Cell of origin
Cell of origin (COO) is a
Overview
Crude COO positioning considers the location of the base station to be the location of the caller. This is not very accurate, as the majority of mobile network cells are projected from an antenna with a spread of 120° (i.e. three mounted on a mast to give complete coverage) giving a signal coverage area with the base station at one corner, rather than the centre. Omnidirectional cells may be used in rural locations (which typically have large ranges and hence uncertain locations for phones within them) and in cities (where they may have ranges of a few hundred metres). The underlying issue is that mobile phone networks are optimised for capacity and call handling rather than locating phones.
Mechanism
Most commercially implemented systems rely on 'enhanced' COO. In the
All networks generate 'splash maps' predicting signal coverage when planning and managing their networks. These maps can be processed to analyse the area which will be dominated by each base station and to approximate each area by a circle (the actual area of coverage may not be exactly where predicted... and in any case will be an irregular shape, rather than a circle).
Application
In practice a network offering location services to third parties will present an
COO is the only positioning technique that is widely used in wireless networks and is used for Phase 1 of