with QoS (Quality of Service)
Prof. N. A. Dawande
Dr. D Y Patil College of Engineering
Talegaon, Pune, India
Dr. P. M. Patil
Principal & Professor
RMD Sinhgad College of Engineering
Abstract: Ad hoc mobile networking is a current active research area. They can be used in agriculture for monitoring and control of environmental parameters in the form of wireless sensor networks. The aim of this paper is performance evaluation of protocol of these Ad hoc networks i.e. QoS-enabled AODV protocol. The performance evaluation is done by means of its comparison with normal AODV protocol. QoS stands for Quality of Service. The research proposed some enhancements to the AODV protocol to provide QoS by adding extensions to Route Discovery messages, related to bandwidth estimation. This paper focuses on three of the parameters namely Traffic Rate, Speed of nodes & Pause Time of mobile nodes. For evaluation purpose the performance metrics used are Average end-to end Delay, Packet Delivery Ratio (PDR), Normalized Overhead Load (NOL) and Throughput. Performance of the AODV protocol for QoS as well as Non-QoS is evaluated with respect to these parameters.
Keywords: Ad hoc, AODV, Bandwidth Estimation
In an Ad hoc mobile network, every node in the network carries its own router with it, and all nodes cooperate in carrying traffic. The whole philosophy of the Ad hoc networking model is a radical departure from the highly structured and frequently hierarchical models employed for both local area and wide area networking, currently in use. The range of possible situations in which Ad hoc networking can be exploited is huge. What mature and robust Ad hoc networking offers is virtually universal connectivity, limited only by the link performance and routing delays of the participating nodes, and their connectivity to the established fixed network. As shown in Fig.1 Ad hoc networks are well within the bounds of today's technology, provided that suitable Ad hoc routing protocols exist and are implemented.
Fig. 1. Ad-hoc Networking
Static networks mostly use either Distance Vector (DV) or Link State (LS) routing algorithms, neither of which are spectacularly well suited to highly dynamic topologies. In a highly dynamic wireless network, such protocols run into a number of difficulties: • topologies may be highly redundant, with some nodes being in the situation of being able to connect to a very large number of neighbors, while others see very few neighbors. • bandwidth is scarce and cannot be wasted.
• battery power on portable equipment is a finite resource that cannot be wasted. • high rates of topology change require high update rates.
A. Routing Models
Routing models can also be divided in following ways:
1) Proactive Routing
2) Reactive Routing
3) Hybrid Routing
This paper focuses on three of the parameters namely traffic rate, speed & pause time of mobile nodes. For evaluation purpose the performance metrics used are average end-to end delay, packet delivery ratio (PDR), normalized overhead load (NOL) and throughput. Evaluate the AODV protocol for QoS as well as Non-QoS is done with three of the parameters & four performance metrics by means of graphical representation of their interrelations.
B. AODV Protocol Overview
AODV routing protocol is an on-demand reactive routing protocol that uses routing tables with one entry per destination. When a source node needs to find a route to a destination, it starts a route discovery process, based on flooding, to locate the destination node, as shown in Fig. 2. [pic]
Fig. 2. Route Discovery Cycle
Upon receiving a route request (RREQ) packet, intermediate nodes update their routing tables for a reverse route to the source. Similarly, the forward route to the...