Ad Hoc Networks: Routing, Qos and Optimization

Chapter 2

Routing in MANETs

 

 

 

2.1. Introduction

Within a network, several routes usually exist for the transmission of a packet from a source to a destination node. The aim of a routing protocol is to find one or more optimal routes from a list of possibilities, minimizing the cost function. Mobile ad hoc networks (MANETs), as we saw in Chapter 1, have particular characteristics that distinguish them from wired networks, including the absence of a routing infrastructure, the unreliability of links, and a highly dynamic topology.

We must begin by considering whether existing Internet routing protocols are adapted to use in MANETs. We shall begin by reviewing routing protocols used in networks with a routing infrastructure and study the possibility of adapting these protocols to the demands of MANET. Next, we review the best-known routing protocols from current literature on the subject, with particular emphasis on the modifications needed to cope with the specific demands of ad hoc networks. Particular consideration will be given to the ad hoc on-demand distance-vector (AODV) [PER 03] and optimized link-state routing (OLSR) [CLA 03] protocols, the best candidates for normalization.

2.2. Internet routing protocols

Given a data packet, Internet protocol (IP) routing consists of determining the optimal route to take in order to reach the desired destination. In practice, a routing node (for example, a router) uses a routing protocol to generate a routing table in which all possible ...