Patent ID: 8681765

Claim:
An apparatus to control an access mode of a communication system that uses an unlicensed band or a shared band, the apparatus: recognizes a usage rate of the unlicensed band or the shared band that is used by an adjacent communication system of a target communication system; determines, as an access mode, any one of a contention access mode and a contention-free access mode, by comparing the usage rate of the unlicensed band or the shared band with a reference value; and transmits mode information associated with the determined access mode to member nodes or a base station of the target communication system; updates the usage rate of the unlicensed band or the shared band at least once in a time slot when the target communication system operates in the contention-free access mode or the contention access mode; determines whether to change the access mode based on the updated usage rate; determines whether a random access mode is appropriate for the access mode based on at least one of a length of a transmission message and a delay requirement of the transmission message; and determines, as the access mode, any one of the random access mode, a Carrier Sense Multiple Access/Collision Avoidance (CSMA/CA) mode, and the contention-free access mode based on the usage rate of the unlicensed band or the shared band.