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Bluetooth Technology
By,
Ms.Vicky HSU
Computer Networks-I
SVU
Rajan Avudaiappan
[A1604]
CS-426
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Introduction
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Originally developed by:
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Ericsson Mobile Communication (Sweden)
Initiated the study (1994)
Low power, low cost radio interference between mobile phones and
its accessories
Eliminate cables between the devices
Later IBM, INTEL, Nokia & Toshiba formed the “Bluetooth
Special Internet Group (SIG)” [1998]
Developed Bluetooth 1.0 Specification (1999)
Promoter group: Microsoft, Motorola, 3Com and Lucent
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Bluetooth History
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Harald Bluetooth Gormson
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Name of a king (Denmark, 10th century)
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To honor him for his contributions for
communication technology
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Bluetooth!!
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Bluetooth networking standard is:
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a set of rules for radio frequencies &
communication (Voice and Data application)
[i.e.]
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Bluetooth:
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A physical standard for radio signals
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Part of radio spectrum with ISM devices
(Industrial, Scientific and Medical Devices)
Operates in 2.45 GHz range of RF spectrum
A protocol standard communications
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Bluetooth communication
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Uses different radio waves to communicate
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Perfect for short range communication
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Uses FHSS (Frequency Hopping Spread- Spectrum)
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Doesn’t interfere with other
Support 8 connection [ < 10 meter ]
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Switches b/w 79 frequencies (random) or Channel
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Bluetooth communication
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Bluetooth Device
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Piconet
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Changes frequencies - 1600 times / Sec
 (Disturbance could be avoided)
It is a type of network connection
 (Generated by the Bluetooth devices)
Bluetooth – Other Bluetooth devices
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able to connect automatically
 (in discoverable mode)
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Bluetooth classification
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Based on the power levels
Based on maximum transmission capacity
Classification Power level
Class I
Class II
Class III
20 dBm
0-4 dBm
0 dBm
Capacity
100 m
10 m
1m
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Bluetooth operation
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Bluetooth: Radio
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Bluetooth RF (Physical layer)
Operates in the unlicensed ISM band (2.4 GHz)
It makes use of a frequency hop transceiver
 To prevent interference and fading
 To make available of many FHSS carriers
 It makes use of a binary FM
(to reduce transceiver complexity)
Data rate - up to 1 Mbps
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‘Radio channel’ is shared by devices (group)
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They are synchronized to a common clock &
Frequency hopping pattern
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Bluetooth operation
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Bluetooth: Radio
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‘ Bluetooth Piconet ’
 A type of network connection
(Group of devices will occupying shared physical channel)
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‘ Frequency Hopping ’
 Devices use a explicit Frequency hopping pattern
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Master (Synchronization reference)
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clock & device address - decide channel characteristics
Slave devices (Devices - that connected with the master)
Algorithm ( Bluetooth specification address & master’s clock)
Pseudo - Random sequence hopping pattern (ISM 79 freq.)
‘ Full Duplex ’
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Uses Time - Division Duplex method
Data transmission in the form of packets
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Bluetooth operation
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Bluetooth: Link & Protocols
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‘ Control Layers ’
 Placed above the physical channel
 Layer of links and Channels
 Control Protocols
‘ Physical Links ’
 Connection established between
 Two Piconet Bluetooth devices
 Master & Slave - possible
 Slave & Slave - impossible
 Can be used to transport more than one logical layer
 Supports synchronous, asynchronous traffic
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Bluetooth operation
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Bluetooth: Link & Protocols
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Logical Links
 Data traffic in logical link is being multiplexed
(into the physical link by occupying slots )
Link Manager Protocol (LMP)
 It is a control protocol (for baseband & physical layers)
 Link manager uses this LMP (to control device operations)
 Provide services to manage (for radio & baseband layers)
Logical Link Control and Adaptation Protocol (L2CAP)
 Based above the baseband layer
 Provides abstraction to applications and services
 Multiplexing & De-multiplexing of many channels
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Bluetooth Wireless Technology
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Bluetooth - for voice and data application
Penetration  can penetrate solid objects like walls
Bluetooth chip cost : (< $3 ~ $5) – Economically efficient
Easy to use
Security – Allows 3 diff. Modes
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Non-secure, Service level, Link level
Max bandwidth : 1 Mbps (theoretically) : 721 Kbps
Low power consumption
Interference  very short time
Good for Wireless Personal Area Network (WPAN)
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Bluetooth Wireless Technology
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Quick synchronization between Bluetooth enabled devices
Omni directional --> No line-of-sight requirement
Ability to establish connection
(between any portable devices and a wired network)
Uses globally available unlicensed ISM radio band
Frequency range :
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Need not require operator’s license from:
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902 - 928 MHz
2.4 – 2.484 GHz
Federal Communication Commission (FCC)
Any other International Regulatory Board
Adopt common frequency band
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Can use virtually anywhere (any country in the world)
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Bluetooth Wireless Technology
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System consists of:
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Bluetooth Baseband protocol
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Existing component boards or an adapter devices
Bluetooth equipment integrate easily in TCP/IP network
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Combination of “Circuit & Packet switching”
Easy to embedded directly into:
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Software, Hardware and interoperability requirements
It uses wireless LAN & IEEE standards for data transmissions
Bluetooth frequency range used in:
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USA - 2402 MHz to 2480 MHz
Europe - 2402 MHz to 2480 MHz
Japan - 2472 to 2497 MHz
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Bluetooth (IEEE standards)
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IEEE 802.15 Working group for Wireless Personal Area
Networks (WPANs)
Bluetooth technology follows “IEEE 802.15.1” standards
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Ver 1.0, 1.1, 1.2 & 2.0
1.2  Adaptive Frequency Hopping  Reduce interference
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Technology Characteristics
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Uses small data packets
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Minimize interference by:
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Quick Frequency Hopping
Adaptive output power
Forward Error Correction
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Improve & Maximize interface capacity
Specific method used by receivers
 Detect errors in the transmission
 Correct errors -> Ability to correct them
Maximum availability of devices in a Piconet:
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1 Master device
7 Slave devices
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Technology Characteristics
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Service Support: Asynchronous, Synchronous
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Asynchronous Connectionless Link (ACL)
 Supports for data transfer
 Carry either user data or control data
 Efficiency is best
Synchronous Connection Oriented (SCO) Link
 Real-time Voice support
 Multimedia Traffic
 Uses reserved bandwidth
 Maximum three SCO connection (64,000 bits/sec) is possible
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Bluetooth Links
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Data & Voice transmitted as packets
Errors detected at receiver side
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Notification  to the header of the return packet
Only lost or erroneous packets need to be retransmitted
ACL supports: (Data transmission)
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Symmetrical Connection Link
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Symmetrical or Asymmetrical
Packet Switched
Point-to-multi point connections
Max. Data rate : 433.9 Kbps (in both direction)
Asymmetrical Connection Link
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Max. Data rate: 723.2 Kbps (in one direction)
57.6 Kbps (in reverse direction)
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Bluetooth Links
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SCO link supports: (voice transmission)
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Three synchronous channels of 64 Kbps
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Symmetrical
Circuit Switched
Point-to-Point connection
They use either:
 Pulse Code Modulation
 Std. for encoding speech (Analog ~ Digital) - PSTN
 Continuously Variable Slope Delta Modulation (CVSD)
 Std. for encoding speech (Analog ~ Digital)
 More immunity to interference
 Best for Voice transmission than PCM over wireless link
Appropriate voice-coding scheme is being selected
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(After communication between: link managers of the devices)
Bluetooth protocol stack
Application
OBEX
Two
way
voice
WAP
TCS
Data
&
Control
SDP
Control
RFCOMM
L2CAP
Host Controller Interface
Link manager
Voice
Baseband and link controller
Radio
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Bluetooth protocol stack
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TCS (Telephony Control Protocol)
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SDP (Service Discovery Protocol)
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Allows Bluetooth devices can find out what all are services
supported by other Bluetooth devices
WAP (Wireless Application Protocol) &
OBEX (Object Exchange)
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Gives information about telephony services
Gives interfaces to the higher layer parts of other communication
protocols
RFCOMM (Radio Frequency Communication)
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It is the Bluetooth serial port emulator
It provides serial interface services (RS 232)
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Bluetooth protocol stack
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L2CAP (Logical Link Control and Adaptation Protocol)
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Host Controller Interface
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Multiplexes the data from higher-level layers and also alters
between different packet sizes
Makes virtual connection between hosts and keeps track of
multiple concurrent sessions (Ex: file transfers)
Breaks the application data into Bluetooth-size fragments for
transmission, and it will do the reverse operation for the received
data
Controls communication between a separate host and a Bluetooth
module
Link Manager
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Handles and configures links with other devices
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Bluetooth protocol stack
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Broadband and Link Controller
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It handles the physical links through radio as well as assembling of
packets
It also controls the frequency hopping
Radio
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It uses for modulation and demodulation of data for transmission
and reception
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Bluetooth Protocols
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Bluetooth Protocols
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Bluetooth devices…(examples)
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Bluetooth Head phones
Bluetooth PDAs
Bluetooth Access points
Bluetooth adapters
Bluetooth projectors
Bluetooth cameras
Bluetooth printers
Bluetooth car adapters
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Bluetooth mice, keyboard
Bluetooth Handsets
Bluetooth Modems
Bluetooth Medical devices
Bluetooth Flash cards
Bluetooth projectors
Bluetooth MP3 players
Bluetooth mobile PCs
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References
14.
www.bluetooth.com
Bluetooth Demystified, Nathan J.Muller, McGraw-Hill, NY, USA 2000
Bluetooth- Connect without cables, By Jennifer Bray and Charles F Sturman,
Prentice Hall PTR,
Upper Saddle River, New Jersey 07458, 2001
Bluetooth Operation and Use, By Robert Morrow, McGraw-Hill, New York, 2002
http://www.baracoda.com/shared_docs/bluetooth_protocol.pdf
http://www.cs.fsu.edu/~yasinsac/group/slides/carter3.pdf
http://stephen.ksuettc.org/bluetooth.pdf
http://www.rzo.free.fr/docs_jean/bluetooth.pdf
www.cs.utk.edu/.../bluetooth/whatisbluetooth.gif
www.palowireless.com/.../spec_stack.gif
http://www.palowireless.com/infotooth/knowbase.asp
http://www.ericsson.com/ericsson/corpinfo/publications/review/2000_04/files/2000046.pdf
http://www.ieee802.org/15/
http://www.cs.fsu.edu/~yasinsac/group/slides/carter3.pdf
15.
http://electronics.howstuffworks.com/bluetooth.htm
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Queries ?
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