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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 Presentation
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IT 284 Unit 5 21 June 2022 1
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Page 1: IT 284 Unit 5

IT 284 Unit 5

21 April 2023 1

Page 2: 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)

— 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

Page 3: IT 284 Unit 5

A Comparison

21 April 2023 3

WLAN

Page 4: IT 284 Unit 5

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

21 April 2023 4

•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

Page 5: IT 284 Unit 5

File Transfer Profile

21 April 2023 5

• Profile provides:• Enhanced client-server interactions:

- browse, create, transfer folders- browse, pull, push, delete files

Page 6: IT 284 Unit 5

Other Products…

• 2004 Toyota Prius & Lexus LS 430 — hands free calls

• Digital Pulse Oximetry System• Toshiba Washer & Dryer• Nokia N-gage

21 April 2023 6

Page 7: IT 284 Unit 5

Headset Profile

21 April 2023 7

• 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.

Page 8: IT 284 Unit 5

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

21 April 2023 8

Page 9: IT 284 Unit 5

Special Interest Group

21 April 2023 9

Page 10: IT 284 Unit 5

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

21 April 2023 10

Page 11: IT 284 Unit 5

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

21 April 2023 11

Page 12: IT 284 Unit 5

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

21 April 2023 12

Page 13: IT 284 Unit 5

Classification

POWER RANGE

CLASS I 100 mW 100 m

CLASS II 2.5 mW 10 m

CLASS III 1 mW 1 m

21 April 2023 13

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

Page 14: IT 284 Unit 5

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)

21 April 2023 14

m s

s s s

m

Page 15: IT 284 Unit 5

Piconet Structure

21 April 2023 15

Master

Active Slave

Parked Slave

Standby

• All devices in piconet hop together.• Master’s ID and master’s clock determines frequency hopping

sequence & phase.

Page 16: IT 284 Unit 5

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

21 April 2023 16

Page 17: IT 284 Unit 5

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

21 April 2023 17

M

M

SS

S

S

P

sb

sb

P

P

Page 18: IT 284 Unit 5

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

21 April 2023 18

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

Page 19: IT 284 Unit 5

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)

21 April 2023 19

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

Page 20: IT 284 Unit 5

The Bluetooth protocols

• A hardware/software description• An application framework

21 April 2023 20

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

Page 21: IT 284 Unit 5

Bluetooth Protocol Stack

21 April 2023 21

Page 22: IT 284 Unit 5

Baseband

21 April 2023 22

Page 23: IT 284 Unit 5

Packet Structure

21 April 2023 23

Voice

No CRC

Data CRCheader

ARQ

FEC (optional) FEC (optional)

72 bits 54 bits 0 - 2744 bits

Access Code

Header Payload

Page 24: IT 284 Unit 5

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

21 April 2023 24

Connection State Machine

Page 25: IT 284 Unit 5

Link Manager Protocol

21 April 2023 25

Page 26: IT 284 Unit 5

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)

21 April 2023 26

Page 27: IT 284 Unit 5

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.

21 April 2023 27

Page 28: IT 284 Unit 5

Middleware Protocol Group

21 April 2023 28

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.

Page 29: IT 284 Unit 5

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.

21 April 2023 29

Page 30: IT 284 Unit 5

Core Bluetooth Products

• Notebook PCs & Desktop computers

• Printers• PDAs• Other handheld

devices• Cell phones• Wireless peripherals:

• Headsets• Cameras

21 April 2023 30

• CD Player

• TV/VCR/DVD

• Access Points

• Telephone Answering Devices

• Cordless Phones

• Cars

Page 31: IT 284 Unit 5

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.

21 April 2023 31


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