What is Bluetooth Technology?
Bluetooth is a wireless technology that enables any electrical
device to wirelessly communicate in the range of 2.5 GHz ISM
frequency band. Mobile phones, headsets, PDA's and portable
computers can communicate and send data to each other without
wires or cables to link to devices together. The name of Bluetooth
derived from the name of an English king Harold Bluetooth.
It a low cost, low power, radio technology, which is particularly
suited to the short range Personal Area Network (PAN) application.
Bluetooth Special Interest Group is authorized to develop its
specifications & license.
The Main Features of Bluetooth are given below:
It operates in the 2.4GHz frequency band without
having a license for wireless communication.
Up to 10-100 meters data can be transfer in real time.
Close proximity & accuracy is not required for Bluetooth
as in case of infrared data (IrDA) communication device.
Bluetooth does not suffer from interference from obstacles
such as walls while infrared suffers due to obstacles.
Bluetooth supports both point-to-point and point-to-multipoint
wireless connections without cables between mobile phones
and personal computers.
Data transfer rate of blue tooth varies from version to version.
Data rate of 1 Mbps for Version 1.2 Up to 3 Mbps for Version 2.0.
Then major parts of Bluetooth system are RF transceiver, base band,
and protocol stack. Bluetooth is used for small-area networking without
user intervention. Due to extremely low transmission power in Bluetooth
technique battery power is saved. It is a networking standard that
works at two levels:
∑ Physical level.
∑ Protocol level
Due to these levels mobiles have to agree on these levels
when bits are sent. It decides the amount of data to be
sent at a time, and how the parties in a conversation
can be sure that the message received is the same
as the message sent..
Bluetooth networking transmits data through low-power radio waves.
It can connect up to eight devices simultaneously. With in the range
of about ten meters you must think that the devices will not interfere
with each other. Bluetooth solved the problem of devices interference
while sending the data by using the technique of Spread-Spectrum
Frequency Hopping due to which devices may transfer data at the
same frequency at the same time. The question rises here is how
Bluetooth send the same data using same frequency band
without devices interferences? In Bluetooth technique,
transmitters change frequencies 1,600 times in every
second. In this way devices can make full use of a limited
band of the radio spectrum.
When Bluetooth devices came into the range of each other,
conversations take place automatically. This conversation
automatically determines whether they have the data to share
or not. In this way Bluetooth devices not only share the data
but also control the data to be transferred. When the
connection is established, the devices either they are part of
a computer system or a network, Bluetooth systems create
a personal-area network.
The technology used in Bluetooth also provides security in three ways:
∑ Pseudo-random frequency hopping,
Frequency hops make it difficult for anyone to eavesdrop.
Authentication allows a user to limit connectivity to specified
devices. Encryption uses secret keys to make data intelligible
only to authorized parties.
Service-level security and device-level security work together
to protect Bluetooth devices from unauthorized data transmission.
Many serious problems create only due to improper security issues.
Some of them are given below:
It is used to send a business card in the form of text message
via Bluetooth to other users. It should be noted that the distance
between two users is not more than 10 meters. If the user
doesn't found the proper text, he should add the contact to
his phone book. After saving his contact in his address book
retry to send the same message. In this way the user can get
business card from other user via Bluetooth. Itís all because
of the known destination from where the massage is being coming.
Due to this hackers can access userís phone.
It not only access oneís mobile phone, but also use
its features including placing call, messaging. Even though
the user doesn't realize itís happening.
Car whisper is a type of software due to which hackers can
send and receive audio file from a Bluetooth-enabled car stereo.