Max-min fairness based radio resource management in fourth generation heterogeneous networks

In the heterogeneous networks, radio resource management (RRM) plays an important role to utilize the potential network diversity. In this paper, we study the RRM strategy in the heterogeneous networks involved with an orthogonal frequency division multiple access (OFDMA) network, with the aim of maximizing the minimum user throughput. An analytical model which reflects the feature of heterogeneous networks is presented in order to formulate the RRM problem. Assuming that the system can support multi-homing access and the subcarrier can be shared by multiple users in the OFDMA network, the problem can be formulated by a convex optimization problem and the optimal solution is obtained. We also propose a suboptimal RRM algorithm for practical applications, including network selection and resource allocation in each network. The performance of the proposed RRM algorithms is evaluated in the heterogeneous long term evolution (LTE)-wireless local area network (WLAN) networks. Our simulation results show considerable gains in comparison to the performance of LTE-Only and WLAN-First strategies. In addition, the performance gap between the optimal solution and suboptimal algorithm becomes minor as the number of users increases.