Dynamic channel selection method for direct spectrum division transmission in CSMA systems

This paper proposes a dynamic channel selection method for direct spectrum division transmission systems, which are autonomous decentralized control systems like CSMA/CA systems, in order to use frequency resources efficiently. In the method each terminal monitors the usage status of the whole system bandwidth, then searches for and memorizes all combinations of currently vacant channels. When the terminal transmits data it selects the combination having the lowest occupancy rate for the transmission. The method´s effectiveness was confirmed in discrete event simulations with probabilistic resource sharing between terminals. The aggregate throughput improvement compared with simple random selection achieved in the simulations ranged between 2.5% and 11%.