The $20 Billion Question: Can Satellite and Terrestrial Wireless Co-Exist in C-band? David Hartshorn Secretary General Global VSAT Forum

Why Is SatCom Important in C-band?

Spectrum ITU table of allocations allows FSS only in selected bands Bandwidth requirements for traditional FSS applications need to be met in the selected band Civilian Use

Industry Supply, User Demand Only band where FSS services can realistically be provided with high availability due to rain fade characteristics Many satellites available Well established, increasingly inexpensive technology Wide coverage enabling services in remote and sparsely populated areas and areas with low traffic density Important part of the telecommunications infrastructure for many developing countries

Widely used for a multitude of satellite services TV broadcast to cable networks TV broadcast to individual receivers VSAT networks Internet providers Point-to-multipoint links Satellite News Gathering Communication for ships Disaster relief

ILLUSTRATIVE DIAGRAM Compare the coverage possibilities over the Pacific Islands region –1 C-band beam vs. –Multiple Ku-band beams C-band Ku-band What connectivity can be provided in C-band and what connectivity in Ku-band

Example: 180° E Global, Hemispheric and Zone C-band beams … … vs. Spot Ku-band beams

Newcomers in C-band downlinks Band commonly used by FSS satellites Additional band (FSS, feederlinks for MSS, …) Future mobile phone networks (IMT Advanced, 4G, ….) Broadband Wireless Access (BWA), WiMax, FWA, …. Is being considered by ITU Is currently being introduced country by country worldwide BWA or IMT in ANY part of satcom C-band downlink will have an impact on FSS reception in ALL of the band Std. C Etx. C

Impact on FSS Reception In-band interference Interference from unwanted emissions (outside the signal bandwidth (e.g. spurious emissions)) Overdrive of LNB’s  Exclusion zones around earth stations are required if these terrestrial wireless services are to operate in the band

Distortion of received FSS spectre by BWA signal Overdrive of LNB Intermodulation products BWA carrier 3.3 GHz 4.3 GHz Intermodulation product Satellite signals

Overdrive of LNB 1. BWA signal off 3. BWA EIRP 1.6 W 2. BWA EIRP 0.5 W4. BWA EIRP 5 W Example of gain compression and intermodulation of LNB by single BWA base station (BWA signal at GHz (bandwidth 3.5 MHz), spectrum plots GHz)

Example of zone for short-term interference protection* in moderately hilly area FSS earth station Protection contour 100 km * I/N not to exceed -1.3 dB for more than % of the time. (From Intelsat study to ITU Working Party 8F (Document WP 8F/1109))

Circles of 150 km radius around earth stations Registerd earth stations (except TVROs) in Europe operating to satellites within MHz Impact of protection of earth stations in overlapping frequency bands

Impact of protection of earth stations in overlapping frequency bands 150 km exclusion zones around one earth station in Washington DC and one in New York City..

Impact of protection of earth stations in non-overlapping frequency bands (e.g. BWA in 3.5 GHz and FSS in GHz) ATLAS OF THE WORLD.. 2 km exclusion zones around one earth station at the White House and one earth station at the Pentagon (protection against micro- cell base station used in urban areas)

International, intergovernmental organizations ITU (provisional CPM Report (regarding IMT)) –“If FSS is deployed in a ubiquitous manner and/or with no individual licensing of earth stations, sharing is not feasible in the same geographical area since no minimum separation can be guaranteed.” Asia-Pacific Telecommunity (APT, Wireless forum) –“As BWA is being introduced, harmful interference and loss of service for FSS receivers have been reported many places” –“However, when the BWA stations and/or FSS earth stations are deployed in a ubiquitous manner and/or without individual licencing or registration, the locations of the stations are not known and hence, no minimum separation distance can be guaranteed. Coexistence of BWA networks operating within the MHz range and FSS networks operating in any part of the MHz range therefore in this case becomes difficult within the same geographical area.”

Conclusions BWA or IMT in a part or all of the FSS C-band downlink will be incompatible with general FSS reception in any part of C-band in the same geographical area BWA or IMT in a part of C-band may be compatible with FSS reception by a small number of earth stations if: –Appropriate exclusion zones around each of the earth stations are established –User terminals are designed not to emit any signals when not in contact with a base station Introduction of BWA or IMT by one country can block FSS reception in another country