Data required for satellite networks subject Article 22 EPFD limits (Nos. 22.5C, 22.5D, 22.5E and 22.5L)
Appendix 4 items
Orbital information:
- Indicator showing whether the space station uses station-keeping to maintain a repeating ground track and, if yes, the time (period) for the constellation to return to its starting position (items A.4.b.6.c and A.4.b.6.d of Appendix 4);
- Indicator showing whether the space station should be modelled with a specific precession rate of the ascending node instead of the J2 term and, if yes, the precession rate (degrees/day), measured counter-clockwise in the equatorial plane (items A.4.b.6.e and A.4.b.6.f of Appendix 4);
- Longitudinal tolerance of the LAN (item A.4.b.6.j of Appendix 4).
Parameters for both directions:
- Minimum elevation angle at which any associated earth station can transmit to or receive from (item A.4.b.7.cbis of Appendix 4);
- Type of zone (based on topocentric angle) and the width of the zone, in degrees (items A.4.b.7.d.1 and A.4.b.7.d.2 of Appendix 4).
Parameters for Earth-to-space direction:
- Maximum number of non-GSO satellites receiving simultaneously (Nco) with overlapping frequencies from the associated earth stations within a given cell (item A.4.b.7.a of Appendix 4);
- Average number of associated earth stations (1/km2) with overlapping frequencies per square kilometre within a cell (item A.4.b.7.b of Appendix 4);
- Average distance (km) between co-frequency cells (item A.4.b.7.c of Appendix 4).
Parameters for space-to-Earth direction:
- Maximum number of non-GSO satellites transmitting with overlapping frequencies (Nco) to a given location within the latitude range (item A.4.b.6.a.1 of Appendix 4).
Masks data:
- EIRP mask used by the non-GSO space station (item A.14.a of Appendix 4) (EIRP SS mask);
- Associated earth station EIRP mask (item A.14.b of Appendix 4) (EIRP ES mask);
- PFD mask used by the non-GSO space station (item A.14.c of Appendix 4) (PFD mask).
Frequency ranges subject to Article 22 EPFD limits
The frequency bands, directions of emission and EPFD limits applicable to these frequency bands in accordance with provisions of Nos. 22.5C, 22.5D, 22.5F and 22.5L are shown in the table below. These EPFD limits are applicable only for the frequency bands in the fixed-satellite service or space operation functions (such as space telemetry, space telecommand or space tracking functions) for which the main service is fixed-satellite service.
| Minimum frequency, MHz | Maximum frequency, MHz | Direction of emission (E or R) | Required PFD/EIRP masks |
| 3700 | 4200 | E | PFD mask |
| 5925 | 6725 | R | EIRP ES mask |
| 10700 | 12750 | E | PFD mask EIRP SS mask (only for 10700-11700 MHz and 12500-12750 MHz) |
| 12500 | 13250 | R | EIRP ES mask |
| 13750 | 14500 | R | EIRP ES mask |
| 17300 | 17700 | E | PFD mask EIRP SS mask |
| 17300 | 17800 | R | EIRP ES mask |
| 17800 | 18100 | R | EIRP ES mask |
| 17800 | 18600 | E | PFD mask EIRP SS (only for 17800-18400 MHz) |
| 19700 | 20200 | E | PFD mask |
| 27500 | 28600 | R | EIRP ES mask |
| 29500 | 30000 | R | EIRP ES mask |
| 37500 | 42500 | E | PFD mask |
| 47200 | 50200 | R | EIRP ES mask |
| 50400 | 51400 | R | EIRP ES mask |
Examination scenarios
“Examination scenario” defines as an individual scenario sharing the same set of operating parameters applicable to specific frequency ranges, including items A.4.b.7.cbis, A.4.b.7.d.1, A.4.b.7.d.2, A.4.b.7.a, A.4.b.7.b, A.4.b.7.c and A.4.b.6.a.1 of Appendix 4.
Different “examination scenarios” can be submitted for different frequency ranges, but only one “examination scenario” can be submitted for each frequency range and orbital configuration.
Capturing of different “examination scenarios” is now available in the new version of BR software SpaceCap v10. The instructions for submission of specific parameters for non-GSO satellite networks or systems subject to EPFD limits (Article 22) can be found here: https://www.itu.int/en/ITU-R/space/support/Pages/space-submission-instructions.aspx.
Database structure (SNS v10)
There are 7 tables in SNS v10 structure for additional data required for non-GSO satellite networks subject Article 22 EPFD limits.
epfd_param, epfd_freq and sat_oper tables contain sets of operating parameters for each “examination scenario”.
epfd_param table:
| Fields | Description |
| ntc_id | Unique identifier of the notice |
| scen_id | Identifier of the “examination scenario” |
| scen_name | Scenario name |
| nbr_sat_td | Maximum number of non-GSO satellites receiving simultaneously with overlapping frequencies from the associated earth stations within a given cell |
| density | Average number of associated earth stations transmitting with overlapping frequencies per km2 in a cell, 1/km2 |
| avg_dist | Average distance between co-frequency cells in kilometers, km |
| f_x_zone | Type of the exclusion zone (“Y” – based on topocentric angle only) |
| x_zone | Width of the exclusion zone, degrees |
| elev_min | Minimum elevation angle, degrees |
epfd_freq table contains frequency ranges associated with “examination scenarios”:
| Fields | Description |
| ntc_id | Unique identifier of the notice |
| scen_id | Identifier of the “examination scenario” |
| seq_no | Sequence number |
| emi_rcp | Direction of emission (“E” or “R”) |
| freq_min | Minimum frequency, MHz |
| freq_max | Maximum frequency, MHz |
sat_oper table:
| Fields | Description |
| ntc_id | Unique identifier of the notice |
| scen_id | Identifier of the “examination scenario” |
| lat_fr | Start of the latitude range, degrees |
| lat_to | End of the latitude range, degrees |
| nbr_op_sat | Maximum number of non-GSO satellites transmitting with overlapping frequencies to a given location within the latitude range |
mask_info table contains the list of PFD/EIRP masks:
| Fields | Description |
| ntc_id | Unique identifier of the notice |
| mask_id | Identifier of the mask |
| freq_min | Lowest frequency for which the mask is valid, MHz |
| freq_max | Highest frequency for which the mask is valid, MHz |
| f_mask | Type of the mask (“P” – PFD mask, “E” – EIRP ES mask, “S” – EIRP SS mask or “R” – operaring parameters mask ) |
| f_mask_type | Type of the PFD/EIRP mask (“O” – off-axis angle/ off-axis angle, lattitude, “D” – azimuth, elevation and difference in longitude, “A” – alpha angle, difference in longitude, latitude or “Z” – azimuth, elevation, lattitude) |
mask_lnk1, mask_lnk2 tables establish links between PFD/EIRP masks and “examination scenarios”, orbital planes (satellites).
mask_lnk1 table contains such links for PFD and EIRP SS masks:
| Fields | Description |
| ntc_id | Unique identifier of the notice |
| scen_id | Identifier of the “examination scenario” |
| seq_no | Sequence number |
| orb_id | Identifier of the orbital plane -1, if mask applies to all orbital planes |
| sat_orb_id | Identifier of the satellite in the orbital plane -1 or Null, if mask applies to all satellites in the orbital plane |
| mask_id | Identifier of the mask |
mask_lnk2 table contains such links for EIRP ES masks:
| Fields | Description |
| ntc_id | Unique identifier of the notice |
| scen_id | Identifier of the “examination scenario” |
| seq_no | Sequence number |
| e_as_id | Identifier of the associated earth station -1, if mask applies to all ES |
| orb_id | Identifier of the orbital plane -1, if mask applies to all orbital planes |
| sat_orb_id | Identifier of the satellite in the orbital plane -1 or Null, if mask applies to all satellites in the orbital plane |
| mask_id | Identifier of the mask |
mask_lnk3 table establishes links between the notice and operating parameters mask:
| Fields | Description |
| ntc_id | Unique identifier of the notice |
| param_id | Identifier of the operating parameters mask |
Guidelines for capturing scenario
In case there are several operational modes, different sets of EPFD characteristics need to be captured. Some examples include:
- Uplink operation representing user terminals and gateway stations. Each type of earth station may require different earth station distributions (density, average distance) as well as exclusion zone angles.
- Similarly, downlink transmission may vary depending if link is established with user terminal or gateway station.
- There are several orbital configurations (orbital sets).
In each of this case a separate scenario to represent each mode of operation.
Running examination software in SNS v10
Currently EPFD examination software does not support an input database in SNS v10 format.
To enable examination of the notice prepared in SNS v10 format, GIBC/EPFD Prepare should be used to convert input SNS v10 database in to examination database which can be read by EPFD Examination software.
In case SNS v10 database contain several scenarios, for each scenario an individual database is prepared using GIBC/EPFD Prepare software.
This process is illustrated on the figure below.
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