Meteorological Spectrum Issues- Outcome of the 2003 World Radiocommunication Conference

1. Meteorological Spectrum Issues-Outcome of the 2003 World Radiocommunication Conference Presented By: David Franc National Weather Service December 2, 2003

2. 2003 World Radiocommunication Conference • June 9 – July 4, 2003 in Geneva Switzerland • Considered proposals to modify the International Radio Regulations. • Allocate and reallocate frequency bands to radio services. • Modify rules that govern how radio services can use radio spectrum. • U.S. Delegation: ~50 Government and ~120 Private Sector Personnel. • Total of ~3000 delegates from 150 countries.

3. World Radiocommunication Conference Decisions • Decisions are based on several factors: • Compatibility between existing and new services. • Availability of unused spectrum. • Spectrum efficiency of existing services. • The relative importance (economic, humanitarian, safety-of-life) of new service in comparison to existing services.

4. Definitions • International Telecommunications Union (ITU) – U.N. organization responsible for international regulation of radio spectrum use. • International Radio Regulations –Treaty text maintained and enforced by the ITU that provides the regulations and table of frequency allocations for international radio spectrum use. • Radio Service - A type of radio operation, such as meteorological satellites, broadcasting, mobile-satellite. • Allocation– The authority for a radio service to use a particular frequency band. • License (or Assignment) – Authority for a particular radio station to use a specific frequency under the defined technical conditions and consistent with a frequency allocation.

5. Meteorological Bands Considered on WRC-2003 Agenda • Agenda Item 1.20: 400.15-406 MHz - radiosondes and meteorological satellites • Agenda Item 1.31: 1668.4-1700 MHz -radiosondes and meteorological satellites • Agenda Item 7.2: 2700-2900 MHz - meteorological radars • Agenda Item 1.5: 5600-5650 MHz - meteorological radars

6. WRC Agenda Item (AI) 1.20 400.15-406 MHz

7. AI 1.20 (400.15-406 MHz): Background • Band is used for radiosondes and meteorological satellite data links. • Under consideration since 1992 for use by mobile-satellite service (MSS) – U.S. was primary proponent. • WARC-92 allocated 400.15-401 MHz to MSS to share with meteorological users. • Proposals were made to subsequent WRCs to allocate more spectrum to MSS – no action taken by WRC-95, WRC-97, or WRC-2000.

8. AI 1.20 (400.15-406 MHz): Main U.S. Operations • Radiosonde systems operated by DoD and other Federal agencies. • NOAA Data Collection System (DCS) – Federal agency data collection platforms. • NOAA Polar Orbiting Environmental Satellites (POES). • Defense Meteorological Satellite Program (DMSP). • National Polar Orbiting Environmental Satellite System (NPOESS).

9. AI 1.20 (400.15-406 MHz):Issues • Studies showed the MSS and radiosondes could not operate in the same spectrum. • MSS and meteorological satellite operations are compatible. • If an additional allocation was made to MSS in part of 400.15-406 MHz, radiosondes would need to vacate that part of the band.

10. WRC-2003 Decision onAI 1.20 (400.15-406 MHz) • No proposals were made to allocate additional spectrum to the MSS in 400.15-406 MHz. • No new allocations were created for the MSS in 400.15-406 MHz by WRC-2003. • WRC-2003 concluded this issue will not be considered again at a future WRC.

11. WRC Agenda Item (AI) 1.31 1668.4-1700 MHz

12. AI 1.31 (1668.4-1700 MHz): Background • Band is used for radiosondes and meteorological satellite data links. • Under consideration since 1992 for use by MSS. • WARC-92 allocated 1675-1710 MHz to MSS in Americas (ITU Region 2), to share with meteorological users. • Proposals made to subsequent WRCs to allocate more spectrum to MSS - no action taken by WRC-95, WRC-97, or WRC-2000.

13. AI 1.31 (1668.4-1700 MHz):Main U.S. Operations • NWS current radiosonde network and Radiosonde Replacement System (RRS). • NOAA GOES and POES data transmission. • DoD radiosonde operations. • FCC licensed commercial operations – under OBRA-93, Government operations were phased out to allow commercial use of 1670-1675 MHz.

14. AI 1.31 (1668.4-1700 MHz):Issues • Previous WRC decisions removed 1675-1683 MHz and 1690-1700 MHz from consideration. • GOES user data downlinks operated in 1683-1690 MHz (GVAR) – MSS and data links incompatible. • Commercial fixed and mobile operations in 1670-1675 MHz incompatible with MSS.

15. WRC-2003 Decision onAI 1.31 (1668.4-1700 MHz) • WRC-2003 agreed to provide the MSS an allocation in 1668.4-1675 MHz and to delete the ITU Region 2 allocation in 675-1700 MHz. • Most radiosonde operations worldwide are conducted above 1675 MHz. • MSS must protect few main metsat stations operating below 1675 MHz. • MSS operations in 1670-1675 MHz not allowed in the U.S to protect fixed and mobile operations.

16. WRC Agenda Item (AI) 7.2 2700-2900 MHz

17. AI 7.2 (2700-2900 MHz):Background • Band is used worldwide for radar operations. • Identified in 1998 as a possible source of spectrum for 3rd generation mobile phones (3G). • Considered at WRC-2000 – decision deferred to WRC-2007 to allow time for completion of technical studies.

18. AI 7.2 (2700-2900 MHz):Main U.S. Operations • NWS/DoD/FAA NEXRAD meteorological radar network, including sites overseas. • The band is already sufficiently congested in the U.S. that NEXRAD operations have frequency assignments that extend up to 3000 MHz. • FAA airport surveillance radars – provide air traffic control coverage out to approximately 60 miles from airports (some radars contain data channel).

19. AI 7.2 (2700-2900 MHz):Issues • Studies showed that mutual interference will occur between 3G, and meteorological and airport surveillance radars. • Estimated cost to replace NEXRAD network with C-band radars: $7.9B (FY2000). • C-band radar performance inferior to S-band in severe weather conditions – will not meet NWS requirements.

20. WRC-2003 Decision on AI 7.2 (2700-2900 MHz) • Placing 3G in the band 2700-2900 MHz was on the WRC-2007 agenda. • All studies complete in time for WRC-2003. • WRC-2003 was responsible for finalizing the WRC-2007 agenda - agreed to delete the issue from the WRC-2007 agenda. • Could still be considered under a WRC-2007 general 3G agenda item.

21. WRC Agenda Item (AI) 1.5 5600-5650 MHz

22. AI 1.5 (5600-5650 MHz):Background • Band is used worldwide for radar operations. • Identified as a possible source of spectrum for radio LAN (RLAN) devices. • Studies showed mutual interference could occur between radars and RLAN devices. • Dynamic Frequency Selection (DFS) was proposed as a solution for RLAN devices to avoid radar frequencies that are in use. • DFS is unproven in use with radars.

23. AI 1.5 (5600-5650 MHz):Main U.S. Operations • FAA Terminal Doppler Weather Radar (TDWR). • Other DoD, Governmentand private sector radar operations, including meteorological radars.

24. AI 1.5 (5600-5650 MHz):Issues • DFS is not proven to work with radars: • Radar antennas rotate. • Radar signals are pulsed. • Radar systems not always in operation. • As a result, DFS must be properly designed to detect radar signal under conditions where the signal may only be directed at the RLAN device for very brief periods of time.

25. WRC-2003 Decision onAI 1.5 (5600-5650 MHz) • RLAN devices way operate in the band 5600-5650 MHz with limited transmitter power. • RLAN devices must use interference mitigation techniques such as DFS. • The ITU should continue studies on the use of mitigation techniques to prevent interference to radars. • RLAN devices are responsible for preventing interference.

26. Summary of WRC Agenda Items • AI 1.20 (400.15-406 MHz): Issue closed with no additional spectrum lost. • AI 1.31(1670-1700 MHz): 1668.4-1675 MHz allocated to MSS. No impact to U.S. meteorological operations. • AI 7.2 (2700-2900 MHz): Removed from WRC-2007 agenda, though could be considered under a general 3G agenda item. • AI 1.5 (5600-5650 MHz): Allocated for use by RLANS. RLANS must protect radars.

27. Future WRC Issues WRC-2007 and WRC-2010

28. WRC-2007 Agenda Itemsof Meteorological Interest • Agenda Item 1.2: New and expanded allocations to the meteorological satellite service. • May provide additional meteorological satellite data transmission spectrum. • Agenda Item 1.3: Upgrade radiolocation service from secondary to primary in 9300-9500 MHz so it has equal status with meteorological radars. • May result in additional limitations on X-band meteorological radars.

29. WRC-2010 Agenda Itemsof Meteorological Interest • Agenda Item 2.2: Consider creating frequency allocations between 275 GHz and 3000 GHz. • The current ITU International Table of Frequency Allocations stops at 275 GHz. • The meteorological community should begin to consider future requirements in this range • Active and passive remote sensing (ground and space based) • Data transmission • Radar systems

30. Need for Meteorological Spectrum Coordination in U.S. • All U.S. meteorological interests are primarily represented by the NWS. • Knowledge of systems and operations of other Federal agencies is limited. • Establish a coordination network: • Would assist the NWS in gathering necessary information from other agencies. • Would provide a mechanism to disseminate information to meteorological users in other agencies.

31. Conclusion • While WRC-2003 concluded on several issues that could impact meteorological operations, the threat of spectrum loss continues. • Better coordination in the U.S. meteorological community would help in defending meteorological spectrum requirements.