On multicast routing in wireless mesh networks

There are two fundamental approaches to multicast routing: shortest path trees (SPTs) and minimum cost trees (MCTs). The SPT algorithms minimize the distance (or cost) from the sender to each receiver, while the MCT algorithms such as minimum Steiner trees (MSTs) minimize the overall edge cost of the multicast tree. In wireless multi-hop networks, the tree cost can be redefined to exploit the wireless broadcast advantage: a minimum cost tree is one which connects sources and receivers by issuing a minimum number of transmissions (MNT). Among the different approaches, SPT is the more commonly used method for multicast routing in the Internet. The MNT approach was originally considered for energy-constrained wireless. networks such as sensor and mobile ad-hoc networks. It is not clear how the different types of trees compare when used in WMNs. In this paper, we present a simulation-based performance comparison of SPTs, MSTs and MNT trees in WMNs using most concerned performance metrics such as packet delivery ratio, throughput, end-to-end delay, delay jitter and multicast traffic overheads. Based on the experimental results, we provide insights into the performance of multicast routing algorithms in WMNs and recommendations for suitable routing approaches. (C) 2008 Elsevier B.V. All rights reserved.