Presentation from the UK Spectrum Policy Forum Plenary meeting on 14th July 2015. Guest talk by Prof. Barry Evans, The Alec Harley Reeves Chair in Information Systems Engineering, CCSR, University of Surrey

1. Company
LOGO
UK spectrum Policy forum-- presentation of CoRaSat project
A Database Approach to Extending the Usable
Ka-band Spectrum for FSS Satellite Systems
The CoRaSat project
Prof. Barry Evans
Institute for Communication Systems (Home of 5G Innovation Centre)
University of Surrey

2. The Consortium
CoRaSat
COgnitive RAdio for SATellite communications
EC FP7 ICT STREP Project (Oct. 2012 – Sep.
2015)
www.ict-corasat.eu
Project
Electrical and Inf
alessano.it
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University%of%Surrey%(UniS)%
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3. CoRaSat Vision and Objectives
• Establish the benefits of CR to Satcomms and the opportunities provided
Cognitive Radio Satellite Communications (CoRaSat) system
implementing flexible and smart spectrum usage to exploit unused or
underused frequency resources assigned to satellite services as primary or
secondary allocation.
CoRaSat providing guidelines for the definition of regulatory, standardization, and
technology frameworks for the exploitation of cognitive radio in support of the Digital
Agenda for Europe.
B1.1.1 CoRaSat*Vision*
Cognitive%Radio Satellite%Communications flexible%and%
smart%spectrum%usage
maximizes%resource%exploitation
lower% transmission% costs
investigating,%developing,%and%demonstrating
Cogni&ve))
Satellite)Link!
Primary'
Satellite'Link!
Primary'
Terrestrial'Link!
Primary'Link!
Cogni&ve)Link!
!
B1.1.2 CoRaSat*Context*in*the*Digital*Agenda*for*Europe*
broadband%access is%both a%necessity%and%a%human%right
Satellite%communications%are%considered%a%key%element
Incumbent
Link
Cognitive Link
Incumbent
Satellite Link
Cognitive
Satellite
Link
Incumbent
Terrestrial
Link
3

4. Why Spectrum Extension
 The demand for higher rate and reliable broadband
communications in regions not economically
accessible by terrestrial means alone.
 Digital Agenda target by 2020： Universal
broadband coverage of at least 30Mbps across the
whole of Europe and100Mbps to at least 50% of
the households
 Limited available spectrum resource
– 2 x 500MHz exclusive satellite bands at Ka
 Future HTS satellites being designed to use the
exclusive plus the shared bands.
2

5. Why satellite in the Ka band ?
 Up to 50% of households in some regions of
EU will only have satellite available as a
means of accessing broadband and that 5-10
million households are potential satellite
customers*
 Current Ku band satellites do not have the
capacity to deliver such services at a cost per
bit that makes a business case;
 Q/V bands has already been suggested for
feeder links but for user terminals the
additional expense is not considered desirable
so we consider Ka-band for user terminal.
* "EU FP7 Project BATS," [Online]. Available: http://www.batsproject.eu/. 3

6. 4
Ka-band Spectrum Allocation
ITU allocated shared band：
CEPT 27.5-29.5GHz Segmentation:

7. 5
Scenarios in CoRaSat
 Scenario A：17.3-17.7 GHz—the BSS feeder links are determined as
the incumbent links but uncoordinated FSS (downlink) links are also
permitted in this band.
 Scenario B：17.7-19.7 GHz—FS links are considered incumbent but
FSS (downlink) terminals may be deployed anywhere but without right
of protection.
 Scenario C：27.5-29.5 GHz—FSS (uplink) terminals can operate in FS
portions provided they do not interfere with the incumbent FS

8. 9
Topics considered in CoRaSat
 Spectrum awareness.
-Interference analysis using geographic data bases
-spectrum sensing to detect interference
 Spectrum exploitation
-Resource allocation to maximise spectrum availability
-Mitigation e.g. beamforming, site shielding
 Area and capacity analysis
 Demonstration of terminal/gateway equipment
 Integration with Regulators and standards

9. Database Approach
9
Interference
Modeling
Propagation Model (ITU)
System Parameters
Cognitive Zone
Area Analysis
Spectral Analysis
Database
Interference threshold adopted by regulatory bodies
Interference
Matrix
 Mapping database approach to three scenarios:
Scenario A: Single site cognitive zone and Area analysis.
Scenario B: Single site cognitive zone and Area/spectral analysis.
Scenario C: no complete database available (some countries have sold
off parts of the band)
 Data bases are held by national regulators (27 countries in EU).
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10. 7
Database based Interference Modelling
 The interference is modelled using ITU- Recommendation P.452-15 propagation
model which includes LoS, clutter, diffraction, rain scatter, etc. Path profile data is
also included as well as antenna pattern.
 Typical interference threshold on the long term interference(20%) is set at 10 dB
below the noise floor by the regulators, which are thus -154 dBW/MHz for FSS
reception and -149 dBW/MHz for FS reception*.
 A cognitive zone is introduced which is defined as the geographical area around
an incumbent user station inside which cognitive radio technique such as
spectrum sensing and beamforming should be employed to reduce the
interference.
 In other papers in the literature only LoS paths are illustrated, which are too
pessimistic.
* ITU Radio Regulations Appendix 7 and ITU-R Recommendation F.758-5

11. Interference Modelling using of databases
 As with TV Whitespace Satcoms can use databases and propagation models to
evaluate the level of interference at a chosen location.
 Assessment of the power spectral density is compared to set thresholds.
INTERFERER
DATABASE
PROPAGATION
MODEL / ENGINE
ITU-R P.452-15
INTERFERENCE
POWER
SPECTRAL
DENSITY
(dBW/MHz)
TERRAIN
(90m resolution)
CLIMATIC
ZONE (IDWM)
COASTLINE
RADIO
METROLOGICAL
GEOMETRICAL
FACTORS
BANDWITH
OVERLAP FACTORS
8

12. 10
Database for Scenario A (BSS)
 BSS feeder link database supplied by UK regulator (OFCOM):_
- 442 carriers from a total of 31 BSS uplink earth stations at 8 physical
sites, to 12 different satellites.
- Carrier number of each BSS earth station ranges from 1 to 42.
- Typical carrier bandwidth 26 MHz, 33 MHz, 36 MHz or 66 MHz
- EIRP of these earth station antennas ranges from 69 dBW-84 dBW
- Antenna radiation patterns defined in ITU Recommendation S.465
or S.580 .

13. 12
UK BSS and FS links
Registered BSS (left) and FS (right) Links in the UK

14. 15
Free space model vs. Full ITU model (Scenario A - Example of
CR zones for UK BSS Feeder links to an FSS)
*FSS pointing to a satellite at 53 degrees E longitude

15. 16
Scenario A - Example of 17.3 - 17.34 GHz ,Sub-
band 1 Full model with terrain diffraction
The band of 17.3-17.7GHz is split into 10 x 40 MHz sub-bands (SB1-SB10). This
example is for SB1 (17.3-17.34 GHz).
*Area of 1 degree box in figures above is approximately 111 x 68 = 7,548 sq km (UK area 243,610 sq km)

16. Scenario A is not an issue. It has been shown that BSS interference only affects
(above the interference threshold) less than 2% of the area so that 400MHz will
be available for FSS ( 80% increase) for more than 98% of the area in the UK
Luxembourg – other countries similar.
Scenario A (UK) –Area analysis by full ITU Model
17

17. 11
Database for Scenario B (FS)
 Actual database for the UK supplied by OFCOM:
- 12712 links with 15970 carriers
 Partial database for France from ITU. –BR.IFIC:
- 11548 links with 17384 carriers
 Database for other countries sourced from ITU. –BR.IFIC
(in the case of Poland from the online regulators database)
- not all links notified for all countries
- Partially complete cf. actual

18. Scenario B: Databases analysis
EIRP of FS links in the UK (dBW) EIRP of FS links in France (dBW)
Number of carriers per FS link in the UK Number of carriers per FS link in France
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19. 14
Analysis of database statistics (FS)
 In the UK more than 80% of links have only one carrier and 96% have only up
to 2 carriers with majority of carriers bandwidth from 3.5 to 55 MHz.
 At a particular location in the UK, little spectrum resource (<5%) from the
available 2 GHz band is used by the FS but the exact spectrum varies with
location. This demonstrates that FSS can have available most of the additional 2
GHz
 Using a FS data base from ITU. –BR.IFIC we have shown that a similar situation
exists in France.

20. 18
Scenario B - Example of Cognitive Zone for FS -
LOS and Full ITU Model
Affected area up to approximate 192 km Affected area up to approximate 49 km
(at -155dBW/MHz) (at -155dBW/MHz)
*Area of 1 degree box in figures above is approximately 111 x 68 = 7,548 sq km (UK area 243,610 sq km)

21. Scenario B – FS links in the UK
UK FS links (totally 12712 links with
15970 carrier records )
10 sub-bands
17.7-18.7 GHz
Scenario B includes very large number of FS links and from the evaluation in the UK we
have shown that a large percentage of the 2GHz band is available at most locations but not
the same spectrum at all locations. Thus a database approach for resource allocation is
required. CEPT FM44 has started to engage with regulators to investigate how databases
can be used.
19

22. Scenario B - Example of LOS result and Full ITU model result of all
UK FS links, interfering to FSS terminal at a particular location 1
(lat of 52.5 degs, long of -0.1 degs)
Interfering FS links based on LoS model
Interfering FS links based on full ITU model
Spectrum Occupancy based on LoS model
(X: 17.7 - 19.7 GHz; Y: PSD from -160 to -130 dBW/MHz )
Spectrum Occupancy based on full ITU model
(X: 17.7 - 19.7 GHz; Y: PSD from -160 to -130 dBW/MHz )20

23. Scenario B: Spectrum availability
map
13E UK -154.5 dBW/MHz
21

24. Scenario B: Spectrum availability
map
13E France -154.5 dBW/MHz
22

25. Scenario B: Spectrum availability
CDF of total Bandwidth of FS link interference per FSS Site (MHz)
% of UK FRANCE POLAND HUNGARY SLOVENIA
sites MHz MHz MHz MHz MHz
10% 139 58 80 45 50
1% 450 258 190 270 160
0.1% 700 550 400 820 405
% of
sites UK FRANCE POLAND HUNGARY SLOVENIA
10% 7% 3% 4% 2% 3%
1% 23% 13% 10% 14% 8%
0.1% 35% 28% 20% 41% 20%
CDF OF TOTAL BANDWIDTH OF FS LINK INTERFERENCE PER FSS SITE (% OF 17.7 – 19.7 GHZ)
23

26. 25
Forward Capacity Gains
Coverage Exclusive band Exclusive + Shared Exclusive+shared
Sc A+B No FS int With FS Int
Capacity/beam Capacity/beam Capacity/beam
UK -11 beams 5.4 Gbps 25.1 Gbps 22.8 Gbps
FRANCE-26 beams 12.7 Gbps 59.2 Gbps 53.5 Gbps
With RA regains full capacity—approx 5 x Exclusive alone
 62.4MHz carriers
 Carrier roll off 20%
 1450 MHz transponders
 20 carriers per transponder
 Sat eirp 70.7dBW
 Sat G/T 25.5 dB/K
 OBO 2.6dB

27. 24
Scenario B 17.7-19.7 GHz and Scenario C 27.5-
29.5 GHz
Scenario B includes very large number of FS links and from the evaluation in the
UK we have shown that a large percentage of the 2GHz band is available at most
locations but not the same spectrum at all locations. Thus a database approach
for resource allocation is required. CEPT FM44 /SE 40 has started to engage with
regulators to investigate how databases can be used.
For scenario C we only have preliminary results* because we do not have access
to an adequate 28GHz database on which to operate. But it can be addressed in
detail using the same approach as in scenario A/B, if databases become available.
*A. Mohamed, M. Lopez-Benitez, B. Evans, “Ka band satellite terrestrial co-existence: A statistical modeling
approach,” In proceeding of Ka band Conference, Salerno, Italy, Oct. 2014.

28. 25
Conclusions
 We have shown that 17.3-17.7GHz band can be used for FSS downlinks except
for very small area around BSS stations in the UK and other EU countries . Maps
are available.
 We have demonstrated that the 17.7-19.7GHz band can be used by FSS in
greater than 90% of the EU coverage area and that capacity advantages of 4x
that in the exclusive band can be achieved by using a data base interfaced to
carrier allocation at the gateway..
 Initial evaluation of the up link band 27.5-29.5 GHz has produced similar
conclusions although use of just the HDFSS bands may be sufficient in the EU..
 Laboratory demonstration of the terminal/gateway equipment planned for 2015
 CEPT—SE-40/FM44 have initiated data base acquisition and in ETSI an SRDoC
has been published.

29. Company
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