Network Selection Policy Based On Network Coding In Heterogeneous Wireless Networks

The integration of heterogeneous wireless networks is the inevitable development trend of next generation mobile communication. The handoff management is an important part of mobility management, and network selection policy that serves as a link between past and future is the key factors affecting the handoff quality. On the other hand, network coding can reduce the number of retransmissions and improve the bandwidth efficiency of wireless broadcasting. Combining the network selection with network coding can play the advantages of both and provide more fast and reliable network services. We analyze the application of network coding in the network selection techniques, which has an important significance.For single user network selection, we propose a fast network selection policy based on network coding in broadcast environment. Because the computational complexity of the optimal network-coding-based network selection is too high to be used in practice, we use the central limit theorem and the estimation algorithm to simplify the computation, and to ensure the accuracy of network selection. The simulation results show that the performance of our proposed policy is very close to the optimal approach based on network coding, but much faster. And our policy has a higher transmission rate compared with existing approaches.For the group mobility scene, we propose a group network selection policy based on network coding in unicast environment. Because group users usually stay together and network coding can reduce the number of retransmissions, we deduce the formula of the application of network coding in the group network selection. Besides, we use a centralized network selection to avoid the problem of information asymmetry, and solve the best solution according to the principle of integer programming. The simulation results show that our proposed policy can get a smaller average transmission delay compared with the group network selection based on channel condition.