Queuing Theory Applied In ATM Switching Fabrics

In this paper,the theory of ATM switching fabrics and queuing is introduced. Then,the Independent Window Access scheme for input-buffered ATM switching fabrics is analyzed by means of a queuing theory. It also conducts the analysis and study on cell scheduling strategies of priority class.Finally,it has a quantitative analysis in cost of cell scheduling strategies which have two priority classes. The reason which we study the Independent Window Access scheme is that: the IWA scheme makes the switching fabric have better performances than the DWA scheme. In media service system ,the problem of scheduling strategies for cells which have priority classes is popular. We can say that, this analytical approach in this paper overcomes the calculation complexity of probability generating functions approach and numerical methods. the formula of the average cell delay and cell loss ratio are infered.At the same time, computer simulation and contrastive analysis have been done ,which based on the conclusions. From the formula, we can also come out cell service ratio which curbs the average cell delay and cell loss ratio in permissive range.All these are important for us to insure the QOS of media service and improve the lost phenomenon of cell. At the times full of competition,the study on the cost of cell scheduling strategies is alse an important theoretical reference for us.