Towards the Personal Communicator

Presentation / Towards the Personal Communicator

Date Submitted: 06 June 2001

Written by RPC Telecommunications. Website: http://www.rpctelecom.com

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A short lecture presented to the Surrey Section of the IEE (the IEE is the British Institution of Electrical Engineers) by Mark C J Posen of RPC Telecommunications Ltd.

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 Printable Version
-Section 1
"Beam Me Up Scottie"
-Section 2
Concept
-Section 3
Orbit Mechanics
-Section 4
Iridium
-Section 5
ICO
-Section 6
Globalstar
-Section 7
Implementation & The Future

Globalstar

SLIDE 27

Globalstar (1)

  • Proposal of SS/Loral, Qualcomm, Alcatel - other partners, e.g. Vodafone
  • 56 satellite constellation in 8 planes
  • ~1,400 km inclined LEO orbit
  • Transparent transponder
  • no cross-linking

Notes:
Let's look at a third proposal. This is something of a halfway house between Iridium and ICO - 48 operational satellites with 8 spares (1 per plane). Each satellite weighs 450 kg and has a total transponder power of 1 kW. Lifetime is 7.5 years.

SLIDE 28

Globalstar (2) - Network

Notes:
Key point... transparent transponders and no crosslink ISLs.

SLIDE 29

Globalstar (3) - CDMA Soft Handover / Redundancy

Notes:
CDMA... signals relayed through more than one satellite at a time... blockage and handover is SOFT.

SLIDE 30

Globalstar (4) - Coverage

Notes:
Coverage resembles ICO but more satellites and much lower so more complex.

Next: Section 7 - Implementation & The Future

 
 

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