Energy-Efficient Multicast Routing in Mobile Ad Hoc Networks

The Mobile Ad Hoc Network (MANET) is an emerging network topology based on a radio propagation model. The network topology, which is neither fixed nor predetermined, can be rapidly deployed and does not need to rely on a pre-existing infrastructure. It is noteworthy that this salient feature makes it suitable for the network operations that, by their nature, are unpredictable during the design stage.

However, a lot of critical challenges in the design and operation of MANET need to be solved. The three main challenges come from: 1) the lack of a centralized entity, 2) the possibility of platform movements, 3) the fact that all the communication is carried over the wireless medium.

The issues we address here are 1) a node operates on limited battery resources, and 2) multi-hop routing paths are used over constantly changing network environments due to node mobility. Hence, efficient utilization of routing packets and immediate recovery of route breaks are critical in routing and multicasting protocols in MANET.

Our approach to energy-efficient communication departs from the traditional layered structure in that we jointly address the issues of transmitted power levels (a network connectivity function, related to the Physical layer) and multicast tree formulation (a routing function, associated with the Network layer).

We model the problem as a linear integer mathematical programming problem. In addition, we propose a set of heuristic solution procedures based on Lagrangian relaxation methods to solve the complicated problem.