Réseaux et Télécommunications4 - Introduction aux réseaux par satellite
Edoardo BereraTelelinea
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
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
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.
Orbits
• GEO Geostationary (or geosynchronous) : – 36000 km
• MEO Medium Earth Orbit : – 1500 - 10000 km
• LEO Low Earth Orbit :– < 1500 km
Coverage
Broadcast
“Bent Pipe” (Mirror)
– VSAT Very Small Aperture Terminal – Terrestrial Switching Center– Two bonds
X
On Board Processing (Switching)
– One bond
x
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
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
EuroSkyWay
• Aggregate capacity – 45 Gbps
– cluster of five satellites
– geostationary satellites
• Digital on-board processing (OBP)
• Inter-satellite links (ISL)• Alenia Aerospazio
Terminals
Coverage and antennas
Africa and West Asia
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
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
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
e-BIRD 1
• Eutelsat, Paris• Boeing satellite• Ariane 5 launch Sep. 2003• Operational Nov. 2003• Internet broadband service
References
• Aleniaspazio EuroSkyWay• Globalstar• SkyBridge• Teledesic• Sky Station• Eutelsat
• http://www.ee.surrey.ac.uk/Personal/L.Wood/constellations/orbcomm.html
High Speed Networks5 - Fiber Optic Networks
Edoardo BereraTelelinea
Plan
• Fiberoptic cables• UNSA: ATM & Gigabit networks• Renater 2• NTI• TEN-155 / GEANT• FLAG• SEA-ME-WE 3• Project OXYGEN
Fiberoptic Cables
UNSA
• Backbone– ATM 155 Mb/s
• User access– IP over ATM– Ethernet 10/100 Mb/s
UNSA
• Backbone– ATM 155 Mb/s
• Evolution to Gigabit/s campus network– Tests Commutateurs
Gigabit Ethernet
• User access– IP over ATM– Ethernet 10/100 Mb/s
Gigabit Ethernet
Renater 2
• Réseau National de Télécommunication pour l’Enseignement et la Recherche
• IPv4 et IPv6 (G6)
NTI
• Noeud de Transit International
TEN-155
• Trans-European Network
• 155 Mb/s
GEANT
FLAG
• Fiber Link Around the Globe
FLAG Cable
• Two fibre pairs - each operating at 5 Gb/s.• Over 28,000 kilometres of cable. • 120,000 digital circuits operating at 64 kb/s. • Up to 600,000 simultaneous conversations per segment. • 326 erbium-doped optical amplifiers. • Four fibre-switched branching units.• Diversely routed land crossings - two in Egypt and two in Thailand.• Operational since November 22, 1997• Installed and commissioned in 27 months• Cost 1.5 B$
Erbium doped optical amplifier
Source: IEEE Spectrum
SEA-ME-WE 3
• South East Asia-Middle East-Western Europe 3– Germany to Australia, Taiwan, Korea and Japan
• operational since August 30, 1999• 38 000 Km, 2 pairs of fibers
– direct optical amplification
– wavelength division multiplexing (WDM)
– 8 wavelengths (colors) per pair of fibers
– bypass units allow the insertion/extraction of one or two colors per fiber
– 30 000 telephone circuits per wavelength
– 483 840 digital 64 kb/s circuits
• 33 countries, 25 years of lifetime, 1.5 B$
WDM and DWDM
• Wavelength Division Multiplexing• Dense Wavelength Division Multiplexing
Source: S.V. Kartalopoulos, « Introduction to DWDM Technology: Data in a Rainbow », chapter 5, IEEE/SPIE
Project OXYGEN
• Neil Tagare, the originator of the FLAG cable
– Bechtel Corporation is OXYGEN's project manager
– Lehman Brothers serves as its financial advisor
• 169000 km
• DWDM technology
• 2.56 terabits of capacity
• 97 landing points in 76 countries
• Initial budget 15 B$
Landing Points
• Phase 1B – Egypt - Port Said
– Egypt - Alexandria
– France - Antibes
– Gibraltar - Gibraltar
– Greece - Athens
– Ireland - Dublin
– Israel - Tel Aviv
– Italy - Genoa
– Italy - Lido Di Ostia
– Lebanon - Beirut
– Malta - Valletta
– Monaco - Monaco
– Spain - Conil
– Spain - Barcelona
– Syria - Tartus
– Tunisia - Tunis
– Turkey - Izmir
– U.K. - Fareham
– U.S.A. - Tuckerton
Project OXYGEN
• Subscription price
– 10 M$ for 1.24 Gb/s network access for 25 years
– plus 9% per year for Operations and Maintenance of Network and Terminal Station
References
• CRI, UNSA• Renater• DANTE• FLAG• FCR• Project OXYGEN