metallic termination having an impedance of 
135 ohms.
    (iv) Peak Voltage. The total peak voltage for all frequency 
components in the 4 kHz to 6 MHZ band shall not exceed 4.0 volts.
    (3) Longitudinal voltage. Frequencies below 4kHz: The weighted rms 
voltage in the frequency band from 10 Hz to 4 kHz,averaged over 100 
milliseconds is the resultant of all the component longitudinal 
voltages in the band after weighing according to the transfer function 
of f/4000, where f is the frequency in Hz, shall not exceed the maximum 
indicated below under the conditions stated in paragraph (g) of this 
section.
    (i) Frequencies below 4 kHz. The weighted rms voltage in the 
frequency band from 10 Hz to 4 kHz,averaged over 100 milliseconds is 
the resultant of all the component longitudinal voltages in the band 
after weighing according to the transfer function of f/4000, where f is 
the frequency in Hz, shall not exceed the maximum indicated below under 
the conditions stated in paragraph (g) of this section.

------------------------------------------------------------------------
             Frequency range                    Maximum RMS voltage     
------------------------------------------------------------------------
10 Hz-4 kHz..............................  -37 dBV.                     
------------------------------------------------------------------------

    (ii) 4 kHz to 270 kHz.

------------------------------------------------------------------------
                                                           Longitudinal 
  Ctr freq (f) of 8 kHz bands     Max voltage in all 8     terminating  
                                        kHz bands           impedance   
------------------------------------------------------------------------
8 to 12 kHz....................  -(18.4+20 log f) dBV..  500 ohms.      
12 to 42 kHz...................  (3-40 log f) dBV......  90 ohms        
42 to 266 kHz..................  -62 dBV...............  90 ohms.       
------------------------------------------------------------------------
Where f = center frequency in kHz of each of the possible 8-kHz bands.  

    (iii) 270 kHz to 6 MHZ. The rms value of the longitudinal voltage 
components in the frequency range of 270 kHz to 6 MHZ shall, averaged 
over 2 microseconds, not exceed -30 dBV. This limitation applies with a 
longitudinal termination having an impedance of 90 ohms.
    (d) Longitudinal voltage at frequencies below 4 kHz. The weighted 
rms voltage \4\ averaged over 100 milliseconds that is resultant of all 
of the component longitudinal voltages in the 100 Hz to 4 kHz band 
after weighting according to the transfer function of f/4000 where f is 
the frequency in Hertz, shall not exceed the maximum indicated under 
the conditions stated in Sec. 68.308(g).

    \4\ Average magnitudes may be used for signals that have peak-
to-rms ratios of 20 dB and less. The rms limitations must be used 
instead of average values if the peak-to-rms ratio of the 
interfering signal exceeds this value.

------------------------------------------------------------------------
                                  Maximum weighted rms                  
        Frequency range                  voltage            Impedance   
------------------------------------------------------------------------
100 Hz to 4 kHz................  -30 dBV...............  500 ohms.      
------------------------------------------------------------------------

    (e) Voltage in the 4 kHz to 6 MHZ frequency range--general case--2-
wire and 4-wire lossless interface (except LADC). Except as noted, rms 
voltage as averaged over 100 milliseconds at the telephone connections 
of registered terminal equipment and registered protective circuitry in 
all of the possible 8 kHz bands within the indicated frequency range 
and under the conditions specified in paragraph (g) of this section 
shall not exceed the maximum indicated below. For paragraph (e)(1) and 
paragraph (e)(2)(i) of this section, ``f'' is the center frequency in 
kHz of each of the possible 8-kHz bands beginning at 8 kHz.
    (1) Metallic Voltage. 4 kHz to 270 kHz:

------------------------------------------------------------------------
                                                             Metallic   
 Center frequency (f) of 8 kHz    Max voltage in all 8     terminating  
              band                      kHz bands           impedance   
------------------------------------------------------------------------
8 kHz to 12 kHz................  -(6.4 + 12.6 log f)     300 ohms.      
                                  dBV.                                  
12 kHz to 90 kHz...............  (23-40 log f) dBV.....  135 ohms.      
90 kHz to 266 kHz..............  -55 dBV...............  135 ohms.      
------------------------------------------------------------------------

    (2) Longitudinal voltage
    (i) 4 kHz to 270 kHz.
    (ii) 270 kHz to 6 MHZ. The rms value of the longitudinal voltage 
components in the frequency range of 270 kHz to 6 MHZ, shall not exceed 
-30 dBV. This limitation applies with a longitudinal termination having 
an impedance of 90 ohms.

------------------------------------------------------------------------
                                                           Longitudinal 
  Center frequency (f) of 8kHz    Max voltage in all 8     terminating  
              band                      kHz bands           impedance   
------------------------------------------------------------------------
8 kHz to 12 kHz................  -(18.4 + 20 log f) dBV  500 ohms.      
12 kHz to 42 kHz...............  (2-40 log f) dBV......  90 ohms.       

[[Page 61676]]

                                                                        
42 kHz to 266 kHz..............  -62 dBV...............  90 ohms.       
------------------------------------------------------------------------

    (f) LADC interface. The metallic voltage shall comply with the 
general requirements in paragraph (f)(1) of this section as well as the 
additional requirements specified in paragraphs (f)(2) and (3) of this 
section as stated. The requirements apply under the conditions 
specified in Sec. 68.308(g). Terminal equipment for which the magnitude 
of the source and/or terminating impedance exceeds 300 Ohms, at any 
frequency in the range of 100 kHz to 6 MHz, at which the signal 
(transmitted and/or received) has significant power, shall be deemed 
not to comply with these requirements. A signal is considered to have 
``significant power'' at a given frequency if that frequency is 
contained in a designated set of frequency bands that collectively have 
the property that the rms voltage of the signal components in those 
bands is at least 90% of the rms voltage of the total signal. The 
designated set of frequency bands must be used in testing all 
frequencies.
    (1) Metallic voltages--frequencies below 4 kHz.
    (i) Weighted rms voltage in the 10 Hz to 4 kHz frequency band. The 
weighted rms metallic voltage in the frequency band from 10 Hz to 4 
kHz, averaged over 100 milliseconds that is the resultant of all the 
component metallic voltages in the band after weighting according to 
the transfer function of f/4000 where f is the frequency in Hertz, 
shall not exceed the maximum indicated below under the conditions 
stated in paragraph (g).

------------------------------------------------------------------------
              Frequency range                      Maximum voltage      
------------------------------------------------------------------------
10 Hz to 4 kHz.............................  +3 dBV.                    
------------------------------------------------------------------------

    (ii) RMS Voltage in 100 Hz bands in the frequency range 0.7 kHz to 
4 kHz. The rms metallic voltage averaged over 100 milliseconds in the 
100-Hz bands having center frequencies between 750 Hz and 3950 Hz shall 
not exceed the maximum indicated below.

------------------------------------------------------------------------
                                              Max voltage in all 100-Hz 
      Center freq (f) of 100-Hz bands                   bands           
------------------------------------------------------------------------
750 to 3950 Hz.............................  -6 dBV.                    
------------------------------------------------------------------------

    (2) Metallic Voltages--frequencies above 4 kHz--LADC interface.
    (i) 100-Hz bands over frequency range of 4 kHz to 270 kHz. The rms 
voltage as averaged over 100 milliseconds in all possible 100-Hz bands 
between 4 kHz and 270 kHz for the indicated range of center frequencies 
and under the conditions specified in Sec. 68.308(g) shall not exceed 
the maximum indicated below:

------------------------------------------------------------------------
Center freq (f) of all 100-Hz bands    Max voltage in all 100-Hz bands  
------------------------------------------------------------------------
4,05 kHz to 4.6 kHz................  0.5 dBV.                           
4.60 kHz to 5.45 kHz...............  (59.2-90 log f) dBV.               
5.45 kHz to 59.12 kHz..............  (7.6-20 log f) dBV.                
59.12 kHz to 266.00 kHz............  (43.1-40 log f) dBV.               
------------------------------------------------------------------------
Where f = center frequency in kHz of each of the possible 100 Hz bands. 

    (ii) 8-kHz bands over frequency range of 4 kHz to 270 kHz. The rms 
voltage as averaged over 100 milliseconds in all of the possible 8-kHz 
bands between 4 kHz and 270 kHz for the indicated range of center 
frequencies and under the conditions specified in Sec. 68.308(g) shall 
not exceed the maximum indicated below:

------------------------------------------------------------------------
   Center freq (f) of 8-kHz bands       Max voltage in all 8-kHz bands  
------------------------------------------------------------------------
8 kHz to 120 kHz...................  (17.6-20 log f) dBV.               
120 kHz to 266 kHz.................  (59.2-40 log f) dBV.               
------------------------------------------------------------------------
Where f = center frequency in kHz of each of the possible 8-kHz bands.  

    (iii) RMS Voltage at frequencies above 270 kHz. The rms value of 
the metallic voltage components in the frequency range of 270 kHz to 6 
MHZ, averaged over 2 microseconds, shall not exceed -15 dBV. This 
limitation applies with a metallic termination having an impedance of 
135 ohms.
    (iv) Peak Voltage. The total peak voltage for all frequency 
components in the 4 kHz to 6 MHZ band shall not exceed 4.0 volts.
    (3) Longitudinal voltage.
    (i) Frequencies below 4kHz. The weighted rms voltage in the 
frequency band from 10 Hz to 4kHz, averaged over 100 milliseconds is 
the resultant of all the component longitudinal voltages in the band 
after weighing according to the transfer function of f/4000, where f is 
the frequency in Hz, shall not exceed the maximum indicated below under 
the conditions stated in Sec. 68.308(g).

------------------------------------------------------------------------
                 Frequency range                    Maximum RMS voltage 
------------------------------------------------------------------------
10 Hz-4 kHz......................................  -37 dBV.             
------------------------------------------------------------------------

    (ii) 4 kHz to 270 kHz

[[Page 61677]]



------------------------------------------------------------------------
                                                           Longitudinal 
 Center freq (f) of 8-kHz bands   Max voltage in all 8-    terminating  
                                        kHz bands            Voltage    
------------------------------------------------------------------------
8 kHz to 12 kHz................  -(18.4 + 20 log f) dBV  500 ohms.      
12 kHz to 42 kHz...............  (3-20 log f) dBV......  90 ohms.       
42 kHz to 266 kHz..............  -62 dBV...............  90 ohms        
------------------------------------------------------------------------
Where f = center frequency in kHz of each of the possible 8-kHz bands.  

    (iii) 270 kHz to 6 MHZ. The rms value of the longitudinal voltage 
components in the frequency range of 270 kHz to 6 MHZ shall, averaged 
over 2 microseconds, not exceed -30 dBV. This limitation applies with a 
longitudinal termination having an impedance of 90 ohms.

BILLING CODE 6712-01-P

[[Page 61678]]

[GRAPHIC] [TIFF OMITTED] TR19NO97.011



BILLING CODE 6712-01-C

[[Page 61679]]

    (g) Requirements in paragraphs (d), (e) and (f) of this section 
apply under the following conditions: (1) All registered terminal 
equipment, except equipment to be used on LADC, and all registered 
protective circuitry must comply with the limitations when connected to 
a termination equivalent to the circuit depicted in Figure 68.308(a) 
and when placed in all operating states of the equipment except during 
network control signaling. LADC registered terminal equipment must 
comply with the metallic voltage limitations when connected to circuits 
of Sec. 68.3(i) and must comply with the longitudinal limitations when 
connected to circuits of Figure 68.308(a), as indicated.
    (2) All registered terminal equipment and registered protective 
circuitry must comply with the limitations in the off-hook state over 
the range of loop currents that would flow with the equipment connected 
to an appropriate simulator circuit.
    (3) Registered terminal equipment and registered protective 
circuitry with provision for through-transmission from other equipments 
shall comply with the limitations with a 1000 Hz tone applied from a 
600-ohm source (or, if appropriate a source which reflects a 600-ohm 
impedance across tip and ring) at the maximum level that would be 
applied during normal operation. Registered protective circuitry for 
data shall also comply with the tone level 10 dB higher than the 
overload point.
    (4) For registered terminal equipment or registered protective 
circuitry with non-registered signal source input, such as music on 
hold, the out of band signal power requirements shall be met using an 
input signal with a frequency range of 200 Hz to 20 kHz and the level 
set at the overload point.
    (5) Except during the transmission of ringing (Sec. 68.306(d)) and 
Dual Tone Multi-frequency (DTMF) signals, LADC registered terminal 
equipment shall comply with all requirements in all operating states 
and with loop current that may be drawn for such purposes as loop back 
signaling. The requirements in paragraph (f)(1) of this section except 
in paragraphs (f)(1)(i) and (f)(1)(ii) of this section also apply 
during the application of ringing. The requirement in paragraph (d) and 
the requirements in paragraphs (f)(1)(i) and (f)(1)(ii) of this section 
apply during ringing for frequencies above 300 Hz and with the maximum 
voltage limits raised by 10 dB. DTMF signals which are used for the 
transmission of alphanumeric information and which comply with the 
requirements in paragraph (f)(1)(i) and in paragraphs (f)(2) or (f)(3) 
of this section as applicable, shall be deemed to comply with the 
requirements in paragraph (f)(1)(ii) of this section provided that, for 
automatically originated DTMF signals, the duty cycle is less than 50 
percent.
    (6) LADC registered terminal equipment shall comply with all 
applicable requirements, except those specified in paragraphs (f)(1) 
(i) and (ii) of this section, during the transmission of each possible 
data signal sequence of any length. For compliance with paragraph 
(f)(3)(i) of this section, the limitation applies to the rms voltage 
averaged as follows:
    (i) For digital signals, baseband or modulated on a carrier, for 
which there are defined signal element intervals, the rms voltage is 
averaged over each such interval. Where multiple carriers are involved, 
the voltage is the power sum of the rms voltages for the signal element 
intervals for each carrier.
    (ii) For baseband analog signals, the rms voltage is averaged over 
each period (cycle) of the highest frequency of the signal (3 dB point 
on the spectrum). For analog signals that are modulated on a carrier 
(whether or not the carrier is suppressed), it is averaged over each 
period (cycle) of the carrier. Where multiple carriers are involved, 
the voltage is the power sum of the rms voltage for each carrier.
    (iii) For signals other than the types defined in paragraphs 
(g)(6)(i) and (ii) of this section, the peak amplitude of the signal 
must not exceed +1 dBV.
    (7) Equipment shall comply with the requirements in paragraphs 
(f)(1)(i) and (ii) of this section, during any data sequence that may 
be transmitted during normal use with a probability greater than 0.001. 
If the sequences transmitted by the equipment are application 
dependent, the user instruction material shall include a statement of 
any limitations assumed in demonstrating compliance of the equipment.
    (8) In addition to the conditions specified in paragraph (g)(5) of 
this section, LADC registered terminal equipment which operates in one 
or more modes as a receiver, shall comply with requirements in 
paragraph (f)(3) of this section with a tone at all frequencies in the 
range of potential received signals and at the maximum power which may 
be received.
    (h) Interference limitations for transmission of bipolar signals 
over digital services.--(1) Limitations on Terminal Equipment 
Connection to Subrate Digital Services--(i) Pulse repetition rate. The 
pulse repetition rate shall be synchronous with 2.4, 3.2, 4.8, 6.4, 
9.6, 12.8, 19.2, 25.6, 38.4, 56.0, or 72 kbps per second.
    (ii) Template for maximum output pulse. When applied to a 135 Ohm 
resistor, the instantaneous amplitude of the largest isolated output 
pulse obtainable from the registered terminal equipment shall not 
exceed by more than 10% the instantaneous voltage defined by a template 
obtained as follows: The limiting pulse template shall be determined by 
passing an ideal 50% duty cycle rectangular pulse with the amplitude/
pulse rate characteristics defined in Table 68.308(c) through a single 
real pole low pass filter having a cutoff frequency in Hertz equal to 
1.3 times the bit rate. For bit rates of 2.4, 3.2, 4.8, 6.4, 9.6 and 
12.8 kbps, the filtered pulses shall also be passed through a filter 
providing the additional attenuation in Table 68.308(d).

                Table 68.308(c).--Driving Pulse Amplitude               
------------------------------------------------------------------------
                                                               Amplitude
         Line rate (kbps)           User data rate (R) (kbps)     (A)   
                                                                (volts) 
------------------------------------------------------------------------
2.4...............................  2.4......................       1.66
3.2...............................  2.4 with SC \1\..........       1.66
4.8...............................  4.8......................       1.66
6.4...............................  4.8 with SC \1\..........       1.66
9.6...............................  9.6......................       0.83
12.8..............................  9.6 with SC \1\..........       0.83
19.2..............................  19.2.....................       1.66
25.6..............................  19.2 with SC \1\.........       1.66
38.4..............................  38.4.....................       1.66
51.2..............................  38.4 with SC \1\.........       1.66
56................................  56.......................       1.66
72................................  56 with SC \1\...........       1.66
72................................  64.......................      1.66 
------------------------------------------------------------------------
\1\ SC: Secondary Channel.                                              


            Table 68.308(d).--Minimum Additional Attenuation            
------------------------------------------------------------------------
                                                Attenuation  Attenuation
                                                     in           in    
             Line rate (R) (kbps)                frequency    frequency 
                                                 band 24-32   band 72-80
                                                  kHz (dB)     kHz (dB) 
------------------------------------------------------------------------
2.4...........................................           5            1 
3.2...........................................           5            1 
4.8...........................................          13            9 
6.4...........................................          13            9 
9.6...........................................          17            8 
12.8..........................................          17           8  
------------------------------------------------------------------------
Note: The attenuation indicated may be reduced at any frequency within  
  the band by the weighting curve of Table 68.308(e). Minimum rejection 
  is never less than 0 dB; i.e., the weight does not justify gain over  
  the system without added attenuation.                                 


                   Table 68.308(e).--Attenuation Curve                  
------------------------------------------------------------------------
                                                  72-80 kHz  Attenuation
                 24-32 kHz band                      band     factor dB 
------------------------------------------------------------------------
24..............................................         72         -18 

[[Page 61680]]

                                                                        
25..............................................         73          -3 
26..............................................         74          -1 
27..............................................         75           0 
29..............................................         76           0 
29..............................................         77           0 
30..............................................         78          -1 
31..............................................         79          -3 
32..............................................         80         -18 
------------------------------------------------------------------------

    (iii) Average power. The average output power when a random signal 
sequence, (0) or (1) equiprobable in each pulse interval, is being 
produced as measured across a 135 ohm resistance shall not exceed 0 dBm 
for 9.6 and 12.8 kbps or +6 dBm for all other rates shown in Table 
68.308(b).
    (iv) Encoded analog content. If registered terminal equipment 
connecting to subrate services contains an analog-to-digital converter, 
or generates signals directly in digital form that are intended for 
eventual conversion into voiceband analog signals, the encoded analog 
content of the digital signal must be limited. The maximum equivalent 
power of encoded analog signals for other than live voice as derived by 
a zero level decoder test configuration shall not exceed -12 dBm when 
averaged over any 3-second time interval. The maximum equivalent power 
of encoded analog signals as derived by a zero level decoder test 
configuration for signals intended for network control signaling shall 
not exceed -3 dBm when averaged over any 3-second interval.
    (2) Limitations on Terminal Equipment Connecting to 1.544 Mbps 
Digital Services.--(i) Pulse repetition rate: The free running line 
rate of the transmit signal shall be 1.544 Mbps with a tolerance of 
32 ppm., i.e., 50 bps.
    (ii) Output pulse templates. The registered terminal equipment 
shall be capable of optionally delivering three sizes of output pulses. 
The output pulse option shall be selectable at the time of 
installation.
    (A) Option A output pulse. When applied to a 100 ohm resistor, the 
instantaneous amplitude of the largest output pulse obtainable from the 
registered terminal equipment shall fall within the pulse template 
illustrated in Figure 68.308b). The mask may be positioned horizontally 
as needed to encompass the pulse, and the amplitude of the normalized 
mask may be uniformity scaled to encompass the pulse. The baseline of 
the mask shall coincide with the pulse baseline.
    (B) Option B output pulse. When applied to a 100-ohm resistor, the 
instantaneous amplitude of the output from the registered terminal 
equipment obtained when Option B is implemented shall fall within the 
pulse template obtained by passing the bounding pulses permitted by 
Figure 68.308(b) through the following transfer function.
[GRAPHIC] [TIFF OMITTED] TR19NO97.025

where:
n0=1.6049 x 106
n1=7.9861 x 10-1
n2=9.2404 x 10-8
d0=2.1612 x 106
d1=1.7223
d2=4.575 x 10-7
d3=3.8307 x 10-14
S=j 2  f
f=frequency (Hertz)

    (C) Option C output pulse. When applied to a 100-ohm resistor, the 
instantaneous amplitude of the output from the registered terminal 
equipment obtained when Option C is implemented shall fall within the 
pulse template obtained by passing the pulses obtained in Option B 
through the transfer function in Option B a second time.

BILLING CODE 6712-01-P

[[Page 61681]]

[GRAPHIC] [TIFF OMITTED] TR19NO97.012



BILLING CODE 6712-01-C


                                                                     Maximum Curve                                                                      
--------------------------------------------------------------------------------------------------------------------------------------------------------
                         Nano-seconds                             -500     -250     -175     -175     -75       0       175      220      500      750  
--------------------------------------------------------------------------------------------------------------------------------------------------------
Normalized Amplitude..........................................      .05      .05       .8      1.2      1.2     1.05     1.05     -.05      .05      .05
--------------------------------------------------------------------------------------------------------------------------------------------------------


                                                                     Minimum Curve                                                                      
--------------------------------------------------------------------------------------------------------------------------------------------------------
                Nano-seconds                    -500     -150     -150     -100      0       100      150      150      300      396      600      750  
--------------------------------------------------------------------------------------------------------------------------------------------------------
Normalized Amplitude........................     -.05     -.05       .5       .9      .95       .9       .5     -.45     -.45     -.26     -.05     -.05
--------------------------------------------------------------------------------------------------------------------------------------------------------

Figure 68.308(b) (Ref. EIA/TIA 547-1989)--Isolated Pulse Template 
and Corner Points for 1.544 Mbps Equipment

    Note to Figure 68.308(b): The pulse amplitude is 2.4 to 3.6 V. 
(Use constant scaling factor to fit normalized template.)
    (iii) Adjustment of signal voltage. The signal voltage at the 
network interface must be limited so that the range of pulse amplitudes 
received at the first telephone company repeater is controlled to 
4 dB. This limitation is achieved by implementing the 
appropriate output pulse option as a function of telephone company 
cable loss as specified at time of installation.

------------------------------------------------------------------------
                                               Terminal equipment       
                                       ---------------------------------
      Cable loss at 772 kHz (dBV)                                Loss at
                                             Output pulse        772 kHz
------------------------------------------------------------------------
15 to 22..............................  Option A..............       0  
7.5 to 15.............................  Option B..............       7.5
0 to 7.5..............................  Option C..............      15  
------------------------------------------------------------------------

    (iv) Output power. The output power in a 3 kHz band about 772 kHz 
when an all ones signal sequence is being produced as measured across a 
100 ohm terminating resistance shall not exceed +19 dBm. The power in a 
3 kHz band about 1.544 MHz shall be at least 25 dB below that in a 3 
kHz band about 772 kHz.
    (v) Encoded Analog Content. If registered terminal equipment 
connected to 1.544 Mbps digital service contains an analog-to-digital 
converter, or generates signals directly in digital form that are 
intended for eventual conversion into voiceband analog signals, the 
encoded analog content of the subrate channels within the 1.544 Mbps 
signal must be limited. The maximum equivalent power of encoded analog 
signals for other than live voice that are not intended for network

[[Page 61682]]

control signaling as derived by a zero level decoder test configuration 
shall not exceed -12 dBm when averaged over any 3-second time interval. 
The maximum equivalent power of encoded analog signals as derived by a 
zero level decoder test configuration for signals intended for network 
control signaling shall not exceed -3 dBm when averaged over any 3-
second interval.
    11. Section 68.310 is revised to read as follows:


Sec. 68.310  Transverse balance limitations.

    (a) Technical description and application. The Transverse 
Balancem-1, coefficient is expressed as
[GRAPHIC] [TIFF OMITTED] TR19NO97.026

    (1) Where eL is the longitudinal voltage produced across 
a longitudinal termination Z1 and eM is the 
metallic voltage across the tip-ring or tip 1 and ring 1 interface of 
the input port when a voltage (at any frequency between f1 
and 2, see Table 68.310(a) is applied from a balanced 
source with a metallic impedance Z0 (see Table 68.310(a). 
The source voltage should be set such that eM = E volts (see 
Table 68.310(a) when a termination of Z0 is substituted for 
the terminal equipment.
    (2) The minimum transverse balance coefficient specified in this 
section (as appropriate) shall be equalled or exceeded for all 2-wire 
network ports, OPS line ports and the transmit pair (tip and ring) and 
receive pair (tip 1 and ring 1) of all 4-wire network ports at all 
values of dc loop current that the port under test is capable of 
drawing when attached to the appropriate loop simulator circuit (See 
Sec. 68.3). An illustrative test circuit that satisfies the above 
conditions is shown in Figure 68.310-1(a) for analog and 68.310-1(b) 
for digital and subrate; other means may be used to determine the 
transverse balance coefficient specified herein, provided that adequate 
documentation of the appropriateness, precision, and accuracy of the 
alternative means is provided by the applicant.
    (3) The minimum transverse balance requirements specified below 
shall be equalled or exceeded under all reasonable conditions of the 
application of earth ground to the equipment or protective circuitry 
under test.

                                                 Table 68.310(a)                                                
----------------------------------------------------------------------------------------------------------------
                                      Analog voiceband              Subrate digital           1.544 Mbps digital
----------------------------------------------------------------------------------------------------------------
Longitudinal Termination--Zl....  500 ohms................  See Table 310(b)...............  90 ohms.           
Metallic Source Impedance--Z0...  600 ohms................  135 ohms.......................  100 ohms.          
Lower Frequency--f1.............  200 Hz..................  200 Hz.........................  10 kHz.            
Upper Frequency--f2.............  4 kHz...................  (\1\)                            1.544 MHz.         
Metallic Voltage for Test--E....  0.775 V.................  0.367 V........................  0.316 V.           
----------------------------------------------------------------------------------------------------------------
\1\ The upper frequency equals the digital line rate for the subrate service under test (See Table 68.310(b)).  

    (b) Analog voiceband equipment. All registered analog voiceband 
equipment shall be tested in the off-hook state. The minimum transverse 
balance requirement in the off-hook state shall be 40 dB, throughout 
the range of frequencies specified in Table 68.310(a). For some 
categories of equipment, additional requirements also apply to the on-
hook state. When both off-hook and on-hook requirements apply, they 
are:

------------------------------------------------------------------------
             State                     Frequency (f)           Balance  
------------------------------------------------------------------------
Off-hook......................  200 Hz : f : 4000 Hz.......  40 dB.     
On-hook.......................  200 Hz : f : 1000 Hz.......  60 dB.     
On-hook.......................  1000 Hz : f : 4000 Hz......  40 dB.     
------------------------------------------------------------------------

    (1) For analog one-port 2-wire terminal equipment with loop-start, 
ringdown, or inband signaling or for voiceband metallic channel 
applications, both off-hook and on-hook requirements apply.
    (2) For analog one port equipment with ground-start and reverse-
battery signaling only off-hook requirements apply.
    (3) For analog registered protective circuitry for 2-wire 
applications with loop-start, ringdown, or inband signaling; or for 
voiceband metallic channel applications, both off-hook and on-hook 
requirements apply. Criteria shall be met with either terminal of the 
interface to other equipment connected to earth ground. The interface 
to other equipment shall be terminated in an impedance that will be 
reflected to the telephone connection as 600 Ohms in the off-hook state 
of the registered protective circuit, and the interface should not be 
terminated in the on-hook state. Figure 68.310(b) shows the interface 
of the protective circuitry being tested and the required arrangement 
at the interface to other equipment.
    (4) For analog registered protective circuitry with ground-start 
and reverse-battery signaling only off-hook requirements apply. 
Criteria shall be met with either terminal of the interface to other 
equipment connected to earth ground. The interface to other equipment 
shall be terminated in an impedance that will be reflected to the 
telephone connection as 600 ohms in the off-hook state of the 
registered protective circuit. Figure 68.310(b) shows the interface of 
the protective circuitry under test and the required arrangement at the 
interface to the other equipment.
    (5) For analog multi-port equipment with loop-start signaling both 
off-hook and on-hook requirements apply. Criteria shall be satisfied 
for all ports when all the ports not under test are terminated in their 
appropriate networks, as will be identified below, and when interface 
connections other than the ports are terminated in circuits appropriate 
to that interface. The minimum transverse balance coefficients shall 
also be satisfied for all values of dc loop current that the registered 
equipment is capable of drawing through each of its ports when these 
ports are attached to the loop simulator circuit specified in these 
rules. The termination for all ports other than the particular one 
whose transverse balance coefficient is being measured shall have a 
metallic impedance of 600 ohms.
    (6) For analog multi-port equipment with ground-start and reverse-
battery signaling, only off-hook requirements apply. Criteria shall be 
satisfied for all ports when all ports not under test are terminated in 
their appropriate networks as will be identified below, and when 
interface connections other than the ports are terminated in circuits 
appropriate to that interface. The minimum transverse balance 
coefficients shall be satisfied for all values of dc loop current that 
the registered equipment is capable of drawing through each of its 
ports when these ports are attached to the loop simulator circuit 
specified in these rules. The terminations for all ports

[[Page 61683]]

other than the particular one whose transverse balance coefficient is 
being measured shall have a metallic impedance of 600 ohms and a 
longitudinal impedance of 500 ohms. Figure 68.310(c) shows this 
termination.
    (7) For analog registered terminal equipment and protective 
circuitry for 4-wire network ports, both the off-hook and on-hook 
requirements apply. The pair not under test shall be terminated in a 
metallic impedance of 600 ohms. Other conditions are as follows:
    (i) For analog registered protective circuitry with loop-start, 
ground-start, reverse battery, ringdown, or inband signaling; or for 
voiceband metallic channel applications. Criteria shall be met with 
either terminal of the interface to other equipment connected to earth 
ground. The interface to other equipment shall be terminated in an 
impedance that will result in 600 ohms at each of the transmit and 
receive pairs of the 4-wire telephone connection in the off-hook state 
of the registered protective circuit, and the interface should not be 
terminated in the on-hook state. Figure 68.310(d) shows the interface 
of the protective circuitry being tested and the required arrangement 
at the interface to other equipment.
    (ii) For analog multiport equipment with loop start, ground start, 
and reverse battery, ringdown, or inband signaling; or for voiceband 
metallic channel applications. Criteria shall be satisfied for all 
network ports when all the ports not under test are terminated as 
defined below, and when interface connections other than the network 
ports are terminated in circuits appropriate to the interface. The 
criteria shall also be satisfied for all values of dc loop current that 
when the port is connected to the appropriate 4-wire loop simulator 
circuit. The terminations for both pairs of all network ports not under 
test shall have a metallic impedance of 600 ohms and a longitudinal 
impedance of 500 ohms. Figure 68.310(c) shows this termination.
    (8) For analog PBX equipment (or similar systems) with class B or 
class C off-premises interfaces, only off-hook requirements apply. 
Criteria shall be satisfied for all off-premises station interface 
ports when these ports are terminated in their appropriate networks for 
their off-hook state, and when all other interface connections are 
terminated in circuits appropriate to that interface. The minimum 
transverse balance coefficients shall also be satisfied for all values 
of dc loop current that the registered PBX is capable of providing 
through off-premises station ports when these ports are attached to the 
off-premises line simulator circuit specified in these rules.
    (9) For Type Z equipment with loop-start signaling, both off-hook 
and on-hook requirements apply. Equipment that has on-hook impedance 
characteristics which that do not conform to the requirements of 
Sec. 68.312 (e.g., Type Z), shall comply with minimum transverse 
balance requirements of 40 dB in the voiceband. See Sec. 68.312(h) for 
conditions upon registration of ``Type Z'' equipment.
    (c) Digital equipment. The minimum transverse balance requirements 
for registered terminal equipment connected to digital services shall 
be equalled or exceeded for the range of frequencies applicable for the 
equipment under test and under all reasonable conditions of the 
application of earth ground to the equipment. All such terminal 
equipment shall have a transverse balance in the acceptable region of 
Figure 68.310(e) for the range of frequencies shown in Table 68.310(b) 
for the specified digital service in question. The metallic impedance 
used for the transverse balance measurements for all subrate services 
shall be 135 ohms and for 1.544 Mbps shall be 100 ohms. The 
longitudinal termination for 1.544 Mbps and subrate services shall be 
as defined in Table 68.310(b).

                    Frequency Ranges of Transverse Balance Requirements for Digital Services                    
----------------------------------------------------------------------------------------------------------------
                                                                                       Longitudinal    Metallic 
                Digital service                            Frequency range              termination  termination
                                                                                          (ohms)        (ohms)  
----------------------------------------------------------------------------------------------------------------
2.4...........................................  200 to 2.4 kHz.......................           500          135
3.2...........................................  200 to 3.2 kHz.......................           500          135
4.8...........................................  200 to 4.8 kHz.......................           500          135
6.4...........................................  200 to 6.4 kHz.......................           500          135
9.6...........................................  200 to 9.6 kHz.......................           500          135
12.8\1\.......................................  200 to 12.8 kHz......................        500/90          135
19.2\1\.......................................  200 to 19.2 kHz......................        500/90          135
25.6\1\.......................................  200 to 25.6 kHz......................        500/90          135
38.4\1\.......................................  200 to 38.4 kHz......................        500/90          135
56\1\.........................................  200 to 56 kHz........................        500/90          135
72\1\.........................................  200 to 72 kHz........................        500/90          135
1.544.........................................  10 kHz to 1.544 MHz..................            90         100 
----------------------------------------------------------------------------------------------------------------
\1\ For 200 to 12 kHz the longitudinal termination shall be 500 ohms and above 12 kHz the longitudinal          
  termination shall be 90 ohms.                                                                                 


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    12. Section 68.312 is revised to read as follows:


Sec. 68.312  On-hook impedance limitations.

    (a) General. Requirements in this section apply to the tip and ring 
conductors of 2-wire interfaces. These requirements also apply to 4-
wire loop-start or ground-start interfaces, in the following 
configuration:
    (1) The tip and ring conductors are connected together and treated 
as one of the conductors of a tip and ring pair.
    (2) The tip 1 and ring 1 conductors are connected together and 
treated as the other conductor of a tip and ring pair.

    Note to Sec. 68.312: Throughout this section, references will be 
made to simulated ringing. Ringing voltages to be used and impedance 
limitations associated with simulated ringing are shown in Table 
68.312(a).

                                                 Table 68.312(a)                                                
----------------------------------------------------------------------------------------------------------------
                                                                                                      Impedance 
             Ringing type               Range of compatible ringing     Simulated ringing voltage    limitations
                                              frequencies (Hz)        superimposed on 56.5 volts dc     (ohms)  
----------------------------------------------------------------------------------------------------------------
A....................................  203..............  40 to 130 volts rms..........         1400
                                       303..............  40 to 130 volts rms..........         1000
B....................................  15.3 to 34...................  40 to 130 volts rms..........         1600
                                       >34 to 49....................  62 to 130 volts rms..........         1600
                                       >49 to 68....................  62 to 150 volts rms..........         1600
----------------------------------------------------------------------------------------------------------------

    (b) Limitations on individual equipment intended for operation on 
loop-start telephone facilities. Registered terminal equipment and 
registered protective circuitry shall conform to the following 
limitations:
    (1) On-hook resistance, metallic and longitudinal (up to 100 Vdc). 
The on-hook dc resistance between the tip and ring conductors of a loop 
start interface, and between each of the tip and ring conductors and 
earth ground, shall be greater than 5 megohms for all dc voltages up to 
and including 100 volts.
    (2) On-hook resistance, metallic and longitudinal (100 V to 200 
Vdc). The on-hook dc resistance between tip and ring conductors of a 
loop start interface, and between each of the tip and ring conductors 
and earth ground shall be greater than 30 kOhms for all dc voltages 
between 100 and 200 volts.
    (3) DC current during ringing. During the application of simulated 
ringing, as listed in Table 68.312(a), to a loop start interface, the 
total dc current shall not exceed 3.0 milliamperes. The equipment must 
comply for each ringing type which is listed as part of the ringer 
equivalence.
    (4) Ringing frequency impedance (metallic). During the application 
of simulated ringing, as listed in Table 68.312(a), to a loop start 
interface, the impedance between the tip and ring conductors (defined 
as the quotient of applied ac voltage divided by resulting true rms 
current) shall be greater than or equal to the value specified in Table 
68.312(a). The equipment must comply for each ringing type which is 
listed as part of the ringer equivalence.
    (5) Ringing Frequency Impedance (longitudinal). During the 
application of simulated ringing, as listed in Table 68.312(a), to a 
loop start interface, the impedance between each of the tip and ring 
conductors and ground shall be greater than 100 kohms. The equipment 
must comply with each ringing type listed in the ringer equivalence.
    (c) Limitations on individual equipment intended for operation on 
ground start telephone facilities. Registered terminal equipment and 
registered protective circuitry shall conform to the following 
limitations:
    (1) DC current during ringing. During the application of simulated 
ringing, as listed in Table 68.312(a), to a ground start interface, the 
total dc current flowing between tip and ring conductors shall not 
exceed 3.0 milliamperes. The equipment must comply for each ringing 
type listed as part of the ringer equivalence.
    (2) Ringing frequency impedance (metallic). During the application 
of simulated ringing, as listed in Table 68.312(a), to a ground start 
interface, the total impedance of the parallel combination of the ac 
impedance across tip and ring conductors and the ac impedance from the 
ring conductor to ground (with ground on the tip conductor) shall be 
greater than the value specified in Table 68.312(a). The equipment must 
comply for each ringing type listed as part of the ringer equivalence.
    (d) Ringer Equivalence Definition. The ringer equivalence number is 
defined to be the value determined in paragraphs (d)(1) or (d)(2) of 
this section, as appropriate, followed by the ringer type letter 
indicator representing the frequency range for which the number is 
valid. If Ringer Equivalence is to be stated for more than one Ringing 
Type, testing shall be performed at each frequency range to which 
Ringer Equivalence is to be determined in accordance with the above, 
and the largest resulting Ringer Equivalence Number so determined will 
be associated with each Ringing Type letter designation for which it is 
valid.
    (1) For individual equipment intended for operation on loop-start 
telephone facilities, the ringer equivalence is five times the 
impedance limitation listed in Table 68.312(a), divided by the minimum 
measured ac impedance, as defined in paragraph (b)(1)(iv) of this 
section, during the application of simulated ringing as listed in Table 
68.312(a).
    (2) For individual equipment intended for operation on ground-start 
telephone facilities, the ringer equivalence is five times the 
impedance limitation listed in Table 68.312(a), divided by the minimum 
measured ac impedance, defined in paragraph (c)(2) of this section, 
during the application of simulated ringing as listed in Table 
68.312(a).
    (e) Ringer equivalence number labeling. Registered terminal 
equipment and registered protective circuitry shall have at least one 
Ringer Equivalence Number shown on the registration label. Where 
options that will vary the Ringer Equivalence are involved, either each 
option that results in a Ringer Equivalence Number greater than 0.1 and 
its corresponding Ringer Equivalence shall be listed on the 
registration label, or the largest Ringer Equivalence Number that can 
result from such options shall be stated on the label. A trained, 
authorized agent of the Grantee may disconnect ringers, bridge ringers 
to another line, or execute options affecting Ringer Equivalence after 
the telephone company has been notified in accordance with Sec. 68.106.
    (f) Maximum ringer equivalence. All registered terminal equipment 
and registered protective circuitry that can affect the ringing 
frequency impedance shall be assigned a Ringer Equivalence. The sum of 
all such Ringer Equivalences

[[Page 61690]]

on a given telephone line or loop shall not exceed 5. In some cases, a 
system that has a total Ringer Equivalence of 5 or less may not be 
usable on a given telephone line or loop.
    (g) OPS interfaces for PBX with DID (Ring trip requirement). PBX 
ringing supplies whose output appears on the off-premises interface 
leads shall not trip when connected to the following tip-to-ring 
impedance that terminates the off-premises station loop: A terminating 
impedance composed of the parallel combination of a 15 kohms resistor 
and an RC series circuit (resistor and capacitor) whose ac impedance is 
as specified in Table 68.312(b) below.

                             Table 68.312(b)                            
------------------------------------------------------------------------
                                                    ac impedance ohms   
                                               -------------------------
                Ringing freq Hz                 Class  B or             
                                                     C         Class A  
------------------------------------------------------------------------
20  3.............................       7000/N         1400
30  3.............................       5000/N        1000 
------------------------------------------------------------------------
N--Number of ringer equivalences, as specified by the manufacturer,     
  which can be connected to the off-premises station loop.              

    (h) Type Z Ringers. Equipment that has on-hook impedance 
characteristics which do not conform to the requirements of this 
section may be conditionally registered, notwithstanding the 
requirements of this section, provided that it is labeled with a 
Ringing Type designation ``Z''. It should be noted that registration of 
equipment bearing the designation ``Z'' does not necessarily confer any 
right of connection to the telephone network under these rules. Any 
equipment registered with the type Z designation may only be used with 
the consent of the local telephone company, provided that the local 
telephone company does not discriminate in its treatment of equipment 
bearing the type Z designation.
    (i) Transitioning to the Off-Hook State. Registered terminal 
equipment and registered protective circuitry shall not by design leave 
the on-hook state by operations performed on tip and ring leads for any 
other purpose than to request service or answer an incoming call, 
except that terminal equipment that the user places in the off-hook 
state for the purpose of manually placing telephone numbers in internal 
memory for subsequent automatic or repertory dialing shall be 
registerable. Make-busy indications shall be transmitted by the use of 
make-busy leads only as defined in Sec. 68.3 and Sec. 68.200(j).
    13. Section 68.314 is revised to read as follows:


Sec. 68.314  Billing protection.

    (a) Call duration requirements on data equipment connected to the 
public switched network, or to tie trunks, or to private lines that 
access the public switched network. Registered data terminal equipment 
and registered protective circuitry shall comply with the following 
requirements when answering an incoming call, except in off-hook states 
in which the signals are transmitted and/or received by electroacoustic 
transducers only.

    Note to paragraph (a) of this section: This paragraph is 
applicable to terminal equipment and registered protective circuitry 
employed with digital services where such digital services are 
interconnected with the analog telephone network.

    (1) Registered protective circuitry. Registered protective 
circuitry connected to associated data equipment shall assure that the 
following signal power limitations are met for at least the first 2 
seconds after the off-hook condition is presented to the telephone 
network in response to an incoming call:
    (i) Signals that appear at the protective circuitry/telephone 
network interface for delivery to the telephone network shall be 
limited to -55 dBm, (at any frequency in the range of 200 to 3200 
Hertz), as such signals are delivered into a loop simulator circuit or 
a 600 ohm termination, as appropriate; and
    (ii) Signals that appear at the protective circuitry-associated 
data equipment interface for delivery to associated data equipment 
shall be limited as follows: for any received signal power (appearing 
at the protective circuitry-telephone network interface) up to 0 dB 
with respect to one milliwatt (at any frequency in the range of 200 to 
3200 Hertz), the power of signals delivered to associated data 
equipment shall be no greater than the signal power that would be 
delivered as a result of received signal power of -55 dBm.
    (2) Registered terminal equipment. Registered terminal equipment 
for data applications shall assure that, when an incoming telephone 
call is answered, the answering terminal equipment prevents both 
transmission and reception of data for at least the first two seconds 
after the answering terminal equipment transfers to the off-hook 
condition. For the purpose of this requirement, a fixed sequence of 
signals that is transmitted (and originated within) and/or received by 
the registered terminal equipment each time it answers an incoming call 
shall not be considered data, provided that such signals are for one or 
more of the following purposes:
    (i) Disabling echo control devices,
    (ii) Adjusting automatic equalizers and gain controls,
    (iii) Establishing synchronization, or
    (iv) Signaling the presence and if required, the mode of operation, 
of the data terminal at the remote end of a connection.
    (b) Voice and data equipment on-hook signal requirements for 
equipment connected to the public switched network, or to tie trunks, 
or to private lines that access the public switched network. Registered 
protective circuitry and registered terminal equipment shall comply 
with the following:
    (1) The power delivered into a 2-wire loop simulator circuit or 
into the transmit and receive pairs of a 4-wire loop simulator or into 
a 600 ohm termination (where appropriate) in the on-hook state, by 
loop-start or ground-start equipment shall not exceed -55 dBm within 
the voiceband. Registered protective circuitry shall also assure that 
for any input level up to 10 dB above the overload point, the power to 
a 2-wire loop simulator circuit or the transmit and receive pairs of a 
4-wire loop simulator circuit or into a 600 ohm termination (where 
appropriate) does not exceed the above limits.
    (2) The power delivered into a 2-wire loop simulator circuit or 
into the transmit and receive pairs of a 4-wire loop simulator circuit, 
in the on-hook state, by reverse battery equipment shall not exceed -55 
dBm, unless the equipment is arranged to inhibit incoming signals.
    (c) Voice and data equipment loop current requirements for 
equipment connected to the public switched network. The loop current 
through registered terminal equipment or registered protective 
circuitry, when connected to a 2-wire or 4-wire loop simulator circuit 
with the 600 ohm resistor and 500 microfarad capacitor of the 2-wire 
loop simulator circuit or both pairs of the 4-wire loop simulator 
circuit disconnected shall, for at least 5 seconds after the equipment 
goes to the off-hook state that would occur when answering an incoming 
call:
    (1) Be at least as great as the current obtained in the same loop 
simulator circuit with minimum battery voltage and a maximum loop 
resistance when a 200 ohm resistance is connected across the tip and 
ring of the 2-wire loop simulator circuit or connected across the tip/
ring and tip 1/ring 1 conductors (tip and ring connected together and 
tip 1 and ring 1 connected together) of the 4-wire loop simulator 
circuit in place of

[[Page 61691]]

the registered terminal equipment or registered protective circuitry; 
or
    (2) Not decreased by more than 25 percent from its maximum value 
attained during this 5-second interval; unless the equipment is 
returned to the on-hook state during the above 5 second interval.
    (3) The above requirements also apply in the hold state and any 
off-hook state.
    (d) Signaling interference requirements. (1) The signal power 
delivered to the network interface by the registered terminal equipment 
and from signal sources internal to registered protective circuitry in 
the 2450 Hz to 2750 Hz band shall be less than or equal to the power 
present simultaneously in the 800 Hz to 2450 Hz band for the first 2 
seconds after going to the off-hook state.
    (2) Registered terminal equipment for connection to subrate or 
1.544 Mbps digital services shall not deliver digital signals to the 
telephone network with encoded analog content energy in the 2450 to 
2750 Hertz band unless at least an equal amount of encoded analog 
energy is present in the 800 to 2450 Hertz band for the first two 
seconds after going to the off-hook state.
    (e) On-hook requirements for registered terminal equipment for 
connection to subrate and 1.544 Mbps digital services. Registered 
terminal equipment and registered protective circuitry shall comply 
with the following:
    (1) The power delivered to the telephone network in the on-hook 
state as derived by a zero level decoder shall not exceed -55 dBm 
equivalent power for digital signals within the voiceband.
    (2) Registered protective circuitry shall also assure that the 
power to a zero level decoder does not exceed the above limits for any 
input level up to 10 dB above the overload point.
    (3) Reverse battery interface. The power derived by a zero level 
decoder, in the on-hook state, by reverse battery equipment, shall not 
exceed -55 dBm, unless the equipment is arranged to inhibit incoming 
signals.
    (f) Off hook requirements. Off-hook signal requirements for 
registered terminal equipment connecting to 1.544 Mbps digital 
services. Upon entering the normal off-hook state, in response to 
alerting, for subrate channels, registered terminal equipment shall 
continue to transmit the signaling bit sequence representing the off-
hook state for 5 seconds, unless the equipment is returned to the on-
hook state during the above 5-second interval.
    (g) Operating requirements for direct inward dialing. (1) For 
registered terminal equipment, the off-hook state shall be applied 
within 0.5 seconds of the time that:
    (i) The terminal equipment permits the acceptance of further digits 
that may be used to route the incoming call to another destination.
    (ii) The terminal equipment transmits signals towards the calling 
party, except for the call progress tones, i.e., busy, reorder and 
audible ring, and the call is:
    (A) Answered by the called, or another station;
    (B) Answered by the attendant;
    (C) Routed to a customer controlled or defined recorded 
announcement, except for ``number invalid,'' ``not in service'' or 
``not assigned;''
    (D) Routed to a dial prompt; or
    (E) Routed back to the public switched telephone network or other 
destination and the call is answered. If the status of the answered 
call cannot be reliably determined by the terminal equipment through 
means such as, detection of answer supervision or voice energy, removal 
of audible ring, etc., the off-hook state shall be applied after an 
interval of not more than 20 seconds from the time of such routing. The 
off-hook state shall be maintained for the duration of the call.
    (2) For registered protective circuitry:
    (i) Registered protective circuitry shall block transmission 
incoming from the network until an off-hook signal is received from the 
terminal equipment.
    (ii) Registered protective circuitry shall provide an off-hook 
signal within 0.5s following the receipt of an off-hook signal from the 
terminal equipment and shall maintain this off-hook signal for the 
duration of the call.
    14. Section 68.316 is amended by revising the section heading to 
read as follows:


Sec. 68.316  Hearing aid compatibility: Technical requirements.

* * * * *
    15. Section 68.317 is amended by revising the section heading to 
read as follows:


Sec. 68.317  Hearing aid compatibility volume control: technical 
standards.

* * * * *
    16. Section 68.318 is revised to read as follows:


Sec. 68.318  Additional limitations.

    (a) General. Registered terminal equipment for connection to those 
services discussed below must incorporate the specified features.
    (b) Registered terminal equipment with automatic dialing 
capability. (1) Automatic dialing to any individual number is limited 
to two successive attempts. Automatic dialing equipment which employ 
means for detecting both busy and reorder signals shall be permitted an 
additional 13 attempts if a busy or reorder signal is encountered on 
each attempt. The dialer shall be unable to re-attempt a call to the 
same number for at least 60 minutes following either the second or 
fifteenth successive attempt, whichever applies, unless the dialer is 
reactivated by either manual or external means. This rule does not 
apply to manually activated dialers that dial a number once following 
each activation.

    Note to paragraph (b)(1): Emergency alarm dialers and dialers 
under external computer control are exempt from these requirements.
    (2) If means are employed for detecting both busy and reorder 
signals, the automatic dialing equipment shall return to its on-hook 
state within 15 seconds after detection of a busy or reorder signal.
    (3) If the called party does not answer, the automatic dialer 
shall return to the on-hook state within 60 seconds of completion of 
dialing.
    (4) If the called party answers, and the calling equipment does 
not detect a compatible terminal equipment at the called end, then 
the automatic dialing equipment shall be limited to one additional 
call which is answered. The automatic dialing equipment shall comply 
with paragraphs (b)(1), (b)(2), and (b)(3) of this section for 
additional call attempts that are not answered.
    (5) Sequential dialers shall dial only once to any individual 
number before proceeding to dial another number.
    (6) Network addressing signals shall be transmitted no earlier 
than:
    (i) 70 ms after receipt of dial tone at the network demarcation 
point; or
    (ii) 600 ms after automatically going off-hook (for single line 
equipment that does not use dial tone detectors); or
    (iii) 70 ms after receipt of CO ground start at the network 
demarcation point.

    (c) Line seizure by automatic telephone dialing systems. Automatic 
telephone dialing systems which deliver a recorded message to the 
called party must release the called party's telephone line within 5 
seconds of the time notification is transmitted to the system that the 
called party has hung up, to allow the called party's line to be used 
to make or receive other calls.
    (d) Telephone facsimile machines; Identification of the sender of 
the message. It shall be unlawful for any person within the United 
States to use a computer or other electronic device to send any message 
via a telephone facsimile machine unless such message clearly contains, 
in a margin at the top or bottom of each transmitted page or on the 
first page of the transmission, the date and time it is sent and an 
identification of the business, other entity, or individual sending the

[[Page 61692]]

message and the telephone number of the sending machine or of such 
business, other entity, or individual. Telephone facsimile machines 
manufactured on and after December 20, 1992, must clearly mark such 
identifying information on each transmitted message.
    (e) Requirement that registered equipment allow access to common 
carriers. Any equipment or software manufactured or imported on or 
after April 17, 1992, and installed by any aggregator shall be 
technologically capable of providing consumers with access to 
interstate providers of operator services through the use of equal 
access codes. The terms used in this paragraph shall have meanings 
defined in Sec. 64.708 of this chapter (47 CFR 64.708).

[FR Doc. 97-29925 Filed 11-18-97; 8:45 am]
BILLING CODE 6712-01-P