Priority Based Rate Control Schemes for Wireless Sensor Networks

Abstract

Congestion is one of the key issues in Wireless Sensor Networks (WSNs), which degrades the newlineQoS parameters of the network. Different congestion control algorithms have been proposed in newlinethe literature. This thesis addresses the problem of congestion control by proposing different newlinedata rate control schemes based on the notions of prioritization of different traffic classes, fair newlinedistribution of bandwidth, and adaptive queue management. All the proposed algorithms are newlinetested on a tree topology though these are valid for a general topology. Besides, the algorithms newlinewith the topology are implemented in NS3 simulator. The first two proposed novel rate control newlinealgorithms are based on prioritizing the traffic classes such as Real Time (RT) and Non Real newlineTime (NRT) traffic classes. The first rate control algorithm is the Difference of Differential Rate newlineControl (DDRC) algorithm which is based on the notion of higher order derivative based rate newlinecontrol at a given node. The second proposed algorithm is based on the notion of higher order newlinederivative with weighted priority traffic classes and is known as Weighted Priority Difference newlineof Differential Rate Control (WPDDRC) algorithm. The performance of these two algorithms newlinewith respect to the Quality of Service (QoS) metrics such as throughput of a node, packet loss, newlineand packet delay are compared with the existing algorithms and found to be superior. Besides, newlinethe effect of limited node mobility and different traffic class pattern on the QoS metric is also newlinestudied. It is found that traffic class pattern affects the QoS metric where as the limited node newlinemobility does not affect the QoS. newlineThe third proposed rate control algorithm is known as Priority based Fairness Rate Control newline(PFRC) algorithm. This algorithm is based on the combined notion of fair distribution of available newlinebandwidth among the nodes and the weighted priority of the traffic classes with a fixed newlinequeue size of a node. The queue size is fixed for all the nodes of a given layer of the tree topology. newlineThe data rate at a given