Mariusz Glabowski

Uplink Blocking Probability Calculation for Cellular Systems with WCDMA Radio Interface, Finite Source Population and Differently Loaded Neighbouring Cells

This paper presents the uplink blocking probability calculation method in cellular systems with WCDMA radio interface, finite source population and differently loaded neighbouring cells. The method is based on the model of the full availability group with multi-rate traffic streams. A fixed point methodology has been used in the proposed method. The proposed scheme could be utilized for cost-effective radio resource management in 3G mobile networks and can be easily applied to network capacity calculations

Point-to-point blocking probability in switching networks with reservation

In this paper reservation algorithms for multi-service switching networks are proposed. Two new approximate methods of the point-to-point blocking probability calculation in the multi-service switching networks are also presented in the paper. These methods can be used for blocking calculation in the switching networks with and without reservation. Special attention is paid to the method for determining the effective availability, which directly affects the accuracy of the final results. The results of analytical calculations are compared with the data of digital simulation of switching networks without and with reservation.In this paper reservation algorithms for multi-service switching networks are proposed. Two new approximate methods of the point-to-point blocking probability calculation in the multi-service switching networks are also presented in the paper. These methods can be used for blocking calculation in the switching networks with and without reservation. Special attention is paid to the method for determining the effective availability, which directly affects the accuracy of the final results. The results of analytical calculations are compared with the data of digital simulation of switching networks without and with reservation.RésuméCet article présente les algorithmes de réservation dans les réseaux de connexion à trafic intégré. On propose deux méthodes approchées du calcul de la probabilité du blocage point à point dans les réseaux de connexion multiservices. Ces méthodes proposées peuvent être appliquées au calcul du blocage dans les reseaux avec (et sans) mécanisme de réservation. En particulier, on fait attention à la manière de déterminer l’accessibilité effective de laquelle dépend l’exactitude du résultat final. Les résultats du calcul analytique de la probabilité du blocage sont comparés aux résultats de la simulation numérique des réseaux de connexion avec et sans réservation.

Asymmetric convolution algorithm for blocking probability calculation in full-availability group with bandwidth reservation

The paper proposes a new approximate calculation method of occupancy distribution and blocking probability in the full-availability group (FAG) with multi-rate traffic streams and bandwidth reservation. The algorithm involves calculation of system state probabilities by a convolution operation. In the paper, an effective method of calculating state probabilities in a reservation space of the system is derived. The analytical results of blocking probabilities in the FAG with bandwidth reservation, obtained on the basis of the proposed analytical method, are compared with the data obtained on the basis of other known analytical methods and with the simulation results. The accuracy of the proposed method is evaluated for different multi-rate Bernoulli (Erlang), Poisson (Engset), Pascal traffic streams. The method proposed is characterised by lower complexity than the convolution algorithm for the FAG with bandwidth reservation devised earlier.

Erlang's Ideal Grading in DiffServ modelling

Traffic overflow is one of the most effective mechanisms of the management of traffic distribution in telecommunications systems. The paper considers a possibility of using traffic overflow in present-day IP networks. Additionally, a new simplified method for the calculation of the blocking probability in overflow systems is proposed in the paper. The method is based on the model of Erlangs Ideal Grading (EIG) with multi-rate (multi-service) traffic and different availabilities. The method does not require calculations of the parameters of overflow traffic and its accuracy is not lower than the accuracy of other methods for the calculation of overflow systems with multi-rate traffic available in the literature of the subject. The results of the analytical calculations have been compared with the results of the simulations, which has confirmed the high accuracy of the proposed model.

Modeling Erlang's Ideal Grading with Multirate BPP Traffic

This paper presents a complete methodology for modeling gradings (also called non-full-availability groups) servicing single-service and multi-service traffic streams. The methodology worked out by the authors makes it possible to determine traffic characteristics of various types of gradings with state-dependent call arrival processes, including a new proposed structure of the Erlang’s Ideal Grading with the multirate links. The elaborated models of the gradings can be used for modeling different systems of modern networks, for example, the radio interfaces of the UMTS system, switching networks carrying a mixture of different multirate traffic streams, and video-on-demand systems. The results of the analytical calculations are compared with the results of the simulation data for selected gradings, which confirm high accuracy of the proposed methodology.

Simulator of Full-Availability Group with Bandwidth Reservation and Multi-Rate Bernoulli-Poisson-Pascal Traffic Streams

This paper presents an approach to simulation investigations of a full-availability group with multi-rate Poisson, Bernoulli and Pascal traffic streams. In the paper the models of a full-availability group with and without bandwidth reservation are described. The particular distributions of various traffic streams are also presented. The proposed simulator is based on events-scheduling approach. The paper deals also with implementation issues related to simulation research of the systems with Bernoulli, Poisson and Pascal traffic streams.

Modelling of systems with overflow multi-rate traffic and finite number of traffic sources

The paper proposes an analytical method for determining basic traffic characteristics of systems servicing multi-rate overflow traffic streams generated by a finite number of sources. The basis of the proposed analytical model is the Bretschneider method extended in this paper for systems with multi-rate traffic. Analytical results of blocking probability calculated using the presented methodology have been compared with the data obtained from the system simulation process.

Recurrent Calculation of Blocking Probability in Multiservice Switching Networks

This paper presents a new analytical recurrent method of blocking probability calculation in multistage multiservice switching networks. The method is based on the concept of effective availability. The results of analytical calculations of the probabilities of blocking are compared with the simulation results of multistage switching networks, and, therefore, the validity of the assumptions used in the model is proved

Equalisation of Blocking Probability in Switching Systems with Limited Availability

Three reservation algorithms for the limited-availability system are proposed and compared in the paper. These algorithms can be used for call blocking equalisation in outgoing links of multiservice switching networks. Two approximate methods of equalised blocking probability calculation in the system with limited availability are proposed. Results of analytical calculations are compared with results of digital simulation of limited availability groups and switching networks with reservation. These researches have confirmed a great accuracy of the proposed calculation methods. The formulae derived by the authors can be useful for the analysis and design of ISDN and B-ISDN systems.

Continuous threshold model for multi-service wireless systems with PCT1 and PCT2 traffic

This paper proposes an analytical calculation method for determining occupancy distribution and blocking probability in multi-threshold state-dependent systems that simultaneously service multi-rate PCT1 and PCT2 traffic streams. The proposed analytical model is applied to calculate traffic characteristics in UMTS networks with streaming, adaptive and elastic services. The results of analytical calculations of blocking probability in the UMTS cell are compared with simulation data in order to evaluate accuracy of the proposed analytical model.