Fuzzy expert systems are becoming more and more widespread in the fiel
d of real-time control in various applications thanks to the potential
offered by fuzzy logic and the possibility of implementation using ve
ry large scale integration (VLSI) technology, In this paper, we deal w
ith a fuzzy logic-based system which has been purposely designed to ac
hieve real-time traffic control in high-speed networks using the async
hronous transfer mode (ATM) technique, In this kind of network, one of
the most critical functions is ''policing,'' which has the task of en
suring that each user source complies with the traffic parameters nego
tiated in the call setup to avoid network congestion. This function is
difficult to implement on account of certain conflicting requirements
such as selectivity and responsiveness, This is confirmed by the seve
re limits affecting the most popular mechanisms proposed so far, based
on conventional logic. The capacity to formalize approximate reasonin
g processes offered by fuzzy logic is exploited to derive rules of beh
avior for a policer starting from the know-how of an expert in the fie
ld, In the paper, we address two key issues related to the implementat
ion of the fuzzy policer, The first focuses on the possibility of hard
ware implementation of the mechanism using VLSI technology; we present
the design of a VLSI fuzzy processor which exhibits a level of perfor
mance of over three mega fuzzy logic inferences per second (MFLIPS), T
he second issue concerns the suitability of applying the fuzzy policer
to the policing of several classes of sources to reach high levels of
cost effectiveness and scalability, As the results presented in the p
aper show, both these aims are reached.