Y. Jiao’s research while affiliated with Xidian University and other places

For efficient network resources dispatching in heterogeneous wireless network scenarios, a Quality of Service (QoS) aware load-balancing algorithm was proposed. Based on the characteristics of different wireless services, the algorithm defines a utility function for each terminal to represent its QoS experience and a utility function for each Radio Access Network (RAN) to represent its load level. The definitions apply to all heterogeneous RANs. The algorithm conducts an iterative load-balancing procedure, where it always tries to handover a terminal, which is with low QoS utility and resource utilization served by the busiest RAN, to another RAN, which has the lightest load among the RANs. This RAN with the lightest load is capable of increasing the terminal's QoS utility, until network load balance is reached. Such a procedure can help to realize better wireless resource deployment and ensure terminal QoS. Simulation results show that the proposed algorithm can effectively increase the throughput, reduce the time-delay and packet loss rate of the network.

Due to the complicated architecture of the mesh mode in WiMAX networks, resource scheduling is a significant but difficult problem. Appropriate resource scheduling scheme is capable of improving the network capacity. This work, based on an odd-even layered architecture, proposes a cross-layer resource scheduling scheme. The proposed scheme operates at medium access control (MAC) layer and physical (PHY) layer. At MAC layer, a hierarchical bandwidth allocation algorithm is designed to enhance concurrent transmissions and thus the network throughput. At PHY layer, a power control algorithm is derived to reduce interferences and meet the demands of links at different layers. Experimental results validate the availability and effectiveness in terms of resource utilization and network throughput.

Quality of service (QoS) is a critical issue in the design and management of worldwide interoperability for microwave access (WIMAX) networks. In this study, the authors propose a novel two-tier QoS framework and a scheduling scheme for QoS provisioning in WiMAX networks based on the Nash bargaining solution (NBS) obtained from cooperative game theory. The framework cannot only offer Pareto optimality for the entire system, but also assure fairness for each service and connection. They apply the NBS into the issue of QoS service in WiMAX networks. They utilise the equivalent optimisation problem to obtain the bargaining point. The parameters of the optimisation model have been verified by analysing the characteristics of each service flow in the WiMAX networks. A heuristic scheduling algorithm has been designed to implement the optimised solution. The effectiveness of the proposal has been verified by experimental results, which can show much better performance in terms of delay, loss rate and throughput.