GSM localization

GSM localization is the use of multilateration to determine the location of GSM mobile phones, usually with the intent to locate the user [ [ "Location Based Services for Mobiles: Technologies and Standards“] , Shu Wang, Jungwon Min and Byung K. Yi, IEEE International Conference on Communication (ICC) 2008, Beijing, China] .

Types of LBS Technology

Localization-Based Systems can be broadly divided into:
* Network based
* Handset based
* Hybrid

Network Based

Network-based techniques utilize the service provider's network infrastructure to identify the location of the handset. The advantage of network-based techniques 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. This technique determines the location of the handset by computing its location by cell identification, signal strengths of the home and neighboring cells or the latitude and longitude, if the handset is equipped with a GPS module. The calculated location is then sent from the handset to a location server.

The key disadvantage of this technique is the necessity of installing software on the handset. It requires the active cooperation of the mobile subscriber as well as software that must be able to handle the different operating systems of the handsets. Typically, only a smart phone, such as one based on Symbian or Windows Mobile, would be able to run such software.

One of the proposed work-arounds is the installation of embedded hardware or software on the handset by the manufacturers. However, the obvious difficulty of convincing different manufacturers to cooperate on a common mechanism and to address the cost issue means that this avenue has not made any significant headway.

Another difficulty would be to address the issue of foreign handsets that are roaming in the network.


Hybrid-based techniques use a combination of network-based and handset-based technologies for location determination. One example would be Assisted-GPS, which uses both GPS and network information to compute the location. Hybrid-based techniques give the best accuracy of the three but inherit the limitations and challenges of network-based and handset-based technologies.

Examples of LBS technologies

*Cell Identification - The accuracy of this method can be as good as a few hundred meters in urban areas, but as poor as 32 km in suburban areas and rural zones. The accuracy depends on the known range of the particular network base station serving the handset at the time of positioning.
*Enhanced Cell Identification - With this method, one can get a precision similar to Cell Identification, but for rural areas, with circular sectors of 550 meters.
*TDOA - Time difference of arrival - The network determines the time difference and therefore the distance from each base station to the mobile phone.
*TOA - Time of arrival - Same as TDOA, but this technology uses the absolute time of arrival at a certain base station rather than the difference between two stations.
*AOA - Angle of arrival - AOA mechanism locates the mobile phone at the point where the lines along the angles from each base station intersect.
* E-OTD - This is similar to TDOA, but the position is estimated by the mobile phone, not by the base station. The precision of this method depends on the number of available LMUs in the networks, varying from 50 to 200 m.
* Assisted-GPS - A largely GPS-based technology, which uses an operator-maintained ground station to correct for GPS errors caused by the atmosphere/topography. Assisted-GPS positioning technology typically falls back to cell-based positioning methods when indoors or in an urban-canyon environment.


ee also

* Assisted GPS
* Base station
* Cell site
* Global Positioning System
* GPS Phone
* GSM localization
* Internationalisation : usability, product design, user interface and cultural data collection
* Locating
* Location-based service
* Mobile dating
* Mobile phone
* Multilateration
* Positioning (telecommunications)
* Real Time Locating
* Secure telephone

External links

* [ openB
* [ GSM Localization on Mobile Phones]
* [ OpenCellID: An OpenSource CellID database]
* [ CellSpotting: A Global Cell Id-Based Information Service]
* [ LBS, the ingredients and the alternatives]
* [ Location API for J2ME]
* [ J2ME and Location-Based Services]
* [ Celltrack for Symbian phones]

Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Localization — or localisation may refer to:* Internationalization and localization, the adaptation of computer software for non native environments, especially other nations and cultures * Language localisation, the process of translating a product into… …   Wikipedia

  • GSM — For other uses, see GSM (disambiguation). The GSM logo is used to identify compatible handsets and equipment GSM (Global System for Mobile Communications, originally Groupe Spécial Mobile), is a standard set developed by the European… …   Wikipedia

  • Mobile phone tracking — refers to the attaining of the current position of a mobile phone, stationary or moving. Localization may occur either via multilateration of radio signals between (several) radio towers of the network and the phone, or simply via GPS. To locate… …   Wikipedia

  • Geo (marketing) — As a general term, Geomarketing is the integration of Geographical intelligence into all marketing aspects including sales and distribution. Geomarketing Research is the use of geographic parameters in research methodology starting from sampling …   Wikipedia

  • Proximity marketing — is the localized wireless distribution of advertising content associated with a particular place. Transmissions can be received by individuals in that location who wish to receive them and have the necessary equipment to do so. Distribution may… …   Wikipedia

  • Time of arrival — (ToA), also named Time of Flight (ToF), which both means the travel time of a radio signal from a single transmitter to a remote single receiver. By the relation between light speed in vacuum and the carrier frequency of a signal the time is a… …   Wikipedia

  • Location-based service — A location based service (LBS) is an information and entertainment service, accessible with mobile devices through the mobile network and utilizing the ability to make use of the geographical position of the mobile device. [ [http://www.geo.unizh …   Wikipedia

  • Waypoint — A waypoint is a reference point in physical space used for purposes of navigation.ConceptWaypoints are sets of coordinates that identify a point in physical space. For the purposes of terrestrial navigation, these coordinates usually include… …   Wikipedia

  • Mobile dating — Relationships Types …   Wikipedia

  • Global Positioning System — GPS redirects here. For other uses, see GPS (disambiguation). Geodesy Fundamentals …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”