This thesis is about Location Based Computing Systems (LBCS), with emphasis on their underlying positioning systems. The first part of the thesis introduces a three-layered reference model for discussing LBCS, and gives background information on positioning systems in general---components, designs, properties, and techniques. It also includes an overview of existing systems for indoor positioning.
The second part of the thesis introduces a case study, which consists of two parts. One is an in-depth overview of a specific Location Based Service (LBS) called a mobile electronic tour guide, a service typically implemented on hand-held devices which are given to visitors at different exhibitions as a means for enhancing their experience of it. This results in a requirements specification. The other part of the case is a detailed description of a given museum, as an example of an indoor exhibition.
The third part of this thesis is an analysis of existing positioning solutions against the requirements specification and museum description. Based on the learning from this analysis, two proposals are provided. The first is a decision flow diagram which can help future developers to choose positioning system for a given LBS. The other is the proposal of a system wide service oriented architecture for future LBCSs, which can improve on the short-comings of existing systems' ability to accomodate various environments and services.