The multiplexer protocol described in the present document operates between an UE and a TE and allows a number of
simultaneous sessions over a normal serial asynchronous interface. Each session consists of a stream of bytes
transferring various kinds of data; for instance, voice, fax, data, SMS, CBS, phonebook maintenance, battery status, GPRS, USSD etc.
This permits, for example, SMS and CBS to be transferred to a TE when a data connection is in progress. Many other combinations are possible including digital voice. It is, for instance, possible to transfer digital voice in combination with SMS. The multiplexer allows a complete system to be partitioned in a flexible way between a UE and TE.
The scope of the present document is to define a multiplexing protocol between a UE and a TE. The multiplexing
protocol can be used to send any data, for instance voice, SMS, USSD, fax etc.
This TS describes the protocol, but not the commands or data transported with it.