SDR PHY vs Calypso

What's so special about SDR?

  • General purpose hardware
    • i.e. not limited to any particular technology and/or protocol stack,
    • could be used as PHY for GSM, LTE, IEE802.11, GPS, Bluetooth, etc.
  • Becomes cheap and available for everyone
    • e.g. RTL-SDR, LimeSDR-Mini
  • Becomes even smaller than a credit card
    • e.g. XTRX
  • Open Source friendly
    • GNU Radio, GQRX, OpenBTS, OsmoTRX, srsLTE, etc.
    • some drivers, firmware and PCB schematics are available

Advantages over Calypso

  • No need to rely on a 'black box' DSP
  • No hardware availability problem
  • No reverse engineering required
  • No freq. band limitations


  • Low output power
  • General purpose hardware
    • No screen, no keyboard,
    • No built-in SIM reader,
    • No built-in audio
    • etc.

What is it for?

  • Another hardware platform for OsmocomBB
  • 100% Open Source GSM L1 implementation
    • GSM TS 05.02 scheduling
    • GSM TS 05.03 channel coding
    • GSM TS 05.04 (de)modulation
    • GSM TS 05.10 synchronization

Updated by ptrkrysik about 4 years ago · 2 revisions

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