Impacts of Channel Switching Overhead on the Performance of Multicast in Wireless Mesh Networks

Wireless mesh networks (WMNs) have emerged as a promising technology for next generation wireless networking. A WMN extends network coverage using wireless mesh routers that communicate with each other via multi-hop wireless communications. One technique to increase the network capacity of WMNs is to use routers equipped with multiple radios capable of transmitting and receiving on multiple channels. In a Multi-Channel Multi-Radio wireless mesh network (MCMR WMN), nodes are capable of transmitting and receiving data simultaneously through different radios and at least theoretically doubling the average throughput. On the other hand, the use of multi-radio and multi-channel technology in many cases requires routers to switch channels for each transmission and/or reception. Channel switching incurs additional costs and delay. In this thesis, we present a simulation-based study of the impacts of channel switching overheads on the performance of multicast in MCMR WMNs. We study how channel switching overheads affect the performance metrics such as packet delivery ratio, throughput, end-to-end delay, and delay jitter of a multicast session. In particular, we examine:

1. the performance of multicast in MCMR WMNs with three orthogonal channels versus eleven overlapping channels defined in IEEE 802.11b.

2. the performance of the Minimum-interference Multi-channel Multi-radio Multicast (M4) algorithm with and without channel switching.

3. the performance of the Multi-Channel Minimum Number of Transmissions (MCMNT) algorithm (which does not do channel switching) in comparison with the M4 algorithm (which performs channel switching).