Patent ID: 7315524

Claim:
A master station used in a communication system including at least one slave station in a system environment in which the communication system and a plurality of other communication systems share a same channel, each of the other communication systems comprising a respective other master station and at least one slave station, said master station comprising: a communication section for dividing a first communication bandwidth into a beacon period in which said master station and all other master stations compete for transmission of a beacon packet, a first carrier sense multiple access (CSMA) period in which only authorized specific stations are allowed to compete for access, and a second CSMA period in which all stations are allowed to compete for access, and repeatedly communicating on a periodic basis; an acquisition section for acquiring a status of use of communication bandwidths in the other communication systems; and a determination section for calculating a second communication bandwidth available in the communication system to which said master station belongs, in the first CSMA period, based on the status of use of the communication bandwidths in the other communication systems acquired by the acquisition section, and determining whether communication requested by a slave station of the communication system to which said master station belongs is accepted or rejected in accordance with the calculated second communication bandwidth; wherein the beacon packet includes system information providing at least a start time of the beacon period and a transmission time of the beacon packet in accordance with a timer value of the master station transmitting the beacon packet.