SINK BASED CROSS LAYER MMRE AOMDV MODEL FOR IMAGE DELIVERY IN WIRELESS SENSOR NETWORKS

摘要

With the advent of Wireless Technology, various applications in traditional wired networks have been adopted in Wireless Networks such as Ad Hoc Networks, Wireless Sensor Networks etc. Owing to limited energy in these devices power saving is very critical to prolong the lifetime of these devices. If the objective is to transmit multimedia, it is required to balance the power and lifetime with the end to end Quality Constraints. Our work finds a mechanism to minimize the energy consumption while satisfying the QoS for Multimedia. In this work, we use cross-layer optimization mechanism based on power and modulation rate control for a multipath routing protocol and the optimization mechanism is subject to certain QoS requirementsspecified using Packet Error Rate and time constraint of the application. Whenever the source node wants to send multimedia data to the sink nodeitbroadcastsaRoute Request Packet(RREQ)packet containing information such as node id, image size, delay constraint, quality level, residual battery energy to itsneighbornodesand each intermediate node appends its remaining battery energy, link gain, node id and average noise powerto this RREQ packet. UponreceivingtheRREQpacketson the multiple paths thesinknode finds all the node disjoint paths which satisfy the delay constraint of the application.Using cross layer power and rate optimization algorithm, the sink calculates the optimal power and rate vectorsfor each disjoint path.Then Sink based Maximal Minimal Residual Energy (Sink based MMRE) AOMDV algorithm finds the total number of image packets that can be sent on each path so as to improve the lifespan of the network by balancing the energy conservation of these paths.The sink sends Route Reply packets to the source on each disjoint path which contains the information such as optimal power vector, modulation vector, and remaining battery energy for the nodes on the path and number of image packets that can be sent on the path by the source. The source is freed from the complex algorithmic executions and hence the energy needed for this purpose is conserved. It is assumed that sink has abundant computational power and energy is not a constraint The simulation results indicate that considerable amount of energy can be saved with our novel Sink Based MMRE AOMDV algorithm which can be deployed forenergy efficient delivery of multimedia datawith end to end QoS constraint in Wireless Sensor Networks.