Real-time locating system

Real-time localization (English Real - time locating ), a term used in radio navigation and radiolocation, it is first determining the location of an identified object in a previously unknown place without further determination of the corresponding orientation. This location and residence of any object, vehicle or person may be determined and related to the particular identity.


The location determination requires a well-defined terrestrial coordinate system - eg the geographical coordinates or the WGS84 system of GPS satellites. The positions to be located can be fixed or moving.

The detection is generally carried out continuously, wherein the time interval between the change in position of a moving object and the position relative to fixed objects ( reference points ) remains small. Since the location determination quickly follow the moving object, it can be regarded almost as a measure of the movement.

Real-time fixes is also available in astronomy, such as the rapid localization of gamma-ray bursts to judge other telescopes automatically on this sky position, or in the very near-Earth asteroids orbit determination.

Real-time systems

If the task not only of a "off-line " request, ie not bound to response time requirements, but exacerbated from an "on -line" search with the expectation of the answer within a short latency ( dead time, response time), it is Where the function to the class of real-time location and at the appropriate support systems for real -time location systems. These are defined in international standards, such as from the committee ISO / IEC JTC1/SC31 with the discussion proposal ISO / IEC FDIS 19762-5. Such a RTLS (Real Time Locating System ) as defined by the Joint Technical Committee is treated on the specified website. RTLS is a combination of special radio components with a for use in real-time ( real-time) -compatible software, with the help of a multiply repeated delay time measurement the locations of objects, vehicles or persons are determined continuously. Individual characteristics of such systems are also standardized in ISO / IEC 24730-1 ff

Satellite positioning

Technically, the use of an apparatus for satellite positioning system (GPS) in conjunction with a mobile telephone (GSM), a method of real-time location. Of a resolution of the standard setting body, originally known as ISO / IEC 24730-4 provided standardization of the GPS system from the planning of this committee was deleted without source references. Thus, the combination is (GPS with GSM) no formal RTLS method according to ISO 19762-5.

Cellular localization

Technically, the posting of a mobile phone is used in a base station for the local determination. By detecting the direction and distance of a place can be determined with respect to polar coordinates on the base station by such GSM positioning. This applies accordingly except for the GSM network for other wireless networks UMTS and future networks. The resolution of the analysis depends on the quality of the measurement means. As a rule, even in dense occupation of an urban area with base stations no better resolution than with errors of -30m is possible. In rural areas, the resolution is still coarse.

Informational self-determination

The Informational self-determination conflicts in general with the use and acceptance of systems for determining location. In some gazettes is claimed by real-time location the rights of informational self-determination would be restricted. This is legal nonsense.

Each RTLS method according to ISO / IEC 19762-5 is always tied to a fixed base and the deliberate taking along a RTLS mark. However, the participants in a system utilization for real -time location must be specifically and individually to give consent in order to ensure the legality of the application. Therefore, the explicit consent of the parties is mandatory for the legal use of technical solutions.

In some publications RTLS is set equal to (according to ISO / IEC 19762-5 ) with RFID ( ISO / IEC 19762-3 ). This is technical nonsense. However, functions of the radio-frequency identification ( RFID) are a subset of the functions of the real-time location (RTLS ). In promotional statements for the part between systems for RTLS and RFID solutions is not clearly separated. Each RFID process with features of localization is always tied to a fixed installation and the deliberate carry an RFID tag.

By interested parties allege that the real-time location of a person is technically possible without the knowledge of the person concerned. The remains of technical nonsense. However, it is possible to locate objects and from the location of objects close to the place where there is its wearer or user. This is true for example for mobile phones. This procedure is called GSM-tracking or cell network location. It is not, this is a method RTLS according to ISO / IEC 19762-5.

A so-called retention of the German Interior Ministries formally fulfilled the violation of the basic right of informational self-determination. By jurisdiction of the federal courts in 1983 and most recently in 2006, it was clarified that at least subsequently and promptly the person concerned must be informed. This also applies to any local determination, by whatever technical means. It is, however, not generally to a method RTLS according to ISO / IEC 19762-5. This method is always tied to a fixed base and the deliberate taking along a RTLS mark.

Indicator in identity card and passport

The FRFID - plates used in the new German ID cards and passports are with the allowed RF field strengths can only be read at close range and therefore do not support RTLS location in real time.