1. Réseaux et Télécommunications 4 - Introduction aux réseaux par satellite Edoardo Berera Telelinea

2. Plan Orbits and coverage: GEO, MEO, LEO –Broadcast, point-to-point –“Bent-pipe” vs. on-board processing Examples –Iridium –Globalstar –EuroSkyWay –SkyBridge –Teledesic –Sky Station –e-BIRD 1

3. Satellites From Sputnik... to military –Since the first russian Sputnik satellite in 1957 : 5000 satellites have been launched –2500 are still in orbit Half of them are used by the military

4. Civilian usage The remaining ones (> 1200) are used for: –telecommunications (Telecom-1, Telecom-2,...) –television (Astra, HotBird 5,...) –meteorology (Meteosat, Med Hycos) –earth observation (Landsat, Spot) –astronomy (Hubble) 2000 are expected to be launched in the next 10 years, including a number of satellite constellations.

5. Orbits GEO Geostationary (or geosynchronous) : –36000 km MEO Medium Earth Orbit : –1500 - 10000 km LEO Low Earth Orbit : – < 1500 km

6. Coverage

7. Broadcast

8. “Bent Pipe” (Mirror) –VSAT Very Small Aperture Terminal –Terrestrial Switching Center –Two bonds X

9. On Board Processing (Switching) –One bond x

10. Iridium Consortium: –Motorola main contractor Operational service since November 1998 $ 5 bn, 7 years 66 LEO fast-moving satellites (+ 14 spares), –780 km –Unique inter-satellite "cross-links" 11 earth stations

11. Globalstar Consortium –Loral Space and Communications –Qualcomm –France Telecom –Vodafone Group (UK) –Hong Kong Telecom Service operational since September 1999 –$ 3 bn –48 LEO satellites (+ 4 back-up), 1400 km –50 earth stations Primary market is "cellular network extension" Call price: 0.70 €/min

12. EuroSkyWay Aggregate capacity –45 Gbps –cluster of five satellites –geostationary satellites Digital on-board processing (OBP) Inter-satellite links (ISL) Alenia Aerospazio

13. Terminals

14. Coverage and antennas

15. Africa and West Asia

16. SkyBridge Consortium: –Alcatel –Loral Space & Communications –Toshiba –Mitsubishi Constellation –80 LEO satellites –1469 km Space segment cost: $4.2 bn Ground segment cost: $1.9 bn By working through local operators, SkyBridge is positioned as –a local access system, “DSL in the sky” –solving the "last mile problem" as well as –providing Universal Service worldwide low cost terminals ( < $500) 20 Mbps down-link / 2 Mbps up-link per residential user 100 Mbps down-link / 10 Mbps up-link per business user

17. Teledesic Project Bill Gates (Microsoft) –Craig McCaw (McCaw Cellular now sold to AT&T) –Prince Alwaleed of Saudi Arabia –Boeing and Motorola Initially 840, now down to 288 LEO satellites at 700 km $ 9 bn Subscribers service at 64 Mb/s downlink and 2 Mb/s uplink Broadband terminals at 64 Mb/s bidirectional

19. Sky Station Project Telecommunications Earth Sciences Applications –250 Sky Stations (157 x 62 m) –22 km (stratosphere) –coverage 20 000 km2 – 2 - 10 Mb/s Alenia Aerospazio Thomson-CSF Daimler-Benz Aerospace COMSAT Laboratories United Solar Systems Corp

20. e-BIRD 1 Eutelsat, Paris Boeing satellite Ariane 5 launch Sep. 2003 Operational Nov. 2003 Internet broadband service

21. References Aleniaspazio EuroSkyWay Globalstar SkyBridge Teledesic Sky Station Eutelsat http://www.ee.surrey.ac.uk/Personal/L.Wood/ constellations/orbcomm.htmlhttp://www.ee.surrey.ac.uk/Personal/L.Wood/ constellations/orbcomm.html