On Multi hop Performance of Nearest Neighbor Based Forwarding in CDMA Wireless Sensor Networks

Energy conservation is one of the most important issues in wireless ad hoc and sensor networks, where nodes are likely to rely on limited battery power. In the present paper we evaluate the performance of  a static CDMA wireless sensor network  (WSN), where the positions of nodes are more likely to be  random maintaining a particular minimum distance between any two nodes. Data generated from the source nodes are received by a sink via multi hop. A routing scheme called nearest neighbor based forwarding where an intermediate node in the route selects the nearest node within a search angle ( ) towards the direction of the destination as the next hop. Energy consumption considering start up energy at each node and delay in successful delivery of data packet from source to sink using end-to-end ARQ under such routing scheme is estimated. Network lifetime, which is an important performance indicator for energy constrained wireless sensor networks, is also evaluated.  Further, energy consumption is estimated by incorporating different error control schemes as applicable to WSN and compared with uncoded  scheme. A scheme for packet size optimization is introduced which captures the effects of multi hop routing by varying search angle, the broadcast nature of information transmission as in CDMA network. Optimization solution is formalized by using different objective functions, i.e., packet throughput, and resource utilization, which has importance in case of delay sensitive WSN.