Impact of mobility on connection in ad hoc networks

The performance of mobile ad hoc networks is highly sensitive to changes in node-to-node connections (communication links) caused by node movement. Link instability of this kind has proven very difficult to analyze mathematically so previous work has relied heavily on simulation. We present a mathematically tractable model of node motion, the constant velocity model, and use it to derive a precise relation between mobility and connection stability. Our analysis also allows determination of the appropriate frame length for successful and efficient single-hop communication. We further investigate connection stability in multi-hop communication, and uncover some underlying properties of previously proposed mobility metrics. In particular, we demonstrate that link duration has a strong invariant relationship with the stability of multi-hop connections for a wide range of mobility models, and thus is an excellent mobility metric.