CSD (Circuit Switched Data)¶

• Table of contents
• CSD (Circuit Switched Data)
  • L1 PHY support
  • L23 support state
    • TODO/limitations

This page documents Circuit Switched Data support in the mobile application (see #4396).

L1 PHY support¶

At the time of writing this wiki page, CSD support is implemented for the following L1 PHYs:

• Layer1bin firmware for Calypso based phones
• SDR PHY (osmo-trx-ms) + trxcon application
• SDR PHY (grgsm_trx) + trxcon application
• FakeTRX (virtual Um) + trxcon application

L23 support state¶

• async (soft-UART) transparent V.110 calls
• [not tested] sync transparent V.110 calls
  • [not tested] including fax calls
• TCH/F9.4, TCH/F4.8, TCH/F2.4 (only @ 2400 bps)
• [not tested] TCH/H4.8, TCH/H2.4 (only @ 2400 bps)

TODO/limitations¶

• non-transparent calls (V.110 RLP, V.120)
• TCH/F14.4 (see also #6167)
• TCH/F2.4 and TCH/H2.4 @ 300 bps, 1200/75 bps
• ECSD (multi-TCH support)
• CUSE