An Erlang multirate loss model supporting elastic traffic under the threshold policy

In this paper, we propose a multirate teletraffic loss model of a single link with certain bandwidth capacity that accommodates Poisson arriving calls, which can tolerate bandwidth compression (elastic traffic), under the threshold policy. When compression occurs, the service time of new and in-service calls increases. The threshold policy provides different QoS among service-classes by limiting the number of calls of a service-class up to a pre-defined threshold, which can be different for each service-class. Due to the bandwidth compression mechanism, the steady state probabilities in the proposed model do not have a product form solution. However, we approximate the model by a reversible Markov chain, and prove recursive formulas for the calculation of call blocking probabilities and link utilization. The accuracy of the proposed formulas is verified through simulation and found to be very satisfactory

Performance analysis of CDMA-based networks with interference cancellation, for batched poisson traffic under the Bandwidth Reservation policy

CDMA-based technologies deserve assiduous analysis and evaluation. We study the performance, at call-level, of a CDMA cell with interference cancellation capabilities, while assuming that the cell accommodates different service-classes of batched Poisson arriving calls. The partial batch blocking discipline is applied for Call Admission Control (CAC). To guarantee certain Quality of Service (QoS) for each service-class, the Bandwidth Reservation (BR) policy is incorporated in the CAC; i.e., a fraction of system resources is reserved for high-speed service-classes. We propose a new multirate loss model for the calculation of time and call congestion probabilities. The notion of local (soft) and hard blocking, users activity, interference cancellation, as well as the BR policy, are incorporated in the model. Although the steady state probabilities of the system do not have a product form solution, time and call congestion probabilities can be efficiently determined via approximate but recursive formulas. Simulation verified the high accuracy of the new formulas. We also show the consistency of the proposed model in respect of its parameters, while comparison of the proposed model with that of Poisson input shows its necessity

QoS Equalization in a W-CDMA Cell Supporting Calls of Innite or Finite Sources with Interference Cancelation, Journal of Telecommunications and Information Technology, 2014, nr 3

In this paper, a multirate loss model for the calculation of time and call congestion probabilities in a Wideband Code Division Multiple Access (W-CDMA) cell is considered. It utilizes the Bandwidth Reservation (BR) policy and supports calls generated by an innite or nite number of users. The BR policy achieves QoS equalization by equalizing congestion probabilities among calls of dierent service-classes. In the proposed models a multiple access interference is considered, and the notion of local blocking, user's activity and interference cancelation. Although the analysis of the proposed models reveals that the steady state probabilities do not have a product form solution, the authors show that the calculation of time and call congestion probabilities can be based on approximate but recursive formulas, whose accuracy is veried through simulation and found to be quite satisfactory

Journal of Telecommunications and Information Technology, 2014, nr 3

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