| 摘要 |
PURPOSE:To allow the system to select an ISDN with an economical line utility charge. CONSTITUTION:Each radio calling transmitter 14 takes bit synchronization of a received signal via an ISDN 12 and sends the signal from an antenna 18 to a radio calling receiver 19 in each service area. Thus, each radio calling transmitter 14 is provided with a timer circuit 15 operated upon the receipt of a standard radio wave and a high stable crystal oscillation circuit 16 respectively and generates a bit synchronization reference signal Ss while making the oscillating signal from the high stable crystal oscillation circuit 16 in subordinate synchronization with the standard radio wave and a bit synchronization circuit 17 implements synchronization processing in response to the bit synchronization reference signal Ss. |
