Improving
the Radio Regulations,
Prospective WRC
(WRC-15) Agenda Items
Per Hovstad,
Principal Spectrum Engineer
Asia Satellite Telecommunications Co. Ltd.
1
E-mail: phovstad@asiasat.com
ITU Workshop, Limassol April 2014
Four steps
in the righ direction
• Improved due diligence
procedures
• Elimination of API for
satellite networks subject
to coordination
• Reduction of "unecessary
coordination"
2
• Balancing up- and downlink
spectrum
ITU Workshop, Limassol April 2014
Four steps in the right direction
Does not solve all problems
associated with;
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Equitable access
Efficient spectrum usage
Congestion of real operational satellites in the arc
Commercial value of controlling access to orbit spectrum
resources
"Paper satellites"
"Virtual satellites"
However, they are steps in the right direction
3
Improved due diligence
procedures
4
Improved due diligence procedures

Purpose; to remove “virtual satellites”

Resolution 49

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(Planned) date of launch

No obligation to renew information when satellites are relocated or deorbited
Improved due diligence procedures

Information submitted after launch (exact date)

Requirement to renew information whenever changes occur

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Specific ID of satellite, based upon submissions by administrations, to allow
tracking of location of satellite in time and avoid same satellite recorded as
operational in several locations simultaneously
Resolution 552

Attempt to improve procedures for BSS networks in 21.4-22 GHz band by
WRC-12
5
Elimination of API for
satellite networks subject
to cordination
6
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Geostationary satellite networks subject to coordination
Advance Public Information was originally used as a “precoordination” to assess potential orbit location and other
parameters of later coordination requests
Over time, the API information has been reduced to a bare
minimum enabling no pre-coordination
The API process is not suitable for an environment of
commercial and competitive satellite operators

No advantages

Disadvantages
7
API process
RR 9.1
API period of validity = 2 years
Coordination
request not
receivable
= 6 months
Coordination request receivable = 1.5 years
Administration A
Publication of plans
Earliest possible
date of filing priority
API gives no ITU filing priority
Coordination request receiveable within
+/- 6° of the location of the API
APIs every 12° enables coordination
requests to be submitted anywhere in
GSO arc
Administration B can submit a coordination
request for a network which is incompatible
with Administration A and receive higher
priority than Administration A
APIs are not subject to filing fees
Administration B
8
Reduce "uneccessary"
coordination
9
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Congestion in the arc
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"Paper satellites"
"Virtual satellites"
Real operational satellites (every 2°-3° around the GSO
arc)
In particular in unplanned C- and Ku-band
Well established and mature technology and
applications
Relatively homogeneous technical parameters have
evolved
10

Large number of administrations and networks
identifed as affected
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E.g. ASIASAT-105.3T
 1802 networks identified
 49 administrations
 All orbital separations (up to 157.8°)
Coordination needs to be completed within 7 years
of API, i.e. within ≤ 6.5 years of coordination
request
Force administrations to notify without completing
coordination (RR 11.41)
Need to avoid unneccessary coordination
11
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In reality, first adjacent satellite networks on either
side will completely dominate adjacent satellite
interference
Further away networks will have little impact
Need to be able to live with first adjacent satellite
network will limit operation

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Causing interference to others
Receiving interference from others
This will also allow compatibility with further away
networks
12
Current types of coordination triggers/protection criteria
RR 9.7
Identification of coordination
requirements
Coordination arc
RR 9.41
Inclusion in coordination of
networks outside the
coordination arc
ΔT/T = 6%
Determination of probability of
harmful interference (in case of
outstanding coordination
requirements)
C/I = C/N + 12.2
RR
11.32A
Calculated from filed parameters
13
(ΔT/T = 6%)
C/N calculated from filed parameters
What interfering level should trigger coordination?
Practical adjacent
satellite interference
in real operation
Practical adjacent satellite
interference in real operation
Actual ΔT/T as a function of orbital separation for different antenna sizes
4 GHz
12 GHz
ITU coordination
trigger/protection
criteria (ΔT/T = 6%)
(D1, D2 and D3 denote antenna sizes of 1.8, 2.4 and 3.5 m at 4 GHz and 0.45, 0.6 and 0.9 m at 12 GHz)
In practical operation, satellite networks operate with adjacent satellite interference
corresponding to:
Significant overprotection in ITU criteria:
C-band: ΔT/T > ~ 28%
Ku-band: ΔT/T > ~ 55%
•
•
•
•
Unneccessary coordination
Complicating coordination
Complicating access to spectrum orbit resources
Leading to inefficient usage of spectrum orbit
resources14
WRC-12 reduced the size of the coordination arc by
2° for unplanned C- and Ku-band. However:
 Inclusion under RR 9.41 increases
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1854 networks requested included between 01.01.2013
and February 2014
33 networks requested included on average per
coordination request (20 before 01.01.2013)
Criteria under RR 9.41 and RR 11.32A are based
upon filed parameters
Filings can be designed with parameters that are
artificially sensitive to interference, triggering
coordination and unduly blocking access for other
networks
15

Give adequate protection to satellites with a reasonable
range of technical parameters inside and outside the
coordination arc
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Protection criteria not based upon parameters contained in
individual filings
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No additional protection for networks with parameters outside this
range
Avoid overprotection stemming from unrealistic parameters
contained in filings
Has already been implemented in Appendix 30 and for BSS in 21.422 GHz band (pfd masks)
Requires fairly stable technology and relatively
homogeneous parameters
16
Required representative parameters
and their possible values
to determine pfd masks/values
ΔT/T
20%
20%
f (GHz)
4
12
Range of antenna
diameters (m)
1.2 – 18
0.45 – 11
Ts (K)
95
125
Downlink
Antenna efficiency 70
(%)
70
Uplink
f (GHz)
6
14
Space station G/T
(dB/K)
≤0
≤ 11
17
Example of downlink
pfd masks to obtain
ΔT/T = 20%
12 GHz
4 GHz
Maximum uplink pfd at GSO
(dBW/m2 ∙ Hz):
6 GHz
-198.8
(-204 for ΔT/T = 6%)
14 GHz -202.8
(-208 for ΔT/T = 6%)
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Pfd downlink masks and uplink values:
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Defined protection inside and outside coordination
arc
Independent of filed parameters
Artificial parameters will not unduly block
coordination of other networks
No need to define allowable range for parameters
to be contained in a filing
Could be introduced at RR 9.7, 9.41 and/or 11.32A

Proposed introduced only at RR 11.32A
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WRC-15, Agenda Item 9.1, Issue 9.1.2
The issue of types of coordination trigger /
protection criteria was considered by WRC-12
together with proposals to reduce the size of the
coordination ard (Agenda Item 7, Issue 2A)
• WRC-12 reduced the size of the coordination arc
for C- and Ku-band, but
• decided to further study this issue under WRC-15
Agenda Item 9.1, Issue 9.1.2 (Resolution 756
(WRC-12), resolves 1)
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Resolution 756

resolves to invite ITU-R

1 to carry out studies to examine the effectiveness and
appropriateness of the current criterion (ΔT/T > 6%) used in
the application of No. 9.41 and consider any other possible
alternatives (including the alternatives outlined in Annexes
1 and 2 to this Resolution), as appropriate, for the bands
referred to in recognizing e);

2 to study whether additional reductions in the
coordination arcs in RR Appendix 5 (Rev.WRC-12) are
appropriate for the 6/4 GHz and 14/10/11/12 GHz
frequency bands, and whether it is appropriate to reduce
the coordination arc in the 30/20 GHz band,
21
Resolution 756
Two separate issues:


Size of coordination arc (resolves 2)
Types of protection criteria/coordination trigger
(resolves 1)
22
Balancing up- and
downlink spectrum
23
Commercial communication satellites normally use
"bent-pipe" technology:
frequency change
Uplink
Downlink
BWdown = BWup
• Amount of spectrum for up- and downlink should match
• Due to satellite antenna design, waveguide and OMTs etc., it is normally most
24 frequency bands in the vicinity of each
efficient to have up- and downlink in
other
Example 1: Current ITU-R Region 3 table of allocations, Ku-band
12.75
13.0
13.75 14.0
13.25
14.5
14.8 17.3
Uplink
17.7
18.1
Downlink
10.7
10.95
11.2
11.45
Uplink
FSS
(unplanned/planned)
1250 MHz
BSS
(unplanned/planned)
and uplinks limited to
1100 MHz
only feederlinks for
25
BSS
11.7
12.2
12.5
12.75
Downlink
1550 MHz
750 MHz
300 MHz of downlink
capacity cannot be
efficiently used due to lack
of uplink capacity
350 (600) MHz of uplink
capacity cannot be
efficiently used due to lack
of downlink capacity
Example 2: Current ITU-R Region 1 table of allocations, Ka-band
24.65
25.25
31
27.5
Uplink
Downlink
21.2 21.4
17.3
Uplink
Downlink
FSS (unplanned)
3500 MHz
BSS (unplanned) and
uplinks limited to only
feederlinks for BSS
22
600 MHz
26
3900 MHz
600 MHz
400 MHz of downlink
capacity cannot be
efficiently used due to lack
of uplink capacity
Up until corrected by
WRC-12, no uplink
assignments existed
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To facilitate efficient spectrum usage, up- and
downlink spectrum should be balanced
WRC-15 Agenda Item 1.6.2 is addressing spectrum
imbalance in Ku-band for unplanned FSS in
Regions 2 and 3.
27
Thank you!
28
Per Hovstad,
Asia Satellite Telecommunications Co. Ltd.
e-mail:
phovstad@asiasat.com
ITU Seminar, Almaty September 2011