Optimizing Patching-based multicast for video-on-demand in wireless mesh networks

Abstract

In this work, we study the application of video-on-demand (VoD) in wireless mesh networks (WMN), a next generation edge technology to provide broadband data access in residential, business and even citywise networks. We adopt a Patching-based multicast technique to better utilize the bandwidth resources in the mesh network. We optimize the Patching-based multicast by addressing two critical problems, namely, the Minimum Cost Multicast Tree (MCMT) problem and the Maximum Benefit Multicast Group (MBMG) problem. The MCMT problem is to find a MCMT in the network. We show that finding such a tree in the WMN can be formulated as a graph theory problem, which is to find the tree with minimum number of non-leaf nodes, and which spans all the nodes in the multicast group. We further prove the problem is NP-hard and propose a fast greedy algorithm to accommodate the real-time feature of the VoD application. We solve the MBMG problem by minimizing the communication of a Patching group in the entire network. A Markov model is proposed to capture the growth of the multicast group in the WMN. Simulation study results validate the proposed solutions of the two problems. Copyright © 2009 John Wiley & Sons, Ltd.