OFFICE-PURPOSE DIGITAL CORDLESS TELEPHONE SYSTEM, INTERFERENCE AVOIDANCE METHOD, AND NONTEMPORARY COMPUTER READABLE MEDIUM ON WHICH INTERFERENCE AVOIDANCE PROGRAM HAS BEEN STORED

Provided is a digital cordless telephone system for business use that can avoid radio wave interference with a communication channel of PHS system by another type of radio system. A carrier sense unit (121) of a PHS base station (12) periodically carrier-senses nearby radio waves and monitors whether radio wave interferences with a communication channel to be used for communication with a PHS terminal (13) is occurring. A communication channel management unit (122) ranks communication channels to be used for communication with the PHS terminal (13) based on a monitoring result by the carrier sense unit (121). When a request for acquiring or a request for switching to a communication channel to be used for communication with the PHS terminal (13) is made, a communication channel switching control unit (123) preferentially selects and allocates a communication channel ranked high as a communication channel where radio wave interference is not occurring from among usable communication channels ranked and managed by the communication channel management unit (122).