Agent-driven backbone ring-based reliable multicast routing in mobile ad hoc networks

Routing in mobile ad hoc networks (MANETs) for groups should aim at providing reliable and robust multicast routes to the group members against link failures, node failures and mobility conditions. The authors propose an agent-based multicast routing scheme in MANET that builds a backbone in the form of a reliable ring and finds multicast routes. The authors use the convex hull algorithm to find the outer boundary of the network area that helps in creating a reliable ring at an optimum distance between the centroid and outer boundary. The reliability of such a backbone is modelled by using reliable links based on the probabilistic measure of link failures. Later, a mesh of multicast routes are found by connecting: (i) source to source's nearest ring node and (ii) destination to destination's nearest ring node. The scheme consists of a set of static and mobile agents, which coordinate through knowledge base and identify links to form a reliable ring at an optimal distance from the centre of MANET area. Agents are also used to recover routes against link failures, node failures and mobility of nodes with local patching of failed links/nodes. The results show that there is an improvement in control overheads, packet delivery ratio, group reliability and packet delivery latency as compared to two protocols: (i) on demand multicast routing protocol and (ii) agent-based multicast routing scheme in MANETs.