OLSR vs DSR: A comparative analysis of proactive and reactive mechanisms from an energetic point of view in wireless ad hoc networks

Untethered nodes in mobile ad hoc networks strongly depend on the efficient use of their batteries. Despite the fact that devices are getting smaller and more powerful, advances in battery technology have not yet reached the stage where devices can autonomously operate for days. At the network layer, routing protocols may balance power consumption at nodes according to their routing decisions. In this paper, an in-depth performance comparison of the DSR (Dynamic Source Routing) and the OLSR (Optimized Link State Routing) is presented in terms of energy consumption. Using the ns-2 simulator an evaluation is made of how the different approaches affect the energy use of mobile devices. It was found that a reactive protocol takes advantage of its routing policy when the traffic load is low. However, at higher traffic rates, a proactive routing protocol can perform better with an appropriate refresh parameter. Also, it is demonstrated that independently of the routing protocol selected, the overhearing activity can seriously affect performance. To the best of our knowledge, this is the first simulation study addressing the power saving issue to extensively compare the DSR and OLSR protocols under a wide variety of networking scenarios.