WMO Radio Spectrum Workshop-WMO Radio Spectrum Workshop-Radiosonde Spectrum IssuesRadiosonde Spectrum Issues

Presented By:

David Franc

Office of Radio Frequency Management

March 2006

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PurposePurpose

Provide information on current status of radio frequency issues that may impact global radiosonde operations

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OutlineOutline

Definitions ITU-R Recommendations History- Past Issues Current Issues

– Meteorological Satellites– COSPAS-SARSAT– Optical Metaids– Equipment Standards

Important Points

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DefinitionsDefinitions

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

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Definitions Applied to Definitions Applied to RadiosondesRadiosondes In the ITU, radiosondes fall under the radio

service of meteorological aids (metaids)– Metaids include dropsondes and rocketsondes

ITU Working Party 7C (WP 7C) is responsible for metaids

Metaids allocations: 400.15 – 406 MHz, 1668.4 – 1700 MHz and 35.2 – 36 GHz

Metaids stations are licensed or provided frequency assignments by the country in which they operate

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ITU RegionsITU Regions

5-01

75°

60°

40°30°20°

0°

20°30°

40°

60°

75°

60°

40°

30°20°

0°

20°30°

40°

60°

170° 140°160° 100°120° 60°80° 20°40° 0° 20° 40° 60° 80° 100° 120° 140° 160° 180°

170°

170°

140°160° 100°120° 60°80° 20°40° 0° 20° 40° 60° 80° 100° 120° 140° 160° 180° 170°

ABC

ABC

REGION 1

REGION 2

REGION 3 REGION 3

Source: ITU Radio Regulations, 2004 Edition

Metaids ITU-R Metaids ITU-R RecommendationsRecommendations

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Access to ITU-R RecommendationsAccess to ITU-R Recommendations

Available at: http://www.itu.int/publications/sector.aspx?lang=en&sector=1

Copyrighted material- must be purchased– Single recommendation– Full series on CD– Yearly subscription

May obtain 3 free recommendations per year

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ITU-R SA.1165ITU-R SA.1165

Content: Technical characteristics, operational characteristics, and performance criteria for metaids systems

Use: Provides technical and operational characteristics to others conducting sharing studies

Recently updated and is passing through the ITU-R approval process

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ITU-R SA.1263ITU-R SA.1263

Content: Interference criteria for metaids systems

Use: Provides aggregate interference levels for conducting sharing studies

Currently under revision in ITU-R WP 7C

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ITU-R SA.1262ITU-R SA.1262

Content: Sharing and coordination criteria (levels applicable to individual interference sources)

Use: Provides single entry interference levels for conducting sharing studies

This recommendation is out of date and will be updated upon completion of the ITU-R SA.1263 update

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ITU-R SA.1264ITU-R SA.1264

Content: Addresses sharing between the mobile-satellite service and metaids

Use: Supported the work of the WRCs (WRC-97 through WRC-2003)

This recommendation is obsolete and is recommended for suppression

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ITU-R SA.1258ITU-R SA.1258

Content: Sharing between meteorological satellite (metsat) and Earth exploration satellite service (EESS) uplinks, and metaids in the band 401-403 MHz

Use: Support work of WRC-97Needs to reviewed by WP 7C

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ITU-R SA.1346ITU-R SA.1346

Content: Recommended interference mitigation techniques for medical implant devices operating in the 401-406 MHz band

Use: Guidance to administrations developing rules for medical implant devices

Needs to be reviewed by WP 7C

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ITU-R SA.[OPTICAL METAIDS]ITU-R SA.[OPTICAL METAIDS]

Content: Technical and operational characteristics of metaids devices operating in the optical frequency range

Use: Information to the ITU-RPassing through the ITU-R approval

process- currently on the ITU-R website as document SA.7BL7

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ITU-R SA.[USE 1.7 GHz]ITU-R SA.[USE 1.7 GHz]

Content: Facilitate sharing between metaids and metsat in 1670-1700 MHz

Use: Guidance to metaids and metsat operators for selection of operating frequencies

Passing through the ITU-R approval process- currently on the ITU-R website as document SA.7BL8

History- Metaids History- Metaids Spectrum IssuesSpectrum Issues

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History- Metaids Spectrum History- Metaids Spectrum IssuesIssues The bands 400.15-406 MHz and 1668.4-1700

MHz were identified as potential sources of spectrum for the mobile-satellite service (MSS) in 1992

400.15-401 MHz allocated worldwide to MSS at WARC-92

1670-1700 MHz allocated in ITU Region 2 (N. and S. America) to MSS at WARC-92

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History- Metaids Spectrum History- Metaids Spectrum Issues (continued)Issues (continued) Studies within the ITU show that the MSS

would cause interference to metaids if common spectrum is used by both

Proposals were made to WRC-95, WRC-97 and WRC-2000 for additional allocations to MSS in both metaids bands

No action taken by WRC-95, WRC-97 or WRC-2000

WRC-2003 was held June 2003

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History- Outcome of WRC-2003History- Outcome of WRC-2003

No MSS allocation proposals in 400.15-406 MHz MSS an allocation in 1668.4-1675 MHz Suppressed Region 2 allocation in 1675-1700

MHz Radio Regulations Footnote 5.379E

– Encourage metaids operations move out of 1668.4-1675 MHz

– Metaids in China, Iran (Islamic Republic of), Japan, and Uzbekistan are protected from MSS interference

Completed work on MSS sharing with metaids

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Summary of Past IssuesSummary of Past Issues

Current MSS allocations in 400.15-401 MHz and 1668.4-1675 MHz

MSS operations in 400.15-401 MHz will cause metaids data loss

Radio Regulations Footnote 5.379E– Metaids operations in 1668.4 – 1675 MHz should

be avoidedNo future actions for MSS spectrum

anticipated

Current Metaids Current Metaids Spectrum IssuesSpectrum Issues

Meteorological SatellitesCOSPAS-SARSATOptical MetaidsEquipment Standards

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Meteorological SatellitesMeteorological Satellites

Share 400.15- 403 MHz and 1670-1700 MHz Metaids cause interference to meteorological

satellite (metsat) ground receivers in 1668.4 –1700 MHz

Metaids/metsat coordination has been ineffective in the past- is improving due to the actions of SG-RFC

New ITU Recommendation developed by Study Group 7

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Meteorological Satellites-Meteorological Satellites-Study Group 7 RecommendationStudy Group 7 RecommendationAvoid interfering with metsat user

stations operating above 1683 MHz– Metaids operations should be limited to the

frequency range 1675-1683 MHz– Metsat operations avoided in the range

1675-1683 MHz– Metsat downlinks to the main CDA stations

may still extend into 1675-1683 MHz

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COSPAS/SARSATCOSPAS/SARSAT

COSPAS/SARSAT is a satellite-based search and rescue system for locating emergencies, operating at 406-406 .1 MHz

Some metaids transmitters and associated windfinding radars are suspected of causing interference to the satellite receiver

Interference can prevent detection of a life-threatening emergency situation

Causes:– Metaids signals drifting above 406 MHz – Transmitter unwanted emissions above 406 MHz

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Optical MetaidsOptical Metaids

The ITU-R is collecting information on devices operating at optical frequencies

ITU-R is not regulating frequency use in the optical range

WP 7C recommendation- optical metaids technical and operational characteristics– sensor types: precipitation, visibility, sunshine and

laser ceilometers

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Equipment StandardsEquipment Standards

Under development in Europe and in other administrations

Will improve interference immunity and reduce spectrum use

More details in later briefing

Important Points for MembersImportant Points for Members

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Improve Radiosonde Improve Radiosonde TransmittersTransmitters Inefficient use of radio spectrum can lead to

forced reduction of available spectrum WMO- radiosondes are being improved and

spectrum requirements will decrease Reduce spectrum requirements by reducing

transmitter bandwidth, drift and unwanted emissions

Limit radiosonde operations to the allocated bands and preferably to the sub-bands recommended by the SG-RFC and ITU-R WP 7C

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Document Radiosonde Document Radiosonde Characteristics and OperationsCharacteristics and Operations Recommendation SA.1165 documents

radiosonde characteristics and operations SA.1165 forms the basis for assumptions used in

conducting spectrum sharing studies Information is missing on Asia, Africa, and S.

America Members should submit information on their

systems and operations to ITU Working Party 7C or the SG-RFC

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Work with Your National Work with Your National Spectrum RegulatorsSpectrum Regulators Every administration that is a member of the

ITU-R has a national spectrum regulatory organization

Members should develop a working relationship with their spectrum regulatory agency– Raise awareness of national spectrum regulators

to national meteorological spectrum requirements– Provides a mechanism for coordinating national

responses to proposals that could impact meteorological operations

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ConclusionConclusion

The meteorological community should strive to deploy radiosonde systems that:– Decrease spectrum requirements and make

efficient use of radio spectrum– Eliminate interference to other services

Become involved at the national level to ensure meteorological spectrum requirements are adequately defended

Participate in ITU-R meetings if resources allow