【作者】 方世；

【导师】 林亚平；

【作者基本信息】 湖南大学 ， 通信与信息系统， 2008， 硕士

【摘要】 随着无线传感器网络的广泛应用,提高网络的能量有效性成为无线传感器网络设计和研究的关键,MAC协议对网络能量有效性有重要影响。网络仿真作为一种实验手段,在无线传感器网络研究中发挥着至关重要的作用。当实验设备、节点功能、部署环境、网络规模等因素不能满足研究课题所需的条件时,仿真能为我们提供强有力的帮助和研究支撑。本文主要从基于异步通信模式的MAC协议和仿真系统的开发展开研究,主要工作如下:一、以低功耗异步通信模块硬件构架的可行性为基础,提出异步通信模式的概念。针对异步模式可能带来的对于传感器网络各层协议及整体性能的影响,设计了一种采用周期性唤醒/睡眠、局部时钟同步、交互确认ACK等机制的异步MAC协议。其中根据传感器网络内数据的相关性和实际网络需求,设计了顺序唤醒和交错唤醒两种不同的机制。通过系统仿真,验证该协议能在低速率网络场景中获取高能量有效性。二、结合传感器网络的独特需求,设计开发了一个适用于传感器网络研究的仿真系统。该系统以C++为底层语言,增强了系统仿真效率,提高了网络仿真规模;采用层结构,以实现单个传感器节点的分层和各层功能行为定义,节点各层的相互独立使模块代码复用率大大提高;该系统集成了传感器网络能耗、时延和丢包统计模型,并采用后台数据库支持技术,增强了仿真实验的数据储存和处理能力;支持配置文件和仿真文件的脱平台运行,具有很好的可移植性。最后通过三个仿真实例验证了该系统具有建模快、重构有效、功能完整、真实可靠的特点。更多还原

【Abstract】 As the extensive application of wireless sensor networks, improving the energy-validity of networks has been crucial to the research and design of wireless sensor networks. The MAC protcol also takes an important part in this area. As an experimental method, networks simulation plays an very important role in the research on wireless sensors networks. It can provide powerful supports on research, when some experimental condition can not meet because of the equipment, the node function, the deployment environment and the networks scale etc. This paper mainly opens out the research based on the MAC protocol of the asynchronous communication mode and the development of simulaton system, with the follow production:Firstly, this paper proposes a concept of asynchronous communicaton mode, based on the feasibility of low-power asynchronous communicaton module. In allusion to the possible effects on each-layer protocol and global performance of wireless sensors networks from the asynchronous mode, it has designed an asynchronous MAC protocol using peridical awake-sleep, partial time-synchronization and interactive-confirmation ACK mechanism etc. Then based on the data-correlation and actual-demand of wireless sensors networks, the peridical awake-sleep mechanism mainly include two different kinds of mechanism, which are sequential-awake and interleaving-awake. With the system simulation, experimental results show that the MAC mechanism is good at energy-saving in the low-ratio scene .Secondly, it has designed and developed a suitable simulation system for wireless sensors networks in order to meet its special demands. This system adopts C++ as programming language, which improves the simulation efficency and the network scale on simulation. It also adopts layer structure to implement the single node layered and define the function behaviors on each layer. In this system, one layer is independent from each other in order to improve the reuse rate of the module code. In addition, it integrates energy-consumption, time-delay, packet-loss models and adopts database as a backstage supporter to strengthen simulation function and capability of storaging and processing experimental data. If providing the configuration file, We can simulate without the platform, improving the portabillity. Finally, the results of three simulation experiments show that the system is a good experimental platform for WSNs, with the feature of modeling fast, remodeling effectively, complete function and more reliable experimental data.更多还原