无线传感器网络的多对一通信方式、无线链路的相互干扰、网络的动态变化和资源受限等特性,使得无线传感器网络容易出现拥塞,严重影响网络的QoS传输性能和生存周期,因此拥塞控制成为无线传感器网络服务质量保障机制的关键技术之一.在分析无线传感器网络特,点的基础上,说明了拥塞检测和拥塞避免的策略,重点介绍和分析了基于速率控制、流量调度和传输调度等典型的拥塞解除算法,最后对拥塞控制技术的发展趋势进行了展望.
In wireless sensor networks (WSNs), the many-to-one communication mode, mutual interference of wireless links, dynamic changes of network topology and the memory-restrained characteristic of node, all make network more vulnerable to congestion. Since network congestion may deteriorate the transmitting performance and network lifetime, congestion control has become one of the most important technologies to decrease such impact and guarantee the network quality of service (QoS). Because the energy supply, computational power and wireless communication capabilities of sensor nodes are all limited and the network scale is always very large, higher requirements are imposed on the congestion control technology and researches on congestion avoidance and congestion release are more challengeable. This paper is a survey of congestion control technology for wireless sensor networks. In this paper, the main characteristics of wireless sensor networks, and causes and damages of network congestion are presented, and then three kinds of congestion detection strategies based on data buffer length, wireless channel sampling and data transmitting rate, and two kinds of congestion avoidance mechanisms based on data rate allocation and buffer announcement are introduced. The classical congestion release algorithms based on rate control, flow schedule and transport schedule are analyzed, and finally the development trend and future prospect of congestion control technology for wireless sensor networks are presented.