Differentiated Service to Improve QoS in Sensor Networks

Improving performance is one of the major concerns in wireless sensor network; since it impacts the network Qos. In wireless sensor network applications, timely packet delivery is fundamental requirement. Data generated in wireless sensor network may not be alike; some data may be more important than others and hence may have different delivery requirements in congested sensor network. As deployment sizes and data rate grow, congestion arises as major problem in sensor networks leads to dropping of data. In this paper we propose a class of algorithm that enforce differentiated routing based on congested areas of network and data priority. The basic approach called Congestion Alert Routing (CAR) dynamically discovers congested zone of the network that exist between high priority data sources and data sink and, using simple forwarding rules, dedicates this portion of the network to forwarding primarily high priority traffic. While high priority packets are routed inside the conzone, low priority packets generated outside the conzone use off-conzone nodes for routing; there by providing better service. CAR increases the fraction of high priority data delivery, decreases delay and jitter for such delivery while using energy uniformly in deployment. Since CAR reduces the energy consumed in the nodes, it leads to an increase in connectivity life time. Moreover, we look at issues related to real time audio/video traffic and CAR can effectively handle such data.