Michał Dominik Stasiak

Modelling of multiservice switching networks with overflow links for any traffic class

This study proposes a new analytical model of a multi-service switching network with overflow links with finite capacity in the first stage of the network. The proposed model assumes that overflow links can service a number of selected call classes from among all classes offered to the network. A particular attention is given to the method for a determination of the effective availability parameter for networks with overflow links. The proposed model can be also used to determine the dependence between the internal blocking probability and the capacity of overflow links. A relevant simulation study has confirmed high accuracy of the proposed method as well as the applicability of the model in engineering practice, in modelling of multi-stage switching networks both optical and electronic.

Internal blocking probability calculation in switching networks with additional inter-stage links and engset traffic

This paper presents a method for modeling switching networks with overflow links that are offered multi-service traffic generated by a limited number of sources. A particular emphasis is put on the possibility to achieve a significant reduction in the blocking probability in the switching network that will result from the application of additional overflow links in the first stage of the switching network. Additionally, the paper proves that the accuracy of the proposed method for switching networks with Engset traffic is not lower than that for networks with Erlang traffic. The results of the analytical calculations are compared with the results obtained during the simulation experiments, which confirms the correctness and validity of all adopted theoretical assumptions.

Internal Blocking Probability Calculation in Switching Networks with Additional Inter-Stage Links and Mixture of Erlang and Engset Traffic

Abstract In the article a new analytical approximate method for modeling multi-service switching networks with overflow links is proposed. The method can be used for blocking probability calculation in switching networks that are offered multi-service traffic generated by finite and infinite number of sources, i.e., in switching networks with multi-service Engset traffic, in switching networks with multiservice Erlang traffic, as well as in multi-service switching networks with Erlang and Engset traffic. The simulation study performed proves high accuracy of the method proposed and confirms the correctness and validity of all adopted theoretical assumptions.

Modelling of Switching Networks with Multiservice Traffic by the IPGBMT Method

This paper presents a new analytical method for approximation of blocking probabilities in multiservice switching networks with point-to-group selection. The method is based on the classic PGBMT method which has been adequately modified to improve the accuracy of the final results. In order to estimate and verify the correctness of all theoretical assumptions adopted in the study, the results of the analytical modelling are compared with the results of the digital simulation and the results obtained by the classic PGBMT method in a number of selected three-stage multiservice Clos networks.

Multiservice Switching Networks with Overflow Links and Resource Reservation

This paper proposes a new analytical model of a multiservice switching network with overflow links in the first stage and resource reservation for selected call classes in output directions. The proposed model assumes that both the overflow mechanism and the resource reservation mechanism can be used in a number of selected, or all, classes of calls. A particular attention is given to the way the effective availability parameter for networks with overflow links in the point-to-point selection mode is determined. The proposed model makes it possible to determine dependencies between the internal blocking probability, capacity of overflow links, and the number of reserved resources for call classes to be analysed. Simulation experiments confirm high accuracy of the proposed method and potential applications of the model in engineering issues.

A Study on the Effectiveness of Threshold and Traffic Overflow Mechanisms in Multi-service Switching Networks with Real-time and Non-real-time Traffic

This article presents the results of a simulation study that examines the performance and the effectiveness of threshold mechanisms and traffic overflow mechanisms in multiservice switching networks. A threshold mechanism is used in the study to control those services that do not require data transmission in real time, i.e. the so-called elastic services. Traffic streams that are generated by these services (non-real-time traffic) can have variable transmission time dependent on available resources in the system. The traffic overflow mechanism is used, in turn, to guarantee the delivery of real-time traffic streams for which the amount of demanded resources cannot be reduced. The study confirms the effectiveness of the application of the proposed mechanisms in decreasing the call blocking probability in multi-service switching networks.

Queuing models for wireless mesh networks

Abstract In this paper we discuss a proposition of various applications of new queueing models that have been developed within the CARMNET project in nodes of the mesh network. These models allow characteristics of systems that service multi-rate traffic to be determined, e.g., the average queue length or the average waiting time for calls of a given class. The proposed models can be used to design, analyse and optimize multiservice networks