Modelling of Call Admission Control in 3G Cellular Mobile Networks
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.
Wael Saleh Abughres(7-2008)
Publisher's website
