Bandwidth Allocation And Call Admission Control Mechanism In Heterogeneous Wireless Network

With the rapid development of wireless communication technology, several kinds of Radio Access Technology have been flooding into the market. All kinds of Radio Access Technology have their own characteristics in terms of coverage and resource management. However, any kind of Radio Access Technology can’t meet all needs of users. In order to achieve the best quality of service and realize the connectivity between different networks and seamless access between different access networks, the integration of heterogeneous wireless network has become the inevitable trend of next generation network.The integration of heterogeneous wireless network is a complex project, it involves the architecture of integration, mobility management technology and wireless resource management. It’s a collection of networks, which are based on different kinds of standards. To realize joint radio resource management between different networks, we need the coordination mechanism, which includes the integration architecture、 joint bandwidth allocation 、joint call admission control and so on.First, this paper analyzes typical integration architecture in heterogeneous wireless networks, such as loose coupled network architecture and tightly coupled network architecture, which will not change the existing network architecture. Then this paper does some research on heterogeneous wireless mesh heterogeneous network for the integration and proposes a routing protocol based on channel selection in the network to reduce the routing overhead.Then, this paper proposed a bandwidth allocation algorithm in the heterogeneous networks with multiple users and multiple services scenarios. First, it introduces a utility function which will indicate the utility of services with different allocated bandwidth. Then, Network will allocate bandwidth to users in order to achieve the most benefit.Besides, we will take the call admission control process into consideration with the bandwidth allocation algorithm together. This paper builds the optimization model of network utility function, the proposed algorithm can achieve the maximum benefit of the whole heterogeneous network. Simulation results show that the proposed algorithm can increase the total utility of heterogeneous network, ensure the user fairness and satisfaction in the process of bandwidth allocation.Finally, this paper proposed a session splitting- based joint call admission control algorithm in a heterogeneous wireless network combined of WLAN and 3G. The packet stream is split and admitted into multiple radio access networks when none of the availa ble individual radio access technologies have enough bandwidth to support the incoming call, at the receiver, the split packet stream are combined, which aims to access more call request as far as possible to improve the whole throughput in the system. Then multidimensional Markov chain model is used to simulate the process of joint call admission control and analyze the new call blocking probability and handoff call dropping probability of the proposed algorithm. Simulation result s show that the proposed algorithm can reduce call blocking/dropping probability and improve the utility of networks when networks are almost at full capacity.