An Enhanced Dynamic Priority Packet Scheduling Algorithm in Wireless Sensor Networks

摘要

Recently, many application scenarios like military surveillance, infrastructure protection and environmental monitoring have been accomplished by wireless sensor networks (WSNs). In some cases, applications in WSNs are time restricted, leading to the need of real-time scheduling of data packets. Nowadays, many communication package schedule policies in WSNs apply algorithms in view of First-Come-First-Served (FCFS). However, there are many problems in FCFS, including node-to-node communication packages transport delay as well as starvation in real-time packages. Besides, these schemes cannot respond dynamic inputs quickly. To solve these problems, this paper provides an enhanced dynamic priority packet scheduling algorithm. In the proposed algorithm, there are three different kinds of priority ready queues in every sensor node. Higher priority queue stores real-time communication packages, while middle priority queue stores non-real time data packets which need to be forwarded to other nodes, and lower priority queue stores non-real time packages whose destination is local node. Besides, if non-real time data packets are processing, real-time packets can preempt the usage rights of hardware resource. The scheduling sequence in higher priority is based on the priority of packets, still scheduling sequence in the other queues is FCFS. At last, simulation results illustrate that the proposed scheduling algorithm is better than FCFS and dynamic multilevel queue scheduling scheme when it comes to node-to-node communication packages transport delay.