The choice of routing protocol in an ad hoc network is not always obvious, as each protocol is adapted to very specific environments. Various comparisons have been made between the principal reactive and proactive protocols based on different performance criteria, such as packet delivery rate and the time taken for a packet to travel from source to destination. In this chapter, we first deal with the operating mechanisms of the ad hoc on-demand distance-vector (AODV) and optimized link-state routing (OLSR) protocols. We then present a comparative study based on the results of simulations, which allow us to reach a conclusion regarding the relative performances of the two protocols.
The choice of the AODV and OLSR protocols as subjects for study in the course of this chapter owes nothing to chance; above all, this choice stems from a need to compare an established protocol (AODV) with a more recent one (OLSR).
These protocols are very different from each other, given they belong to two different families. The AODV protocol is an on-demand (reactive) protocol with a flooding-based method of route discovery. OLSR, on the other hand, is proactive (table-driven), a descendent of distance-vector and link-state protocols; OLSR therefore maintains routing tables with information on the state of the network which are updated periodically.
These two protocols are therefore completely opposite in terms of ...