Mobile Intelligence

1.2 A TAXONOMY OF MANET ROUTING PROTOCOLS

The main aims of all routing protocols designed for MANETs are to achieve a high level of performance, in terms of high throughput, low latency, and low energy expenditure by individual nodes. However, these aims are quite often contradictory in the sense that a routing protocol might have to sacrifice one of them in order to satisfy another. For example, assume that we are trying to design a routing protocol that aims for low latency in packet delivery. This may be a quality of service (QoS) requirement in a network that delivers multimedia content from one node to another. If individual nodes want to deliver or forward packets very fast toward a destination node, they must have a very clear idea about the network topology and the routes to the destination should be as accurate as possible. However, the collection of accurate topology information requires exchange of local views of topology among the nodes. In other words, each node should inform other nodes about its neighbors frequently so that all nodes have up-to-date information about the network topology. This type of information exchange is done through sending control messages (this name is used to differentiate from the actual data packets) and requires the nodes to spend substantial amount of energy. Hence, a protocol may have to sacrifice battery power in order to achieve low latency.

All routing protocols implicitly assume that nodes in a MANET cooperate with each other in ...