A mobile ad hoc network (MANET) is a non-centralised, multihop, wireless network that lacks a common infrastructure and hence it needs self-organisation. The biggest challenge in MANETs is to find a path between communicating nodes, which is the MANET routing problem. Biology-inspired techniques such as ant colony optimisation (ACO) which have proven to be very adaptable in other problem domains, have been applied to the MANET routing problem as it forms a good fit to the problem. The general characteristics of these biological systems, which include their capability for self-organisation, self-healing and local decision making, make them suitable for routing in MANETs. In this paper, we discuss a few ACO based protocols, namely AntNet, hybrid ACO (AntHocNet), ACO based routing algorithm (ARA), imProved ant colony optimisation routing algorithm for mobile ad hoc NETworks (PACONET), ACO based on demand distance vector (Ant-AODV) and ACO based dynamic source routing (Ant-DSR), and determine their performance in terms of quality of service (QoS) parameters, such as end-to-end delay and packet delivery ratio, using Network Simulator 2 (NS2). We also compare them with well known protocols, ad hoc on demand distance vector (AODV) and dynamic source routing (DSR), based on the random waypoint mobility model. The simulation results show how this biology-inspired approach helps in improving QoS parameters.
