WAG Briefing Paper
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CASBAA Wireless Action Group (WAG) Briefing Paper:
Protecting the satellite usage of C-band
The C-band has been targeted for some time by many groups seeking to introduce other services in these frequencies. Proponents of Broadband Wireless Access (BWA) systems (e.g. WiMax and UnWired), 4G (IMT) mobile telephone systems and Short-Range Devices (SRDs) are among these groups. Numerous analyses and tests have concluded that these kinds of applications are not compatible with general satellite C-band reception in the same geographical area of more than 100km radius (e.g. ITU-R Reports M.2109 (IMT) and S.2199 (BWA) and ITU-R documents 1A/163 and 164 (SRD)). Where wireless systems have been deployed in C-band, this has had an extremely detrimental effect on satellite reception, and in many cases has caused total loss of service and television signals blockages.
Several countries in ITU Region 3 (the Asia-Pacific region) have licensed fixed BWA systems in the extended C-band, including Australia, China and Pakistan. Through the effort of the WAG and other satellite industry groups, selected countries like, Philippines, Malaysia and Indonesia that had initially introduced fixed BWA in the extended C-band have moved their BWA applications to lower frequency bands.
Many countries are currently adopting emission limits for license-exempt use of SRDs. However, the emission limits considered have been demonstrated to require separation distances of several tens of meters to adequately protect C-band receivers, i.e. there would be a need to guarantee that no SRD-enabled products such as laptop computers, mobile phones, or other devices would be brought within a radius of several tens of meters around a C-band antenna, which is impractical in any urban setting.
In a variety of regional meetings, the IMT community has started to develop proposals under WRC-12 Agenda Item 8.2, to establish a new agenda item for WRC-16 to address their spectrum needs. The proposals being developed at this stage are not specific to any frequency bands that are considered candidates for consolidation or future IMT identification. However, ambitions of the mobile community are clear in targeting both for low frequency bands (for coverage) and high frequency bands (for capacity) to provide sufficient bandwidth to meet their long-term demand. The CASBAA WAG firmly believes it is undesirable to re-open the decisions by WRC-07 and is of the view that any new agenda item for IMT should explicitly exclude the satellite bands.
Major portions of ITU Region 3 (including the Pacific Islands) are heavily reliant on the C-band satellite networks due to their geographic, demographic and climatic situations, and careful planning is needed to ensure effective deployment and protection of satellite networks. The mission of CASBAA’s WAG is to work in conjunction with the satellite Industry and to protect both the standard (3.7-4.2 GHz) and extended (3.4-3.7 GHz) C-band from interference from wireless telecommunications systems. The WAG has bound together over a common goal to ensure the industry and regulators are fully aware of the extremely negative impact on satellite operation if wireless systems are assigned the C-band.
Our main point is simple: the C-band is not suitable for IMT, BWA and SRD usage.
- Countries located in areas with low or scattered population or heavy rainfall rates that rely on FSS C-band operations should not consider allocating the C-band to other applications.
- Many alternative bands to the C-band are available for BWA. In Asia there are already 748 MHz below 2.7 GHz designated for IMT.
- BWA and IMT networks work better and more economically at lower frequencies due to more preferable propagation characteristics.
- Any new WRC agenda item addressing spectrum needs for IMT should explicitly exclude the satellite bands. No re-opening of the decisions by WRC-07 in respect of IMT in C-band should be entertained.
- The satellite and broadcasting industries need to stay alert and involved in spectrum allocation policy with their respective regulators.
Additional Information
CASBAA has published several papers regarding the issue of the C-band interference in Asia, and gathered a wealth of information on this issue:
1. Global C-band Position Paper. Position on the issue of C-band interference by a group of satellite industry associations.
http://www.casbaa.com/images/stories/casbaa/File/Regulatory/C-Band_Satellite/New_Global_CBand_Position_Paper.pdf
2. Summary of ITU Report on Compatibility between BWA and FSS. Summary of the ITU’s report “Studies on compatibility of broadband wireless access (BWA) networks and fixed-satellite service (FSS) networks in the 3,400-4,200 MHz band”.
http://www.casbaa.com/images/stories/casbaa/File/Regulatory/C-Band_Satellite/Summary_of_ITU_Report_on_Compatibility_between_BWA_FSS_rev2.pdf
3. “What’s Up with WiMAX?” Paper providing an update on recent issues about C-band interference.
http://www.casbaa.com/images/stories/casbaa/File/Regulatory/C-Band_Satellite/Whats_Up_with_WiMAX.pdf
4. “WiMAX and FSS in C-band.” Presentation illustrating the negative effects of assigning C-band to BWA.
http://www.casbaa.com/images/stories/casbaa/File/Regulatory/C-Band_Satellite/CASBAA_Presentation_at_ABU_Seminar_KL_27072009.pdf
5. WiMAX in Amsterdam. Field study of the impact of operating an urban BWA system on reception of satellite signals.
http://www.casbaa.com/images/stories/casbaa/File/Regulatory/C-Band_Satellite/New_Skies_paper_on_Amsterdam_Wimax_field_study.pdf