The traffic load and the rapid changes in the coverage area (and even the seasons) have huge influence on the radio interface in CDMA networks. The works presented in this thesis utilises and explores the tradeoffs relationship between capacity and quality versus coverage in CDMA networks. This thesis presents a method to enhance the QoS in Erbil’s WLL Network Erbil coverage area is about 45 sq km of urban and 20 sq Km suburb. The city is generally hilly area with some flat lands around the urban city centre; this geographical topology has been considered in the optimisation procedure accomplished by this work. The work proposes an enhancement to the radio interface, key performance indicators, a reduction of radio interference and a considerable improvement of the require QoS particularly for voice services. All these have generally been achieved through Tilt and Azimuth of the antenna taking into consideration the area physiognomy and conducting repeated field drive test and data collection and analysis. The radio interface performance is represented by four indicators captured by drive test equipment: Ec/Iο, Rx, Tx and FER. The network performance data stats (QoS) is represented by three indicators: call drop rate, call setup success ratio and soft handoff success rate. The coverage problem spots are resolved during drive test by conducting one or a combination of various techniques; Tilt and Azimuth, relocating the site, rechecking the handoff list or RSSI parameters. In this thesis, the influence of coverage area for each sector upon the action is presented in order to solve both coverage problem and the network performance degradation. The results of this works were clearly reflected through the enhancements of the radio interface performance. By adopting the proposed approach a considerable performance of the network has been achieved. The improvements were clearly reflected in the stats collected after optimisation and a reduction of call drop rate reached 34% when compared with non-optimised network. For an operator, the network performance is always a critical issue. The operation improvements achievable through the appropriate actions need to be carefully assessed. This thesis is extending to construct the best network optimisation procedure at the course of operation. From the perspective of system planning, the choice of best optimisation procedure and deployment options depends on the current and future demands for system performance and the available financial resources.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:517946 |
| Date | January 2009 |
| Creators | Alwandy, Sammaer |
| Publisher | Brunel University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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