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Problem positioning of mobile phones involves the automatic determination of their location within cellular networks.

Thus, the term "location" follows understood not find geographic coordinates - latitude and longitude (which, in principle, also possible), and the unambiguous identification of the position of the mobile phone owner terrain (e-card).

This option holds great promise for both mobile operators and for various public services for various purposes, which receive their hands on a powerful tool that allows you to track the location of subscribers, especially as mobile network operators can retrieve data continuously and without any notice owner of the mobile phone.

It is not necessary to intercept party talks; enough to power turned on a mobile phone, which provides periodic communication with the base station, even without challenges.

However, many experts stress the possibility of such dual-use technologies

The fact that the possibility of security solutions that open technology positioning in cellular networks, and pose a threat in the area of privacy. The end user of such technology gets right to direct invasion of privacy, without any consent of the subscriber.

Also, many subscribers of cellular networks is believed that the location of features enjoy not only the police or emergency services, but criminal elements with appropriate technical capabilities. This idea is under a substantiation. Therefore, in cellular networks to solve the problem of the strict confidentiality of information on location of cellular subscribers and protect this information from intruders.

To this end, the European Commission of Communications at the beginning of the introduction of mobile services, which is a queuing system, defined the requirements to be followed by mobile operators. In particular, plant location must be used exclusively for the stated purposes first, for example, to provide technical assistance on the road and avoid the double use. When you run database queries location information should be confidential and to ensure the anonymity of users.

To determine the position of any radiotransmitting device may be used three main parameters of radio signals: their amplitude at the site of the reception, the direction of arrival and the time delay in the distribution.

The amplitude of the received signals, able to characterize the distance between the transmitter and receiver. However, in practice the level of mobile phone signals in place of reception depends on a large number of reasons, in most cases, can not provide the required accuracy of the location and is used as an option.

Ward direction signals can be automatically determined, for example, the phase difference signals at the antenna elements gratings mounted on the base station network. Bearing intersection of two (or more numbers) provides places (with some accuracy) determine the position of the mobile phone.

The delay in propagation of signals can also be used in solving the problem of positioning. At a certain point in time accurately transmit radio signals by measuring the time of arrival at the receiver base station can calculate the distance from the mobile to the base station if tight time synchronization of all system elements. It is this positioning technology cell phones become the basis for most currently used location of the subscriber.

Modern industrial platform caller location in cellular networks based on three alternative technologies:

technology of the time of arrival (TOA), based on measuring and comparing time intervals of the signal from the mobile phone number to several base stations;

technology time difference OTD (Observed Time Difference), is based on measuring and comparing time intervals of signals from multiple base stations to the mobile subscriber;

mobile phones technology is a combination of the satellite navigation A-GPS (Assisted Global Positioning System), based on the embedded GPS-receivers into mobile phones.

The issue of accuracy when positioning objects in mobile networks has led to the emergence of a large number of brand development for special purposes. There are more than two dozen decisions that are used as individual location methods, and combinations thereof.

Source: Authors publication

Published: 5. 11.2013

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