Bluetooth

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Bluetooth

• Presenters Group 6
• Allan Alarcon, Ingrid Anderson, Bhupesh Kapoor,
  Shi-Wu Lee

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- Name given to this new technology, set
to commercially come out this year - It is a
cable-replacement technology
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- Technically, is a chip to be plugged
into computers, printers, mobile phones, etc.
Designed by taking the information normally
carried by the cable, and transmitting it at a
special frequency to a receiver Bluetooth chip
which will then give information received to
these mobile devices.
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History HistoryThe Bluetooth Special
Interest Group (SIG) was founded by Ericsson,
IBM, Intel, Nokia and Toshiba in February 1998 to
develop as open specification for short-range
wireless connectivity.
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Key FeaturesRobustness, low complexity,
low power and low cost
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Main Strength Ability to simultaneously
handle both data and voice transmissions such as
headset for voice calls.
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UsageHome Having multiple PCs and need
for networks that are simple to install and
maintainCommercially Handhelds and other
mobile devices
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Some System requirements- Universal
framework to access information across a diverse
set of devices- Should offer similar protection
as in cables. There should not be any compromises
on security- It should be simple, small and
power efficient for easy mobile usage
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The standard requirement - must enable the
devices to establish ad hoc connections.
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Wireless connectivity over Bluetooth
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Works with Any laptop, handheld PC or PDA with a
spare Type II PCMCIA slotOperating Systems
Windows XP, Windows 2000, Windows 98, Windows 95
or Windows CE
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Bluetooth Components

• Four major components
• Radio Unit (radio transceiver)
• Baseband Unit (flash memory CPU)
• Software Stack (driver software)
• Application Software (user interface)

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Bluetooth Radio

• Radio transceiver supports spectrum spreading
  and operates at a
• frequency between 2.402 GHz - 2.480 GHz ISM
  band.
• Spectrum spreading is accomplished by frequency
  hopping in 79
• hops displaced by 1MHz. (maximum of 1600
  hops/sec.)
• Each device can optionally vary its transmitted
  antenna power

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Bluetooth Baseband

• Better term Link Controller Unit
• Actual hardware unit which enables the physical
  link between devices
• Implements baseband protocols and Link Manager
  (LM) routines.
• link connection and power control
• asynchronous and synchronous links
• handles packets, paging and inquiry
• applies a time-division duplex scheme
  (alternate transmit and
• receive)

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Connection Establishment

• All devices are in Standby Mode by default,
  unconnected and
• periodically scan for messages.
• 2 types of scans
• Page Scan - device is listening for Data Access
  Code (DAC)
• used for set up connection
• Inquiry Scan - device is listening for Inquiry
  Access Code (IAC)
• used to discover which units are in range

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Bluetooth Network Topology

• capable of point to point point to
  multi-point connections
• Piconet
• a master device
• one to seven active slave units
• a piconet channel
• Scatternet
• a group of piconets, up to maximum of ten
• a way of connecting a device to multiple
  masters
• Full-duplex rate of more than 6Mb/s.

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Link and Packet Types

• 2 types of physical links
• Synchronous Connection-Oriented (SCO)
• voice and data transmission, a point to point
  connection between a master and a specific slave
• Asynchronous Connection-Less (ACL)
• data transmission only, a point to multi-point
  connection between a master and all the active
  slaves

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Bluetooth Capacities

• Bluetooth can support
• one asynchronous data channel
• asymmetric link of 723.2 kb/s in either
  direction while permitting 57.6 kb/s in the
  return direction
• symmetric link of 433.9 kb/s
• up to three simultaneous synchronous voice
  channels
• each supports 64 kb/s in each direction
• one channel which simultaneously supports
  asynchronous data and synchronous voice

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Connection Modes

• 4 Connection Modes
• Active Mode device is actively participating in
  a channel. Its
• assigned an Active Member Address (AM_ADDR)
• Hold Mode maintains AM_ADDR. Supports
  synchronous but not
• asynchronous packets
• Sniff Mode maintains AM_ADDR. Supports both
  synchronous and
• asynchronous packets
• Park Mode no activity within a channel but
  remains synchronized to
• a channel

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Security Features

• specification includes security features at the
  link level.
• supports authentication (unidirectional or
  mutual) and encryption.
• devices transmit on the heavily used, unlicensed
  2.45 GHz radio band ( the same used by
  microwaves.)
• to keep transmission from breaking up, frequency
  hopping is employed.

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Security Features contd

• Each Bluetooth device has a unique address
• Associating the ID with a person facilitates
  tracking
• i.e. individuals can be traced and their
  activities easily logged.
• For Bluetooth devices to communicate, an
  initialization process uses a PIN.
• While some devices allow users to punch in an ID
  number, the PIN can also be stored in the
  non-volatile memory of the device

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Security Modes

• Bluetooth security is divided into three modes
• Security Mode 1 non-secure
• Security Mode 2 service level enforced security
• Security Mode 3 link level enforced security

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Security Architecture
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Security Implementation within the Architecture

• Three levels of security for services
• Authorisation Required
• access granted to trusted devices
• Authentication Required
• the remote device must be authenticated
• Encryption Required
• The link must be changed to encrypted mode,
  before access to the service is possible

• Two possible security modes for devices
• Trusted Device
• Such a device would have access to all services
  for which the trust relationship has been set.
• Untrusted Device
• Such a device would have restricted access to
  services.

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Potential Weaknesses

• PIN code problems
• Spoofing due to non-secret link key
• Spoofing Bluetooth device addresses

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Drawbacks
Benefits

• Bluetooth is WPAN (Wireless Personal Area
  Network) not LAN replacement. low cost, low
  profile, low power wireless link for convenience
• BT not designed for large file nor fast transfer
  for mobility and convenience
• wireless devices always have security issues,
  but BTs range is 10 meters ?need to be within
  this range to pick up transmission

• Limited transport in 2.4 GHz band. Mbps for
  BlueTooth. Need higher rate for Local Area
  Networks. (sending graphics to be printed)
• mutual perturbation (cross-talk) of corresponding
  office equipment within a same building
• frequency hopping provides some level of
  security, confidentiality may be compromised via
  currently available decoder technology.

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Drawbacks
Benefits

• 60 GHz - Not Cost Effective (potentially higher
  cost of necessary adapters. Power drain and may
  be larger in size. BlueTooth designed to
  circumvent these issues. Cheap, low power, and
  convenient.

• Higher frequency 60GHz a. free world
  wide b. less cross talk
  thus more confidentiality of
  transmitted information
  c. larger bandwidth than
  2.4 GHz

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Compatibility of BlueTooth Upgrade to BT

• PC's quite easy. Bluetooth PCMCIA cards, USB
  connectors etc. are developed at this stage, thus
  only a matter of installing the device, and
  loading up some bluetooth software
• Upgrade PDAs with BlueTooth add-on chips or buy
  PDAs with chip already in place
• current Mobile Phones may not be upgraded , due
  to their cheap cost and relativity limited
  complexity, and lack an interface for any kind of
  bluetooth device (such as a USB port). Although
  Ericsson will be offering a bluetooth chip add-on.

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Future Is it already here? Bluetooth
vs Airport (802.11)

• 1MB/sec, 10 meters, 7 active devices
• can be used wherever you are home, office or on
  the move. (PDA, mobile phone)
• Cheap various applications to drive the price
  down (electronics, telecoms, automotive and
  computing)
• BT future revision may be as a high speed network
  solution

• 10 MB/sec, 50 meters, 10 active devices
• wireless networking only
• pricer
• higher speed wireless networking solution