Cell of Origin (COO) is a mobile positioning method. It uses a GSM network to determine where a mobile device and its users are located. The COO provides the geographic coordinates of the radio cell in which the user's device has entered. The accuracy depends on the size and shape of the radio cells. The smaller the radio cells, the more accurate is the determined position. In the urban area, a position accuracy of approx. 300 m is possible. The determination of the signal propagation time can be improved by an order of magnitude.
The Cell-ID method is also used by the Björn-Steiger-Stiftung as a mobile phone emergency call.
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