Patent ID: 6052576
Filing Date: 2000-04-18
Classification: H04W

Abstract:
Radiocommunications equipment, comprising a radio terminal capable of communicating through a public mobile telephone network supporting voice transmission channels and data channels, and an extension unit having an external appearance similar to that of a radiocommunications terminal, wherein the radio terminal comprises a data interface for connecting a data input/output unit for communicating on the data channels of the network, wherein the extension unit is connected to the data interface as said data input/output unit, wherein the extension unit comprises at least a microphone, an earphone, a vocoder and a ciphering module, the equipment having a security call mode wherein the vocoder forms, from a signal input by the microphone, a binary stream processed by the ciphering module in order to produce data sent to the data interface for transmission on a data channel, and data presented at the data interface upon reception on a data channel are deciphered by the ciphering module in order to produce a binary stream decoded by the vocoder in order to drive the earphone.