Future Technology Satellite Networking

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Future Technology Satellite Networking

• Dr. Zhili Sun Centre for Communication Systems
  Research (CCSR)University of SurreyEmail
  Z.Sun_at_surrey.ac.uk

NETWORKSHOP 30 26-28 March 2002 Nottingham
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Outline

• Satellite networking today
• Satellite services, technologies and applications
• Broadband access via satellites using ATM
• Broadband access using DVB-S and DVB-RCS
• Issues on IP over satellites
• Satellite UMTS (S-UMTS)
• Satellite IP multicast and Broadband Britain
• Summary and conclusion

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Satellites networking today

• International telephony and data networks
• Internet and Intranet interconnections
• Satellite broadcasting
• Corporate VSAT networks
• Broadband satellite access and transit networks
• Satellites for maritime and aeronautic services

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Satellites networking today (cont.)
VSAT
PHD/SDH (switched or lease line)
Home TV
ISP
Internet
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INTELSATs Product Lines
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Satellite Services

• Fixed Satellite Services (FSS)
• 6/4 GHz (C band), 8/7 GHz (X band), 14/12 GHz (Ku
  band), 30/20 GHz (Ka band)
• Mobile Satellite Services (MSS)
• 2/3 GHz (L band), 30/20 GHz, Ka band
• Broadcast Satellite Services (BSS)
• 12 GHz (Ku band)

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Satellite technologies

• Satellite communication payload
• Transparent transponder
• On board digital signal processing
• On board circuit switch or packet switch to
  come
• Ground earth station
• Large size for network interconnections with high
  speed
• Small size for access with mobility
• Multiple access control schemes
• FDMA, TDMA and CDMA
• Bandwidth on demand, Random access

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Applications and data rates

• Voice (lt 64 Kbit/s)
• Voice band data (lt 64 Kbit/s)
• Narrowband 64 kbit/s digital data (ISDN and
  leased line)
• Broadband 2 Mbit/s gt 155 Mbit/s
• Variety of data rates
• From 16 kbit/s to 45 Mbit/s
• 140 Mbit/s and 155 Mbit/s possible

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Role of satellite networks
Convergence, IntegrationInternetworking
Ground Station
SUB - URBAN AREA
RURAL AREA
URBAN AREA
Fixed
Terminals
Transportable
Portable
Mobile
Bit rate
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Satellite global coverage

• LEO MEO GEO HEO
• Altitude (km) lt2000 10000 35786
  1250-39105
• RTT Delay (ms) 5-15 75-100 250
  9-260
• Handover (min) 5-10 60-120 -
  -
• Path loss (dB) 170 180 190
  -
• Doppler (kHz) 42 13 0 -
• Note Used for digital radio in US will begin
  in Europe (S-DAB), HEO gives better diversity

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Basic Technical Problems

• Propagation Delay
• Limited bandwidth
• Transmission Errors
• Transmission Power
• Note LEO/MEO not so interesting now

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Broadband Access using ATM

• For many years, satellite networking technologies
  have followed the terrestrial network
  technologies
• In 1990s, significant works have been done on ATM
  over satellites
• Based on Transparent (bent pipe) or on-board ATM
  switch satellites
• The ATM based broadband access is fading away,
  due to the limited capacity and availability of
  ATM terminals and applications
• ATM is considered as backbone technology

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Broadband access based on DVB

• Recently, satellite broadcasting services based
  on DVB-S and DVB-RCS reach millions of
  users/terminals
• Transport IP traffic over DVB-S with return
  channel using terrestrial link (such as telephone
  line)
• And over DVB-RCS with return channel over
  satellite
• This is different from the DVB-T which is used
  for cable networks

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IP over DVB protocol stack
Return link
Forward link
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Issues on IP over satellite

• Satellite link has high propagation delay and
  relatively high bit error rate which can be
  overcome
• WWW and FTP are based on TCP/IP protocols
• TCP uses slow start and congestion avoidance
  algorithm for flow control and congestion control
• It may take a long time to reach full
  transmission speed
• Transmission errors may trigger the TCP to go
  back to the slow start and congestion avoidance
  algorithm
• Real-time applications based on UDP/IP do not
  have such problem

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S-UMTS (Satellite 3G)

• Complimenting the Terrestrial UMTS (T-UMTS) in
  different operation environment
• Maritime Aeronautical S-UMTS
• Open rural, highway Suburb T- S-UMTS
• Urban Indoor T-UMTS
• Terminal and Services
• Mobile and portable terminal up to 384 Kbit/s
• Fixed broadband access up to 2 Mbit/s
• Voice, data, video and multimedia

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S-UMTS architecture concepts
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System architecture definition
System architecture selections
Terminal Architecture Selection
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Intermediate Module in Different Environment
Satellite
Unicast Multicast traffic
Air interface
T-UMTS Node B
Gateway
Gap filler
Terminal
Urban (B-M services/ Intl. roamers)
Vehicular/High way (Most of the services, mainly
entertainment)
Ships and Planes (Most of the services, mainly
entertainment)
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IP multicast over GEO satellites

• Satcom industry has been severely affected by the
  failure of systems based on constellations
  Iridium, Globalstar (Teledesic, ??)
• Still, a number of success factors can not be
  denied 200 GEO spacecrafts in operation and
  profitable
• Research and development have been focused on
  satellite DVB-S/DVB-RCS and IP multicast based
  GEO satellites

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New services and applications

• Addressing markets with higher volumes, beyond
  the sole broadcasting sector
• Build up on broadcasting/multicasting capability,
  exploit convergence FSS/BSS and MSS/BSS
• Content Delivery Networks, for broadband
  multimedia
• Full integration with terrestrial networks
  (terminals, services and management), IP
  transparent support

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Satellites for broadband Britain

• Provide alternative network access with global
  coverage (beyond local loop)
• Complement to cable and radio delivery TV via
  satellite high penetration in Europe
• Where obtaining the right of way for laying fibre
  is difficult, not covered at the moment or unduly
  expensive.
• Require global mobility beyond terrestrial mobile
  net.
• Rapid deployment is critical, as backup
  connections and in military communication systems
  in time of war

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Summary and conclusion

• Satellites will play an important role in the
  Global Information Infrastructure in term of
  networking, services and market
• Convergence and internetworking with UMTS,
  Internet and Broadcast
• Special role in network evolution with advance
  satellite technologies for broadband access with
  global coverage
• Research has been focused on DVB and IP multicast
• And on applications to net the drivers

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Acknowledgements

• The authors gratefully acknowledge the support
  from the European 5th Framework IST Programme and
  the GEOCAST project (IST 1999 11754).