COST 257 MID-TERM SEMINAR INTERIM REPORT ON QUEUEING SYSTEMS Queueing Systems

Preface This report gives an overview of the queueing problems addressed in the COST 257 action on " Impacts of new services on the architecture and performance of broadband networks ". Typically, these problems arise in modelling the behavior of the queues appearing in multiplexers, traffic shapers, resequencing units or at the output ports of switching elements. In the report, the evident distinction is made between discrete-time models and continuous-time models, but also between very specific models with long range dependence characteristics as opposed to the classical queueing models. First, an overview is given of the work of COST 257 on classical discrete-time queueing models. Some general relationships for discrete-time single-server queues with a first-in-first-out (FIFO) queueing discipline are introduced and four specific discrete-time models are presented. Three models are analyzed by means of a generating-functions approach, for the other model an iterative algorithm is used. Second, two classical continuous-time queueing models are discussed. Next, queueing problems related to long range dependent input processes are addressed. Also, the queueing analysis of some specific network elements is discussed. Finally, an overview of miscellaneous COST 257 temporary documents, in some sense related to queueing, is given. This interim report is based on technical documents of COST 257 members and experts. Contributions of the following authors have been used: