Multicast Least Cost Anypath Routing: Route Cost Calculations and Forwarding

A wireless network may route packets more efficiently if forwarding decisions are taken based on which downstream nodes actually receive packets from the source or intermediate nodes. This is used for unicast transmissions in Opportunistic Routing (OR) and Least Cost Anypath Routing (LCAR). Here, we extend the LCAR approach to support multicasting from one source to multiple destinations. Multicast cost metrics are calculated and used to determine the forwarder set and the forwarding strategy so that packets can reach all the destination nodes efficiently. Semi-optimal and simpler heuristic approaches are suggested both for calculating the multicast route costs to the destination set and all its subsets and for the packet transmission and forwarding strategy.