Staged Simulation for Improving Scale and Performance of Wireless Network Simulations

This paper describes staged simulation, a technique for improving the run time performance and scale of discrete event simulators. Typical wireless network simulations are limited in speed and scale due to redundant computations, both within a single simulation run and between successive runs. Staged simulation proposes to reduce the amount of redundant computation within a simulation by restructuring discrete event simulators to operate in stages that precompute, cache, and reuse partial results. This paper presents a general and flexible framework for staging, and identifies the advantages and trade-offs of its application to wireless network simulations. Experience with applying staged simulation to the ns2 simulator shows that it can improve execution time by an order of magnitude in typical scenarios and make feasible the simulation of large scale wireless networks.