non-gso subject to coordination and potential steps for their … · 2018-11-30 · fss frequency...
TRANSCRIPT
Non-GSO subject to coordination and
potential steps for their modifications
By SSCITU-R
ITU HQ Geneva, 6 December, 2018
— Only frequency overlap is used to trigger coordination
— Also includes affected networks/systems operating in opposite direction of transmission
Coordination between non-GSO and GSO (9.12A,
9.21/A) and between non-GSOs (9.12, 9.21/B)
FSS frequency bands No hard-
limits for
protection of
GSO
Coordination
between Non-
GSO
Coordination
between Non-
GSO and GSO
Article 22 EPFD
hard-limits are
applicableEarth-space space-Earth
3400-4200 MHz 22.2 Yes (3700-4200)
5725-6700 MHz 22.2 Yes (5925-6700)
6700-7075 MHz 22.2 9.12 Yes (6700-6725)
7250-7750 MHz 22.2
7900-8400 MHz 22.2
10.7-12.95 GHz 22.2 9.12 Yes
11.2-11.45 GHz 22.2 9.12 Yes
11.7-12.75 GHz 22.2 9.12 Yes
12.75-13.25 GHz 22.2 9.12 Yes
13.75-14.0 GHz 22.2 9.12 Yes
17.8-18.6 GHz 22.2 9.12 Yes
18.6-18.8 GHz 22.2
18.8-19.3 GHz 9.12 9.12A
19.3-19.7 GHz (MSS FL) 9.12 9.12A
19.3-19.7 GHz 22.2
19.7-20.2 GHz 22.2 9.12 Yes
20.2-21.2 GHz 22.2
27.5-28.6 GHz 22.2 9.12 9.12A Yes
28.6-29.1 GHz 9.12 9.12A
29.5-30.0 GHz 22.2 9.12 Yes
V-band FSS V-band FSS 22.2
— Frequency overlap is used to trigger coordination in the bands where there is no PFD coordination trigger
— Frequency overlap and PFD trigger is applicable where there is a PFD coordination trigger (1518-1525 MHz)
Coordination between non-GSO and terrestrial services (9.14, 9.21/C)
System design may not be final at the coordination stage
Regulatory schedule is tight for coordination and bringing into use
Solutions
Submit for coordination multiple orbital configurations with only one being brought into use (mutually exclusive configurations)
Modify frequency assignments/orbital characteristics during the coordination
For the submission of a request for coordination to a NGSO satellite network or system, the notice is receivable:
➢ satellite systems with one or more set(s) of orbital characteristics and inclination value(s) with all frequency assignments to be operated simultaneously;
or
➢ satellite systems with more than one set of orbital characteristics and inclination values:
• with a clear indication that the different sub-sets of orbital characteristics would be mutually exclusive;
• frequency assignments to the satellite system would be operated on one of the sub-sets of orbital parameters to be determined at the notification and recording stage of the satellite system at the latest.
Submission of multiple orbital configurations
The non-GSO operator submits MOD to:
- increase the number of satellites in their constellation with the same orbit altitude, inclination, eccentricity
- Decrease orbit altitude with the same inclination, eccentricity
- or with different orbit altitude, eccentricity, inclination?
How to maintain original date of receipt?
Modification of NGSO filing subject to coordination
Kepler elements
1. Inclination of orbit
2. Apogee/perigee, eccentricity
3. Right ascension of ascending node and/or longitude of ascending node
4. Phase angle of the satellite within its orbital plane (mean anomaly)
5. Argument of perigee
Orientation of orbit in space
A. Inclination of orbit- Affects coverage, visibility statistics
Inclination 40 degrees Inclination 81 degrees
This slide contains animations
Orientation of orbit in spaceB. Right ascension of ascending node and/or longitude of
ascending node- RAAN is simply an angle (measured at the center of the Earth)
between the point the Sun’s orbit crosses Earth’s equator in ascending direction, and the point where non-GSO orbit crosses equator
- Actual RAAN may change due to change in planned launching date
- Most importantly, in satellites systems with multiple orbital planes RAAN and LAN define inter-orbital spacing, e.g. orbits with 0, 30, 60, 90 RAAN have spacing of 30 degrees
- Changing RAAN would affect visibility statistics
Orientation of orbit in space
RAAN 10 degrees spacing RAAN 36 degrees spacing
This slide contains animations
Size of the orbit
C. Apogee/perigee, minimum operating height- Affects coverage, visibility statistics
Orbit altitude 500 km Orbit altitude 1000 km
This slide contains animations
Orientation of an ellipse in orbitD. Argument of perigee (degrees)
- For elliptical orbit systems defines position of active arc – service area
- Affects coverage, visibility statistics
Argument of perigee 90 Argument of perigee 270(active arc in southern hemisphere) (active arc in northern hemisphere)
Position of satellites in orbit
E. Phase angle, number of satellites, number of orbits- Affects visibility statistics
10 orbits (50 sats) 5 orbits (25 sats)
This slide contains animations
Guiding principle - RoP on No. 9.27
When the modified frequency assignments are subject to coordination, the conditions to keep the original date:
2.2 The guiding principles for dealing with modifications are:
– general obligation to effect coordination before notification (No. 9.6), and
– coordination is not required when the nature of the change is such as not to increase the interference to or from, as the case may be, the assignments of another administration
Modification of NGSO filing subject to coordination
2.3 Provided that the appropriate coordination trigger limit is exceeded, the modified part of the network will need to effect coordination with respect to space networks that are to be taken into account for coordination:
a) networks with “2D-Date” before D1;
b) networks with “2D-Date” between D1 and D2 where the nature of the change is such as to increase the interference to or from, as the case may be, the assignments of these networks.
In case of non-GSO networks referred to in No. 9.7B, the increase of interference is measured in terms of a cumulative distribution function of equivalent power-flux density (epfd) produced to these earth stations.
2.3.1 Where the coordination requirements of the modification involve any network under b) above, the modified assignments will have D2 as their “2D-Date”. Otherwise, they will retain D1 as their “2D-Date”.
2.3.3 If it is not possible to verify that there is no increase of interference (e.g. in the absence of appropriate criteria or calculation methods), the “2D-Date” of the modified assignments will be D2.
Modification of NGSO filing subject to coordination
Modification of NGSO filing subject to coordination
D1 (Original 2D Date)
D2 (Date of receipt of a MOD)
These network are already identified as affected
These networks to be coordinated with only if:1. Coordination trigger is exceeded2. They could potentially receive more interference or may cause more interference to modified part
Question is:Which 2D Date a modified part would have
How to measure increase of interference
Provision Services Measure
9.7 GSO vs GSO Increase of dT/T
9.14 (PFD Trigger) Non-GSO vs Terrestrial
?
9.14 (FO) Non-GSO vs Terrestrial
?
9.7B Non-GSO vs GSO earth stations
Increase of CDF EPFD curve
9.12/9.12A Non-GSO vs Non-GSO and GSO
?
How to measure increase of interference
Nos. 9.12, 9.12A, since no criteria exists except frequency overlap to identify affected systems,
the Bureau currently verifies whether or not modifications of the system increase the interference and applies paragraph 2.3.1 of the Rule as mentioned in Section 6 of Radiocommunication Bureau Director’s Report to Radio Regulations Board (Doc. RRB17-2/3 rev.1):
“in the absence of appropriate criteria or calculation methods to verify that there is no increase of interference or protection, the Bureau will thoroughly study the technical justifications provided by the notifying administration to make its finding and publish them to ensure the transparency of the process. Such justifications may be based on static and dynamic interference assessments. For the later one, calculation may be e.g. in the form of a cumulative distribution function of the interference level, expressed as an interference-to-noise (I/N) ratio for varying percentages of time and locations into the subsequently filed non-GSO FSS systems.”
Steps to produce studies
1. Identify the list of potentially affected networks/systems under 2.3 b)
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A. Networks/systems received after D1 and before and on D2
B. List may include networks/systems at as-received stage (not yet published by the Bureau)see https://www.itu.int/ITU-R/space/asreceived/Publication/AsReceived
C. Both victim networks/systems operating in the same direction of transmission and in opposite direction of transmission are to be considered
Steps to produce studies
2. Identify representative parameters of the victim system to be studied
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A. Range of victim earth station receivers could include all or several types of earth stations characterized by their antenna pattern used, maximum gain and noise temperature –one with maximum gain/lowest beam width and another with a minimum gain/highest beam width for a range of different antenna patterns used
B. Range of victim space stations receiving antennas
C. If a victim non-GSO utilizes multiple orbital configurations – analysis should consider each orbital configuration
D. For a victim GSO, one representative GSO location could be considered
Steps to produce studies
3. Identify assumptions to be used
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A. When an assumption is made, it should be explained why it leads to worst-case situations so that the analysis based on this assumption guarantees that the I/N levels are not increased by the proposed changes
B. Worst-case latitude or range of different latitudes for victim receivers
C. Operational assumptions of the original (should correspond to already submitted characteristics) and modified part of the network/system, including:
- minimum elevation angle
- maximum number of satellites transmitting simultaneously
- the use or otherwise of any mitigation technique
Steps to produce studies
3. Provide static and dynamic simulation
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A. Static analysis may include comparison of produced PFD-mask, consideration of visibility statistics, variation in interference mechanism
B. Dynamic analysis may include I/N statistics, or PFD statistics once coordination with terrestrial services is required
C. Identify whether transmission power needs to be decreased to compensate orbit change (decrease in antenna gain, change of antenna pattern, decrease of power spectral density)
D. Statistics is provided in form of cumulative distribution function plots of I/N, PDF
E. Each particular plot should to extent practicable include all levels of I/N – from minimum to maximum, even if these levels are considered to be unrealistically high due to worst-case assumptions
Actions of the Bureau
When examining submitted evidences that a modified part of the network/system would not cause any more interference as compared to an original one
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A. The Bureau will make findings based on the analyses provided by the notifying administration and the analyses will be published and available for review by other administrations
B. Once findings are published other administrations might challenge to the findings based on its own analyses/calculation
Additional considerations
A. With respect to interference received from networks/systems submitted after or on D1 and before or on D2, a notifying administration may wish to commit to not requiring any more protection from other non-GSO systems or GSO networks than that required for the original parameters.
B. For the frequency bands subject to Article 22 EPFD limits, modification should include an updated information (PFD/EIRP masks, other relevant characteristics) which would enable the Bureau to examine modification under Article 22. Since no coordination is required under No. 9.12A, no need to provide analysis towards GSO as long as EPFD limits are met
