Priority leaky buckets with extra token pool for policing traffic in ATM networks

One of the most important tasks in Asynchronous Transfer Mode (ATM) networks is to meet Quality of Service (QoS) requirements for different classes of service. The priority leaky bucket has been proposed to cope with this problem by providing priority level for each service class according to its requirement. However, this scheme has a disadvantage of having to trade off QoS between high and low priority classes, where the low one obtains degraded QoS. In this paper, new priority leaky bucket mechanism with extra token pools in order to improve quality for low priority class is introduced. Fuzzy logic system is also applied with this new scheme, thus token generation rate of the scheme can be dynamically adjusted. The simulation results demonstrate that fuzzy mechanism leads the traditional leaky bucket in terms of cell loss ratio and cell mean delay time, when performing as the traffic shaper and policer.