Priority control mechanism based on cell service ratio in ATM switch

We propose a priority control mechanism for handling the cell service ratio according to the loss sensitive class cell occupancy of the buffer. We also analyze theoretically the cell loss probability and the mean cell delay time for the proposed priority control mechanism. The two service classes of concern are the delay sensitive class and the loss sensitive class. The loss sensitive class cell occupancy represents the number of the loss sensitive class cells stored in the buffer. In other words, the proposed priority control mechanism has methods to control the cell service ratio according to the number of the loss sensitive class cells stored in the buffer. Here, the cell service ratio K means that only a loss sensitive class cell is served whenever the maximum number K of delay sensitive class cells are consecutively served. The analytical results show that the proposed priority control mechanism is able to improve the cell loss probability for loss sensitive class cells and the mean cell delay time for delay sensitive class cells by properly controlling the cell service ratio according to the loss sensitive class cell occupancies of the buffer.