OLSR and approximate distance routing: loops, black holes, and path stretch

Abstract

With the proliferation of high-performance mobile devices, there has been renewed interest in MANETs. This Thesis focuses on the impact of stale topology information in OLSR, a widely used proactive MANET routing protocol. Specifically, we examine routing loops, black holes, and path stretch when the topology information is stale. We find that as the topology information becomes stale, OLSR suffers from all of these problems. Moreover, OLSR specifies some optimizations that exasperate these problems. As an alternative, we propose a simple approximate distance-based routing scheme that computes routes slightly differently than OLSR, and is less impacted by stale topology information. In particular, we prove the forwarding is loop-free under a mild condition. Routers can maintain this condition in a distributed fashion that results in far less overhead than OLSR.