Analyses of location-based services in Africa and investigating methods of improving its accuracy

摘要

The subject area of this thesis analyses the provision of location-based services (LBS) in Africaudand seeks methods of improving their positional accuracy. The motivation behind this work isudbased on the fact that mobile technology is the only modern form of information andudcommunication technology available to most people in Africa. Therefore all services that can beudoffered on the mobile network should be harnessed and LBS are one of these services. Thisudresearch work is novel and is the first critical analysis carried out on LBS in Africa; therefore itudhad to be carried out in phases.udA study was first carried out to analyse the provision of LBS in Africa. It was discovered thatudAfrica definitely lags much of the World in the provision of LBS to its mobile subscribers; onlyuda few LBS are available and these are not adapted to the needs of the African people. A field dataudempirical investigation was carried out in South Africa to evaluate the performance of LBSudprovided. Data collected indicated that the LBS provided is not dependable due to the inaccuracyudintroduced by two major factors - the positioning method and the data content provided.udAnalyzing methods to improve the positional accuracy proved quite challenging because Africaudbeing one of the poorest continents has most mobile subscribers using basic mobile phones.udConsequently, LBS often cannot be provided in Africa based on the capability of the mobileudphones but rather on the capability of the mobile operator’s infrastructure. However, provision ofudLBS using the network-based positioning technologies poses the challenge of dynamicallyudvarying error sources which affects its accuracy.udThe effect of some error sources on network-based positioning technologies were analysed and audmodel developed to investigate the feasibility of making the RSS-based geometric positioningudtechnologies error aware. Major consideration is given to the geometry of the BSs whoseudmeasurements are used for position estimation.udResults indicated that it is feasible to improve location information in Africa not just byudimproving the positioning algorithms but also by using improved prediction algorithms,udincorporating up-to-date geographical information and hybrid technologies. It was alsoudconfirmed that although errors are introduced due to location estimation methods, it is impossibleudto model the error and make it applicable for all algorithms and all location estimations. This isudbecause the errors are dynamically varying and unpredictable for every measurement.