Analyzing the Impact of Neighbor Sensing on the Performance of the OLSR protocol

This paper presents an analysis of several neighbor sensing approaches for the OLSR routing protocol. While several performance studies of OLSR proceed this work, few attention has been paid to the impact of neighbor sensing on the performance of ad hoc routing protocols. The goal of this article is to better understand how neighbor sensing can contribute to packet loss in an OLSR network and thus degrade the overall performance. Three neighbor sensing schemes are compared: the OLSR HELLO messaging protocol, Fast-OLSR and a link-layer feedback scheme that uses information of the 802.11 MAC to determine lost links. To allow more detailed analysis of the events occuring in the network we initially limit our simulation setup to a simple scenario. As a result we are able to seperate the loss of packets into loss due to the neighbor sensing mechanism used and loss due to the impact of neighbor sensing on the other protocol operations. In the second part of this paper we compare the performance of the link-layer feedback scheme to OLSR in a random waypoint scenario.