# Presentation: 668169

## Spectrum Issues 

**Sally L. Frodge**
- Dept. of Transportation, Office of the Assistant Secretary for Transportation Policy
- ITS America Annual Meeting
- Detroit, Michigan  May 6, 1998

## Select Spectrum Issues -- GPS

- Mobile Satellite Service (MSS) proposal for reallocation of the lower portion of the GPS band
- MSS out-of-band (oob) emissions level -- protection of GNSS
- GPS Modernization:  a new second and third frequency
- Spectrum Allocation and Regulation
- Legislative Activities
- Potential for Unintentional Interference -- TV
- WRC Preparation

## MSS wants the lower portion of the band GPS is currently using -- the US has opposed this activity being waged at the international level -- the reallocation was narrowly averted at WRC-97 ... it comes up again at WRC-99 

## Slide 4

## WRC-97 Outcome on MSS Proposal

- The U.S. has had a close call that has been deferred but not defeated
- To defeat this effort, coordination and outreach must continue and the technical work must be supported
- The final decision will be made at WRC-99

## Is there a 100 foot wide car Problem?

## Is this a 100 Foot Wide Car Problem? 

- International Telecommunications Union (ITU) Action to adopt:
- -70 dBW/MHz in the 1559-1605 MHz band for TDMA (ie GLONASS) systems and 1559-1580.42 MHz band for CDMA systems (ie GPS)
- Pending approval for ITU-R M.1343, *Essential Technical Requirements for Mobile Earth Stations for Global Non-Geostationary Mobile-Satellite Services Systems in the Bands 1-3 GHz*

## What does this mean?

- This figure (-70 dBW/MHz) was developed by the aviation community and published in RTCA SC-159 Report, *Assessment of Radio Frequency Interference Relevant to the GNSS, *January 27, 1997.  Some main assumptions were made in deriving this value:
- this is at 100 feet spacing from aircraft to the Mobile Earth Station (ie the phone)
- the analysis assumption was that the interference to the AC would be momentary
- AC antenna would be open to the sky and be able to mask out satellite of lower elevations

## No, really...what does this mean?

- Aviation is developed this number and is aviation use of GPS is protected -- ***land, marine and timing applications may not be***
- DOT is concerned about the continued successful operation of GPS-based systems in the presence of MSS phones, once these systems -- already licensed and currently being launched -- begin operations and become widespread
***Do you know if your systems are protected from interference by this value?***

## Action

- Determine if this value protects your vested interests
- Comment on the results to the FCC
- A Public Notice was put out by the FCC on this subject Sep. 23, 1997
- the comment period was through December 1997
- GPS users did not comment
- LEOs commented heavily wanting this standard *relaxed further*

## GPS:  New Frequencies -- New Opportunities

- L1 - the authorized civil frequency (1575.42 MHz)
- L2 - the “unauthorized civil frequency”       (1227.6 MHz)
- now will be authorized and coded
- provides civil applications with improved performance for dual frequency applications, back up for single or new single frequency opportunities
- Lx - Third civil frequency

## GPS Spectrum Protection

- International perception of GPS as a military only system lingers
- International support is necessary to protect any worldwide frequency, including GPS L1 and the new civil frequencies
- Building a strong international coalition between government and non-government will protect frequencies on a worldwide basis

## Questions?

**                ****Sally L. Frodge**
- Department of Transportation
- Office of the Assistant Secretary for Transportation Policy
- Tel:  202-366-4894
- Fax:  202-366-7206 / x3393
- Sally.Frodge@ost.dot.gov
**www.navcen.uscg.mil** under ***“RNAV SPECTRUM ISSUES”***

## BACKUP SLIDES

## 1997 World Radio Conference (WRC-97)

- A proposal was made for a reallocation of the “GPS L1 band” to allow Mobile Satellite Service functions in the lower portion of that band
- Proposal was for a new MSS service in the 1559-1567 MHz band
- Proposal was supported by the European coalition (CEPT) (40+ nations) and the Asian coalition (APT) (20+ nations)
- Proposed system could interfere directly (unproven either way), and would open the way for further incursions
- U.S. opposed the proposal
- The decision has been postponed for further consideration at WRC-99 within Working Party 8D

## US Domestic Spectrum Management

- Domestic US Spectrum Management
- A division of regulation and allocation between National Telecommunications and Information Administration (NTIA) and the Federal Communications Commission (FCC)
- NTIA is responsible for Government spectrum
- FCC is responsible for non-Government spectrum

## International Spectrum Management

- International US positions are coordinated through the FCC, NTIA and final approval is through the State Department
- International spectrum allocation is through the            International Telecommunications Union (ITU), World Radio Conferences (WRCs)
- Internationally, defense and aviation, do not typically have as much presence for spectrum issues as do the Post, Telephone & Telegraph (PTT) administrations
- Each (paid up) ITU member nation, has one vote

## Worldwide Spectrum:  New Pressures and Competition

**Worldwide Spectrum:  New Pressures and Competition**

- Spectrum is a valuable and scarce resource -- there are more applications than there is available useful spectrum
- The ability of the private sector to successfully create and maintain space-based systems adds to the international demand for orbital slots and fuels an aggressive competitive atmosphere for worldwide spectrum
- US. domestic policy has recently included spectrum auctioning which has taken spectrum from actively used systems
- Budget impact
- Efficiency improvements
- International spectrum policy is moving the same direction