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Sunday, August 7, 2011

LBS Location Based Services

A Location-Based Service (LBS) 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 [1] [2] [3] .[4]
LBS can be used in a variety of contexts, such as health, indoor object search[5], entertainment[6], work, personal life, etc. .[7]
LBS include services to identify a location of a person or object, such as discovering the nearest banking cash machine or the whereabouts of a friend or employee. LBS include parcel tracking and vehicle tracking services. LBS can include mobile commerce when taking the form of coupons or advertising directed at customers based on their current location. They include personalized weather services and even location-based games. They are an example of telecommunication convergence.
This concept of location based systems is not compliant with the standardized concept of real-time locating systems and related local services (RTLS), as noted in ISO/IEC 19762-5 [8] and ISO/IEC 24730-1.[9]

History

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 Timo Rantalainen, in 1994.
In 1996 the US Federal Communication Commission (FCC) issued rules requiring all US mobile operators to locate emergency callers. This rule was a compromise resulting from US mobile operators seeking the support of the emergency community in order to obtain the same protection from law suits relating to emergency calls as fixed-line operators already had.
In 1997 Christopher Kingdon, of Ericsson, handed in the Location Services (LCS) stage 1 description to the joint GSM group of the European Telecommunications Standard Institute(ETSI) and the American National Standards Institute (ANSI). As a result the LCS sub-working group was created under ANSI T1P1.5. This group went on to select positioning methods and standardize Location Services (LCS), later known as Location Based Services (LBS). Nodes defined include the Gateway Mobile Location Centre (GMLC), the Serving Mobile Location Centre (SMLC) and concepts such as Mobile Originating Location Request (MO-LR), Network Induced Location Request (NI-LR) and Mobile Terminating Location Request (MT-LR).
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). This forum first specified the Mobile Location Protocol (MLP), an interface between the telecom network and an LBS application running on a server in the Internet Domain. Then, much driven by the Vodafone group, LIF went on to specify the Location Enabling Server (LES), a "middleware", which simplifies the integration of multiple LBS with an operators infrastructure. In 2004 LIF was merged with the Open Mobile Association (OMA). A LBS work group was formed within the OMA.
The first consumer LBS-capable mobile web device was the Palm VII, released in 1999.[10] Two of the in-the-box applications made use of the ZIP code-level positioning information and share the title for first consumer LBS application: the Weather.com app from The Weather Channel, and the[11] TrafficTouch app from Sony-Etak / Metro Traffic.
The first LBS services were launched during 2000 by TeliaSonera in Sweden (friendfinder, yellow pages, houseposition, emergency call location etc.) and by EMT in Estonia (emergency call location, friend finder, TV game). TeliaSonera and EMT based their services on the Ericsson Mobile Positioning System (MPS).
Other early LBS include friendzone, launched by swisscom in Switzerland in May 2001, using the technology of valis ltd. The service included friend finder, LBS dating and LBS games.[12] The same service was launched later by Vodafone Germany, Orange Portugal and Pelephone in Israel[11]. Microsoft's Wi-Fi-based indoor location system RADAR (2000), MIT's Cricket project using ultrasound location (2000) and Intel's Place Lab with wide-area location (2003).[13]
The first commercial LBS service in Japan was launched by DoCoMo, based on triangulation for pre-GPS handsets in July 2001, and by KDDI for the first mobile phones equipped with GPS in December 2001.[14] Mobile handset makers have tended to take 'upstream initiative' to embed LBS in their mobile equipment. Originally, LBS was developed by mobile carriers in partnership with mobile content providers.
In May 2002, go2 and AT&T launched the first (US) mobile LBS local search application that used Automatic Location Identification (ALI) technologies mandated by the FCC. go2 users were able to use AT&T’s ALI to determine their location and search near that location to obtain a list of requested locations (stores, restaurants, etc.) ranked by proximity to the ALI provide by the AT&T wireless network. The ALI determined location was also used as a starting point for turn-by-turn directions.
The main advantage is that mobile users don't have to manually specify ZIP codes or other location identifiers to use LBS, when they roam into a different location. GPS tracking is a major enabling ingredient, utilizing access to mobile web.
In 2010, location-based services power Mobile Local Search to enable the search and discovery of persons, places, and things within an identifiable space defined by distinct parameters. These parameters are evolving. Today[when?] they include social networks, individuals, cities, neighborhoods, landmarks, and actions that are relevant to the searcher's past, current, and future location. These parameters provide structure to vertically deep and horizontally broad data categories that can stand alone or are combined to form searchable directories.[15]



Locating methods

Control Plane Locating

Sometimes referred to as positioning, with control plane locating the service provider gets the location based on the radio signal delay of the closest cell-phone towers (for phones without GPS features) which can be quite slow as it uses the 'voice control' channel.[4] In the UK, networks do not use trilateration; LBS services use a single base station, with a 'radius' of inaccuracy, to determine a phone's location. This technique was the basis of the E-911 mandate and is still used to locate cellphones as a safety measure. Newer phones and PDAs typically have an integrated A-GPS chip.
In order to provide a successful LBS technology the following factors must be met:
  • Coordinates accuracy requirements that are determined by the relevant service;
  • Lowest possible cost;
  • Minimal impact on network and equipment.
Several categories of methods can be used to find the location of the subscriber.[2][16] The simple and standard solution is GPS-based LBS. 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

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 through various techniques like time difference of arrival (TDOA) or Enhanced Observed Time Difference (E-OTD).

Others

Another example is Near LBS (NLBS), in which local-range technologies such as Bluetooth, WLAN, infrared and/or RFID/Near Field Communication technologies are used to match devices to nearby services. This application allows a person to access information based on their surroundings; especially suitable for using inside closed premises, restricted/ regional areas.
Another alternative is an operator- and GPS-independent location service based on access into the deep level telecoms network (SS7). 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.
Many other Local Positioning Systems are available, especially for indoor use. GPS and GSM don't work very well indoors, so other techniques are used, including Bluetooth, UWB, RFID and Wi-Fi[17]. But which technique provides the best solution for a specific LBS problem? A general model for this problem has been constructed at the Radboud University of Nijmegen.[18]

LBS applications

Some examples of location-based services are [2]:
  • Recommending social events in a city[1]
  • 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 wouldn't 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
More examples are listed in.[2]
For the carrier, location-based services provide added value by enabling services such as:
  • Resource tracking with dynamic distribution. Taxis, service people, rental equipment, doctors, fleet scheduling.
  • Resource tracking. Objects without privacy controls, using passive sensors or RF tags, such as packages and train boxcars.
  • Finding someone or something. Person by skill (doctor), business directory, navigation, weather, traffic, room schedules, stolen phone, emergency calls.
  • Proximity-based notification (push or pull). Targeted advertising, buddy list, common profile matching (dating), automatic airport check-in.
  • Proximity-based actuation (push or pull). Payment based upon proximity (EZ pass, toll watch).
In the U.S. the FCC requires that all carriers meet certain criteria for supporting location-based services (FCC 94-102). The mandate requires 95% of handsets to resolve within 300 meters for network-based tracking (e.g. triangulation) and 150 meters for handset-based tracking (e.g. GPS). This can be especially useful when dialing an emergency telephone number - such as enhanced 9-1-1 in North America, or 112 in Europe - so that the operator can dispatch emergency services such as Emergency Medical Services, police or firefighters to the correct location. CDMA and iDEN operators have chosen to use GPS location technology for locating emergency callers. This led to rapidly increasing penetration of GPS in iDEN and CDMA handsets in North America and other parts of the world where CDMA is widely deployed. Even though no such rules are yet in place in Japan or in Europe the number of GPS-enabled GSM/WCDMA handset models is growing fast. According to the independent wireless analyst firm Berg Insight the attach rate for GPS is growing rapidly in GSM/WCDMA handsets, from less than 8 percent in 2008 to 15 percent in 2009.[19]
European operators are mainly using Cell-ID for locating subscribers. This is also a method used in Europe by companies such as Podsystem that are using cell based LBS as part of systems to recover stolen assets. In the US companies such as Rave Wireless in New York are using GPS and triangulation to enable college students to notify campus police when they are in trouble. Rave Wireless and other companies with location based offerings are powered by a variety of companies, including Skyhook Wireless and Xtify.


Mobile messaging

Mobile messaging plays an essential role in LBS. Messaging, especially SMS, has been used in combination with various LBS applications, such as location-based mobile advertising. SMS is still the main technology carrying mobile advertising / marketing campaigns to mobile phones. A classic example of LBS applications using SMS is the delivery of mobile coupons or discounts to mobile subscribers who are near to advertising restaurants, cafes, movie theatres. The Singaporean mobile operator MobileOne carried out such an initiative in 2007 that involved many local marketers, what was reported to be a huge success in terms of subscriber acceptance.
Companies offering location-based messaging (sometimes referred to as 'geo-messaging') include The Coupons App [1](US), Centrl [2](International), Zhiing (international), BluePont (US),[20] Loopt (US), Dodgeball (US) and GeoMe [3](Spain).

Privacy issues

With the passing of the Can Spam Act in 2005, it became illegal in the United States to send any message to the end user without the end user specifically opting-in. This put an additional challenge on LBS applications as far as 'carrier-centric' services were concerned. As a result, there has been a focus on user-centric location-based services and applications which give the user control of the experience, typically by opting in first via a website or mobile interface (such as SMS, mobile Web, and Java/BREW applications).
The European Union also provides a legal framework for data protection that may be applied for location-based services, and more particularly several European directives such as: (1) Personal data: Directive 95/46/EC); (2) Personal data in electronic communications: Directive 2002/58/EC; (3) Data Retention: Directive 2006/24/EC. However the applicability of legal provisions to varying forms of LBS and of processing location data is unclear.[21]
One implication of this technology is that data about a subscriber's location and historical movements is owned and controlled by the network operators, including mobile carriers and mobile content providers.[22]
A critical article by Dobson and Fisher[23] discusses the possibilities for misuse of location information.
Beside the legal framework there exist several technical approaches to protect privacy using privacy-enhancing technologies (PETs). Such PETs range from simplistic on/off switches [24] to sophisticated PETs using anonymization techniques,[25] e.g., related to k-anonymity. Today, only few LBS offer such PETs, e.g., Google Latitude offers an on/off switch and allows to stick one's position to a free definable location. Additionally, it is an open question how users perceive and trust in different PETs. The only study that addresses user perception of state of the art PETs is.[26]. Another set of techniques included in the PETs are the Location obfuscation techniques, which slightly alter the location of the users in order to hide their real location while still bein able to represent their position and receive services from their LBS provider.

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