【作者】 朱永红；

【导师】 丁恩杰；

【作者基本信息】 中国矿业大学 ， 通信与信息系统， 2015， 博士

【摘要】 无线多媒体传感器网络(Wireless Multimedia Sensor Network,WMSN)是在无线传感器网络(Wireless Sensor Network,WSN)的基础上发展起来的,除具有传统WSN的能力之外,节点还具有采集多媒体信息(图像、视频、音频等)的能力。和传统WSN一样,WMSN的节点能量和计算能力有限,与传统WSN不同的是,由于网络中传输的多媒体数据需要提供服务质量(QoS)保证,如何在能力有限的网络中传输数据量巨大的多媒体信息并满足服务质量要求,是WMSN面临的主要问题。其中多媒体信息流的路由选择是一个关键问题,它担负着将多媒体数据在满足约束条件的前提下可靠地从源节点传输到目的节点的任务。矿井救灾通信系统是一个基于WMSN的无线通信系统,节点由救援人员或机器人携带进入救灾区,将汇聚节点(Sink)布置在有线网络末端附近,并在前进的过程中根据需要布置无线通信节点,在巷道固定一些多媒体节点来监控巷道中的状况,防止二次事故发生。信息传送至指挥中心后,指挥人员以视频的形式获知灾难现场的情况,发布调度消息,有效地指挥救灾。本文结合WMSN在矿井救灾通信系统中的实际应用,对系统中网络服务质量进行了需求分析,研究了WMSN的路由及与之相关的网络结构和能量空洞问题。主要包括:(1)针对矿井多媒体救灾通信系统实际应用需求,提出采用异构WMSN网络并提出三层网络结构。矿井救灾系统中只有少量节点需要采集多媒体信息,其他节点只负责将采集到得信息进行处理和传输,为了节约成本的同时能提高节点的便携性采用异构WMSN;WMSN中由于传输的数据量较大,通常采用分布式数据压缩技术,针对这个特点,在传统WSN两层网络结构的基础上提出三层网络结构,增加专门负责协作多媒体采集节点完成数据处理任务的协作层。(2)为了解决矿井狭长空间内数据多跳传输产生的延时与多媒体数据实时性要求之间的矛盾问题,提出了粒子群算法(PSO)优化的实时路由算法。矿井救灾系统需要将灾难现场的救援情况实时传输至指挥中心,是一个实时性要求较高的通信系统。而煤矿井下是一个狭长空间,信息传输需要经过的跳数较多,需要解决在节约能耗、提高能量利用率的前提下,数据实时传输的问题。本文提出了WMSN实时路由协议。给路径探测包设置生命周期来保证实时性;作者结合路由优化过程对PSO的运算规则进行了重新定义。(3)为了解决多媒体传感器网络带宽受限难以满足视频流信息的高带宽要求的问题,提出了多种群PSO的WMSN并行多径路由算法。由于网络传输的主要是数据量大的视频流信息,对带宽要求较高,而WMSN带宽受限,当网络带宽不能满足服务质量要求时,需要采用多条路径同时传输。本文针对目前多径路由算法大都是多次运行算法,先后生成多条路径,可能无法找到足够数量路径的情况,提出了多种群PSO的WMSN并行多径路由算法,路由优化过程中信息共享,互相协作,同时生成一组不相交路径。(4)针对WMSN路由研究与仿真的过程中发现的能量空洞问题进行了研究,证明了在异构WMSN中,能量空洞会出现的网络的任何位置,并提出了基于负载均衡的通信节点布局方法。将网络按单跳距离为单位进行分层,考虑节点数据处理和无线收发的能耗,以负载均衡为目标,在每层布局相应数量的节点,避免异构多媒体传感器网络产生能量空洞。其中,重点分析了数据处理能耗对节点布局的影响。更多还原

【Abstract】 Wireless multimedia sensor network is developed on the basis of the wireless sensor network. The same as the traditional wireless sensor network, the energy of node and the capability in multimedia sensor network is limited, however, the transmission of multimedia data needs to certain guarantee of QoS the network provides, and it’s the major issue in wireless sensor network that how to transmit multimedia information with huge amount of data and satisfy the requirement of QoS in the network of limited capability. Among them, it’s the key problem to choose the route of the multimedia stream of information, and it burdens the task that transmits multimedia data from source node to node of destination reliably in a certain constrained conditionThe thesis combines with practical application of the mine rescue system based on wireless multimedia sensor network, analyzing the requirement of QoS in the network, doing some research in the issue of route of wireless multimedia sensor network. The main task of this thesis includes:(1)Heterogeneous multimedia sensor network is put forward to the practical application requirement of mine rescue system and we propose the three-layer network structure. Using heterogeneous networks consisting by different nodes can save costs and improve the portability of the nodes as only a few nodes in the mine rescue system need to collect the multimedia information, the other nodes will only be responsible for data processing and transmitting the information. Distributed data compression technology is usually used in wireless multimedia sensor networks. The three layer network architecture is proposed Increasing the collaboration layer that are specifically responsible for collaborative multimedia multimedia nodes to complete data processing tasks based on two layer network architecture.(2)The real-time routing algorithm optimized with Particle Swarm Optimization(PSO)is proposed, which solves the contradiction between the time delay of data multi hop transmission and real-time requirements of multimedia data. mine rescue system is a real-time communication system but the information transmitted by Multiple hops transmission as the coal mine is a long and narrow space. Data realtime transmission problem Need to be solved on the premise of saving energy consumption, improve energy utilization. The real-time routing algorithm is proposed wich set life cycle for the path detection package to ensure real-time performance. PSO algorithm is redefined Based on the routing optimization process(3)A parallel multi-path routing algorithm for WMSN optimized with multipopulation PSO is proposed in order to solve the contradiction between Bandwidth requirements of multimedia transmission and the bandwidth limitation of WMSN. As the network transmission is mainly streaming video information wich demands higher bandwidth, while the bandwidth of WMSN is limited, when bandwidth can not meet the requirement of the quality of service, to transmit data with multiple paths at the same time is valid. At present, the multipath routing algorithm may not be able to find enough paths because they are mostly run the algorithm multiple times to find the paths one after another. We propose multi-path routing algorithm for WMSN based on multi-population PSO that can find multiple paths in a time by information sharing and cooperation in route optimization process.(4)We prove that the energy hole problem would appear in any position in heterogeneous Wireless Multimedia Sensor Networks and propose a method of the node distribution based on load balancing to solve the problem. The network is stratified by single hop distance and corresponding number of node being distributed in different regions considering the data compression ratio and the energy consumed for data transmission and processing. We also discuss and prove that in heterogeneous WMSNs the energy consumption of data processing will affect the node distribution.更多还原