# Presentation: 719396

## Meteorological Spectrum Issues-Outcome of the 2003 World Radiocommunication Conference

- Presented By:
-   David Franc
-   National Weather Service

- December 2, 2003

## 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.

## 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.

## 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.

## 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

## WRC Agenda Item (AI) 1.20

- 400.15-406 MHz

## 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.

## 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).

## 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**. **

## WRC-2003 Decision onAI 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.

## WRC Agenda Item (AI) 1.31

- 1668.4-1700 MHz

## 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.

## 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.

## 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.

## WRC-2003 Decision onAI 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.

## WRC Agenda Item (AI) 7.2

- 2700-2900 MHz

## 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.

## 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).

## 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.

## 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.

## WRC Agenda Item (AI) 1.5

- 5600-5650 MHz

## 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.

## AI 1.5 (5600-5650 MHz):Main U.S. Operations

- FAA Terminal Doppler Weather Radar (TDWR).
- Other DoD, Government** **and private sector radar operations, including meteorological radars.** **

## 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.

## WRC-2003 Decision onAI 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.

## 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.

## Future WRC Issues

- WRC-2007 and WRC-2010

## WRC-2007 Agenda Itemsof 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.

## WRC-2010 Agenda Itemsof 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

## 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.

## 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.