SimCOM A76XX limitations

• Sending/receiving USSD is compleatly broken.

• No DTMF detection (?).

• No VoLTE support.

  Voice calls are performed in 2G mode. Switching between LTE and 2G takes a very long time (>30s).

• Simplified audio path.

  • No echo cancellation.
  • No noise supression.
  • No sidetone (good!).

• Some AT commands are silently ignored without any result (!) (OK or ERROR).

• Manufacturer reported as INCORPORATED (!).

  ATI
  Manufacturer: INCORPORATED
  Model: A7670E-LASE
  Revision: A7670M7_V1.11.1
  IMEI: XXXXXXXXXXXXXXX
  +GCAP: +CGSM,+FCLASS,+DS