Delegate Report – WGFM PT FM34 10th Meeting 16 Mar. 2000 Geneva

Technical Studies

FM34(00)19 [ANFR(France)] – This paper considered that the FS/FSS adjacent band compatibility could be resolved with an EIRP density limit of –35 dBW/MHz for the uncoordinated FSS earth stations. This figure matches the specified off-axis spurious emissions limit for the FSS earth stations. However, it was recognised that this study had only considered the out of band emissions on a short-term non-aggregate basis.

FM34(00)21 [UK RA] (BFWAtg(00)17) – This paper considered interference due to both out of band and in-band emissions from the FSS earth stations. It concluded that a 28 MHz guard band was required between FSS and FS bands to ensure adequate protection from FSS earth station in-band emissions. The proposed changes to the band segmentation plan, to accommodate guard bands, did not affect the FS exclusive bands.

After some general discussion it was agreed that SE19 would be asked to consider the above two proposals at the next meeting (5 – 7 April 2000) and that the ERC Decision would include text for both options within square brackets at this time.

Both BT and ANFR remarked that they were undertaking Monte Carlo analyses using the recently approved (SE21) Seamcat tool which would consider both in-band and out of band interference on a statistical basis. They expected results to be available at the next SE19 meeting.

FM34(00)20 [CNES(France)] and (00)24 [ANFR(France)] – these two papers discussed Automatic Transmitter Power Control (ATPC), (00)24 being in response to (00)20. There seemed to be some confusion over what ATPC covered with paper (00)20 proposing a dynamic range of 16 dB. Paper (00)24 was very clear and resolved some of the erroneous probability statistics used in (00)20 and identified that FS terminal stations employ a fixed power setting with ATPC being used to address the rain fade margin.

FM34(00)22 [Eutelsat] and (00)25 [Teledesic(Spain)] – these two papers reopened the debate on the capacity loss of the FS and FSS services and re-evaluated the figures for conventional (hard) and geographical band segmentation. Both papers in the main favoured conventional band segmentation. After lengthy debate the Chairman concluded that geographical band segmentation still provided the most efficient means of planning the band.

Draft ERC Decision

Inputs: FM34(00)18 [ANFR(France)], (00)21 [UK RA], (00)23 [Sweden] – paper (00)18 was used as the basis for discussion. The following were the salient points:

considerings

	k) modified to read "that without Automatic Power Control and fixed power setting, …"
	new l) added – "[that an adjacent band EIRP limitation is needed in order to solve the FS/FSS adjacent band compatibility;]"
	new m) added – "[that a guard band of 28 MHz between FS and FSS bands is necessary to ensure adequate protection from earth station in-band emissions;]"

DECIDES

	editorial footnote added to 1, 2 and 5 – "these values will need to be revised if guard bands are required"
	using (00)24 text, decides 6 appended with "hence ensuring a maximum level of [X] dBW/MHz transmitted towards the GSO arc"
	new Decides added (between 5 and 6) – "that administrations are urged to make publicly available the information on the geographical areas referred to within decides 5 [within 6 months from the adoption of the Decision]"
	new decides added after decides 6: "that for uncoordinated FSS earth stations operating in the bands referred to in Decides 1 and 5: - the off axis EIRP density radiated in the adjacent bands used by the FS according to Decide 2 and 5 shall be limited to -35 dBW/MHz; - the elevation angle shall be higher than 10° ; "  with a footnote that off axis refers to angles greater than 7° from the main beam
	review period in decides 7 reduced from three to two years.

The Chairman concluded that as the draft ERC Decision was not stable enough for adoption it would be presented to the next WGFM meeting (10 – 14 April 2000) for information only.

Next FM34 Meeting
The next meeting will be 11 – 12 July 2000 location tbd.

Jim Nixon
RA2/BPMU Broadband Fixed Wireless Access Team
17 March 2000

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