2.3.3 Voice Calls
The wireless modem offers the capability of MO (mobile originated) and MT (mobile terminated) voice calls, as well as supporting emergency calls. Multi-party, call waiting and call divert features are available. Some of these features are network- operator specific.
For the inter-connection of audio, the wireless modem offers both single ended and balanced analogue input and output lines. Direct interface to the digital PCM (pulse code modulation) bus used within the wireless modem is available, thus by-passing the internal analogue circuitry. The wireless modems support HR, FR, EFR and AMR vocoders.
2.3.4 Data
The wireless modem supports the following data protocols:
•GPRS (General Packet Radio Service)
The wireless modem is a Class B terminal. The wireless modem is GPRS multi-slot class10 (4+2) enabled, capable of receiving at a maximum of four timeslots per frame (down link), and transmitting in two timeslots per frame (up link). See section 2.3.5 for multi-slot allocation by class.
•CSD (Circuit Switched Data)
The GR64 wireless modem is capable of establishing a CSD communication at 9.6 kbps over the air.
