Changing the radio zone of fixed stations by mobile subscribers

In radio telephone systems an economical use of bandwidth can be obtained with small distances between the fixed radio stations. In radio networks with small zones for the mobile subscriber it must be possible during an established connection to change the radio zone of the fixed stations. In contrast to a radio telephone system using frequency division multiplexing for channel separation this problem can be solved simply with code division multiplexing because the mobile subscriber has neither to change the transmitting and receiving band nor the communication channel.