Multimedia applications have different QoS requirements such as, bounded latency or delay, throughput, jitter, availability, and energy consumption. Since energy efficiency is considered as the main goal of most WSNs routing protocols, the majority of these protocols does not perform well when applied to QoS-constrained WMSN. Routing techniques in WMSN can be classified similarly to those of WSNs.
The Expected Transmission Count (ETX) [12] metric is an estimation of the expected total number of transmissions (including retransmissions) required to deliver a packet to the destination node successfully. ETX allows finding high throughput paths on a multi-hop wireless network, and incorporates the effects of link loss ratios, asymmetry in the loss ratios between the two directions of each link, and the interference among the successive links of a path.
This paper proposes a new multi-objective approach for the WMSN routing problem that takes into account QoS parameters such as delay and ETX. A comparison of the proposed approach with two alternative routing protocols was also presented.