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FIXED SATELLITE SERVICE andUAS

(22 September 2010)

ACP WGF23/IP26Abdolmajid Khalilzadeh

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COMMERCIAL SATELLITES

• The FSS may be able to fulfill the UAS spectrum requirements without the need for a new AMS(R)S allocation

• Existing commercial FSS systems at Ku and Ka-band offer immediate access to spectrum for UAS

• ITU-R studies have shown that the commercial Ku/Ka bands can support UAS control links and meet the desired UAS link availability.

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UAS OPERATING UNDER FSS

• Requires modification of ITU Radio Regulations to permit UAS to communicate with a FSS satellite

• Requires a WRC Resolution that contains the UAS technical and regulatory requirements

• The performance, responsibilities and liabilities of the FSS and UAS operators would be specified in a commercial contract

• UAS would not be operating under the AMS(R)S service allocation, but rather as an FSS application

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• Space-to-Earth Direction10.95 – 11.20 GHz

11.45 – 11.70 GHz

11.70 – 12.20 GHz (Region 2)

12.20 – 12.50 GHz (Region 3)

12.50 – 12.75 GHz (Regions 1 and 3)

• Earth-to-Space Direction14.00 – 14.50 GHz

Non-Planned Ku Band FSS Frequencies

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Non-Planned Ka Band FSS Frequencies

• Space-to-Earth Direction17.30 – 17.70 GHz (Region 1)

17.70 – 18.80 GHz

19.70 – 21.20 GHz

• Earth-to-Space Direction27.50 – 28.60 GHz

29.50 – 31.00 GHz

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SATELLITE CHARACTERISTICS

• Long lifetime (≥ 15 years)• Low satellite and transponder failure rates• High EIRP and G/T levels over large geographic areas• Well suited for links that utilize small transmit/receive

antennas• High radio link availability• Connectivity over large geographic areas, which

terrestrial links cannot provide• Multiple transponders are available on each satellite, e.g.

24 Ku-band 36 MHz transponders• Bandwidths typically range from 24 to 120 MHz – the

most common bandwidth being 36 MHz

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Ñ+6

+6

+4+2

0

-2

-4

52.8

50.850.8

48.8

48.8

46.8 44.8 42.8

Uplink Coverage Downlink Coverage

SATELLITE COVERAGE

Note: This is an example coverage map; actual coverage varies depending on actual satellite design.

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COMMERCIAL SATELLITE CAPACITY

• TRANSPONDER LEASING– Customer can lease all or portion of a transponder– Transponder can be leased on a non-premptible basis

• Carrier cannot be moved to restore another carrier

• BACK-UP CAPACITY– Due to large number of satellites and transponders,

back-up (bandwidth) capacity can be provided.• Back-up capacity available on the same satellite• Back-up capacity available on another satellite

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LINK DEGRADATION

• A satellite link can be degraded by two primary sources– Atmospheric effects– Adjacent satellite interference

• Typical commercial satellite link availabilities range from 99.50% to 99.96%

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ADJACENT SATELLITE INTERFERNCE

• A satellite link is subject to interference from the transmissions of other co-frequency satellite networks

• Interference can occur in the Earth-to-space direction or in the space-to-Earth direction.

• Adjacent satellite interference are managed through ITU coordination.

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Note: 2º orbital separation is typical of the separation between adjacent satellites

ADJACENT SATELLITE INTERFERNCE

ES1 ES2 ES3

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3 4

A

C

B

D

SAT 1 SAT 2 SAT 3

UAE F

G

H

2º±0.05º 2º±0.05º

IJ

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COORDINATION

• Satellite operators coordinate the maximum power and EIRP density level of their transmissions, the off-axis gain characteristics of their antennas and the placement of any high power density carriers, e.g. TV/FM– A known and stable interference environment– Links are designed to withstand the expected interference

• Internationally, coordination agreements are contained in a formal document that is approved by the involved satellite operators and their respective administrations

• Domestically, a formal agreement may or may not be required – depends on the regulations of each administration

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ATMOSPHERIC DEGRADATION

• Rain is the primary atmospheric source of link degradation at Ku and Ka-band frequencies

• The effects of rain can be overcome in various ways– Increasing carrier power level– Changing the carrier modulation & FEC scheme– Increasing the transmitting and/or receiving antenna

size

• Typical commercial Ku-band link availabilities range from 99.50% to 99.96%

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• At some point in time, links will degrade or drop-out for various reasons

• UAS systems need to incorporate hardware redundancy

• UAS systems need to incorporate spectrum redundancy– Capacity– Frequency

UAS REDUNDANCY