Transcript WMO Radio Spectrum WorkshopRadiosonde Spectrum Issues Presented By: David Franc Office of Radio Frequency Management March 2006

WMO Radio Spectrum WorkshopRadiosonde Spectrum Issues
Presented By:
David Franc
Office of Radio Frequency Management
March 2006
Purpose
 Provide
information on current
status of radio frequency issues
that may impact global radiosonde
operations
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Outline

Definitions
 ITU-R Recommendations
 History- Past Issues
 Current Issues
–
–
–
–

Meteorological Satellites
COSPAS-SARSAT
Optical Metaids
Equipment Standards
Important Points
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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
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Definitions Applied to
Radiosondes

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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160° 140° 120° 100° 80° 60° 40°
20°
C
0°
B
20° 40° 60° 80° 100° 120° 140° 160° 180°
170°
170°
ITU Regions
A
75°
75°
60°
60°
REGION 1
REGION 2
40°
30°
20°
40°
30°
20°
0°
0°
20°
30°
40°
20°
30°
40°
REGION 3
C
170°
60°
160° 140° 120° 100° 80° 60° 40°
B
20°
A
60°
0°
20° 40° 60° 80° 100° 120° 140° 160° 180°
Source: ITU Radio Regulations, 2004 Edition
5-01
170°
REGION 3
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Metaids ITU-R
Recommendations
Access 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.1165
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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.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.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.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.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-97
 Needs to reviewed by WP 7C

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ITU-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]
Content: Technical and operational
characteristics of metaids devices
operating in the optical frequency range
 Use: Information to the ITU-R
 Passing 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]
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
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History- Metaids
Spectrum Issues
History- Metaids Spectrum Issues

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 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-2003


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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 1668.41675 MHz
– Metaids in China, Iran (Islamic Republic of), Japan,
and Uzbekistan are protected from MSS interference
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Completed work on MSS sharing with metaids
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Summary of Past Issues
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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 avoided

No future actions for MSS spectrum
anticipated
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Current Metaids
Spectrum Issues
Meteorological
Satellites
COSPAS-SARSAT
Optical Metaids
Equipment Standards
Meteorological Satellites
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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 SatellitesStudy Group 7 Recommendation

Avoid 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/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 lifethreatening emergency situation
 Causes:
– Metaids signals drifting above 406 MHz
– Transmitter unwanted emissions above 406 MHz
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Optical 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 Standards
Under development in Europe and in
other administrations
 Will improve interference immunity and
reduce spectrum use
 More details in later briefing

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Important Points for Members
Improve Radiosonde
Transmitters
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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
Characteristics and Operations
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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
Spectrum 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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Conclusion

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
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