This topic contains with overview of Bluetooth and architecture

1. BLUETOOTH
By
P.Vanjipriya
Assistant professor
KIT-Kalaignar Karunanidhi Institute of
Technology
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2. BLUETOOTH
 Universal radio interface for ad-hoc wireless
connectivity
 Interconnecting computer and peripherals,
handheld devices, PDAs, cell phones –
replacement of IrDA
 Bluetooth devices operate at 2.4GHz, low power
consumption.
 in the globally available, license-free, ISM band
(from 2400-2480 MHZ)and they use FH-CDMA
technique because of its inherent interference
rejection capability.
 The Bluetooth radio technology usually uses 79
different channels and can be used at a range of
up to 30 feet.
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3.  10 meters With more power, this range can be increased to up top
100 meters.
 Voice and data transmission, approx. 1 Mbit/s gross data rate
 A cable replacement technology
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BLUETOOTH

4. 4
APPLICATIONS AREAS
 Data, audio, graphics, video
 Data and voice access points, Cable replacement, Ad
hoc networking
Personal Ad-Personal Ad-
hoc Networkshoc Networks
Landline
Data/VoiceData/Voice
AccessAccess
PointsPoints

5. 5
Bluetooth Histroy
 Harald Blaatand “Bluetooth” II
 King of Denmark 940-981
 Son of Gorm the Old (King of Denmark) and Thyra
Danebod (daughter of King Ethelred of England)
• This is one of two Runic stones
erected in his capitol city of
Jelling (central Jutland)
• The stone’s inscription (“runes”) say:
Harald controlled Denmark and
Norway
Harald thinks “notebooks” and
“cellular phones” should
seamlessly communicate

6. Bluetooth
 Advantages
 Bluetooth: interoperable
 IrDA: line of sight needed, point-to-point
 WLAN: higher power consumption
 Disadvantages
 Bluetooth: only up to 1 Mbps
 IrDA: much cheaper, faster (up to 16 Mbps)
 WLAN: faster (up to 11 Mbps)
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7. 7
Protocol Architecture
 Bluetooth has a layered protocol architecture
 Core protocols
 Cable replacement and telephony control protocols
 Adopted protocols
 Core protocols
 Radio
 Baseband
 Link manager protocol (LMP)
 Logical link control and adaptation protocol (L2CAP)
 Service discovery protocol (SDP)

8. Protocol Architecture
 Cable replacement protocol
 RFCOMM
 Telephony control protocol
 Telephony control specification – binary (TCS BIN)
 Adopted protocols
 PPP
 TCP/UDP/IP
 OBEX
 WAE/WAP
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9. Protocol Stack
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10. Radio Band
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11. Baseband
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 the physical layer of the Bluetooth that provides
• Error correction
• Flow control
• Hopping sequence
• Security
 hopping through 79 channels
 data is divided in packets
 access code: e.g. timing synchronization
 header: e.g. packet numbering, flow control, slave address
 payload: voice, data or both

12. Baseband cont…
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 Connection Modes
describes the set of rules by which all bluetooth devices must
abide in order to establish a link a communicate with one
another
 STANDBY : not connected in a piconet
 ACTIVE : active participation on the channelPower Saving
Modes
 SNIFF : slave listens to the channel at a reduced rate
(decreasing of duty cycle ) least power efficient
 HOLD : data transfer is held for a specific time period,
medium power efficient
 PARK : synchronized to the piconet but does not participate in
traffic

13. HCI (Host Controller Interface)
provides a command interface to baseband controller and link
manager
also to hardware status, control and event register
Bluetooth defined Host Controller Transport Layers:
UART (HCI over serial interface)
RS232(HCI over serial interface)
USB(HCI over USB interface e.g. USB dongle)
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14. SDP (Service Discovery
Protocol)
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 discovers which services are available
 identifies the characteristics of the services
 uses a request/response model where each transaction consists of one
request protocol data unit (PDU) and one response PDU
 SDP is used with L2CAP is optimized for the dynamic nature of bluetooth
 SDP does not define methods for accessing services

15.  Audio
interfaces directly with the baseband. Each voice
connection is over a 64Kbps SCO link.
The voice coding scheme is the Continuous Variable
Slope Delta (CVSD
Link Manager Protocol
link setup and control, authentication and encryption
Host Controller Interface: provides a uniform method of
access to the baseband, control registers etc through
USB, PCI, or UART
Logical Link Control and Adaptation Layer
higher protocols multiplexing, packet
segmentation/reassembly, QoS
Telephony Control Specification
defines the call control signaling for the establishment of
speech and data calls between Bluetooth devices
RFCOMM
provides emulation of serial links (RS232). Upto 60
connections15

16. Usage Models
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 File transfer
 Internet bridge
 LAN access
 Synchronization
 Three-in-one phone
 Headset

17. 17
Wireless Network Configurations

18.  a: piconet with a single slave
 b: piconet with a multi slave
 c: scatternet
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Ad-hoc-networking

19. The Bluetooth network topology
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Piconet
Basic unit of Bluetooth networking
Master and one to seven slave devices
Master determines channel and phase
• All devices in a piconet hop together
–Master gives slaves its clock and device ID
• Non-piconet devices are in standby
• Master can connect to 7 simultaneous or 200+ active
slaves per piconet
• Each piconet has maximum capacity (1 MSps)
• Unique hopping pattern/ID
MS
S
SP
P
SB
SB

20. 20
Scatternets
 Scatternet
 Device in one piconet may exist as master or
slave in another piconet
 Allows many devices to share same area
 Makes efficient use of bandwidth
 Not implemented in COTS equipment
M
M
SS
S
S
P
sb
sb
P
P

21. Connection Establishment States
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22. 22
Frequency Hopping (FH)
 Resists interference and multipath effects
 Provides a form of multiple access among co-located devices in different
piconets
 Total bandwidth divided into 1 MHz channels
 FH occurs by jumping from one channel to another in pseudorandom sequence
 Hopping sequence shared across entire piconet
Piconet access:
 Bluetooth devices use time division duplex (TDD)
 Access technique is TDMA
 FH-TDD-TDMA

23. 23
Frequency Hopping
frame uses a single hop frequency for its duration

24. Multislot Frames
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25. Transmit Power
 The power steps shall form a monotonic sequence, with a maximum
step size of 8 dB and a minimum step size of 2 dB.
 A class 1 equipment with a maximum transmit power of +20 dBm must
be able to control its transmit power down to 4 dBm or less.
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26. Baseband protocol
 Standby
 Waiting to join a piconet
 Inquire
 Ask about available radios
 Page
 Connect to a specific radio
 Connected
 Actively on a piconet (master or slave)
 Park/Hold
 Low-power connected states
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Inquiry Page
Connected
AMA
Transmit
data
AMA
HOLD
AMA
PARK
PMA
T =2mstpcl
Low-power
states
Active
states
Standby
Connecting
states
Unconnected:
Standby
Detach
T =2mstpcl
T =0.6stpcl
T =2stpcl
releases
AMA address

27. Baseband link types
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 Polling-based (TDD) frame transmissions
 1 slot: 0.625msec (max 1600 slots/sec)
 master/slave slots (even-/odd-numbered slots)
 polling: master always “polls” slaves
 Synchronous connection-oriented (SCO) link
 “circuit-switched”

periodic single-slot frame assignment
 symmetric 64Kbps full-duplex
 Asynchronous connection-less (ACL) link
 Frame switching
 asymmetric bandwidth

variable frame size (1-5 slots)
 max. 721 kbps (57.6 kbps return channel)
 108.8 - 432.6 kbps (symmetric)
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
SCO
ACL
master
slave

28. Bluetooth Frame Fields
 Access code
 used for timing synchronization, offset compensation,
paging, and inquiry
 Header
 used to identify frame type and carry protocol control
information
 Payload
 contains user voice or data and payload header, if present
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29. Bluetooth Frame Structure
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ACCESS CODE - based on identity and system clock of Master
Provides means for synchronization; Unique for channel;
Used by all frames on the channel
Frame

30. Future Usage
 Home Automation
 Home Entertainment/Games
 Electronic Commerce/M-Commerce
 Industrial Control
 Surveillance
 Access Control
 Location Based Services
 Current Trials: Shopping Malls, Train Stations
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