Staged simulation

This article describes staged simulation , a technique for improving the run time performance and scale of discrete event simulators. Typical network simulations are limited in speed and scale due to redundant computations encountered both within a single simulation run and between successive runs. Staged simulation proposes to restructure discrete event simulators to operate in stages that precompute, cache, and reuse partial results to drastically reduce redundant computation within and across simulations. We present a general and flexible framework for staging, and identify the advantages and trade-offs of its application to wireless network simulations, a particularly challenging simulation domain. Experience with applying staged simulation to the ns2 simulator shows that staging can improve execution time by an order of magnitude or more and enable the simulation of wireless networks with tens of thousands of nodes.