Analysis of a Generalized Retrial System with Coupled Orbits

Abstract

We study a single-server retrial queueing model with N classes of customers following independent Poisson inputs. A class-i customer, which meets server busy, joins a type-i orbit. Then orbital customers try to occupy the server using a modified constant retrial policy called coupled orbit queues policy. Namely, the orbit i retransmits a class-i customer to server after an exponentially distributed time with a rate which depends in general on the binary states (busy or not) of other orbits j /= i. The service times have general class-dependent distribution and the model is described by a non-Markov regenerative process. This model is motivated by increase the impact of wireless interference. We apply regenerative approach and local balance equations to obtain necessary stability conditions and some bounds on the important performance measures of the model. Moreover, we suggest also a sufficient stability condition and verify our results numerically by simulation experiments.

Keywords

• coupled orbits
• stability
• queuing model
• multi-server system
• simulation