Hybrid positioning systems are systems for finding the location of a mobile device using several different positioning technologies

Positioning technologies

Positioning systems will use positioning technology to determine the position and orientation of an object or person in a room, building or in the world.-Time of flight:...

. Usually GPS (Global Positioning System

Global Positioning System

The Global Positioning System is a space-based global navigation satellite system that provides location and time information in all weather, anywhere on or near the Earth, where there is an unobstructed line of sight to four or more GPS satellites...

) is one major component of such systems, combined with cell tower signals, wireless internet signals, Bluetooth

Bluetooth

Bluetooth is a proprietary open wireless technology standard for exchanging data over short distances from fixed and mobile devices, creating personal area networks with high levels of security...

 sensors or other local Positioning Systems

Local Positioning Systems

A local positioning system is a navigation system that provides location information in all weather, anywhere within the coverage of the network, where there is an unobstructed line of sight to three or more signaling beacons of which the exact position on earth is known...

.

These systems are specifically designed to overcome the limitations of GPS, which is very exact in open areas, but works poorly indoors or between tall buildings (the urban canyon

Urban canyon

An urban canyon is an artefact of an urban environment similar to a natural canyon. It is manifested by streets cutting through dense blocks of structures, especially skyscrapers, which causes a canyon effect...

 effect). By comparison, cell tower signals are not hindered by buildings or bad weather, but usually provide less precise positioning. Wi-Fi signals may give very exact positioning, but only in urban areas with high Wi-Fi density - and depend on a comprehensive database of Wi-Fi access points.

Hybrid positioning systems are increasingly being explored for certain civilian and commercial location-based service

Location-based service

A Location-Based Service is an information or 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....

s and location-based media, which need to work well in urban areas in order to be commercially and practically viable.

Different hybrid positioning systems are currently being developed and used in services from Combain Mobile, Navizon

Navizon

Navizon is a hybrid positioning system combining GPS, Wi-Fi and Cellular triangulation techniques. It calculates the geographic location of a wireless device by analyzing the signals from nearby Wi-Fi access points and cellular towers and comparing it against a database of known data points...

, Xtify, PlaceEngine, SkyHook

Skyhook

Skyhook or sky hook may refer to:- Technology :* Skyhook , explanation of design complexity in the universe that does not build on lower, simpler layers* Skyhook , "hook" used to lift an object on a long cable hanging from the sky...

, Devicescape, Google Maps for Mobile, openBmap for application in smartphone

Smartphone

A smartphone is a high-end mobile phone built on a mobile computing platform, with more advanced computing ability and connectivity than a contemporary feature phone. The first smartphones were devices that mainly combined the functions of a personal digital assistant and a mobile phone or camera...

s. The maturity of the approaches used by these systems needs to be proved in operational use.

Early works in this area include the Place Lab project, which started on 2003 and went inactive in 2006.