Optimization On Resource Allocation And Transmission In Wireless Multimedia Sensor Network

Wireless Multimedia Sensor Network (WMSN) is a special kind of wireless sensornetwork, which is integrated with sensor technology, multimedia information techniques,wireless communication technology and distributed information processing technology.Comparing with the conventional wireless sensor networks, WMSNs are being deployedfor some practical applications, including military sensing and tracking, environmentand security monitoring, equipment and human monitoring and tracking. Thus, it hasreceived considerable attention and become a hotspot in research area. This paper in-vestigates the hotspots of the research on the lifetime of wireless multimedia sensornetworks, network utility maximum, opportunities routing protocol joint with networkcoding.This paper addresses the performance optimization of network lifetime and re-source allocation for wireless video sensor networks. First, we construct a power con-sumption model for video sensors, in which video encoding, data communication anderror-control behavior are completely considered. Second, we propose a joint optimiza-tion of video coding rate, aggregate power consumption and flow control to maximizethe network lifetime and meet video quality requirements. Last, using Lagrange dualand subgradient approach, we solve the target convex optimization problem in a fullydecentralized manner, and evaluate its performance in a large-scale random topology aswell as in a small static network.Reliable communication over time-varying and error prone wireless channels cur-rently is still challenging. In most FEC-based schemes, the maximum error control re-dundancy is upper-bounded by the FEC-code symbol size, However, diferent encod-ing/decoding structures are required for various redundancy levels. Therefore, the im-plementation complexity is too high to be applicable to real systems. To combat packetloss over wireless channels, a hybrid error-control scheme integrating network codingand ARQ protocol is introduced. It adaptively adjusts the number of redundant codedpackets according to ARQ feedbacks with a fixed code structure and decoding algorithm.This paper also studies the problem of data gathering framework in wireless sensornetworks and formulates it as a network utility maximization problem. And an oppor-tunistic routing scheme, based on the optimization problem, is proposed to contribute adistributed framework for data gathering. We propose a new local metric for forward-ing selection and coordination. Moreover, this paper proposes a dynamic coding policywhich allows network coding applied across sessions and develops a necessary condi-tion for coding policy by denoting the flow gaining from coding. With the coding policy,intermediate nodes can independently judge whether the coding operation is appropri-ate and easily decide which packet to transmit among the incoming flows. To make thenetwork coding feasible in practical, a control mechanism for an intermediate node ispresented, which illustrates the operations for the incoming packet flows. This paper also studies the problem of correlated data gathering in wirelesssensor networks. An opportunistic routing protocol joint with opportunistic networkcoding is proposed for correlated sources. In order to reduce the total transmission,the expected number of coded transmission (ECTX) is introduced as metric for therouting selection. Moreover, the coding gain is defined for the network nodes to countthe coding opportunistic, with which the throughput of the wireless sensor network isfurther increased.