Airbus Defence and Space

TELECOM

Broadband processors

OBMM – Technical Overview

Flexible connectivity between small gateways and user–user terminals in multi-beams

  • 37.125 MHz bandwidth, regenerative switchable on a MPEG packet basis
  • Uplink (nine sub-channels/channel)
    • DVB-RCS (MPEG profile) MF-TDMA, QPSK
    • 1 HR (4224kbps), 2 MR (2112 kbps) or 8 LR (528 kbps) carriers per sub-channels
  • Downlink
    • Single DVB-S TDM carrier per channel
  • Controller support both standard
    • Spacecraft TMTC
    • 100 kbps high speed TMTC via traffic carriers
  • Utilises advanced second-generation packaging
  • Unit capacity range from 6 to 27 active channels plus redundancy
    • Small unit (typically): <3.8 kg and <50 W per channel
    • Large unit (typically): <3 kg and <45 W per channel

Features / technical details

Uplink key parameters

  • Dynamic range: 10 dB (nom) +10 dB headroom
  • 64 bursts/frame, 1, 4, 8 packets/burst, 128 sym preamble
  • Turbo decoding R 1/3, 1/2, 3/4, 4/5, 6/7, 7/8
  • Min 7.1 dB Es/No for QEF @ R1/2, 3/4 inc phase noise
  • Errored packet detection: programmable, nom four undetected errored packet per day.

Downlink key parameters

  • Symbol rate choice of 13.75 or 27.5 MSps, extendable to 41.25 and 55 MSps
  • RS and Conv encoding: R1, 1/3, 2/3, 3/4, 5/6, 7/8
  • <0.3 dB margin relating to user terminal

Uplink to Downlink routing flexibility

  • Full spatial and time switching at packet level for cross connectivity, multicast, min 16.5 kbps granularity
  • Supports seamless reconfiguration of traffic mapping

Synchronisation supported by

  • Onboard NCR generation and MPEG2 PCR insertion
  • 2 7MHz clock reference
  • Supports Interrogation/TM packets for burst Es/No, freq and timing data, carry forward of add payload data
  • TM on bursts outside nom power range

Applications

Telecommunications