USING THE NEW L BAND MSS ALLOCATIONS Study Group 8 Seminar on Tomorrows Technological Innovations Ge

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USING THE NEW L BAND MSS ALLOCATIONS- Study
Group 8 Seminar on Tomorrows Technological
Innovations Geneva, 9 September 2004

• Marcus Vilaça
• Manager, Systems Engineering
• Advanced Systems Division

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Inmarsat Background

• Established in 1979 as an international
  co-operative
• Privatised in April 1999
• Owns and operates 9 satellites 4 x Inmarsat 2
• 5 x Inmarsat 3
• Contract for 3 x Inmarsat 4 satellites signed in
  May 2000
• Firmly established in maritime, aeronautical and
  land markets
• Customer base of over 320,000 users
• Current services include messaging, voice and
  data
• Global presence network of suppliers of
  services and equipment
• GMDSS

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Inmarsat 1st Generation Space Segment

• Marecs Marisat
• 33 dBW EIRP 30 dBW EIRP
• 2 x 5 MHz bandwidth 2 x 5 MHz
  bandwidth
• 580 kg dry mass 360 kg dry mass
• 13.5 m solar array 2.2 m (w) x 3.8
  m (h)
• Launch A 20/12/81 (22/08/96)
  Launch 1 19/02/76
• B 09/09/82 (F) 2 10/06/76
• B2 10/11/84 (23/01/02) 3 14/10/76

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Inmarsat 2

• 39 dBW EIRP
• 2 x 20 MHz Processed Bandwidth
• 700kg Dry Mass
• 14.5 m Solar Array Span
• Launch F1 30/10/90
• F2 08/03/91
• F3 16/12/91
• F4 15/04/92

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Inmarsat 3

• 49 dBW EIRP
• 2 x 60 MHz Processed Bandwidth
• 1000kg Dry Mass
• 20.5 m Solar Array Span
• Launch F1 03/04/96
• F2 06/09/96
• F3 18/12/96
• F4 03/06/97
• F5 04/02/98

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Inmarsat 4

• 67 dBW EIRP
• 10 dB/K G/T
• 2 x 126 MHz Processed Bandwidth
• 9 m deployable reflector
• 3000 kg Dry Mass
• 6000 kg Launch Mass
• 12 kW spacecraft power
• 10 kW payload power
• 48 m Solar Array Span
• Astriums Eurostar 3000 bus
• Major Subcontractors
• TRW Astro
• EMS
• Alcatel
• Boeing
• Launch F1 February 2005
• F2 July 2005

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Inmarsat 4 Characteristics

• Frequency Bands
• Mobile Link _at_ L Band and Feeder Link _at_ C band
• Transponders
• Transparent bent-pipe, C/L, L/C, L/L, C/C
  Navigational
• Digital Channeliser/Beamformer
• 630 x 200 kHz channels, dynamically allocated to
  beams
• 256 beams
• Mobile Link (RHCP, digital beam former)
• 228 narrow spot beams for BGAN service (1.1
  degree grid)
• 19 wide spot beams for EE service (4.05 degree
  grid)
• 1 global beam
• Feeder Link (RHCP LHCP)
• 1 global beam, dual polarisation

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Inmarsat 4 Coverage

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The MSS L Band Extension
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Amethyst Programme

• Part of the ESAs Artes 3 Line 4 study programme
• Feasibility study focused on the changes required
  to the I4 payload design, to enable utilisation
  of the L band extension
• Study lead by Astrium, supported by Inmarsat
• Scenario 1 Modification of I4 flight model 3
  (FM3)
• 1A - Minimum Changes
• 1B - New DSP
• Scenario 2 Procurement a fourth spacecraft
  (FM4)
• 2A - New DSP
• 2B - Enhanced SSPAs
• Main Outputs Design Solutions, ROM Cost
  Development Plan

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I4 Payload Block Diagram

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I4 Frequency Plan
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Baseline I4 L Band Pre-processor DSP

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Scenario 1 - L Band Pre-processor DSP Changes

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Scenario 1 Other Equipment Changes

• L Band Feed
• New diplexers
• Feed element retuning
• ONets
• New output filters

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Scenario 2 - L Band Pre-processor DSP Changes

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Scenario 2 Other Equipment Changes

• L Band Feed
• New diplexers
• Feed element retuning
• ONets
• New output filters
• New SSPAs
• Increased output power

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Summary of Spectrum Issues

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Planned Spectrum Activities

• Studies into the use of the new bands and related
  sharing studies
• Participation in the work being carried out by
  WP8D.
• Regulatory study of the new bands
• Assess the use of the new bands by existing
  terrestrial services, and the possibility of
  utilization of those bands for the provision of
  MSS in various countries, concentrating in Region
  1 and Region 3.
• Satellite antenna discrimination
• Analyse the impact of PFD limits on the service
  coverage area by taking into account satellite
  antenna discrimination performance.

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Conclusion

• The MSS L Band extensions offer a great
  opportunity to significantly increase the
  capacity of MSS satellites.
• The modifications required to the baseline
  Inmarsat 4 satellites to allow service provision
  in the new bands are significant, but can be kept
  within limits that allow reduced risk and lower
  cost and schedule impact.
• A comprehensive study on the utilisation of the
  extended L band by existing services will be
  carried out, to provide an accurate picture of
  the current situation and of any possible
  constraints.