Fairness-based joint call admission control for heterogeneous wireless networks: an SMDP approach

In heterogeneous wireless networks, both terminal heterogeneity and network heterogeneity give rise to the fairness problem of resource allocation. Due to the capability of exploiting the resources of multiple networks, the behavior of multi-mode terminals will have a great effect on single-mode terminals, and this influence becomes more severe when considering the different demands of different traffic. In this article, we propose a novel joint call admission control (JCAC) scheme to address this problem. The JCAC problem is modeled as a semi-Markov decision process (SMDP) with the aim of maximizing the average network revenue under the constraints of the fairness among different terminals and traffic classes. Based on the SMDP, we design an algorithm to achieve a good tradeoff between revenue and fairness by dynamically adjusting the threshold of fairness constraints imposed on heterogeneous terminals. Simulation results show that the proposed scheme can significantly improve the fairness among heterogeneous terminals and guarantee the priority and fairness among different traffic classes with little loss of network revenue compared with other schemes.