DIFFUSION-BASED STATISTICAL CALL ADMISSION CONTROL IN ATM

We propose a call admission control (CAC) procedure for asynchronous t ransfer mode (ATM) networks using statistical bandwidth as the decisio n criterion, based on closed-form expressions that use diffusion model s. This approach is computationally very efficient and easily implemen table. It is related to Gaussian approximations previously proposed fo r CAC, though our expressions are derived from a more derailed represe ntation of traffic and the buffer length process, The statistical band width expressions we use take into consideration the users' cell loss requirements, their aggregate traffic characteristics, the available b uffer size at the statistical multiplexers, and capture the interactio n between individual traffic streams at the ATM multiplexer. Extensive numerical and simulation results are presented to evaluate the effici ency and adequacy of this CAC procedure. Comparison with existing meth ods such as the Equivalent Bandwidths and Gaussian Approximations indi cate that our approach remains conservative with respect to cell loss compared to previously proposed CAC schemes, yet that it is more econo mical in bandwidth allocation leading to larger admission regions both for homogeneous and heterogeneous traffic.