Mobile phone tracking
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Mobile phone tracking tracks the current position of a mobile phone even on the move. To locate the phone, it must emit at least theroaming signal to contact the next nearby antenna tower, but the process does not require an active call. GSM localisation is then done bymultilateration based on the signal strength to nearby antenna masts. Mobile positioning, i.e. location based service that discloses the actual coordinates of a mobile phone bearer, is a technology used bytelecommunication companies to approximate where a mobile phone, and thereby also its user (bearer), temporarily resides. The more properly applied term locating refers to the purpose rather than a positioning process. Such service is offered as an option of the class oflocation-based services (LBS). Contents [hide] * 1 Technology * 1.1 Network Based * 1.2 Handset Based * 1.3 Hybrid * 2 Examples of LBS technologies * 3 Operational purpose * 4 Bearer interest * 5 Privacy * 6 See also * 7 References * 8 External links| -------------------------------------------------
The technology of locating is based on measuring power levels and antenna patterns and uses the concept that a mobile phone always communicates wirelessly with one of the closest base stations, so if you know which base station the phone communicates with, you know that the phone is close to the respective base station. Advanced systems determine the sector in which the mobile phone resides and roughly estimate also the distance to the base station. Further approximation can be done by interpolating signals between adjacent antenna towers. Qualified services may achieve a precision of down to 50 meters in urban areas where mobile traffic and density of antenna towers (base stations) is sufficiently high. Rural and desolate areas may see miles between base stations and therefore determine locations less precisely. GSM localization is the use of multilateration to determine the location of GSM mobile phones, usually with the intent to locate the user  . Localization-Based Systems can be broadly divided into:
* Network based
* Handset based
Network-based techniques utilize the service provider's network infrastructure to identify the location of the handset. The advantage of network-based techniques (from mobile operator's point of view) is that they can be implemented non-intrusively, without affecting the handsets. The accuracy of network-based techniques varies, with cell identification as the least accurate and triangulation as the most accurate. The accuracy of network-based techniques is closely dependent on the concentration of base station cells, with urban environments achieving the highest possible accuracy. One of the key challenges of network-based techniques is the requirement to work closely with the service provider, as it entails the installation of hardware and software within the operator's infrastructure. Often, a legislative framework, such as E911, would need to be in place to compel the cooperation of the service provider as well as to safeguard the privacy of the information. Handset Based
Handset-based technology requires the installation of client software on the handset to determine its location for E-911 purposes. This technique determines the location of the handset by computing its location by cell identification, signal strengths of the home and neighboring cells, which is continuously sent to the carrier. In addition, if the handset is also equipped with GPS then significantly more precise location information is then sent from the handset to the carrier. The key disadvantage of this technique (from mobile operator's point of view) is the necessity of installing software on the handset. It requires the active cooperation of the mobile subscriber as...