Bluetooth Software Suite
BLUETOOTH INTRODUCTION
An introduction to Bluetooth wireless technology
Contents
About this document page 3
What is Bluetooth? page 4
Technical facts page 5
Interoperability page 7
Device discovery page 7
Wireless networks page 8
Bluetooth in action page 9
Bluetooth glossary page 10
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About this document
This document will give you a short technical
introduction to the Bluetooth
technology. You will find the answers to such
questions as:
What technical principles is the Bluetooth
wireless technology based on?
What is going on behind the features of a
Bluetooth device?
What is meant by the various technical
expressions used in connection with the
Bluetooth wireless technology?
This document is about the Bluetooth wireless
technology in general. For information on how
to install and operate your Bluetooth
equipment, please refer to the installation and
users manuals.
Rev. 1.089 01-05-01
1
wireless
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The Bluetooth trademarks are owned by their proprietor and
used under license.
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What is Bluetooth?
Wireless communications
Bluetooth is a new technology that eliminates
the need for cables between electronic devices:
PCs, mobile phones, headsets, handheld
computers, printers, local area networks, etc.
The technology is based on short-range radio
transmission on a globally available frequency.
The Bluetooth wireless technology provides
fast, reliable, and secure communications.
A little history
Originally invented in Scandinavia, the
Bluetooth wireless technology was named after
the Danish Viking king Harold Bluetooth.
However, when the technology was launched in
1998, it was very much an international
initiative. A handful of leading companies within
the computer and telecommunications industry
formed the Bluetooth Special Interest Group
(SIG). The goal was for devices from different
manufacturers to be able to communicate with
each other. Today, a great number of
companies have joined the SIG as adopters of
the Bluetooth wireless technology, and the
number is increasing all the time. The
magnitude of industry involvement should
ensure that the Bluetooth wireless technology
becomes widely adopted.
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Technical facts
Small size
The Bluetooth wireless technology does not
require much space. In fact, the Bluetooth radio
can be built into a small microchip and
integrated in any electronic device where
wireless operation would be an advantage.
Worldwide operation
You can use the Bluetooth wireless technology
anywhere. The radio operates in the 2.45 GHz
band, which is license-free and available to any
radio system in the world.
Link establishment
You can establish a link between two or more
devices almost instantly. The link will be
maintained even if the devices are not within
line of sight.
Robust link
The Bluetooth wireless technology provides a
very robust link. The technology ensures that,
under normal circumstances, you will not be
bothered by interference from other radio
signals operating in the same frequency band.
Data or voice
You can use a Bluetooth radio for data transfer
or voice communication; or you can use it for
both simultaneously.
Range
As already mentioned, the Bluetooth wireless
technology is based on short-range radio
transmission. The normal range of the
Bluetooth radio is either 10 meters or 100
meters, depending on your Bluetooth
equipment.
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Bandwidth
A Bluetooth radio link has a maximum data
transfer rate of 724 kbit/s, or three voice
channels; the data rate for a voice channel is 64
kbit/s.
Security
Two advanced security mechanisms ensure a
high level of security:
Authentication prevents access to critical
data and makes it impossible to falsify the
origin of a message.
Encryption prevents eavesdropping and
maintains link privacy.
Low power consumption
The Bluetooth radio is very economical, limiting
its output power exactly to what is actually
needed. For instance, when transmitting to a
receiving radio that is only a couple of meters
away, the radio immediately modifies its signal
strength to suit the small distance. The
Bluetooth wireless technology consumes only a
tiny bit of the power that eg. a mobile phone
needs.
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Interoperability
Interoperability refers to the ability of two
devices to communicate with each other. Now,
any Bluetooth device features one or more
applications, known as profiles. For one
Bluetooth device to be able to communicate
with another, the two devices must have at
least one shared profile. If, for instance, your
Bluetooth device features the profile object
exchange, you can exchange business cards
with any other Bluetooth device that has the
object exchange profile. Some other examples
of profiles are: file transfer, serial port, and
network.
Device discovery
When two or more Bluetooth devices are within
range, a link can be established. However, first
of all a Bluetooth device needs to discover the
other Bluetooth devices that are active within
its range. This operation is called device
discovery. When another Bluetooth device
responds, it supplies necessary information,
some of which concerns its identity: the device
name (eg. Adam) or the unique device address
(eg. 00:50:CD:3A:4B:69). A link can now be
established to the discovered device.
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Wireless networks
Piconet
At the very heart of the Bluetooth wireless
technology is the idea of forming small wireless
networks known as piconets. When a Bluetooth
device has established a link to one or more
other devices, a piconet has been formed. The
device that initiates a connection acts as the
master. The other devices are slaves. The
master controls all traffic in the piconet.
Communication between slaves can only take
place via the master. In the below example of a
piconet, the laptop (master) transmits to the
handheld computer (slave 1) and the mobile
phone (slave 2):
Slave 1 Slave 2
Master
One master, up to 255 slaves
As already mentioned, in a piconet there can
only be one master. Furthermore, up to seven
slaves can be active. However, there can be
additional slaves which are not active but
remain synchronized to the piconet. Such
slaves are referred to as parked. A parked
device can very quickly become active and
begin communicating in the piconet. By
swapping active and parked slaves, you can
increase the number of slaves virtually
connected to the piconet from seven to 255
devices.
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Bluetooth in action
Unlimited possibilites
A technology that, like Bluetooth, eliminates the
need for cables offers a great number of
potential applications. The possibilities are
virtually unlimited. Nevertheless, in some areas
it is particularly obvious that the Bluetooth
wireless technology is an ideal solution. This
section gives you a few examples.
Three-in-one phone
Use the three-in-one phone for different
p u rp o s es -----at the office, as an intercom; on the
road, as a mobile phone; at home, as a
portable phone.
Synchronization
Automatic synchronization of eg. your PC,
mobile phone, and handheld computer. An
example: As soon as you enter the office, the
calendar in your handheld computer is
automatically updated to agree with the
calendar in your office PC.
Wireless headset
Use the wireless headset for hands-free
o p er a t io n o f a p ho n e -----in the car, in the office,
or at home.
Internet bridge
Connect to the Internet no matter where you
are, using a laptop and a mobile phone.
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Bluetooth glossary
Authentication
Security mechanism that prevents access to
critical data and makes it impossible to falsify
the origin of a message.
Device address
The unique address of a Bluetooth device.
Device discovery
Before a link can be established, a Bluetooth
device needs to discover the other Bluetooth
devices that are active within its range.
Device name
The name that a Bluetooth device presents
itself with when supplying identity information
to another device.
Encryption
Security mechanism that prevents
eavesdropping and maintains link privacy.
Master
The device that initiates a connection and,
during this connection, controls all traffic in a
piconet.
Park mode
Economical, low-power sub-mode of
standby. In park mode, a slave does not
participate in the piconet but remains
synchronized to it. Park mode is used to
increase the number of slaves connected to a
master.
Piconet
A wireless network formed by two or more
Bluetooth devices.
Profile
Application that a Bluetooth device facilitates.
For one device to communicate with another,
the two devices must have a shared profile. For
instance, to transfer files from one computer to
another, both computers must feature the file
transfer profile.
Slave
A device in a piconet controlled by another
device (the master).
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