Adaptive MANET Routing: A Case Study

Node mobility plays an important role in the routing performance for MANETs. Many protocols provide parameters to adapt to different levels of mobility, but this is a global optimization (i.e., typically all nodes choose the same parameter values and they use these parameters throughout their participation in a MANET). We choose the monitored number of link breaks as key mobility metric and observe that the relative observable mobility varies widely for different nodes and over time for the same node. We utilize this (simple) mobility metric to allow a node using OLSR as routing protocol to dynamically adapt its behavior (changing the Hello Interval, selecting MPRs, etc.). Simulations with different mobility scenarios show that Adaptive OLSR can improve packet delivery ratio, reduce packet latency, and reduce routing overhead, especially in high mobility scenarios. As a general conclusion, we believe that designing adaptive routing protocols (protocols that change their behavior based on mobility and potentially traffic patterns) holds great promise in resourceconstrained environments.