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
.
LBS services can be used in a variety of contexts, such as health,
work, personal life, etc..LBS services 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 services 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 and ISO/IEC 24730-1 .
History
The first
LBS services globally were launched commercially in Japan
in first 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. 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.
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.
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.
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. The simple and standard solution is GPS-based LBS.
Sony Ericcson'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 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. 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 .
LBS applications
Some examples of location-based services are :
- 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
More examples are listed in .
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 dialling 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. In Europe
companies such as
Podsystem 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
examples 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 Centrl
[9826](International), Zhiing (international),
BluePont (US),
Loopt (US),
Dodgeball and GeoMe
[9827](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 dataprotection 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
.
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.
A critical article by Dobson and Fisher 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 to sophisticated PETs using anonymization techniques ,
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 ones 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 .
See also
References
- "Foundations of Location Based Services",
Stefan Steiniger, Moritz Neun and Alistair Edwardes, University of
Zurich
- "Permanent Reference Document SE.23: Location Based
Services“, GSM Association
- "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
- ISO/IEC 19762-5 Information technology --
Automatic identification and data capture (AIDC) techniques --
Harmonized vocabulary -- Part 5: Locating systems
- ISO/IEC 24730-1 Information technology --
Real-time locating systems (RTLS) -- Part 1: Application program
interface (API)
- "Location Based Services FAQ (LBS-FAQ)“,
Location Based Services FAQ (LBS-FAQ)
- "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
- LBS Positioning Methods
http://www.navigationevent.com/pdf/tyntec_kunz.pdf
- Mobile Technology provided by BluePont allows you
to find last minute workout buddy SNEWSNET reviews BluePont - a
Location based service in US
- "Geoslavery", J.E. Dobson and P.F. Fisher, IEEE
Technology and Society Magazine, 2003
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