On the robustness of OLSR in a mobile tactical scenario in rural terrain

This paper investigates the robustness of the optimized link state routing (OLSR) protocol when used for unicast traffic in a highly dynamic military tactical scenario. The importance of the channel model in ad hoc network simulations is shown, as a radio channel model considering terrain effects and real radio transmission behaviour is employed. Results show, among other things, that using an advanced channel model has a large influence on the robustness of OLSR, compared with results obtained with a plane earth model which can produce misleading results. The robustness is evaluated for different network sizes and over different network connectivity. Different system aspects are considered, such as the link metric used by OLSR and the ability to manage small-scale fading. Results show the gain, in terms of robustness of OLSR, from utilizing some kind of diversity at the data link layer to reduce small-scale fading. Moreover, the results show the benefit of using a link metric based on information provided by the physical layer, as the fast link feedback from the physical layer is needed to handle the dynamic channel.