SQ-AODV: A novel energy-aware stability-based routing protocol for enhanced QoS in wireless ad-hoc networks

We propose a novel, energy-aware, routing protocol for quality-of-service (QoS) support in an infrastructure-less ad-hoc network. Our stability-based, QoS-capable ad-hoc on-demand distance vector (SQ-AODV) protocol is an enhancement of the well-known ad-hoc on-demand distance vector (AODV) protocol. Our protocol utilizes a cross-layer approach, in which information about residual node energy is used for route selection and maintenance, and for quickly adapting to network conditions. The uniqueness of our scheme is that it uses only local information, requires no additional communication or co-operation between nodes, possesses a make-before-break capability that minimizes packet drops, and is compatible with the basic AODV data formats and operation, making it easy to adopt. We demonstrate, through extensive simulations in NS-2, that the increased route stability afforded by SQ-AODV leads to substantially better QoS performance. Our results show that under a variety of applicable network loads and network settings, our protocol achieves packet delivery ratio, on average, 10-15% higher than those of AODV and MDR (min. drain rate) routing, and node expiration times 10-50% better than either AODV or MDR, with packet delay and control overhead comparable to that of AODV.