An Energy-Aware On-Demand Routing Protocol for Ad-Hoc Wireless Networks

An ad-hoc wireless network is a collection of nodes that come together to dynamically create a network, with no fixed infrastructure or centralized administration. An ad-hoc network is characterized by energy constrained nodes, bandwidth constrained links and dynamic topology. With the growing use of wireless networks (including ad-hoc networks) for real-time applications, such as voice, video, and real-time data, the need for Quality of Service (QoS) guarantees in terms of delay, bandwidth, and packet loss is becoming increasingly important. Providing QoS in ad-hoc networks is a challenging task because of dynamic nature of network topology and imprecise state information. Hence, it is important to have a dynamic routing protocol with fast re-routing capability, which also provides stable route during the life-time of the flows. In this thesis, we have proposed a novel, energy aware, stable routing protocol named, Stability-based QoS-capable Ad-hoc On-demand Distance Vector (SQ-AODV), which is an enhancement of the well-known Ad-hoc On-demand Distance Vector (AODV) routing protocol for ad-hoc wireless networks. SQ-AODV utilizes a cross-layer design approach in which information about the residual energy of a node is used for route selection and maintenance. An important feature of SQ-AODV protocol is that it uses only local information and requires no additional communication or co-operation between the network nodes. SQ-AODV possesses a make-before-break re-routing capability that enables nearzero packet drops and is compatible with the basic AODV data formats and operation, making it easy to adopt in ad-hoc networks. We demonstrate, through extensive simulation results 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 settings, SQAODV achieves packet delivery ratio, on average, 10-15% better than either AODV or Minimum Drain Rate (MDR) routing protocol, and node expiration times 10-50% better than either AODV or MDR, with packet delay and control overhead comparable to that of AODV.