Archived—Proposed Revisions to the Canadian Table of Frequency Allocations (2009 Edition)

Section D: Fixed Service (FS), Including High Altitude Platform Systems (HAPS) and FSS Above 3 GHz

D1 (AI 1.8) – High Altitude Platform Stations in the 28/31 GHz and 47/48 GHz Bands

Background

Agenda Item 1.8 covered two major issues: 1) Resolution 145 (WRC-03): potential use of the bands 27.5-28.35 GHz and 31-31.3 GHz by HAPS in the FS; and 2) Resolution 122 (Rev. WRC-03): use of the bands 47.2-47.5 GHz and 47.9-49.2 GHz by HAPS in the FS and by other services. Although both Resolutions were addressed under this agenda item, only Resolution 122 implicates the Canadian Table through footnote No. 5.552A.

Resolution 122: The ITU has been considering the implications of HAPS in the FS in the 47.2-47.5 GHz and 47.9-48.2 GHz bands since 1997, when WRC-97 first made provision for the operation of HAPS within the FS. Studies have been ongoing under versions of Resolution 122 since WRC-97.

Resolution 122 (Rev. WRC-2000) indicated that sharing studies are yet to be completed between the fixed-satellite service (FSS) and HAPS operations in the FS. Pending the completion of the studies, Resolution 122 (Rev. WRC-2000) instructed the Radiocommunication Bureau "that from 22 November 1997, and pending review of the sharing studies in considering j) and review of the notification process by WRC-2000, the Bureau shall accept notices in the bands 47.2-47.5 GHz and 47.9-48.2 GHz only for high altitude platform stations in the FS and for feeder links for the broadcasting-satellite service (BSS), shall continue to process notices for FSS networks (except for feeder links for the broadcasting-satellite service) for which complete information for advance publication has been received prior to 27 October 1997, and shall inform the notifying administrations accordingly." In other words, notices received after 22 November 1997, from non-BSS feeder link FSS networks in the 47.2-47.5 GHz and 47.9-48.2 GHz bands, have not been accepted.
 
Resolution 122 (Rev. WRC-03) extended the restriction on processing of notices for FSS networks other than those providing service exclusively within Region 2. It also instructed the Bureau to maintain, until a date to be decided by a future WRC, notices concerning HAPS that were received by the Bureau prior to 22 November 1997, and provisionally recorded in the Master International Frequency Register. The studies regarding HAPS in the 47.2-47.5 GHz and 47.9-48.2 GHz bands have been completed and the results are contained in Recommendation ITU-R SF.1481-1. This Recommendation makes clear that co-frequency operations between HAPS in the FS and FSS networks and systems are feasible in the 47.2-47.5 GHz and 47.9-48.2 GHz bands, even while noting that "there may be a need to develop the maximum allowable power flux density at satellites on the GSO due to aggregate interference caused by ground user terminals of high altitude platform networks." Resolution 122 (Rev. WRC-03) confirms that co-existence between HAPS in the FS and the FSS at 47.2-47.5 GHz and 47.9-48.2 GHz is feasible, as administrations were encouraged to facilitate inter-service coordination.

In Resolution 122 (Rev. WRC-03), the ITU-R was invited to study power limitations on HAPS ground stations to facilitate sharing with space station receivers, as well as regulatory provisions to address deployment of HAPS in the FS near country borders. Technical sharing criteria between HAPS in the FS and both radio astronomy and FSS systems were also studied (taking into account the operational environments and the requirements of FSS systems). With the exception of interference to and from FSS spacecraft, and border area coordination matters in the FS, the deployment of HAPS is considered a national issue.

Summary of Proposed Table Changes

No allocation changes were made for this agenda item as a result of WRC-07; however, some changes were made to No. 5.552A.

MOD 5.552A The allocation to the fixed service in the bands 47.2-47.5 GHz and 47.9-48.2 GHz is designated for use by high altitude platform stations. The use of the bands 47.2-47.5 GHz and 47.9-48.2 GHz is subject to the provisions of Resolution 122 (RevWRC-9707). (WRC-07)

Discussion

Resolution 122 (Rev. WRC-03) was significantly revised to include, in a new resolves, hard on- and off-axis e.i.r.p. density limits on HAPS ground terminals to protect the FSS. For the protection of the FS, PFD limits at the Earth's surface were included in a new resolves. In addition, a "sunset date" (1 January 2012) by which networks must be brought into use was imposed on HAPS systems received by the Radiocommunication Bureau before 22 November 1997.

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