[论文解读] Sensors Lifetime Enhancement Techniques in Wireless Sensor Networks - A Survey

Sami Halawani, Abdul Waheed Khan|arXiv (Cornell University)|May 21, 2010

Energy Efficient Wireless Sensor Networks参考文献 24被引用 40

一句话总结

本综述识别并评估了无线传感器网络（WSNs）中的节能MAC和路由协议，以延长传感器和网络的寿命。通过聚焦于数据为中心和分层路由，以及基于调度和竞争的MAC协议，本文表明，通过优化通信能耗——尤其是减少碰撞和重传——可显著延长能量受限环境下的网络运行时间。

ABSTRACT

Wireless Sensor Networks are basically used for gathering information needed by smart environments but they are particularly useful in unattended situations where terrain, climate and other environmental constraints may hinder in the deployment of wired/conventional networks. Unlike traditional networks, these sensor networks do not have a continuous power supply at their disposal. Rather the individual sensors are battery operated and the lifetime of the individual sensors and thus the overall network depend heavily on duty cycle of these sensors. Analysis on WSNs shows that communication module is the main part which consumes most of the sensor energy and that is why energy conservation is the major optimization goal. Since routing protocols and MAC protocols directly access the communication module therefore the design of protocols in these two domains should take into account the energy conservation goal. In this paper, we discuss different state-of-the-art protocols both in MAC and routing domains that have been proposed for WSNs to achieve the overall goal of prolonging the network lifetime. The routing protocols in WSNs are generally categorized into three groups - data centric, hierarchical and location-based but we focus on only the first two categories because location-based routing protocols generally require a prior knowledge about sensors location which most of the times is not available due to random deployment of the sensors. We then discuss how schedule-based and contention-based MAC protocols can contribute to achieve optimal utilization of the limited energy resource by avoiding or reducing the chances of collisions and thus the need for retransmission.

研究动机与目标

• 解决无线传感器网络（WSNs）中传感器在无持续电源供应下运行的电池寿命有限的挑战。
• 将能量消耗识别为主要瓶颈，其中通信模块是最大的能耗来源。
• 聚焦于MAC和路由层的协议设计，以实现节能并延长网络寿命。
• 评估数据为中心和分层路由类别中的最新协议，排除因部署不切实际而不可行的位置相关协议。
• 分析基于调度和竞争的MAC协议如何通过避免碰撞和高效介质访问来减少能量浪费。

提出的方法

• 将路由协议分类为数据为中心、分层和基于位置的类型，重点强调前两种，因其部署可行性更高。
• 研究基于数据内容而非预定义路径转发数据的数据为中心路由协议。
• 分析将传感器组织为簇并由簇头管理以减少冗余传输的分层路由协议。
• 回顾通过为节点分配时隙以避免碰撞并减少空闲监听的基于调度的MAC协议。
• 评估S-MAC和T-MAC等竞争型MAC协议，其通过载波侦测和周期性休眠来最小化能耗。
• 评估优先考虑MAC和路由层能量效率的协议设计原则，以减少网络整体能耗。

实验结果

研究问题

• RQ1 通信模块在WSNs中如何导致能量消耗？哪些协议可缓解此问题？
• RQ2 在能量效率方面，数据为中心和分层路由协议的关键差异和权衡是什么？
• RQ3 基于调度和竞争的MAC协议以何种方式减少WSNs中的能量浪费？
• RQ4 为何基于位置的路由协议在现实WSNs的随机传感器部署中适用性较低？
• RQ5 MAC和路由层的协议级优化如何共同延长WSNs的运行寿命？

主要发现

• 通信模块是WSNs中主要的能量消耗源，因此在MAC和路由协议中实现节能对延长网络寿命至关重要。
• 与基于位置的协议相比，数据为中心和分层路由协议在随机部署中更具适用性，因其对位置信息的依赖较低。
• 基于调度的MAC协议通过时分多址接入消除空闲监听和碰撞解决，从而减少能耗。
• 如S-MAC和T-MAC等竞争型MAC协议通过实现周期性休眠和减少不必要的传输，提高了能量效率。
• 在MAC和路由层进行最优协议设计，可通过最小化重传和空闲状态显著延长网络寿命。
• 在多个层面上集成能量感知协议对于在能量受限的WSNs中实现可持续运行至关重要。