| 摘要 |
PURPOSE:To prevent disturbance due to irradiation of a radio wave from a communication station whose validity of communication license is expired by providing a time channel in parallel with a common line channel. CONSTITUTION:A managing station uses a time channel 3 to broadcast always time information 5. When start of communication command is inputted to a communication equipment 11, a program is started, the information 5 is received by a transmission/reception antenna circuit 20, a transmission/reception changeover switch and a reception circuit 23 and stored in a T register 6 in a RAM 27 via a coding/decoding circuit 24. Then the content of the T register 6 is compared with a content of a T0 register 7 in a ROM 28 for storing communication party information. The communication equipment 11 uses a common line channel 2 to sent a request 10 to acquire a talking channel and the signal 10 is sent as a signal with a specific bit pattern by the control of a CPU 25. Thus, the access to a radio channel from a communication equipment whose validity of communication license is expired is prevented. |
