www gvf org The 20 Billion Question Can

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

Why Is Sat. Com Important in C-band? www. gvf. org

Spectrum www. gvf. org • 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

www. gvf. org 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

www. gvf. org • • 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

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

Example: IS-701@ 180° E www. gvf. org Global, Hemispheric and Zone C-band beams … … vs. Spot Ku-band beams

Newcomers in C-band downlinks www. gvf. org Is currently being introduced country by country worldwide Broadband Wireless Access (BWA), Wi. Max, FWA, …. 3. 4 3. 5 3. 6 Etx. C Additional band 3. 7 Is being considered by ITU Future mobile phone networks (IMT Advanced, 4 G, …. ) 3. 8 3. 9 4. 0 Std. C 4. 1 4. 2 Band commonly used by FSS satellites (FSS, feederlinks for MSS, …) BWA or IMT in ANY part of satcom C-band downlink will have an impact on FSS reception in ALL of the band

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

Overdrive of LNB www. gvf. org Intermodulation products BWA carrier Intermodulation product 4. 3 GHz Satellite signals 3. 3 GHz Distortion of received FSS spectre by BWA signal

Overdrive of LNB www. gvf. org 1. BWA signal off 3. BWA EIRP 1. 6 W 2. BWA EIRP 0. 5 W 4. BWA EIRP 5 W Example of gain compression and intermodulation of LNB by single BWA base station (BWA signal at 3. 505 GHz (bandwidth 3. 5 MHz), spectrum plots 3. 775 -3. 675 GHz)

Example of zone for short-term interference protection* in moderately hilly area www. gvf. org Protection contour FSS earth station 100 km * I/N not to exceed -1. 3 d. B for more than 0. 001667% of the time. (From Intelsat study to ITU Working Party 8 F (Document WP 8 F/1109))

www. gvf. org Impact of protection of earth stations in overlapping frequency bands Registerd earth stations (except TVROs) in Europe operating to satellites within 3 400 -4 200 MHz Circles of 150 km radius around earth stations

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

www. gvf. org Impact of protection of earth stations in non-overlapping frequency bands (e. g. BWA in 3. 5 GHz and FSS in 3. 7 -4. 2 GHz) . . 2 km exclusion zones around one earth station at the White House and one earth station at the Pentagon (protection against microcell base station used in urban areas)

International, intergovernmental organizations www. gvf. org • 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 3400 -3800 MHz range and FSS networks operating in any part of the 3400 -4200 MHz range therefore in this case becomes difficult within the same geographical area. ”

Conclusions www. gvf. org • 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