ABSTRACT

Location positioning can be of two types: relative or absolute. When using a geometric location data model, there are a number of shapes that can be used to represent a geographic area that describes where a mobile user is located. Additional shapes are required for more advanced location-based services. The location modeling languages can be regarded as application programming interfaces (API) for the location data, which are also used as the communication exchange protocol for the information. Languages for modeling location information must conform to a number of requirements, which come from their aspects as both representation languages and APIs to data models. The most frequently used API for mobile location systems is the Mobile Location Protocol (MLP). The MLP is distributed over a set of common document type definitions (DTD) that define the core elements. In effect, the documents and DTDs together define data structures for the Hypertext Transfer Protocol methods.