A Probabilistic Retransmission Algorithm With Link-state-dependent Packet Scheduling In Wireless Networks

The wireless networks take great changes with the rapid development of the times. They have already become the essential parts of people’s life and production. However, the wireless communication,as one of the fastest growing communication technologies, the issues that how to guarantee the quality of service(Qo S) of the wireless network to meet the different service requirements and get down to considering the reliability as well as the actual real-time problems, which make the research for the Qo S of the wireless networks much more necessary.A good packet scheduling algorithm in wireless networks can greatly affect the performance of the whole wireless network. For studying the scheduling strategies, the strategies need to be analyzed in combination with the actual characteristics of wireless networks:(1) Dependence of geographical factors.(2) Burst of the channel error.(3) Lower bandwidth of the wireless network and the changing capacity of the WALN with time. All these wireless network inherent characteristics make the wireless environment unstable. That the so called HOL problem occurs frequently is because of the unstable state of the link. So, the wireless scheduling cannot work efficiently by means of the developed wired scheduling algorithms. In view of this situation, This paper proposes a new probabilistic retransmission method to solve this problem.The new method has the characteristics listed:(1) Both the state of the link and the congestion degree of the queue are all considered.(2) The proposed link estimation method is used to deal with the state of the link.(3) The improved retransmission scheduling method works with the probabilistic view. Finally,The simulation results show that the proposed algorithm can remove the packets from the bottleneck node, improve the throughput of the networks,and avoid the bad influences happened by the packet backlog.