it 284 unit 5
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IT 284 Unit 5. Who Is Bluetooth?. 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) - PowerPoint PPT PresentationTRANSCRIPT
IT 284 Unit 5
21 April 2023 1
Who Is Bluetooth?
• 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)
— This is the front of the stone depicting the chivalry of Harald.
— The stone’s inscription (“runes”) say:– Harald controlled Denmark and Norway– Harald thinks notebooks and cellular phones
should seamlessly communicate
21 April 2023 2Source: Jim Kardach, Intel, [MobileDemo.ppt] 8Jun00 IEEE ComSoc http://grouper.ieee.org/groups/802/15/pub/2000/Jul00/00184r0P802-15_TG1-Bluetooth_IEEE-ComSoc-Pitch-8Jun00.ppt
A Comparison
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WLAN
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
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•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
File Transfer Profile
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• Profile provides:• Enhanced client-server interactions:
- browse, create, transfer folders- browse, pull, push, delete files
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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Headset Profile
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• 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.
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
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Special Interest Group
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Technical features
Connection Type Spread Spectrum (Frequency Hopping) & Time Division Duplex (1600 hops/sec)
Spectrum2.4 GHz ISM Open Band (79 MHz of spectrum = 79 channels)
Modulation Gaussian Frequency Shift Keying
Transmission Power 1 mw – 100 mw
Data Rate 1 Mbps
Range 30 ft
Supported Stations 8 devices
Data Security –Authentication Key 128 bit key
Data Security –Encryption Key 8-128 bits (configurable)
Module size 9 x 9 mm
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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
POWER RANGE
CLASS I 100 mW 100 m
CLASS II 2.5 mW 10 m
CLASS III 1 mW 1 m
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• Classification of devices on the basis of Power dissipated & corresponding maximum Range.
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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m s
s s s
m
Piconet Structure
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Master
Active Slave
Parked Slave
Standby
• All devices in piconet hop together.• Master’s ID and master’s clock determines frequency hopping
sequence & phase.
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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The Bluetooth network topology• Radio designation
— Connected radios can be master or slave— Radios are symmetric (same radio can be
master or slave)
• Piconet— Master can connect to 7 simultaneous or 200+
inactive (parked) slaves per piconet— Each piconet has maximum capacity (1 Mbps)
— Unique hopping pattern/ID • Scatternet
— Piconets can coexist in time and space
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M
M
SS
S
S
P
sb
sb
P
P
Functional Overview• Standby
— Waiting to join a piconet• Inquire
— Ask about radios to connect to• 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
C onnectedAMA
T ransm itdataAMA
T typ ica l=0.6s
T typ ica l=2s
H O LDAMA
PAR KPMA
T typ ica l=2 m s T typ ica l=2 m s
R e leasesA M A
A ddress
Low Pow erStates
ActiveStates
Standby
ConnectingStates
UnconnectedStandby
Det
ach
The Piconet
• All devices in a piconet hop together— To form a piconet: master gives slaves its clock and device ID
– Hopping pattern determined by device ID (48-bit)– Phase in hopping pattern determined by Clock
• Non-piconet devices are in standby• Piconet Addressing
— Active Member Address (AMA, 3-bits)— Parked Member Address (PMA, 8-bits)
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ID a
P
M Sor
sb
A
D
C
B
E
ID b
ID a
ID c
ID d
ID e
M
P
S
S
sb
ID a
ID c
ID d
ID a
IDa
IDa
ID e
ID b
The Bluetooth protocols
• A hardware/software description• An application framework
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Application Framework and Support
Link Manager and L2CAP
Radio & Baseband
Host Controller Interface
RF
Baseband
AudioLink Manager
L2CAP
Other TCS RFCOMM
Data
SDP
Applications
Con
trol
Bluetooth Protocol Stack
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Baseband
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Packet Structure
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Voice
No CRC
Data CRCheader
ARQ
FEC (optional) FEC (optional)
72 bits 54 bits 0 - 2744 bits
Access Code
Header Payload
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– Standby (no interaction) – Connection (working)– Park/Hold
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Connection State Machine
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 role 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
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RF
Baseband
AudioLink Manager
L2CAP
Data
SDP RFCOMM
IP
Con
trol
Applications
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.
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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Core Bluetooth Products
• Notebook PCs & Desktop computers
• Printers• PDAs• Other handheld
devices• Cell phones• Wireless peripherals:
• Headsets• Cameras
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• CD Player
• TV/VCR/DVD
• Access Points
• Telephone Answering Devices
• Cordless Phones
• Cars
Security• Security Measures
— Link Level Encryption & Authentication.
— Personal Identification Numbers (PIN) for device access.
— Long encryption keys are used (128 bit keys).
— Further encryption can be done at the application layer.
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