Simulation Comparison of Link Scheduling Algorithms: Impacts on Cell Delay Variation

The paper presents preliminary results on the impact of two link scheduling algorithms on CDV (Cell Delay Variation). The traditional FIFO queueing is compared with two versions of the Virtual Spacing algorithm proposed by Roberts in 12, 13]. The intercell time distribution and the 1-point CDV imposed on a CBR traac are investigated. The simulation connguration is a queueing model for a sequence of multiplexers or switches in ATM networks. The delay jitter of the cells of a tagged connection at the multiplexers is compared with the known delay bounds given for Virtual Spacing. From the simulation results it was learned that the modiied Virtual Spacing according to 13] resulted in signiicant improvements in the CDV, and that the CDV of the CBR traac has to be taken into account when the delay bound is calculated.