【作者】 刘晓杰；

【导师】 何迪；

【作者基本信息】 上海交通大学 ， 通信与信息系统， 2008， 硕士

【摘要】 集成了传感器、嵌入式计算、网络和无线通信四大技术而形成的无线传感器网络是一种全新的信息获取和处理技术,它是一种新型的无基础设施的无线网络,能够协作地实时监测、感知和采集各种环境或监测对象的信息,并对其进行处理,传送到需要这些信息的用户。无线传感器网络是一种新型的应用型网络,具有十分广阔的应用前景,引起了学术界和工业界的高度重视,成为当前热门的研究领域。美国《技术评论》杂志把无线传感器网被列为未来十项新兴技术之首。《IEEE?Spectrum》杂志预计无线传感器网络的发展和广泛应用,将对人们的社会生活和产业变革带来极大的影响和产生巨大的推动。?无线传感器网络因为不依赖于固定的基础设施,所以网络节点要求具有自组织的能力。一个节点进入工作区域之后,它只能依赖于MAC层和物理层所能提供的有限的机制获得周围的一跳(one‐hop)邻居的信息,对全网的拓扑结构信息将一无所知。这时候需要有一个算法将这些分散的节点有效地组织起来,协调一致来完成某一个特定的任务。在此之上,各种路由协议、传输层协议以及应用程序才能正常运作。也就是说,需要有一个网络协议为上层结构服务,而构成整个无线传感器网络结构基石的就是MAC层协议。本文从无线传感器网络MAC协议角度出发,进行了如下研究:第一部分,分析了无线传感器网络的特点和当前无线传感器网络的研究方向。第二部分,介绍了无线传感器网络的MAC协议及当前的研究现状,分析了无线传感器网络协议和传统网络协议在设计上的不同点,对已有的MAC协议进行分类,并注重分析了基于竞争的MAC层协议,为设计新的MAC协议打下坚实的基础。第三部分,引入了功率控制的思想,功率控制机制成熟于CDMA系统,随着无线传感器网络的MAC协议的研究,人们发现功率控制机制在无线传感器网络中大有可为,特别是节省能耗的特点,这部分重点介绍了在Ad hoc和WSN中已有的MAC协议。第四部分,提出了一种基于功率控制机制的无线传感器网络MAC协议Distance Prediction Power Control MAC (DPPC-MAC)。DPPC-MAC协议基于目前十分成熟的SMAC协议,引入了功率控制机制以降低数据包发送时的能耗,并且提出了一种新的通过功率预测距离来解决暴露终端和隐藏终端的方法。仿真结果表明,DPPC-MAC能有效降低网络能耗,同时吞吐量性能也得到了一定的改善。在最后部分,总结了全文,展望了未来的研究方向。更多还原

【Abstract】 Wireless Sensor Network (WSN), which is made by the convergence of sensor, embedded computation, networks and wireless communication technologies, is a novel technology for acquiring and processing information. It is a late-model wireless networks of infrastructureless network and can be used for testing, sensing, collecting and processing information of monitored objects. Wireless sensor networks becomes a new research area and has a bright future in application. Both academia and industries are very interested in it. Wireless sensor networks are listed by in 10 emerging technologies which will change the world by“Technology Review”.“IEEE Spectrum”also expects that WSN will make a huge influence on people’s lives.Since WSN don’t rely on any infrastructure, self-organization algorithms are indispensible. When a sensor node enters the working region, it acquires nothing but one-hop neighborhood information via MAC and physical layer protocols. It is impossible to get the topology information about the whole network. Network algorithms effectively organize sensor nodes and take advantage of cooperative effort of sensor nodes to fulfill a specific task. The implementation of routing algorithms, transport protocols and applications is based on MAC protocol algorithms.In the four parts of the thesis,we conduct a deeply research on wireless sensor network MAC protocol:In the first part of the work, we propose the difference between WSN and traditional networks, not only given the characteristic of WSN, we also have illustrate the research orientation in this area. In the second part, the existing MAC protocols are classified and both the advantages and disadvantages are analyzed, we mainly focus on the analysis of the contend based MAC protocols, and have a deeply insight of SMAC and TMAC, which are the most important protocols nowadays.In the third part, we introduce the Power Control mechanism, it is matured in CDMA system,While researchers have found its potential in WSN area, and we also discuss several important power control protocolsIn the fourth part, a power control MAC protocol (DPPC-MAC) for wireless sensor networks is proposed. The new protocol is based on SMAC,and introduces power control mechanism for energy saving. The main contribution of our work is to propose a new approach—distance prediction algorithm—for determining the transmission power to preserve the collision, increase goodput and solve hidden/exposure terminal problem. Simulation results show that DPPC-MAC can provide better energy efficiency and throughput than current important protocols.At the last part of this dissertation, the whole work of the dissertation is outlined and the further research issues are discussed.更多还原