Patent ID: 7953105

Claim:
A communication apparatus belonging to a first communication system, among a plurality of communication systems which coexist on a same communication medium by time division communication using communication slots, the communications apparatus comprising: a controller for managing the communication slots necessary for the first communication system; a communication manager for managing transmission times of data communication performed by all communication modems in the plurality of communication systems in cooperation with the controller, and the communication slots used for data communication; a command generator for generating a request command which requests use of a communication slot necessary for the first communication system, in accordance with an instruction of the communication manager; a transmitter for transmitting the request command generated by the command generator, to a second communication system among the plurality of communication systems; a receiver for receiving the request command representing a request for use of the communication slot, from a second communication apparatus belonging to the second communication system among the plurality of communication systems; and a communication manager for freeing at least half of the communication slots, when the request command is received from the second communication apparatus in a state where an entirety of the communication slots which can be used are used.