OPTIMIZING FAIRNESS AND EFFICIENCY IN MULTICASTING FOR MULTICARRIER WIRELESS CELLULAR NETWORKS: A UTILITY-BASED APPROACH

Broadcasting huge amounts of common data to many mobile users at once via multicast is seen to be an effective method for wireless cellular networks. For this type of single-hop multicasting, the base-station transmitter often modifies its data rate to the worst channel condition across all users in a multicast group to guarantee the quality of service for every mobile user. On the one hand, adding users to a multicast group results in a more effective use of spectrum bandwidth since users within the same group may be serviced simultaneously. As opposed to that, an excessive number of users in a group may cause the base station to transmit data at an unacceptablely low pace. The challenge of how to effectively and equitably convey to many consumers who need the same message therefore naturally emerges. This research looks at the multicasting across many carriers issue in wireless orthogonal frequency division multiplexing cellular networks in an effort to provide an answer to that challenge. We study this issue in two common situations—namely, when users suffer nearly equal path losses and when they experience varied path losses, respectively—using a unified utility maximisation paradigm. Through theoretical research, we find the best multicast techniques for these two scenarios that fulfil different throughput-fairness demands. In particular, we demonstrate that regardless of the utility function used, the traditional multicast strategy is best in the equal-path-loss condition. When users encounter varied route losses, the group multicast scheme—which splits users approximately equally into several multicast groups and multicasts to various groups of users over nonoverlapping subcarriers—is the best option.