Ad Hoc Networks: Routing, Qos and Optimization

Chapter 6

Load Distribution in MANETs

 

 

 

6.1. Introduction

Mobile ad hoc networks (MANETs) are wireless networks that do not require a centralized administration or any fixed infrastructure. As mobile nodes communicate using radio channels of variable quality and reduced bandwidth, wireless links have lower capacity than wired links and, as a result, congestion is more of a problem. Furthermore, nodes in ad hoc networks are powered by batteries with a limited lifespan, reducing their storage capacity and processing power [BAS 04]. These constraints demand an even distribution of traffic across all nodes of a network. Otherwise, overloaded nodes may form a bottleneck, reducing network performance through congestion and long transmission delays, while rapidly consuming energy resources at node level, causing losses of connectivity in the network.

One solution to this problem is load balancing. Load balancing is defined as “the equitable distribution of processing and communication activities between different entities in a computer network to avoid overloading any one element” [ENC 07a]. This technique found favor following the exponential growth in Internet traffic over the last decade, mainly due to its capacity to cope with link failure and improve the quality of service (QoS) offered.

Unfortunately, load balancing is not present in shortest-path routing protocols for MANETs, and the bulk of traffic passes through the center of the network [PHA 02].

For this reason, we shall ...