Improving the Accuracy of Random Waypoint Simulations Through Steady-State Initialization

In simulations of mobile ad hoc networks, the probability distribution governing the movement of the nodes typically varies over time, and converges to a “steady-state” distribution, known in the probability literature as the stationary distribution. Some published simulation results ignore this initialization discrepancy. For those results that attempt to account for this discrepancy, the practice is to discard an initial sequence of observations from a simulation in the hope that the remaining values will closely represent the stationary distribution. This approach is not always reliable. If, however, the initial locations and speeds of the nodes are chosen from the stationary distribution, convergence is immediate and no data need be discarded. Many published simulation results of mobile ad hoc networks use the Random Waypoint Mobility Model (the RWM model). In this paper, we show how to implement a steady-state mobility model generator (mobgen-ss) for the RWM model. We then show, via simulation results, that one is able to construct more reliable simulations for mobile ad hoc networks with mobgen-ss. Our mobgen-ss code is available at http://toilers.mines.edu. Keyword: Simulations