Optimized link state routing for quality-of-service provisioning: implementation, measurement, and performance evaluation
Hassan Sinky, Bechir Hamdaoui · Wireless Communications and Mobile Computing · 2012
This paper provides a measurement-based performance evaluation of the Optimized Link State Routing (OLSR) protocol.Two versions of OLSR, OLSR-ETX and OLSR-ETT, are implemented and evaluated on a mesh network that we built from off-the-shelf commercial components and deployed within our department building.OLSR-ETX uses the Expected Transmission Count (ETX) metric, whereas OLSR-ETT uses the Expected Transmission Time (ETT) metric as a means of assessing link quality.The paper describes our implementation process of the ETT metric using the plug-in feature of OLSRd, and our calculation method of link bandwidth using the packet-pair technique.A series of measurements are conducted in our testbed to analyze and compare the performance of ETX and ETT metrics deemed useful for quality of service.Our measurements show that OLSR-ETT outperforms OLSR-ETX significantly in terms of packet loss, end-toend delay, jitter, route changes, bandwidth, and overall stability, yielding much more robust, reliable, and efficient routing.