Adaptive mesh based routing for efficient multicasting in highly mobile ad hoc networks

Since meshes show much robustness than tree based multicasting and reactive algorithms tend to reduce control overhead in a mobile ad hoc network (MANET). On demand mesh is a strong candidate for efficient multicasting in such a network. While, mesh enables a scoped flooding mechanism among selected nodes, it results in much data overhead. The tradeoff establishment, by efficiently reducing retransmitting mesh members and achieving high packet delivery ratio at the same time is challenging. Likewise, periodic flooding of control packets throughout the network tends to increase control overhead. Some optimized flooding technique needs to be investigated to efficiently reduce periodic broadcast packets. Adapting control packets that refresh mesh members to current mobility/density conditions of the network, was previously addressed by GPS enabled on-demand multicast routing protocol (ODMRP). We propose an alternative for GPS in our case by utilizing mean link duration metric to adapt and reduce refreshing control packets. In addition, we suggest a new reactive multicast mesh construction algorithm, using overhearing technique, which forms a fish bone structure. Motive is to selectively add relevant redundant members to a source based mesh. Each mesh member chooses its forwarding mode independently and entirely in a distributed fashion, based on its own perceived network conditions to provide a tradeoff between reducing data overhead and achieving multicast reliability. Similarly, optimized flooding technique, using multi point relays (MPRs), is also exploited. Thus we propose to solve the problem of limiting control plus data overhead for mesh based multicast routing and that of achieving very high packet delivery ratio at the same time in MANET