Evaluating the effect of path diversity over QoS and QoE in a high speed indoor mesh backbone

Abstract

This paper investigates the effect of wireless channel dynamics over the routing protocols' performance in a high speed backbone wireless mesh network, through the extensive performance evaluation in an IEEE 802.11s+n indoor mesh testbed. The performance is measured for Quality-of-Service (QoS) and Quality-of-Experience (QoE), that are most important parameters for a backbone mesh network to assure users' satisfaction.We show that proactive routing protocols are severely affected by wireless channel dynamics in a high speed mesh network, resulting in poor QoS and QoE. On the other hand, reactive protocols consume considerable amount of bandwidth though control message broadcast, and also affect QoS and QoE through route flapping (frequent route changes). In our earlier paper [1], we have proposed a two phase routing protocol, called `Selective Greedy Forwarding' (SGF) where a `set of potential forwarders' (SPF) is constructed based on the proactive protocol. During the actual data transmissions, one of the nodes from the SPF is selected in a greedy way considering the channel and interference conditions, to work as the next hop router. Though SGF improves QoS and QoE compared to the conventional routing protocols, the performance depends on the size of the SPF. This paper shows that the optimal size of the SPF further depends on the network load, as route flapping occurs more when traffic load is low. We propose an adaptive strategy to find out the size of the SPF, and show that the SGF protocol performs best with the adaptive SPF strategy in terms of QoS and QoE.