Rate Allocation Based on Coalition Formation Game in Low Power Collaborative Transmission

To realize collaborative transmission in wireless overlay access networks, the question of rate allocation arises as how to divide the traffic flow among heterogeneous networks. Different networks role as game players and they try to transmit the traffic flow by a cooperative method. Power costs and transmission capabilities in heterogeneous networks are different according to terminal position, network load etc, so the grand coalition is not always beneficial and the coalition structure should be adjusted in time. With the power cost introduced in the utility function, the rate allocation is formulated in a coalition formation game framework in the paper. The stable coalition structure is formed with the merge-and-split rule, then the utility is distributed to different players and the transmission rates in different networks are determined. Such a process continues until the end of the traffic transmission. The theoretical and experimental results are presented to validate our proposed method. Compared with the Nash Bargaining Solution and the Shapley value, the coalition structure can be adjusted with the terminal position through the new scheme and then the highest coalition utility can be obtained with low power cost. Moreover, the proposed method turns to be the bargaining game framework if the power cost is not considered.