Transcript Slide 1

Bluetooth Technology
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Jason Babel
Kyle Musal
Joshua Turella
Zdravko Tyankov
History
• 1994 – Ericsson
Initiated Study
• Low-power, low-cost
radio interface
• Unite computer
devices and
telecommunications
Beginnings
• 09/1998 – Special
Interest Group
(SIG) Founded
• 12/1999 – Big
Names Join
Movement
• Technology Was
Free To Public
The Name and Logo
• Danish Viking King
Harald Blatand
• United Warring
Factions of
Denmark and
Norway
• Runic Letters Used
For Logo
Bluetooth Communication
• Bluetooth operates on the ISM band
(2.402-2.480GHz)
• The ISM band is set aside for
Industrial, Scientific and Medical
devices.
• ISM is a low powered unlicensed
frequency band.
http://bluetooth.com
Bluetooth Communication
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Bluetooth avoids interference
by using spread-spectrum
frequency hopping and a low
power signal.
By using spread-spectrum
frequency hopping a bluetooth
device will change frequencies
1,600 times per second.
Bluetooth is low powered
which means that only devices
within 32 feet can potentially
cause interference, when used
to FCC standards.
http://bluetooth.com
Avoiding Interference
• By using spread-spectrum frequency
hopping, a bluetooth device can pick from
79 different channels within the ISM band;
1,600 times per second.
• This avoids interference because if two
Bluetooth devices operate on the same
frequency and interfere with each other the
interference will only last 1/1600 second.
• This short period of interference will not be
noticed by the user.
Avoiding Interference
• By using a low power signal a
Bluetooth device reduces its chances
of interference even further.
• The chances of two Bluetooth devices
potentially operating on the same
frequency and interfering is low
because of the short range.
http://gpc.edu/~pgore/PhysicalScience/destructive.gif
Bluetooth Security
• Bluetooth devices
can use a PIN to
prevent
unauthorized
access.
• Bluetooth devices
can be set to
undiscoverable; this
prevents
unauthorized users
from accessing your
Bluetooth device.
http://www.securityfocus.com/infocus/1830
Bluetooth Security
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Bluetooth devices use a unique 48bit device
identifier, a MAC address. This address takes the
form 00:8F:DF:02:BF:7C.
Because of the amount of addresses it is difficult
for a “hacker” to find the MAC address of a
Bluetooth device set to undiscoverable.
The MAC address of Bluetooth devices is not
encrypted during communication and maybe
intercepted potentially allowing unauthorized
access to your Bluetooth device.
Bluetooth Security
• Bluetooth’s frequency hopping technique
makes it difficult to intercept its
communication because the frequency is
always changing. Equipment capable of
synchronizing to the frequency hopping is
needed and is very expensive.
• Usually the data sent by Bluetooth devices
is of low importance, meaning it has a
inherently lower risk of interception or
desire for interception.
http://static.howstuffworks.com/gif/bluetooth-card.jpg
Bluetooth Security
• Overall the risk of unauthorized
access to your Bluetooth device is low
because these methods and the high
cost of equipment capable of
synchronizing with Bluetooth
frequency hopping.
• However with all wireless
communication there is some risk
involved.
http://www.cnet.com/i/ts/ces/2004/ps/BluetoothPhone_OVR_300.gif
So What Exactly is Bluetooth?
• Hardware
• A chip that establishes links and
protocols
• Software
• Where the user actual can interact
• Programs are written to handle the data
Hardware
• A chip that creates a
Bluetooth
connection
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Usually Low Power
• 1 milliwatt signal
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Avoids
Interference
• Limits Range
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10 Meters (32
Feet)
http://www.a7eng.com/products/embeddedblue/images
/eb501_top.jpg
Hardware
• Serial Adapter
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Replaces current
serial wires with this
chip to create a
Bluetooth connection
between devices
Similar designs can
be found for other
I/O ports such as
USB
Antenna Attachment
DC Input
Serial Port
http://www.a7eng.com/products/embeddedblue/images
/eb501_top.jpg
Software
• Once connection is established, the
software determines what to do with
data
• User can create his/her own
applications if savvy enough
Software
• A Multitude of Software is out there
• Software to do things such as:
• Transfer files to and from your phone
• Route Mobile Calls to Your Home Phone
when in Range
• Use your Phone as a remote for you
computer (good for PowerPoint
presentations)
Piconet
• A group of
Bluetooth
devices
communicating
with each other
• 1 master, up to
7 slaves
• Master
determines
hopping pattern
S
M
P
S
S
P
M=Master SB=Standby
P
P=Parked S=Slave
M
S
http://eceserv0.ece.wisc.edu/~sharmav/bluetooth/archive.htm
Sending in a Piconet
fk
fk+1
fk+2
Slot2
625 ms
Slot 3
fk+3
Master
Slave1
625 ms
Slot 1
Frame 1
t
Slot4
Frame 2
http://eceserv0.ece.wisc.edu/~sharmav/bluetooth/archive.htm
Sending in a Piconet
fk
fk+1
fk+2
fk+3
fk+4
Master
Slave1
Slave2
http://eceserv0.ece.wisc.edu/~sharmav/bluetooth/archive.htm
fk+5
Piconet Efficiency
80
80
70
70
• Ten active piconets
60
60
• 1000 transmission slots
50
50
• 56 collisions
• 112 slots corrupted
• ~89% net efficiency
40
30
40
30
20
20
10
10
0
0
10
Piconet A
Contention
20
Piconet B
Contention
Active Piconets: 10
30
Piconet C
Contention
40
Piconet D
Contention
50
Piconet E
Contention
Total Transmission Slots: 1000
60
Piconet F
Contention
70
Piconet G
Contention
Transmission Slots Hit: 112
80
Piconet H
Contention
90
Piconet I
Contention
0
100
Piconet J
Contention
Transmission Efficiency: ~89%
http://eceserv0.ece.wisc.edu/~sharmav/bluetooth/archive.htm
Pairing
• To become paired:
• Two devices A and B
• A is searching for other devices to connect
to it
• B enters the range and A detects it
• A Passkey is entered into both devices
• If A’s Passkey matches B’s passkey
• A trusted pair is formed
• As long as it is enabled on the devices,
authentication shouldn’t have to be done again
if Device B leaves range and enters again later
How it all fits together
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There is a Bluetooth
Piconet already set up.
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Lets say in it there is
currently a computer, a
stereo, and the house
lighting in it.
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Lights
The Computer is the
Master
Another Bluetooth device
is a Bluetooth House
phone not connected to
any system
So what can we do?
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Stereo
Computer can control the
lights and stereo.
Computer
Slave
Master
Home
Phone
Things to Realize
• The Computer talks to both the
Stereo and the Lights, and they both
talk back.
• Stereo and Lights never talk to each
other
• Computer determines hop pattern.
• All Devices Have Been on the
Network Before
• Already Paired
Enter New Device
• Add a Cell phone
• Person Walks into Room
• As it gets in range a radio signal is sent
out with its address
• A range of addresses are given for the type
of device
• If a device can connect to the device (it
knows what range addresses it can connect
to) it will.
We’re Talking Now
• The Computer and Home phone
respond
• The Computer sees that it has paired
with it before and connects it as a slave
to its group
• The Computer sets up the pseudorandom hopping sequence using its clock
and address
• The Cell Phone does the same with
the Home Phone
Alright…
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Now the Cell Phone
can send and
receive files from
the computer.
The Cell Phone will
now route all calls
to the Home
Phone.
Two Piconets have
been formed
Stereo
Lights
Computer
Slave
Master
Home
Phone
Cell
Advantages
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Bluetooth Devices are wireless
Bluetooth Tech is inexpensive
Bluetooth is automatic
Standardized Protocol
Advantages
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Low Interference
Low Energy Consumption
Share Voice and Data
Endless applications…
Disadvantages
• Low Data Transfer Rate
• 721 Kbps
• Range – 30ft
• Mediocre Security
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bluejacking
bluebugging
bluesnarfing
Car Whisperer
Where is it used?
• Wireless Control &
Communication
• Data Transmission
• Cordless Desktop PC
• Mobile Gaming
Wireless Control & Communication
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Communication
between:
• Cell phone and a
hands-free headset
• PC and wireless
input and output
devices
• Game Consoles and
their wireless
controllers
Data Transmission
• Bluetooth enabled
devices:
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Mobile phones
Smartphones
PDAs
Notebooks
GPS Receivers
• Data types:
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Voice, Video,
Images, Files and
Data
Cordless Desktop PC
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Connection between
PC and it’s peripherals:
• Mouse
• Keyboard/game
pad
• Printer/Scanner
• Speaker system
• Modems
• Cameras
Mobile Gaming
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Devices:
• Nokia N-gage
• Gizmondo
Purpose:
• New level of
gaming
• Play with all
your friends
• Play anytime,
anyplace
The Future
• 05/2005 –
Announced To
Team Up With UWB
Developers
(~480mbits/s)
• Estimated 2 Billion
Devices Shipped
Per Year By 2010
Questions
Questions?