| 摘要 |
The invention concerns an equipment comprising a radio terminal (10) adapted for communicating with a public mobile telephone network supporting radio telephone channels and data channels. The equipment further comprises an extension unit (60) capable of being connected to a terminal data interface (10) and for communicating on the network data channels. Said extension unit includes a microphone, an earphone, a vocoder and an encryption module. Said extension unit has the same external appearance as a standard mobile radio terminal. In a secure communication mode, the signal derived from the extension unit microphone is processed by the vocoder then by the encryption module to produce the data sent to the terminal data interface (10), and the data received from the terminal data interface (10) are processed by the encryption module and by the vocoder to control the extension unit (60) earphone. |
