Energy Level Accuracy in Mobile Ad-Hoc Networks Using OLSR

To support energy-efficient routing, accurate state information about energy level should be available. But due to bandwidth constraints, communication costs, high loss rate and the dynamic topology of MANETs, collecting and maintaining up-to-date state information is a very complex task. In this work, we use Optimized Link State Routing (OLSR) as the underlying routing protocol. We report the quantification of state information accuracy under different traffic rates. We are focusing on energy level as QoS metric, which has been used for routing decisions in many energy-efficient routing protocol proposals. State information accuracy is defined as the average difference between perceived energy level (by the node making a routing decision) and its actual value. The results show that state information is inaccurate, especially under high traffic rates. Tuning the OLSR protocol parameters has no noticeable impact on inaccuracy levels. Based on our inaccuracy level analysis, we propose three additional techniques as an attempt to reduce inaccuracies. We compare the different techniques against each other and against the basic OLSR protocol. Two of our proposed techniques show significant improvements in inaccuracy levels. In particular, a technique we call smart prediction achieves highly accurate perceived energy levels under all traffic loads.