Analyzing the impact of mobility in ad hoc networks

The impact of mobility on the link and route lifetimes in ad hoc networks is of major importance for the design of efficient MAC and network layer protocols. Up to now, no real-life measurements were used to study the effect of node mobility on link and route lifetime distributions. In this paper, we present data gathered from a real network of 20 test users and analyze it with regard to link and route lifetime distributions. Besides link breakage due to node mobility, links might also break due to diverse sources of interference or packet collisions. We develop a statistical framework to distinguish between the mobility and interference or collision errors. With this framework, we are able to determine and analyze the lifetime distributions for both error types separately. We use this framework together with our measurements to validate two commonly used stochastic mobility models including the random waypoint and the random reference group mobility model. The results show that the distributions of the two stochastic mobility models match very closely the empirical link lifetime distribution.