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This dissertation investigates the development of new Global system for mobile communications (GSM) improvement algorithms used to solve the nondeterministic polynomial-time hard (NP-hard) problem of assigning cells to switches. The departure of this project from previous projects is in the area of the GSM network being optimised. Most previous projects tried minimising the signalling load on the network. The main aim in this project is to reduce the operational expenditure as much as possible while still adhering to network element constraints. This is achieved by generating new network configurations with a reduced transmission cost. Since assigning cells to switches in cellular mobile networks is a NP-hard problem, exact methods cannot be used to solve it for real-size networks. In this context, heuristic approaches, evolutionary search algorithms and clustering techniques can, however, be used. This dissertation presents a comprehensive and comparative study of the above-mentioned categories of search techniques adopted specifically for GSM network improvement. The evolutionary search technique evaluated is a genetic algorithm (GA) while the unsupervised learning technique is a Gaussian mixture model (GMM). A number of custom-developed heuristic search techniques with differing goals were also experimented with. The implementation of these algorithms was tested in order to measure the quality of the solutions. Results obtained confirmed the ability of the search techniques to produce network configurations with a reduced operational expenditure while still adhering to network element constraints. The best results found were using the Gaussian mixture model where savings of up to 17% were achieved. The heuristic searches produced promising results in the form of the characteristics they portray, for example, load-balancing. Due to the massive problem space and a suboptimal chromosome representation, the genetic algorithm struggled to find high quality viable solutions. The objective of reducing network cost was achieved by performing cell-to-switch optimisation taking traffic distributions, transmission costs and network element constraints into account. These criteria cannot be divorced from each other since they are all interdependent, omitting any one of them will lead to inefficient and infeasible configurations. Results obtained further indicated that the search space consists out of two components namely, traffic and transmission cost. When optimising, it is very important to consider both components simultaneously, if not, infeasible or suboptimum solutions are generated. It was also found that pre-processing has a major impact on the cluster-forming ability of the GMM. Depending on how the pre-processing technique is set up, it is possible to bias the cluster-formation process in such a way that either transmission cost savings or a reduction in inter base station controller/switching centre traffic volume is given preference. Two of the difficult questions to answer when performing network capacity expansions are where to install the remote base station controllers (BSCs) and how to alter the existing BSC boundaries to accommodate the new BSCs being introduced. Using the techniques developed in this dissertation, these questions can now be answered with confidence. / Dissertation (MEng)--University of Pretoria, 2008. / Electrical, Electronic and Computer Engineering / unrestricted

Location dataflow analysis of mobile objects in GSM network is performed in this project. Dataflow are analyzed in these network nodes: BTS, BSC, MSC, and HLR. During research it is analyzed how data flows changes during day period, how these changes influence network nodes. The possibilities to gather and store data about subscribers' location are explored. The main target of this project is to set guidelines for implementation of European Union directive ST15449 in real GSM networks. Statistic data about data flow types is supplied by real GSM network operator. Experiments were performed using emulator of GSM network data flows. Additional features necessary for analysis were specified and implemented. After analysis it is determined that lowest impact of location dataflow is for BSC component. It is proposed to implement any location data gathering device in BSC nodes.

System hardware and software design for a GSM switch with ten switching outputs, controlled via SMS. Description of used GSM module and its properties, feasibility and requirements, design and description of supply circuits for module outputs to relay outputs decoding, plug-in realisation of outputs. GSM module application software creation, remote SMS control requests implementation, sender's phone number check and information about completed requests by call-backs. Adding AT command to set up device. Development of web server providing control of switch throught Internet browser, solving communication between server and device, and data management. Testing of created SW and evaluation of final design from aspects of usage.