An adaptive ISMA-DS/CDMA MAC protocol for third-generation mobile communications systems

摘要

In this paper, an inhibit sense multiple access–direct sequence/code division multiple access (ISMA-DS/CDMA)\udmedium access control protocol for a packet transmission mobile\udradio network is presented. The main feature of this protocol\udis its ability to retain the inherent flexibility of random access\udprotocols while at the same time reducing to some extent the\udrandomness in the access in order to increase the system capacity.\udIn this framework, the protocol is presented together with some\udadaptive mechanisms that improve the protocol performance by\udmeans of regulating the access and varying the transmission bit\udrate according to the channel load that is broadcast by the base\udstation. As a result, an adaptive bit rate algorithm is presented\udthat reaches a throughput value close to the theoretical maximum.