On the Interaction Between Multiple Paths and Wireless Mesh Networks Scheduler Approaches

Abstract

Multi-path routing allows building and use of multiple paths for routing between a source-destination pair. This paper investigates the problem of selecting multiple routing paths to provide better reliability and load balancing in wireless mesh networks with stationary nodes. Previous work has investigated the use of additional data redundancy to improve the throughput of the network. In these specific cases, node disjoint-ness property of the multiple paths is required. In this work we investigate multipath routing without packet duplication, and no disjointed paths for achieving better performance in terms of packet delivery rate and low delay. We propose a very simple reactive on-demand distance vector routing protocol. Multiple paths built through this approach are loop-free. In order to better exploit resources redundancy (with the term resources redundancy we mean the possibility to exploit more nodes to send data packets), it is our belief that a routing protocol cannot be independent of the MAC layer. For this reason, we evaluated our routing protocol on four different MAC approaches specifically designed for Wireless Mesh Networks (WMNs). Firstly, we implemented the Coordinated Distributed Scheduler scheme of the Std. IEEE 802.16. Secondly, since some parameters have been left unstandardized in this scheme, we proposed an enhanced version of the CDS, in which a simple and dynamic criterion has been designed to set one of these parameters. Furthermore, we proposed two different scheduling schemes called Randomized- MAC (R-MAC) and Distributed Scheduling Scheme (DSS). We evaluated the impact of multiple paths in respect of the single path on all the scheduler schemes cited above. Results show as the simple routing approach is effective with every MAC protocol considered.