MOBILE COMMUNICATIONS SYSTEM CAPABLE OF AVOIDING INTERFERENCE WITH CONTROL CHANNEL

摘要

The mobile communications system includes fixed units (21 to 2n, n being an integer) which are connected to a public telephone network by subscriber lines (4). The number n of the subscriber lines (4) is the same as the number n of the fixed units. Portable units (51 to 5m) are connectable to the fixed units (21 to 2n) over radio channels (m is an integer and equal to or grater than n). The radio channels are made up of a single control channel (C-CH) and a plurality of speech channels (S-CH). In this mobile communications system, a transmitter section of any of the fixed units (21 to 2n) and portable units (51 to 5m) which is in a stand-by condition is tuned to a stand-by channel outside of the frequency band of the control and speech channels, whereby the leakage of electro-magnetic wave to the control channel is eliminated. Also the frequency of the stand-by channel may be situated inside the frequency band of the control and speech channels while it is not used for communications.