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Optimization of UMTS access network
Havlíček, Karel ; Kovář, Petr (referee) ; Novotný, Vít (advisor)
This master’s thesis deals with a UMTS radio access network optimization, containing radio interface analysis, services and procedures description, ways to correct parameters calculations and settings and other issues necessary for a correct access network operation. The goal is effective network operation, minimum costs and maximum performance and flexibility of the network. The optimization during system operation is important because of the system character. The UMTS system uses the WCDMA technology, where particular users share the same frequency band and they are distinguished from one another via code sequences. The capacity of such a system is then given by the interference level - each particular user increases the interference level by the value corresponding to his transmit power. The maximum cell capacity is determined by the maximum interference level at which users can still operate with required services, so it is related not only to the number of users, but also to their bit rate. The optimization allows effective usage of the system for different services with different requirements. The main optimization tool is the radio resource management, containing number of algorithms, such as admission control, which decides the acceptance or rejection of a new user demanding certain service, power control, which ensure that users transmit with a minimal power sufficient for required service, handover and cell selection algorithms etc. The major parameter used by these algorithms is a cell load factor, which is related to the interference level margin. There are several methods for the load factor estimation and some of them are described in this work. Some other optimization techniques are mentioned here, too. This work also contains a laboratory exercise proposal for radio resource management introduction using the OPNET Modeler network simulation tool.
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Optimization of UMTS access network
Havlíček, Karel ; Kovář, Petr (referee) ; Novotný, Vít (advisor)
This master’s thesis deals with a UMTS radio access network optimization, containing radio interface analysis, services and procedures description, ways to correct parameters calculations and settings and other issues necessary for a correct access network operation. The goal is effective network operation, minimum costs and maximum performance and flexibility of the network. The optimization during system operation is important because of the system character. The UMTS system uses the WCDMA technology, where particular users share the same frequency band and they are distinguished from one another via code sequences. The capacity of such a system is then given by the interference level - each particular user increases the interference level by the value corresponding to his transmit power. The maximum cell capacity is determined by the maximum interference level at which users can still operate with required services, so it is related not only to the number of users, but also to their bit rate. The optimization allows effective usage of the system for different services with different requirements. The main optimization tool is the radio resource management, containing number of algorithms, such as admission control, which decides the acceptance or rejection of a new user demanding certain service, power control, which ensure that users transmit with a minimal power sufficient for required service, handover and cell selection algorithms etc. The major parameter used by these algorithms is a cell load factor, which is related to the interference level margin. There are several methods for the load factor estimation and some of them are described in this work. Some other optimization techniques are mentioned here, too. This work also contains a laboratory exercise proposal for radio resource management introduction using the OPNET Modeler network simulation tool.
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