Controlling delay differentiation with priority jumps: Analytical study
Tom Maertens - SMACS Research Group, Department of Telecommunications and Information Processing (TELIN), Ghent University (UGent), Sint-Pietersnieuwstraat 41, B-9000 Gent, Belgium (email)
Abstract: Supporting different services with different Quality of Service (QoS) requirements is not an easy task in modern telecommunication systems: an efficient priority scheduling discipline is of great importance.~Fixed or static priority achieves maximal delay differentiation between different types of traffic, but may have a too severe impact on the performance of lower-priority traffic.~In this paper, we propose a priority scheduling discipline with priority jumps to control the delay differentiation.~In this scheduling discipline, packets can be promoted to a higher priority level in the course of time.~We use probability generating functions to study the queueing system analytically.~Some interesting mathematical challenges thereby arise.~With some numerical examples, we finally show the impact of the priority jumps and of the system parameters.
Keywords: Queueing theory, performance evaluation, priority scheduling.
Received: June 2011; Revised: August 2011; Available Online: November 2011.