Performance evaluation of the Fuzzy Policing Mechanism for still picture in ATM networks

Abstract

The Asynchronous Transfer Mode (ATM) technique has been accepted as a basis for future B-ISDN networks. In ATM networks, all information is packetized and transfered in small packets of fixed length, called cells. The packetized information transfer, without flow control between the user and the network and the use of statistical multiplexing, results in a need of a Policing Mechanism (PM) to control the traffic parameters of each virtual connection in order to guarantee the required Quality of Service (QoS). Policing of the peak cell rate is generally not complex. The control of the mean cell rate is more difficult, but is intended to improve the link utilization when it has to handle bursty traffic sources. Conventional PMs, such as the Leaky Bucket Mechanism (LBM) and the Window Mechanisms (WMs), are not well suited to the bursty nature of sources supported by ATM networks, therefore intelligent PMs are needed. In this paper, we propose a Fuzzy Policing Mechanism (FPM) to police the mean cell rate of the still picture source. We consider the case when the peak cell rate of the still picture source is not controlled separately by other PMs. The performance evaluation via simulations shows that the FPM efficiently controls the mean cell rate of the still picture source. The FPM has better responsiveness and selectivity characteristics than the LBM.