Equivalent bandwidth for heterogeneous sources in ATM networks

Considers the problem of equivalent bandwidth in ATM networks. On/off source models are assumed. Most prior work on this topic assumes that the on/off periods are independent and are exponentially or geometrically distributed. The present authors permit the on and off periods to be dependent and generally distributed. As a specific example, simulated video sources are considered: during a frame of fixed duration, the source generates cells at its constant peak rate for a random active period, which is bounded by the frame length. No cells are generated during the remainder of the frame (off period). The sum of the on and off periods is equal to the frame length and, hence, the on and off periods are dependent. The authors present an accurate approximation for computing the equivalent bandwidth for heterogeneous sources, especially for a mixture of voice and simulated video sources. Simulation was performed to verify the accuracy of the approximate results. It is found that the approximation is accurate over a wide range of system parameters. Numerical results indicate that the linear approximation method underestimates the equivalent bandwidth required, these results agree with the previous simulation studies reported in the literature. For the simulated video sources, the required equivalent bandwidth obtained is compared with that obtained by modeling the simulated video sources as two-state on/off sources. It is observed that the two-state on/off source model overestimates the required bandwidth for the simulated video sources