Study of a scheduling policy for diverse deadline-based quality of service

Abstract

One of the most challenging problems in ATM network design is providing diversified Quality of Service (QoS) to applications with distinct characteristics. Buffer management schemes can play a significant role in providing the necessary diversification through the employed cell admission and service policy. A flexible priority service policy for two applications (classes) with strict — and in general distinct — deadlines and different deadline violation rates is studied in this paper. The proposed policy is a generalization of the shortest time to extinction (STE) policy (or the Earliest Due Date policy which discards expired cells), which is more flexible in providing diversified QoS. The relationship of this policy to other standard ones is also discussed. A flexible numerical analysis is presented for the derivation of performance measures such as cell loss, mean cell-delay and the tail of the cell-delay probability distribution for each class. Numerical results illustrate the effectiveness of the studied priority scheme. Finally, a low-complexity implementation scheme is proposed, which does not require time-stamp-based sorting.