International Telecommunication UnionRadiocommunication Bureau

Space Plans’ System (SPS)
Software for Determination of Coordination Requirements for Space Networks of the Planned Services
Alexandre Vassiliev(e-mail: alexandre.vassiliev@itu.int)
What Is the Purpose of SPS?
To determine the coordination requirements for space network belonging to the planned services - Appendices 30, 30A, Resolution 542 (WRC-2000) and Appendix 30B to the Radio Regulations.
To optimise parameters of new networks belonging to the planned services (reduce number of affected).
To estimate negative effect of newly submitted networks or modifications the existing ones.
To perform C/I, C/N calculations under Articles 9 and 11 of the Radio Regulations.
To do “What If Studies” (find the most affected test points, channels, beams, etc.).
Etc.
Plans’/Lists Covered by SPS
WRC-2000 BSS Downlink Plan and List of Additional Uses for Regions 1 and 3; Appendix 30, Resolution 542 (WRC-2000).
WRC-2000 Regions 1 and 3 14 GHz and 17 GHz Feeder-link Plans and Lists of Additional Uses; Appendix 30A, Resolution 542 (WRC-2000).
RARC BC SAT '83 combined feeder/down link Plan for Region 2; Appendices 30, 30A.
WARC ORB '88 FSS Plans in 6/4 GHz and in 13/10-11 GHz bands; Appendix 30B.

Plans’ Basic Technical Principles
Consideration of aggregate interfering effect from all “existing” and “virtual” (e.g. included in the Plan/List but not operational) interfering sources (different comparing with networks belonging to “non-planned” services).
Examination of “non-planned” networks is based on single-entry criteria (no summing up interference from different satellites).
Plans’ Basic Technical Principles
Consideration of the “worst” test point.


Calculate “aggregate” interference for all test points and consider the test point with the lowest wanted signal and the highest interference level.
“Geo-geometrical” Factors Taken into Account in Compatibility Analysis
The effect of the following factors on wanted and interfering signals is taken into account:
space station keeping accuracy (in East/West direction only);
space station antenna rotation accuracy;
space station antenna pointing accuracy.

Earth station antenna considered to be fixed and properly pointed to the wanted satellite.
An Illustration of the Space Station Antenna Rotation Accuracy
A test point which was originally inside of 3 dB antenna gain contour is outside of that contour when we take into account the space station antenna rotation accuracy.
Antenna Characteristics Taken into Account in Compatibility Analysis
The following antenna (transmitting and receiving) characteristics are taken into account in the analysis:
antenna patterns (for all Plans);
antenna polarization type circular (left and right) and/or linear (except FSS Plans);
polarization angle - for linear polarization (except FSS Plans) and relative alignment angle between 2 linearly polarized signals (Rec. ITU-R BO.1212);
polarization discrimination with and/or without depolarization induced by rain (except FSS Plans).
Propagation Loss in Compatibility Analysis
The following propagation factors are taken into account in the analysis:
free-space loss (for all Plans);
atmospheric attenuation (Region 2 BSS Plan only);
atmospheric absorption (Region 2 BSS Plan only);
rain attenuation (Region 2 BSS Plan; Regions 1&3 Feeder-link Plans/Lists Power Control);
rain depolarization (Region 2 BSS Plan; Regions 1&3 Feeder-link Plans/Lists Power Control)
Broadcasting Satellite Service (BSS) Plans/Lists.
Appendices 30, 30A and Resolution 542 (WRC-2000).
Compatibility Criteria (1)
A wanted BSS assignment may receive co-channel and adjacent channel interference. It was decided to employ Equivalent Protection Margin (EPM) or Overall EPM (OEPM) as compatibility criterion for BSS Plans

Where:
n=3 for Regions 1 and 3 and n=5 for Region 2;
i - interference category (1 - co-channel, 2 - first lower adjacent channel, 3 - first upper adjacent channel, 4 - second lower and 5 - second upper adjacent channels)
- protection ratio for a given (i) interference category
Difference between Regions 1 & 3 Approach (EPM) and Region 2 Approach (OEPM)
Compatibility Criteria (2)
Regions 1 and 3 BSS Down-link Plan/List (WRC-2000):
An assignment of the down-link Plan/List is considered as being affected as a result of addition / modification of an assignment(s) if 2 conditions are met:
1. under assumed free-space propagation conditions, the Power Flux Density (PFD) value derived from the PFD mask(s) given in paragraph a) of Section 1 of Annex 1 to Appendix 30 is exceeded at least at one of the test points of the “wanted assignment”; AND
2. the reference EPM at least at one of the test points of that “wanted assignment” falls more than 0.45 dB below 0 dB, or, if already negative, more than 0.45 dB below that reference situation value.
Compatibility Criteria (3)
Regions 1 and 3 Feeder-link Plans/Lists (WRC-2000):

An assignment of a feeder-link Plan/List (“wanted assignment”) is considered as being affected as a result of addition of new assignment(s) or modification of an existing one(s) if the reference EPM at least at one of the test points of that “wanted assignment” falls more than 0.45 dB below 0 dB, or, if already negative, more than 0.45 dB below that reference situation value.
Compatibility Criteria (4)
Region 2 BSS Plan:
A modification to Region 2 Plan considered to be compatible with other assignments in the Plan or earlier submitted additions/modification to the Plan:
if the calculated OEPM values of the assignments in the Plan and earlier submitted modifications for all channels/test points are greater than -.25 dB, OR
if OEPM is already negative, its degradation in negative area resulting from this modification is less than 0.25 dB comparing with the OEPM value for the same channel/test point calculated before that modification was included in analysis.
Non-standard Channeling in BSS Plans/Lists
There are many submissions having so-called non-standard emissions (digital and analogue) with non-standard bandwidth and/or non-standard assigned frequency, e.q.:

“real” (if any) overlap is taken into account in calculations
Grouping in the BSS Plans/Lists
Mainly utilized for:
simulation of several emissions not transmitted simultaneously;
changing the orbital position.


Only one (the worst) interfering signal is selected during EPM/OEPM calculation but all members of the group are protected.
Fixed Satellite Service (FSS) Plans; Appendix 30B.
Compatibility Criteria for FSS Plans
Two main criteria are used for FSS Plans:
aggregate C/I value should be > 26 dB to consider modification/addition to be compatible with the Plan;
single-entry C/I value which should be > 30 dB (value may be increased in when macrosegmentation concept is applied) to consider modification/addition to be compatible with the Plan. The single-entry C/I calculated for each pair of the wanted and an interfering assignments (interference from one interfering source).

Appendix 8 method/criterion (ΔT/T) is also used for compatibility analysis with the “existing” networks.


Specificity of the FSS Plans
Technical aspects:
includes allotments/assignments with both feeder and down links and allotments/assignments having only feeder or down-link;
have different protection criteria (Appendix S8) for determination of compatibility between the “existing” systems;
employ so-called Macrosegmentation concept ( Annex 3B): upper 60% of each allotment band is used for high-density carriers and the lower 40% for low-density carries (leads to a messy situation when it is not respected) ;
different single-entry C/I criterion in case when an allotment is not in consistency with Annex 3B (Macrosegmentation);
predetermined arc concept (PDA): pre-design stage 10; design stage 5, operational state 0 


C/I, C/N and I/N Analysis in non-planned bandsin accordance with Articles 9, 11 of the Radio Regulations – NOT CONSIDERED IN THIS PRESENTATION
Space Plans’ System Structure
From the user’s point of view SPS consists of 3 main components:
technical examination software (MSPACE_G graphical user interface and MSPACEg program for compatibility analyses);
SPS reporting tool (SPS_REPORTs);
utilities to update reference situation of BSS and FSS Plans/Lists; convert input data, etc.

However, SPS also has many modules, objects / components and libraries hidden from the user.

SPS GeneralStructure
SPS Input Data
MSPACEg requires an input file containing the parameters for the particular Plan/List, or portion of a Plan/List, to be analyzed. There are major formats used for Plans/Lists input data:
MSPACEg ASCII (text) input file (used from the first version of MSPACEg software up to now and should be completely suppressed in the future);
Integrated SNS/SPS database format (currently used for BSS Plans/Lists and should be also used for FSS Plans and Articles 9/11 C/I analysis in the future).
Format of input data is described in the SPS User’s Manual.
SPS Output Data
SPS produces many reports / output files. MSPACEg creates few reports itself and the SPS Reporting Tool also produces others in accordance with the user request(s). There are three main types of output data:
ASCII (text) files with analysis results;
relational database with analysis results in MS ACCESS container - currently used for BSS Plans/Lists only; to be expanded for FSS Plans and Articles 9/11 C/I analysis;
RTF and graphical reports on the screen - currently used for BSS Plans/Lists only; to be expanded for FSS Plans and Articles 9/11 C/I analysis.
Starting MSPACEg (input/output & options)
4
5
6
1
MSPACEg “Compressed Report”
Different Reports with information concerning “affected” assignments/allotments. MSPACEg produces “compressed report” when it is running:
Satellite orbital position
Administration symbol
Affected channels identified using PFD criterion
Affected channels identified using EPM criterion
Max. PFD excess
Max. EPM degrad.
Affected channels identified using EPM & PFD criteria(final)
Fin.max. PFD excess
Fin.max. EPM degrad.
Satel-lite name
Beam name
SPS Reporting Tool (SPS_Reports) (for BSS Plans/Lists only)
“Compressed Report”; Printed Version
Three formats (on the screen or “printed” – below):
report for Region 2 Plan;
report for Regions 1 and 3 Down-link Plan/List;
report for Regions 1 and 3 Feeder-link Plans/Lists.
“Reference Situation” Report
Criteria used for data retrieval
“Graphical” Report.Regions 1&3 Down-link
Applying both EPM and PFD criteria.
Fragment of Findings’ Report (FSS)
MSPACEG Version 2.110 (MS Windows) 30.09.2002 18:04:40
ITU Appendix 30B Analysis at 13/10-11 GHz
RS19K.INP, USASAT-13I and USASAT-26 networks are recorded……...

*** FINDING FOR BEAM USA26G00 ***
NOT IN COMPLIANCE WITH ANNEX 3B
FREQUENCY BELOW WHICH PEAK/AVERAGE POWER IS LESS THAN 5 dB IS 12.75000
THIS IS LOWER THAN 40 % OF THE BAND AND THEREFORE OTHER BEAMS WILL BE
CONSIDERED TO BE AFFECTED IF THE SINGLE ENTRY C/I IS LESS THAN 34.50 dB
INSTEAD OF 30.0 dB
.
.
Appendix 30B Analysis

Wanted TP TP New Ref Interfering
Type Beam Long Lat C/I C/I Degradation Beam

S.E. ALS00000 172.00 54.00 29.57 29.64 0.07 URSEEDRL

S.E. USA13I00 -89.10 13.40 25.99 34.50 8.51* USA26G00
S.E. USA13I00 -87.58 13.00 26.30 34.50 8.20* USA26G00
AGG. USA13I00 -83.67 10.83 21.32 21.38 0.06
.
.
A Fragment of a Detailed Report
 Desired Uplink Frequency: 14640.38 MHz; (Channel 7) Sat. Max. Gain: 37.24 dBi;
Transmitter Power: 25.00 dBW (NON-STANDARD)

Pt Spnt Phi FS Atm Rain GSAT GSAT GES GES
Num Err Phi Not Loss Loss Loss Copol X-pol Copol X-pol
1 0.1 1.426 2.824 207.116 0.000 0.000 34.182 2.240 57.000 22.000
2 0.1 1.235 2.803 207.199 0.000 0.000 34.912 2.240 57.000 22.000

X-pol Equiv Cup Min
Discr Gain (K) Cup
999.900 91.912 -91.287 -91.934
999.900 91.912 -91.287 -91.934
.
.
Uplink Interference Power to AFS02100, Channel 7:

Pol QRM QRM QRM QRM Topoc FS Atm Rain GSAT GSAT GES GES
[Beta] Ind Chan Pwr Pt Angle Loss Loss Loss Copol X-pol Copol X-pol
X-Pol 12 7 25.00 1 55.8233 207.954 0.000 0.000 8.078 0.000 -10.000 -10.000
X-Pol 12 7 25.00 2 56.0780 207.899 0.000 0.000 7.002 0.000 -10.000 -10.000

X-pol Equiv Int Adjust QRM
Discr Gain CAT Factor Up
999.900 0.967 1 0.000 -181.988
999.900 0.209 1 0.000 -182.690

.. ……………………………………………………..And many other details
References
Appendices 30, 30A, 30B and Articles S9, S11 of the Radio Regulations
Final Acts RARC-83, WARC-88, WRC-2002
Resolution 542 (WRC-2000)
Space Plans’ System Software Package (includes documentation) Version 2.11, September 2002. Distributed on SRS-on-CD and also available from the ITU Web page: http://www.itu.int/ITU-R/space/plans/MSPACEg_files/index.html
ITU Web side http://www.itu.int