[Federal Register Volume 73, Number 96 (Friday, May 16, 2008)]
[Notices]
[Pages 28433-28435]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E8-11148]


-----------------------------------------------------------------------

DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[Docket No.: 080506632-8633-01]


Codeless and Semi-Codeless Access to the Global Positioning 
System

AGENCY: Office of Space Commercialization, National Oceanic and 
Atmospheric Administration, Department of Commerce.

ACTION: Notice and request for comments.

-----------------------------------------------------------------------

SUMMARY: The Office of Space Commercialization seeks comments on a plan 
to transition the installed base of codeless and semi-codeless Global 
Positioning System (GPS) user equipment to next-generation equipment 
utilizing the modernized civil GPS signals known as L2C and L5. The 
plan was developed under the auspices of the National Executive 
Committee for Space-Based Positioning, Navigation, and Timing (PNT). 
Under the plan, the Department of Defense, as the operator of GPS, will 
continue

[[Page 28434]]

enabling codeless/semi-codeless GPS access until December 31, 2020, by 
which time the L2C and L5 signals will be available on 24 or more 
modernized GPS satellites. Users should re-equip to use the modernized 
signals, since codeless/semi-codeless GPS access cannot be assured 
beyond 2020.

DATES: Submit comments on or before June 16, 2008.

ADDRESSES: You may submit comments by any of the following methods: E-
mail: [email protected]. Fax: (202) 482-4429 (Attn.: Jason Kim). Mail/
Courier: Jason Kim, Office of Space Commercialization, U.S. Department 
of Commerce, 6818 Herbert C. Hoover Building, 14th St. & Pennsylvania 
Ave., NW., Washington, DC 20230. Due to ongoing delays in mail 
delivery, respondents are encouraged to submit comments by mail early, 
or to transmit them electronically. Office hours for courier delivery 
are 9 a.m. to 5 p.m., Monday through Friday, except Federal holidays.

FOR FURTHER INFORMATION CONTACT: Jason Kim, Senior Policy Analyst, 
Office of Space Commercialization, U.S. Department of Commerce, (202) 
482-5827.

SUPPLEMENTARY INFORMATION: The Global Positioning System (GPS) is a 
U.S. Government constellation of 24 or more satellites providing 
precise positioning, navigation, and timing (PNT) capabilities, free of 
direct user fees, on a continuous, worldwide basis. GPS currently 
transmits PNT information on two radio frequencies known as L1 (1575 
MHz) and L2 (1227 MHz). In the future, GPS will also transmit 
information on a third frequency known as L5 (1176 MHz).
    GPS transmits encrypted signals known as Y-code or P(Y)-code at the 
L1 and L2 frequencies. Y-code is intended primarily for U.S. and allied 
military use, but the civilian community has developed techniques that 
exploit Y-code at L1 and L2 to achieve significant accuracy gains. Such 
techniques, collectively known as codeless or semi-codeless GPS access, 
have been integrated into a range of GPS receivers sold commercially 
around the world.
    The Y-code signal was never designed or intended for codeless/semi-
codeless access. However, the Department of Defense, as the GPS 
operator, has historically supported codeless and semi-codeless users 
by documenting a time-limited commitment to the Y-code signal in the 
GPS Standard Positioning Service (SPS) Performance Standard and the 
Federal Radionavigation Plan. For example, the current GPS SPS 
Performance Standard (dated October 2001) includes the statement that, 
``Until such time as a second coded civil GPS signal is operational, 
the U.S. Government has agreed to not intentionally reduce the current 
received minimum Radio Frequency signal strength of the P(Y)-coded 
signal on the L2 link, as specified in ICD-GPS-200C or to intentionally 
alter the P(Y)-coded signal on the L2 link.'' As a result, 
manufacturers have continued to develop codeless/semi-codeless GPS 
equipment.
    The U.S. Government acknowledges the global use of GPS codeless and 
semi-codeless techniques and plans to maintain the existing GPS L1 Y-
code and L2 Y-code signal characteristics until such time that an 
alternative capability exists to replace it. Since 1999, the Department 
of Defense has worked closely with the civilian agencies on the 
National Executive Committee for Space-Based PNT (and its predecessor, 
the Interagency GPS Executive Board) to add new capabilities to GPS 
that supplant the need for codeless/semi-codeless access. In 2005, the 
U.S. Air Force began launching modernized GPS satellites featuring a 
new civil signal at L2 called L2C. L2C is designed to work in 
combination with the legacy civil signal (called C/A) at L1 to enable 
high accuracy without codeless/semi-codeless techniques. In 2009, the 
Air Force will begin adding a third civil signal called L5 to all new 
GPS satellites. L5 will also work in combination with L1 C/A and/or L2C 
to enable high accuracy without codeless/semi-codeless techniques.
    The National Executive Committee for Space-Based PNT seeks to 
encourage the development and adoption of next-generation GPS receivers 
that achieve high accuracy via use of L2C and/or L5 instead of 
codeless/semi-codeless techniques. To facilitate business decisions and 
stable planning for equipment developers and end users, the National 
Executive Committee intends to set a fixed target date for the 
equipment transition.
    The National Executive Committee proposes December 31, 2020, as the 
target date for transitioning the installed base of codeless/semi-
codeless GPS equipment to next-generation capabilities utilizing the 
modernized civil GPS signals. This date is based upon the current 
launch schedule for the GPS program, which will have 24 GPS satellites 
transmitting the L2C signal to users by 2016, and 24 GPS satellites 
transmitting L5 by 2018. The date is also based on preliminary 
discussions the Office of Space Commercialization has held with GPS 
equipment manufacturers. The manufacturers indicated that a transition 
period of approximately ten years should be sufficient to allow the 
installed base of codeless/semi-codeless GPS users to re-equip with 
next-generation receivers as part of their normal equipment 
amortization, obsolescence, and upgrade cycle.
    Should there be unforeseen delays in the GPS modernization program, 
the National Executive Committee will reassess the target date for the 
transition.
    After the transition date, the characteristics of the Y-code 
signals transmitted by modernized GPS satellites may change without 
further notice and may preclude codeless/semi-codeless use of the Y-
code signals. However, for those legacy satellites that have no 
modernized capabilities, codeless/semi-codeless access to Y-code at L1 
and L2 will continue until those satellites are decommissioned.
    The Office of Space Commercialization encourages the GPS user 
community and manufacturing industry to provide feedback on this 
proposed plan within the next 30 days. Both domestic and international 
comments are welcome due to the global nature of GPS use. The National 
Executive Committee will take the public comments into account as it 
prepares a final announcement on the date for the codeless/semi-
codeless GPS transition. The Department of Defense will publish the 
final announcement in the Federal Register.
    Concurrent with the final transition plan announcement, the 
Department of Defense intends to release an update to the SPS 
Performance Standard that no longer includes a reference to Y-code 
stability in support of codeless/semi-codeless access. The final 
announcement would serve to document the government's continued 
commitment to protect codeless/semi-codeless GPS access through the end 
of the transition period. Specifically, the final announcement would 
commit the Department of Defense to maintaining the existing GPS L1 Y-
code and L2 Y-code signal characteristics until December 31, 2020. The 
announcement would also state that should there be unforeseen delays in 
the GPS modernization program, the date will be reassessed.
    Instructions for the submission of comments.
    Page Limit--Submissions should be limited to a maximum length of 
four pages.
    Identification and Cover Sheet--Mark each page of the submission 
with the docket number, submitter's name (and

[[Page 28435]]

organization, if applicable), date of submission, and contact 
information (if the submitter chooses to provide it).
    Additional information--The Office of Space Commercialization 
encourages interested persons who wish to comment to do so at the 
earliest possible time. The Office will consider all comments received 
before the close of the comment period on June 16, 2008. Consideration 
of comments received after the end of the comment period cannot be 
assured. The Office will not accept comments accompanied by a request 
that part or all of the material be treated confidentially because of 
its business proprietary nature or for any other reason. All comments 
submitted in response to this notice will be a matter of public record 
and will be available for public inspection and copying at http://www.space.commerce.gov.

    Authority: NSPD-39; 10 USC Sec 2281(b)(5).

    Dated: May 14, 2008.
Ed Morris,
Director, Office of Space Commercialization.
 [FR Doc. E8-11148 Filed 5-15-08; 8:45 am]
BILLING CODE 3510-HR-P