Modelling of Call Admission Control in 3G Cellular Mobile Networks

Date

2008-7

Type

PhD Thesis

Thesis title

University of Bradford

Issue

Vol. 1 No. 1

Author(s)

Wael Saleh Abughres

Pages

1 - 239

Abstract

Mobile terminals allow users to access services while on the move. This unique feature has driven the rapid growth in the mobile network industry, changing it from a new technology into a massive industry within less than two decades. In this thesis, we address admission control problems in a cellular wireless environment. The admission control is responsible for deciding whether an incoming call or connection can be accepted or not, which are based on the available codes . We provide an extensive survey of the existing admission control algorithms. The issues related to and the approaches for designing admission control in third generation(3G) cellular wireless networks are discussed. An admission control method considering the quality of service(QoS) requirements in wireless is presented along with an analytical traffic model for the Universal Mobile Telecommunication Systems(UMTS). In 3G networks we have dynamic capacity that depends on the interference levels in the covered area and the number of active users. This implies that the distance of a mobile user from the base station, which is called Node B, is also an important factor because of the signal fading. The first part of this work is an algorithm written in C++ programming language that distributes users in different zones assuming that the cell area is divided into Z virtual zones, where Z depends on the number of users. In the rest of this thesis we present a simulation model for the Universal Mobile Telecommunication Systems(UMTS). For validation purposes, we have developed a much more detailed simulation of the system written in C language. The results of the mathematical model showed that, a product form equilibrium distribution holds in the case of two cells. Theses results are used to validate a simulation, and to show that the behaviour of the system is similar to that in the mathematical model. Once the product form of Jackson’s Theorem is known to hold, then it is possible to go to a more advanced stage to analyze the 3G network, and to get the performance measures, which will help in making decisions at the design stage of a network. To be more realistic, we used traffic distributions in the simulator, where a user can generate world wide web sessions(www), file transfer sessions, and Emails. These followed recommendations in the ETSI standard and further demonstrated the feasibility of the model.

Publisher's website

View