Routing Protocol Of Wireless Multimedia Sensor Networks Based On Service Differentiation

Wireless multimedia sensor network (WMSN) is a novel network emerging based on the development of the wireless sensor network. Wireless multimedia sensor nodes are deployed in unmanned environments to complete the assigned tasks independently, such as sensing, collecting, transmising the richer multimedia information related to audios, videos, images than the traditional wireless sensor. Wireless multimedia sensor network can implement monitoring on fine-grained and accurate information, and has been widely used in visualizations of the battlefield surveillance, environmental monitoring, security surveillance, traffic monitoring, intellectualized home, medical and health areas.Recently, the studies of wireless sensor networks, including wireless multimedia sensor network, has laid emphasis on sensor network routing protocols. Traditional wireless sensor network routing protocols primarily consider how to save the energy consumption in the network. In contrast, WMSN involved in multimedia data, beside the energy issue, should care different application requirements for the network delay and package loss rate, and needs to provide the corresponding mechanism realizing QoS. Therefore, the introduction of QoS to WSN routing protocols is of far-reaching significance. In the thesis, a novel routing protocol based on the classification of services is promoted. The main contributions are listed as follows:(1) Wireless multimedia sensor networks and routing protocol based on the QoS in wireless sensor network are researched. The background and development of WMSNs are introduced, and also the characteristics and requirements of WMSNs routing protocol are analyzed. Besides, the design ideas and working process about routing protocol based on QoS in WSNs are summarized, at last, the existing problems and improvement methods of the main routing protocols based on Qos for WMSN sare pointed out.(2) Reliability and latency, which are the most important services distinction parameters in WMSNs are analysed. Reliability is embodied by the fact that sensing data with high priority is transmitted to the base station with higher probability. The reliability probability that the packets are sent to the base station are usually determined by the packet loss rate of the path from source node to destination node. Latency is embodied that the fact that sensing data with high priority has the less latency. In other words, data packets with low priority select relatively long delay path from the source to the destination node and give way to the packets with high priority.(3) Referring the classical directed diffusion routing protocols, the proposed routing protocols based on QoS in WMSNs include three stages of path set-up,path inquiry and path . The path set-up include two phases of interests diffusion and the gradient establishment. Path set-up is planning to look for a group of paths based on QoS, and it is initiated by the sink, sink broadcast interest data packets periodically and inform all nodes in forward network that it needs to seek the source node information and interested QoS parameters. In the gradients estimation stage, every sensor node builds backward gradients from hop-by-hop and collects the services which are offered in the corresponding link. The paths with the optimal performance are recorded in interest packets. In the path inquriy stage, source node selects the path and transmits the sensing data according to the Qos that the users need. In the path repairement stage, path will be set up again for invalided node.(4) With emulation of improved algorithm, we provide detailed analysis and discussion of emulation results, the simulation results indicate that this new algorithm can achieve lower time delay for real-time traffic than directed diffusion algorithm and improve effective packet transmitting ratio for reliability traffic.