Research On QOS Of Wireless Multimedia Sensor Networks

For wireless multimedia sensor networks (WMSNs), the quality of multimediainformation transmission is, in general, affected by the compression coding, networkparameters and network status among other factors. Firstly, according to the featuresof multi-hop for WMSNs, this paper establishes an assessment model based on QoSindicators and achieves a multi-hop video transmission in NS2simulation platform.And then we analyze the impact on quality of multimedia information transmissionof quantitative parameters, GOP type, packet length and packet error rate on thebasis of the NS2-myEvalvid model by comparing the PSRN value. Secondly, basedon the characters of multimedia sensor networks, such as real-time working andtolerant of loss, and the problem that if sensor nodes are densely deployed orrandomly distributed, the channels will compete with each other and interruptionsoccur, this paper analyzes and evaluates the network performance in differentinterference cases by adjusting the number and rate of interference flow.Since the significant feature of WMSNs is with large amount of data and high datatransfer rate, it is necessary to design a real-time, reliable transport layer protocolwith congestion control mechanism. At last, this paper proposes a congestion controlalgorithm called SCATP (sensor networks congestion avoidance algorithm based ontraffic prediction).That algorithm can solve the unique problem of WMSNs: thenetwork congestion because of the many-to-one and multi-hop communication. Forthe purpose of congestion control and reliable data transmission, this algorithm usesARMA model to analyze the current flow through each node and to predict thecongestion condition, and then allocates traffic. The simulation experiment resultsshow that SCATP can improve network quality of service in aspects of delay, jitter,throughput, energy efficiency. What is more, when the compression quantizationparameters and packet error rate value are decreased, the quality of multimediainformation transmission is improved. In addition, the effect of the compressionquantization parameter tends to consistency in the situation of different interferencecircumstances, and when using automatic parameter adjustment mechanism, the effect of the multimedia transmission can be achieved to maximum.