无线自组织网络中时空相变行为的分析与预测

项目名称： 无线自组织网络中时空相变行为的分析与预测

项目编号： No.61004100

项目类型： 青年科学基金项目

立项/批准年度： 2011

项目学科： 无线电电子学、电信技术

项目作者： 张伟

作者单位： 同济大学

项目金额： 7万元

中文摘要： 相变是自然界中普遍存在的一种物理现象，相变的发生意味着系统从一个相对稳定的性态切换为另外一个相对稳定的性态。本项目中网络相变特指通信网中的相变，特别是在以多跳传输为特征的无线Ad hoc网及其特例无线传感器网中。在各种网络行为中，拥塞可认为是宏观尺度上大规模网络相变的一种体现，它使得网络传输性能突变并严重影响整个网络的运行平稳性和服务质量。本项目采用了拟真和实测两条技术路线，获取网络行为数据，并在数据基础上探查网络拥塞和网络相变现象。其中，在拟真路线中，开发了大规模网络仿真程序，获得了网络行为数据，并得出网络在其负荷为网络缓冲容量的一半时网络处于状态转换的临界点以及此时效率最高的结论。在实测路线中，设计开发了可运行于嵌入式芯片中的传感器操作系统平台并进一步在此基础上实现了基于RS485总线的分布式网络嗅探器系统，以在网络宏观全局层面实现对网络行为的测量。已有的进展说明了上述路线的有效性。

中文关键词： 无线传感器网络; 网络相变; 网络测量; 相变预测; 自组织网络

英文摘要： Phase transition is a common phenomenon in nature. It means the system switches from one stable state into another stable state. It has been also found in computer communication networks in particular the multi-hop wireless ad hoc network such as sensor network. Network congestion observed can be regarded as a kind of large scale phase transition. It causes the abrupt changes of service quality and affects the smoothness of communication greatly. This project adopts two technical routes: computer simulation and real network test bed with monitoring. Based on the simulation mimicking the mechanism of real packet switch networks, we found that the network reaches its peak performance and throughput when the traffic load is half percent of total network buffering capacity. And this point is also a transition point from light sparse state to heavy congestion state. Beside this, an embedded operating system openwsn is also developed to help instrumenting real networks and test-bed. A distributed sniffer network is established by using openwsn software and RS485 industry bus.in order to monitoring a target ad hoc network at the macro-scope level. The current approach and the prototype shows the effectiveness of this solution.

英文关键词： wireless sensor networks; network phase transition; network measurement; phase transition prediction; ad hoc network