An Introduction to BLUETOOTH TECHNOLOGY

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An Introduction to BLUETOOTH TECHNOLOGY
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CONTENT

• Overview of Bluetooth History
• The Bluetooth Specifications
• Typical Bluetooth Scenario
• Protocols
• Profiles
• Security
• Comparison with other technologies
• Future of Bluetooth
• Summary

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Example The Networked Home
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What is Bluetooth?

• Bluetooth wireless technology is an open
  specification for a low-cost, low-power,
  short-range radio technology for ad-hoc wireless
  communication of voice and data anywhere in the
  world.

One of the first modules (Ericsson)
A recent module
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Ultimate Headset
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Cordless Computer
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Bluetooth Goals Vision

• Originally conceived as a cable replacement
  technology
• Short-Range Wireless Solutions
• Open Specification
• Voice and Data Capability
• Worldwide Usability
• Other usage models began to develop
• Personal Area Network (PAN)
• Ad-hoc networks
• Data/voice access points
• Wireless telematics

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Overview of Bluetooth History

• What is Bluetooth?
• Bluetooth is a short-range wireless
  communications technology.
• Why this name?
• It was taken from the 10th century Danish King
  Harald Blatand who unified Denmark and Norway.
• When does it appear?
• 1994 Ericsson study on a wireless technology to
  link mobile phones accessories.
• 5 companies joined to form the Bluetooth Special
  Interest Group (SIG) in 1998.
• First specification released in July 1999.

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Timeline

• 1994 Ericsson study complete / vision
• 1995 Engineering work begins
• 1997 Intel agrees to collaborate
• 1998 Bluetooth SIG formed Ericsson, Intel,
  IBM, Nokia Toshiba
• 1999 Bluetooth Specification 1.0A
• SIG promoter group expanded 3Com, Lucent,
  Microsoft Motorola
• 2000 Bluetooth Specification 1.0B, 2000
  adopters
• 2001 First retail products released,
  Specification 1.1
• 2003 Bluetooth Specification 1.2
• 2005 Bluetooth Specification 2.0 (?)

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Special Interest Group
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Technical features
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Bluetooth FHSS

• Employs frequency hopping spread spectrum
• Reduce interference with other devices
• Pseudorandom hopping
• 1600 hops/sec- time slot is defined as 625
  microseconds
• Packet 1-5 time slots long

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Time-Division Duplex Scheme

• Channel is divided into consecutive slots (each
  625 ?s)
• One packet can be transmitted per slot
• Subsequent slots are alternatively used for
  transmitting and receiving
• Strict alternation of slots between the master
  and the slaves
• Master can send packets to a slave only in EVEN
  slots
• Slave can send packets to the master only in the
  ODD slots

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Classification

• Classification of devices on the basis of Power
  dissipated corresponding maximum Range.

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Typical Bluetooth Scenario

• Bluetooth will support wireless point-to-point
  and point-to-multipoint (broadcast) between
  devices in a piconet.
• Point to Point Link
• Master - slave relationship
• Bluetooth devices can function as masters or
  slaves
• Piconet
• It is the network formed by a Master and one or
  more slaves (max 7)
• Each piconet is defined by a different hopping
  channel to which users synchronize to
• Each piconet has max capacity (1 Mbps)

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Piconet Structure

• All devices in piconet hop together.
• Masters ID and masters clock determines
  frequency hopping sequence phase.

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Ad-hoc Network the Scatternet

• Inter-piconet communication
• Up to 10 piconets in a scatternet
• Multiple piconets can operate within same
  physical space
• This is an ad-hoc, peer to peer (P2P) network

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Bluetooth Protocol Stack
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Baseband
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Baseband

• Addressing
• Bluetooth device address (BD_ADDR)
• 48 bit IEEE MAC address
• Active Member address (AM_ADDR)
• 3 bits active slave address
• all zero broadcast address
• Parked Member address (PM_ADDR)
• 8 bit parked slave address
• This MAC address is split into three parts
• The Non-significant Address Part (NAP)
• Used for encryption seed
• The Upper Address part (UAP)
• Used for error correction seed initialization
  FH sequence generation
• The Lower Address Part (LAP)
• Used for FH sequence generation

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Packet Structure
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Connection State Machine
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Channel Establishment

• There are two managed situations
• A device knows the parameters of the other
• It follows paging process
• No knowledge about the other
• Then it follows inquiring paging process
• Two main states and sub-states
• Standby (no interaction)
• Connection (working)
• Seven more sub-states for attaching slaves
  connection establishment

Connection State Machine
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Channel Establishment (contd.)

• Seven sub-states
• Inquiry
• Inquiry scan
• Inquiry response
• Page
• Page scan
• Master response
• Slave response

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Link Manager Protocol
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Link Manager Protocol

• The Link Manager carries out link setup,
  authentication link configuration.
• Channel Control
• All the work related to the channel control is
  managed by the master
• The master uses polling process for this
• The master is the first device which starts the
  connection
• This roles can change (master-slave role switch)

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L2CAP

• Service provided to the higher layer
• L2CAP provides connection-oriented and
  connectionless data services to upper layer
  protocols
• Protocol multiplexing and demultiplexing
  capabilities
• Segmentation reassembly of large packets
• L2CAP permits higher level protocols and
  applications to transmit and receive L2CAP data
  packets up to 64 kilobytes in length.

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Middleware Protocol Group

• Additional transport protocols to allow existing
  and new applications to operate over Bluetooth.
• Packet based telephony control signaling protocol
  also present.
• Also includes Service Discovery Protocol.

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Middleware Protocol Group (contd.)

• Service Discovery Protocol (SDP)
• Means for applications to discover device info,
  services and its characteristics.
• TCP/IP
• Network Protocols for packet data communication,
  routing.
• RFCOMM
• Cable replacement protocol, emulation of serial
  ports over wireless network.

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IP Over Bluetooth

• IP over Bluetooth v 1.0

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IP Over Bluetooth

• IP over Bluetooth v 1.1

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File Transfer Profile

• Profile provides
• Enhanced client-server interactions
• - browse, create, transfer folders
• - browse, pull, push, delete files

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Headset Profile

• Profile provides
• Both devices must provide capability to initiate
  connection accept/terminate calls.
• Volume can be controlled from either device.
• Audio gateway can notify headset of an incoming
  call.

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Core Bluetooth Products

• Notebook PCs Desktop computers
• Printers
• PDAs
• Other handheld devices
• Cell phones
• Wireless peripherals
• Headsets
• Cameras

• CD Player
• TV/VCR/DVD
• Access Points
• Telephone Answering Devices
• Cordless Phones
• Cars

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Other Products

• 2004 Toyota Prius Lexus LS 430
• hands free calls
• Digital Pulse Oximetry System
• Toshiba Washer Dryer
• Nokia N-gage

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Security

• Security Measures
• Link Level Encryption Authentication.
• Personal Identification Numbers (PIN) for device
  access.
• Long encryption keys are used (128 bit keys).
• These keys are not transmitted over wireless.
  Other parameters are transmitted over wireless
  which in combination with certain information
  known to the device, can generate the keys.
• Further encryption can be done at the application
  layer.

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A Comparison
WLAN
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Bluetooth vs. IrD

• Bluetooth
• Point to Multipoint
• Data Voice
• Easier Synchronization due to omni-directional
  and no LOS requirement
• Devices can be mobile
• Range 10 m

• IrD
• Point to point
• Intended for Data Communication
• Infrared, LOS communication
• Can not penetrate solid objects
• Both devices must be stationary, for
  synchronization
• Range 1 m

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Bluetooth Today Tomorrow
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Will Bluetooth become a household name?
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Future of Bluetooth

• Success of Bluetooth depends on how well it is
  integrated into consumer products
• Consumers are more interested in applications
  than the technology
• Bluetooth must be successfully integrated into
  consumer products
• Must provide benefits for consumer
• Must not destroy current product benefits
• Key Success Factors
• Interoperability
• Mass Production at Low Cost
• Ease of Use
• End User Experience

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Summary

• A new global standard for data and voice
• Eliminate Cables
• Low Power, Low range, Low Cost network devices
• Future Improvements
• Master-Slave relationship can be adjusted
  dynamically for optimal resource allocation and
  utilization.
• Adaptive, closed loop transmit power control can
  be implemented to further reduce unnecessary
  power usage.

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Things that think dont make sense unless they
link.
- Nicholas Negroponte, MIT Media Laboratory
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Thank You