Location Based Services

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Location Based Services

Introduction

LBS are defined as "information services accessible with mobile devices, through the mobile network, utilizing the ability to make use of the location of the mobile device” The authors of define LBS as "business and consumer services that give users a set of services starting from the geographic location of the client” (Yan Sun et.al, 2009, pp.305). In accordance with these two definitions, LBS is referred to as a set of services provided to the user based on the location of the user. In relation to this understanding, LBS can be divided into two major parts from a designing perspective:

1)Obtaining the location of a user.

2)Utilizing this geographic location to provide a service or services.

Mechanism

Complex value chain

Location-based services present a complex value chain that involves many actors, as the provision of such services requires the concurrence of telecom operators, content providers, aggregators, device manufacturers, etc.

In a first step in the value chain we find the content providers and developers, such as digital mapping companies developing or business directories. At the apex of this value chain is the telecom operator, in collaboration with the developers of hardware / software platforms provide the technology and communications through which it will provide the service, i.e. the channel the "medium" through which to channel the application. Finally we find marketers of these services, which range from content aggregators' media companies, including services as part of its bid.

There are basically two scenarios for location-based applications: a user may need an information service centre or management may require trace-do tracking - in real time. The LBS (Location Based Services) or LDIS (Location Dependent Information Services) refer to Location Based Services or for some authors simply location service (Hightower et.al, 2001, pp.57).

Range and Detection methods

An IR-based positioning system needs line-of-sight communication between transmitters and receivers without any interference from strong light sources. Therefore, the coverage range of the IR devices is limited. Most IR-based positioning systems install fixed IR tags to cover the entire area.

RFID

RFID operates over a wide range of frequencies, from sub-Megahertz to microwave. RFID-positioning systems normally consist of RFID readers (or scanners) and RFID tags. The RFID scanner is able to interrogate data emitted from the RFID tags, which can be categorized as either passive or active. Active tags are small transceivers, which can actively transmit their ID and operate by using a battery, allowing a longer range to communicate in compared to the passive tags. On the other hand, passive tags are energized by an electromagnetic field from the scanner when scanned; however, they must be close to the scanner. The operating range of the passive tag is hence very short. Consequently, radio transceivers (or active tags) are commonly found in IPSs (Yan Sun et.al, 2009, pp.305).

UWB (IEEE 802.15.3a)

UWB technology is based on transmitting extremely short and low power pulses with a low duty cycle [53]. UWB operates on a range of frequencies from 3.1 G Hz to ...