Input and output queueing ATM switch with backpressure mode and queue loss mode for nonuniform traffic

An input and output queueing ATM switch model with a backpressure (BP) mode and a queue loss (QL) mode to decrease the system delay and the cell loss probability under nonuniform traffic is proposed. In the proposed model, the QL mode is adopted if the size of the backpressure exceeds the threshold. We consider a synchronous system with Bernoulli arrivals under hot-spot traffic that consists of a single output port of higher access rate super-imposed on a background uniform traffic. The system delay and cell loss probability are analyzed under hot-spot traffic. It is shown that the proposed model is useful for nonuniform traffic. We also evaluate the effects of the threshold of the backpressure size for adopting the QL mode on the performance, and consider the optimum value of the threshold.