In addition to the rapid increase in the number of mobile users, the multiplication of the user demands has necessitated the replacement of the third generation mobile networks. With the fourth generation LTE (Long Term Evolution) networks can be served multiple users with better quality and higher data rate.
During my thesis I introduce the main technological features of the LTE 4G mobile networks, the system architecture, the radio access network and the packet switched core network. Within this I review in detail the requirements of the radio interface as well as the process of handover within the 4G cellular networks. Through examples and illustrated by diagrams I present the purpose, function and the role of the X2 interface in the handover process.
The aim of my paper is to examine the load in excess on the transmission networks caused by the user mobility. To perform the examinations I designed a widely usable simulation model which will be able to make further examinations subsequently. By the designed simulation model can be examined the effect of the handover procedure in the 4G networks, the traffic load as well as the data forwarding on the X2 interface.
I implemented the designed model in an own developed software. The automated topology builder algorithm and the network traffic management system are part of the implementation. These two software components ensure the examination of the numerous topology layout. I gave a K-approximation algorithm to the NP-hard (Non-deterministic Polynomial-time hard) automated topology builder algorithm by which the running time of the simulation can be kept under the given constraints.
By using the completed simulation software succeeded to examine the traffic increases on the network links. The examination showed that the traffic increases must be forwarded frequently on the X2 interface but the rate of the increases is not significant compared to a normal traffic.