面向移动目标追踪的无线传感器网络QoS指标体系设计

QoS Framework Design for WSN-Based Tracking of Moving Targets

无线传感器网络(Wireless Sensor Network,WSN)中服务质量(Quality of Service,QoS)的控制目的在于缩减受限资源的开销,它能够最大程度地提高网络的整体性能,延长网络寿命.针对WSN的QoS设计与评价体系因其庞杂的应用场景而难以统一.文中面向移动目标追踪这类特定的应用场合,讨论WSN的QoS指标体系设计.在WSN框架内,现有的面向移动目标追踪的研究更多的是把关注和改进的焦点放在定位和预测的精度上,忽视了由追踪任务本质属性决定的多项必然QoS要求之间的耦合与权衡,单一、片面强调精度的QoS分析对于复杂动态的网络系统来说是欠全面的.文中将基于WSN的移动目标追踪事件按照信息流顺序及数据处理特点,划分成4个任务模块:节点部署、节点选择、数据传输和分布式协作处理算法,并在综合3项QoS指标(即精度、时延、网络生存寿命)的总框架下,依次对各个任务模块中的映射QoS分指标及其支撑架构和现有协议进行阐述,并由此提出基于反馈和跨层设计的QoS保障机制.

As an important resource reservation control mechanism for networks with insufficient capacity, the guarantee of relevant Quality of Service Indicators plays an essential role in both enhancing network performance and prolonging its effective lifetime. Nevertheless, the WSN-specific QoS framework is fundamentally difficult to formulate due to its application-driven nature signifying the fact that QoS requirements vary enormously with different tasks assigned to WSN. Hence, this paper proposes and analyzes the QoS frame work for WSN under the specific scenario of tracking moving targets. Existing literature address mostly how to increase the localization and prediction accuracy while determining the positions of different detected targets before making special tracking strategies. However, the unbalance of the overemphasis on accuracy and the overlook of other equally centrai QoS requirements such as latency can be exparte and devastating for high-order systems with complex dynamics. Therefore, according to the information flow characteristics along the tracking task, the authors divided the task into four consecutive modules, namely sensor deployment, sensor selection, data transmission and distributed collaborative algorithms; and on the whole, and considered three high-level user abstractions of QoS indicators in tracking： accuracy, latency and network lifetime. Further, they seeked to break down those high-level abstractions into each module wherein they propose several related lower-level QoS indicators as well as their supporting technologies and existing protocols to assist the understanding of both general and specific design and evaluation of QoS framework for WSN. Moreover, the authors demonstrate from the global QoS point of view how to guarantee the global QoS by employing feedback control and cross-layer design concepts.