Abstracto

Mixed Scheduling Coupled With Power Control and Routing for Wireless Adhoc Networks

A.Vidya, N.Tamilselvi

In ad hoc networks the communication between mobile nodes are done through wireless channel. Here the connections between mobile nodes are made without the infrastructure support such as base station. A power assignment for the links changes the network topology and thus scheduling is affected. Scheduling determines the link activation and interference and hence the power changes at each link should satisfy the SNIR requirements. In our proposed approach we employ both link scheduling and power control to manage the interference. Here we have assumed a TDMA based wireless ad hoc network where one of the nodes has receiver and other has transmitter, all other nodes occupy different time slots. In our scheduling algorithm priority is given to the links with larger queue which helps in blocking traffic to neighboring links. Also we have studied the scheduling with power control and scheduling without power control mechanisms and found that scheduling with joint power control achieves significantly larger throughput and less delay at the cost of slightly higher energy consumption. In routing the minimum energy route has to be selected at the beginning of the network operation to save energy. But in some cases for general and arbitrary topologies, bandwidth requirement may not be satisfied by scheduling alone, and hence, congestion occurs at some links in the network. In our algorithm, routes are selected using Ant Colony based routing considering QoS factors according to both energy consumption and the traffic accumulation. Our simulation results show that there is a trade-off between energy consumption and the network performance.