| 摘要 |
PURPOSE: To provide a miniaturized and power-consumption saving module by supplying no power to a processor subsystem of a security module, while a telephone set is in a standby mode. CONSTITUTION: A security system controller 29 monitors an external communication bus 34 and an internal communication bus 32 inside a portable radio telephone set. Until a suitable instruction string is detected on the bus 34, a vocoder processor 10 and a modem processor 20 are held in an idle mode. When a suitable instruction string is detected, power is supplied to a vocoder/comsec subsystem processor 11 and a modem/signaling subsystem processor 20, and a security channel with a remote device for communicating with a cellular telephone set is set. Thus, power consumption is reduced, and miniaturization is attained. |
