Everyone knows that location-based services (LBS) is an information or entertainment service, which is accessible with mobile devices through the mobile network and which uses information on the geographical position of the mobile device, so we won’t bother you with that.
But did you know about the different types of methods used to locate users?
- GPS-based LBS is the simple and standard solution. Sony Ericsson's "NearMe" is one such example. It is used to maintain knowledge of the exact location, however can be expensive for the end-user, as they would have to invest in a GPS-equipped handset. GPS is based on the concept of trilateration, a basic geometric principle that allows finding one location if one knows its distance from other, already known locations.
- GSM localization is the second option. Finding the location of a mobile device in relation to its cell site is another way to find out the location of an object or a person. It relies on various means of multilateration of the signal from cell sites serving a mobile phone. The geographical position of the device is found out using various techniques like time difference of arrival (TDOA) or Enhanced Observed Time Difference (E-OTD).
- Near LBS (NLBS) is another example, in which local-range technologies such as Bluetooth, WLAN, infrared and/or RFID/Near Field Communication (NFC) technologies are used to match devices to nearby services. This application allows a person to access information based on their surroundings; especially suitable for use inside closed premises, restricted/ regional areas.
- Operator- and GPS-independent location service based on access into the deep level telecoms network is another alternative. This solution enables accurate and quick determination of geographical coordinates of mobile phone numbers by providing operator-independent location data and works also for handsets that are not GPS-enabled.
- Other Local Positioning Systems are available, especially for indoor use. GPS and GSM do not work very well indoors, so other techniques are used, including Co-Pilot Beacon for CDMA Networks, Bluetooth, UWB, RFID and Wi-Fi.
Localization-Based Systems can be broadly divided:
- Network-based techniques utilize the service provider's network infrastructure to identify the location of the handset. The advantage of network-based techniques - from a mobile operator's point of view - is that they can be implemented non-intrusively, without affecting the handsets.
- Handset-based technology requires installing 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 neighbouring 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 sent from the handset to the carrier.
- By using the SIM in GSM and UMTS handsets, it is possible to obtain raw radio measurements from the handset. The measurements that are available can include the serving Cell ID, round trip time and signal strength. The type of information obtained via the SIM can differ from what is available from the handset. For example, it may not be possible to obtain any raw measurements from the handset directly, yet still obtain measurements via the SIM.
- Hybrid positioning systems use a combination of network-based and handset-based technologies for location determination. One example would be some modes of Assisted GPS, which can both use GPS and network information to compute the location. Both types of data are thus used by the telephone to make the location more accurate (i.e. A-GPS). Alternatively tracking with both systems can also occur by having the phone attain his GPS-location directly from the satellites, and then having the information sent via the network to the person that is trying to locate the telephone. Google Latitude, for instance, allows such mobile phone tracking.
Did you know?
Research forerunners of today's location-based services are the infrared Active Badge system (1989–1993), The Ericsson-Europolitan GSM LBS trial ran during 1995 by Jörgen Johansson and the master thesis written by Nokia employee TimoRantalainen, in 1994. In 1997 Christopher Kingdon, of Ericsson, handed in the Location Services stage 1 description to the joint GSM group of the European Telecommunications Standard Institute (ETSI) and the American National Standards Institute (ANSI) that continued to select positioning methods and standardize Location Services, later known as Location Based Services (LBS). In 2000, after approval from the worlds’ 12 largest telecom operators, Ericsson, Motorola and Nokia jointly formed and launched the Location Interoperability Forum Ltd (LIF) that specified the Mobile Location Protocol (MLP), an interface between the telecom network and an LBS application running on a server in the Internet Domain. LIF went on to specify the Location Enabling Server (LES), a "middleware", which simplifies the integration of multiple LBS with an operators infrastructure and merged in 2004 with the Open Mobile Association (OMA). Already in July 2001 launched the first commercial LBS service in Japan by DoCoMo.
Some examples of location-based services are:
- Recommending social events in a city;
- Requesting the nearest business or service, such as an ATM or restaurant;
- Turn by turn navigation to any address;
- Locating people on a map displayed on the mobile phone;
- Receiving alerts, such as notification of a sale on gas or warning of a traffic jam;
- Location-based mobile advertising;
- Asset recovery combined with active RF to find, for example, stolen assets in containers where GPS would not work;
- Games where your location is part of the game play, for example your movements during your day make your avatar move in the game or your position unlocks content;
- Real-time Q&A revolving around restaurants, services, and other venues.
Source: Wikipedia, the free encyclopedia
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