Réseaux et Télécommunications

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