摘要:无线传感器网路集成了传感器、嵌入式计算、网络和无线通信四大技术，是一种无基础设施的新型无线网络，能够实时监测、感知和采集监测对象的各种信息，并将处理后的信息传输至用户手中。无线传感器网络在环境监测、军事战争、空间探索以及商业生活中具有广阔的应用前景，引起了学术界和工业界的高度重视。
本文以此为切入点，对无线传感器网络中的媒体访问控制（Medium Access Control，MAC）进行研究和设计。因为无线传感器网络的网络节点数量庞大，单个节点能量十分有限，因此MAC协议设计的首要目标是降低节点能耗，延长生命周期，并保证传输质量。在比较中外各种协议后，作者对基于时分复用（TDMA）的DMAC协议进行设计和仿真。
无线传感器网络中的传输方式主要是多个感知节点向汇聚节点发送消息，所有传感器节点转发消息，形成以感知节点为叶子节点，以汇聚节点为根节点的数据汇集树。针对这种网络结构采用DMAC协议的交错调度机制来实现消息的时分复用传输，控制节点的休眠和活动状态，从而降低节点能耗。
作者选择OMNeT++为仿真平台，对基于时分复用的DMAC协议进行仿真，并对结果进行分析，证明了此协议确实能够达到无线传感器网络MAC协议设计要求。
关键字：无线传感器网络 媒体介入控制协议 时分复用
Abstract:The Wireless Sensor Network（WSN） is integrated with techniques of Sensor , Embedded computing , Network and Wireless Transmission. It is a new wireless network without base facilities and can be used to real-time monitoring , apperceiving and collecting information from the objects ,then transmit the information to the user. Wireless sensor network in environmental monitoring, military war, space exploration, and commercial life has wide application prospects, attracted the attention of the academia and industry.
Based on this starting point of wireless sensor network, the paper is researching and designing the Media Access Control （MAC） .Because of WSN has huge number of nodes whose energy is very limited, so therefore MAC protocol designing’s main goal is to reduce node energy consumption and prolong life cycle, at the same time ensure transmission quality. Absorbing other protocols’ merits, the author is designing and simulating the DMAC protocol based on TDMA（Time Division Multiple Access）.
WSN transmission is mainly from perception node to the sink node, shaping a data collection tree. Based on the network structure, using scheduling mechanism of DMAC to control node dormant and activities, thus reduce nodes state power consumption.
The authors choose the OMNeT++ IDE as the simulation platform to simulate the DMAC protocol based on TDMA. Then analysing the results, proving this protocol can actually reach MAC protocol design requirements.
Key Words ：WSN DMAC TDMA OMNeT++
