Resolution 609 (Rev. WRC-07) Consultation Meeting
13-15 May 2008
Record of Decisions Taken at the
Fifth Resolution 609 (Rev. WRC-07) Consultation Meeting
(Xi'an, 13-15 May 2008)
The fifth Resolution 609 (Rev. WRC-07) Consultation Meeting was convened, pursuant to the
requirements of Resolution 609 (Rev. WRC-07), at the Sofitel conference centre in Xi'an, China
from 13-15 May 2008 and hosted by the Radio Regulatory Department of the Chinese Ministry
of Information Industry. A list of participants is available on the Resolution 609 Forum page on
the ITU web site. Approximately 30 delegates from government and industry, along with a
representative of the Radiocommunication Bureau, attended the meeting. Through the
Convenor the delegates expressed their sympathy for the people affected by the Sichuan
province Earthquake which occurred the day before the meeting and wished the Chinese
government every success in its rescue efforts.
The acting Convenor for the meeting was Dominic Hayes, as Hugues de Bailliencourt was
unable to attend at the last minute. The difficult technical work was handled in a sub-group
ably led by Benoit Louvet.
The following actions were taken in regard to Resolution 609:
1. The Meeting agreed to a modification to the Terms of Reference that were adopted in
September 2006 (Bangalore) so that in future only the finer resolution 1 degree epfd data
(instead of both 1 degree and 5 degree) will be used to calculate the aggregate epfd of all
systems. A copy of the modified Terms of Reference has been posted to the Resolution 609
Forum that is maintained by the BR on the ITU web site (http://www.itu.int/ITUR/space/res609/).
2. The Meeting decided that the sixth Resolution 609 (Rev. WRC-07) Consultation Meeting
will be convened at a venue to be determined, for a period of three working days, tentatively in
9-11 June 2009.
The meeting revised the format for the List of System Characteristics which is contained in
Attachment 1 hereto; now only 1degree latitude/longitude steps will be considered. The
following points describe the List of System Characteristics required to be submitted by
Administrations:
3.
a.
Section I-9 of Attachment 1 contains the format of the results of the epfd
calculation for each RNSS individual system, in MS Excel format (see
Attachment 2 at Template, Sheet 1), using 1 degree steps in latitude and
longitude. For non-GSO systems, administrations should also provide the
time step resolution and the number of time steps simulated.
b.
The system spectral adjustment factors (SAF) provided under Section I-8
should be in MS Excel format (see Attachment 2 at Template, Sheet 3).
Note: It was pointed out that in future if calculations determine that the Resolution 609 limit is
theoretically breached by RNSS systems it may be necessary to develop a mechanism that
includes only those systems in operation or close to operation. Administrations are encouraged
to consider if such a mechanism is required, how it might work and bring contributions to the
next meeting.
4. The Meeting agreed that the data provided by one system (Arabsat) could not be included in
the epfd calculations for the fifth meeting because it had not been submitted with sufficient time
for administrations to include it in their preparations and was not in the required format. The
meeting also agreed with respect to the systems that had provided technical characteristics to the
May 2008 Consultation Meeting within the specified deadlines, that it would not be necessary
for the same information to be provided anew to the Sixth Consultation Meeting.
5. The Meeting compared the results (obtained using 5 degree data) from the different tools
used to determine i) the epfd produced by each RNSS system and ii) the aggregate epfd
produced by all considered RNSS systems. After discussions regarding the assumptions and
methodologies used by each tool, the Meeting agreed on the specific epfd matrix to be retained
for each modified or new RNSS system, results obtained through the different tools being
comparible within 0.15dB. Because the various aggregate epfd results calculated before the
meeting and provided through input contributions were unanimously within 2dB of the limit
protecting the ARNS, the Meeting agreed that additional calculations should be performed using
the finer resolution 1 degree epfd data submitted by administrations. A second set of
calculations was thus performed using the same tools and similarly agreed 1 degree epfd
matrices for each RNSS system1. The all-system aggregate epfd results provided by the
different tools, both with 5 degree and 1 degree resolutions, were then found to be comparable
within 0.01 dB at all frequencies and the Meeting was satisfied with this degree of closeness.
6. The Meeting calculated the maximum aggregate epfd produced by all RNSS systems that
provided characteristics to the May 2008 Meeting (see attachments 4.1 and4.2).
7. The Meeting determined that under both of its aggregate epfd calculations, the maximum
epfd of all satellites associated with the referenced RNSS systems would not exceed – 122.33 dB
(W/m2/MHz), i.e. 0.83 dB below the Resolution 609 limit of –121.5 dBW/m2/MHz. The
meeting noted that in both cases, this result is based on the use of worst-case assumptions in
terms of interference from RNSS into ARNS. For example, in the case of non-GSO RNSS
systems using circular orbits, the epfd at a given latitude is considered equal for any longitude to
that of the worst-case longitude.
1
The Nigcomsat-1G network was not able to provide its 1 degree data for this meeting, but the Meeting determined,
based on the 5 degree data, that this system’s particular contibution to the peek aggregate epfd figure for the worst 1MHz is only
0.01 dB. this is reflected in the calculation results given in paragraph 7. The meeting agreed that Nigcomsat should provide the
1 degree epfd data for Nigcomsat-1G network for the next meeting so that it can be formally included in the calculations.
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8. The Meeting agreed on a Report to the Radiocommunication Bureau that contains the results
of the calculation mentioned in Nos. 6 and 7 above, and directed that this Report be
communicated to the BR in the manner contemplated in § 14 of the Terms of Reference. A
copy of the Report to the Radiocommunication Bureau has been posted to the Resolution 609
Forum that is maintained by the BR on the ITU web site (http://www.itu.int/ITUR/space/res609/).
9. The Meeting agreed that it is important, for the orderly operation of the Resolution 609
(WRC-03) consultation process and to ensure the achievement of accurate calculation results,
that administrations providing information to Consultation Meetings comply with the deadlines
established in the Terms of Reference.
10. The Meeting received for information a copy of the BR determination of compliance with
the pfd criterion as per instructs BR 2 from Resolution 609 (WRC-03). After some discussion,
the Meeting noted the document.
11. The Meeting expressed its gratitude to the Chinese Ministry of Information Industry, Radio
Regulatory Department for hosting the Meeting and providing excellent hospitality to the
participants.
List of Attachments
Attachment 1 (Word document) – input format required for RNSS system characteristics.
Attachment 2 (Excel spreadsheet):
Sheet 1. Template for new section I-9 of Attachment 1, longitude/latitude (note orientation
change) format for individual system epfd calculation results (1° steps).
Sheet 2. Template for section I-8 of Attachment 1, spectral adjustment factors (SAF)
relative to the worst 1MHz.
Attachment 3 (Word document):
RNSS System Characteristics provided to the meeting.
Attachment 4 (Excel spreadsheet):
Attachment 4.1 : Simulated per-system epfd of each RNSS system using the 5 degree data
Attachment 4.2 : Simulated per-system epfd of each RNSS system (see footnote 1 above)
using 1 degree data
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