A Mixed Discrete-Time Delay/Retrial Queueing Model for Handover Calls and New Calls Competing for a Target Channel

Abstract

To study the performance of handover calls approaching a target cell in combination with arrivals of new calls competing for the same cell, a mixed discrete-time delay/retrial model with one server and with priorities for the delayed customers is discussed. The handover calls are modeled as high-priority customers and the new calls as low-priority customers. The priority is non-preemptive. Upon arrival high-priority customers are put in a queue which is served on a first come first served basis. The behavior of the low-priority customers is modeled as in a retrial queue. Arrivals are in batches and all customers are served individually according to generally distributed and independent service times. The joint steady-state distribution of the queue length of the high priority customers and the orbit size of the low-priority customers is studied using probability generating functions. Several performance measures will be calculated, such as the mean queue length of the handover calls and the orbit size of the new calls. Also the covariance between the queue length and the orbit size will be studied, among others.