A fuzzy policing mechanism for still picture in ATM networks

The asynchronous transfer mode (ATM) technique has been accepted as a basis for the future B-ISDN networks. In ATM networks, all information is packetized and transferred 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 the need of a policing mechanism to control the traffic parameters of each virtual connection in order to guarantee the required quality of service (QoS). The proposed parameters for monitoring the source traffic characteristics are the mean cell rate, the peak cell rate or the peak burst duration. Policing of the peak cell rate is generally not complex and can be achieved by using a cell spacer or other policing mechanisms (PMs). Monitoring the mean cell rate is more difficult. It is intended to improve the link utilization when it has to handle bursty traffic sources. We propose a policing mechanism called the fuzzy policing mechanism (FPM), by applying fuzzy set theory to police the mean cell rate of the still picture source in ATM networks. The performance evaluation via simulation shows that the FPM efficiently control the mean cell rate of the still picture source. The proposed FPM shows a good response behavior against parameter variations. The selectivity characteristics of the FPM approach the ideal characteristics required for a PM