Abstract: Congestion is one of the major problem in Wireless Sensor Network which occurs when large number of nodes sending data to a common node. Because of this congestion, the node’s buffer gets overloaded which either increases the packet service time or starts dropping the packets which in turn degrades the packet delivery ratio and also increases the node’s energy consumption and end to end delay in the network. In healthcare applications, there is a need for continuous data transmission to the monitoring location and also the delay should be minimized. Also when the sensing parameters gets increased then the number of nodes in the network also gets increased, in such case the remote nodes cannot reach the central location in single-hop manner so there is a need for multi-hop forwarding. In order to overcome the above mentioned issues, multi-hop based congestion avoidance technique has been proposed. The objective of the proposed work is to avoid the congestion and thereby improving the performance metrics such as packet delivery fraction, average remained energy and average end to end delay. Initially performance analysis of different routing protocols like AODV, DSR and DSDV has been done, in order to select a best routing protocol for a multi-hop network. The topology used in the proposed work is clustered topology as multi-hop routing and it is evaluated in NS-2 simulator.

Keywords: Congestion avoidance; Wireless Sensor Network (WSN); multi-hop; routing protocols; clustered topology.