Using fuzzy link cost and dynamic choice of link quality metrics to achieve QoS and QoE in wireless mesh networks

The growth of multimedia applications and wireless systems requires a new behavior of routing protocols for wireless mesh networks (WMNs). It is necessary to provide not only the minimum requirements for quality of service (QoS), but also to assure the quality of experience (QoE) support for multimedia applications. In this context, the usage of only one link quality metric for routing different types of packets within the network is not enough to ensure applications with suitable QoS and QoE levels. This paper presents a variation of the WMN routing protocol optimized link state routing (OLSR), to achieve QoS and QoE requirements for multimedia applications. It is based on the dynamic choice of metrics and in a fuzzy link cost (FLC) to determine the best routes for multimedia packets. The proposed FLC metric is based on a fuzzy system that uses two link quality metrics, namely expected transmission count (ETX) and minimum delay (MD), to define a new metric. Simulations were performed to demonstrate the performance of the proposed metric compared to the ones present in the original OLSR and other current versions of this protocol. For comparison purposes, it was considered different performance evaluation QoS metrics and the quality of videos received by the user in a higher competition scenario.