Bluetooth
Prof. Young Gil Kim University of Seoul
Information regarding Bluetooth is subject to change without noticeBluetooth is a trademark owned by Telefonaktiebolaget L M Ericsson, Sweden
Short-range radio communications with BLUETOOTHTM
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Bluetooth
EMBEDDED CONNECTIVITY
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Bluetooth
z Hidden computingz Hidden communications
BACKGROUND SYNCHRONIZATION
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Bluetooth
Source: IDC, Strategy Analytics, Ericsson, Silver Institute.
Million units
100
200
300
400
500
600
700
800
900
1000
mobile phones
mobile accessories
mobile computers andhandheld devices
desktop computers
desktop accessories
printers
cordless phones
telephone answeringdevices
TV/VCR/DVD
CD-player
Mobile devices Desktop devices Consumer electronics
Internet connectiondevice
cameras & misc.remote control
THE POTENTIAL
Forecasted worldwide sales 2005
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Bluetooth
Harald Bluetooth IIKing of Denmark 940-981
This is one of two Runic stoneserected in his capitol city of Jelling
z The stone’s inscription (“runes”)say:
z Harald christianized the Danes
z Harald made peace
z Harald thinks notebooks and cellularphones should be seamlessly connected
THE NAME
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Bluetooth
z Core design issuesz Application areasz Protocol stack
z radio & basebandz link managerz L2CAP & HCIz software stack
z Profilesz Implementation issues
OUTLINE
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Bluetooth
CORE DESIGN ISSUES
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Bluetooth
z Ad-hoc connectivityz Radio spectrumz Low-cost implementation
CORE DESIGN ISSUES
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Bluetooth
CORE DESIGN ISSUES: mobile systems
fixednetwork
mobilenetwork
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Bluetooth
CORE DESIGN ISSUES: wireless extensions
fixednetwork
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Bluetooth
CORE DESIGN ISSUES: ad-hoc systems
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Bluetooth
CORE DESIGN ISSUES: ad-hoc connectivity
Definition:
In an ad-hoc network, there is no (wired) infrastructure tosupport the connectivity of the portable units.
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Bluetooth
CORE DESIGN ISSUES: ad-hoc connectivity
no basestations or terminals
no up or downlinks
no central controller
no control channel to lock to
PEER-TO-PEER CONNECTIONS
no distinct cells
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Bluetooth
CONVENTIONAL AD-HOC NETWORK
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Bluetooth
SCATTER AD-HOC NETWORK
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Bluetooth
z Scatternet ‘chaos’z uncoordinated channels
z TX powers varyz irregular traffic
z near-far problems
z non-stationary
ROBUSTNESSGRACEFUL DEGRADATION
CORE DESIGN ISSUES: ad-hoc connectivity
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Bluetooth
z Channel definition & allocation (MA)z Medium access (MAC)z Call setupz Power management (standby)z Traffic management (QoS)
CORE DESIGN ISSUES: ad-hoc connectivity
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Bluetooth
CORE DESIGN ISSUES: radio spectrum
z Global availabilityz Unlicensedz Non-dedicated (e.g. DECT, HIPERLAN)z Co-existing and sharing with other applicationsz Regulatory bodies: FCC/ETSI/ARIB
Industrial - Scientific - Medical (ISM) band
2400-2483.5 MHz
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Bluetooth
RF identification
µwave ovens
RF lighting
WLAN
?
CORE DESIGN ISSUES: spectrum sharing
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Bluetooth
CORE DESIGN ISSUES: spectrum sharing
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Bluetooth
z Knownsz 2.45 GHz IS M band applicable wordwide (almost)z regulatory rules (FCC Part 15, Part 18, E T S I, AR IB)z exis ting non-Bluetooth systemsz a new system introduction any time, any where
z Unknownsz rule changesz new sys tems and their deployment
ISM STATUS IS UNPREDICTABLEPREPARE FOR THE WORST
CORE DESIGN ISSUES: spectrum
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Bluetooth
z Prepared for s ingle-chip integrationz Main-s tream technology
air protocol design transceiver design
$5
CORE DESIGN ISSUES: low cost
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Bluetooth
APPLICATION AREAS
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Bluetooth
z Personal net (PNET)z Person-to-person net (PPNET)z Mobile person-to-Internet accessz Person-to-local access pointz Future applications
APPLICATIONS AREAS
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Bluetooth
Ultra portable devices:z Pen inputz Voice input/outputz Exchange/share data
between devices
APPLICATION AREAS: personal net (PNET)
= Potential B luetooth and WL AN device
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Bluetooth
Chat
Gaming
Info S haring
vClips
vPics
vMP3
vApps
= Potential B luetooth and WL AN device
APPLICATION AREAS: person-to-person net (PPNET)
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Bluetooth
Browse
Data Access/storage
S end Postcards
Maps
Voice/text input
S treaming voice and video
APPLICATION AREAS: mobile person-to-Internet access
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Bluetooth
Local InformationPush/Retrieval
M-Commerce
WAP
Mail/Data Access andS torage
Multi mediamessaging
Local data
APPLICATION AREAS: person-to-local access point
= Potential B luetooth and WL AN device
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Bluetooth
z Home automationz Home entertainmentz Electronic commercez Industrial controlz Automotivez Surveillancez Access controlz and countless others…
APPLICATIONS AREAS: future applications
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Bluetooth
z Adapted OSI modelz Implementation & low-power
considerationsz Two major segments:
z Application frame workz Hardware description
PROTOCOL STACK
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Bluetooth
RFBaseband
Link Manager
L2CAP
TCP/IP HID RFCOMM
Applications
Data
Con
trolAudio
PROTOCOL STACK: hardware & softwaredescription
an application framework
a hardware description
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Bluetooth
PROTOCOL STACK: RF layer
z Basic radio functionsz signal amplificationz frequency synthesisz frequency up & downconversionz modulation & demodulationz conversion bits into symbolsz filtering & shaping
TX RXbits in bits out
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Bluetooth
PROTOCOL STACK: baseband layer
z Real-time operationsz time slottingz frequency hoppingz synchronizationz packet handlingz error correctionz basic connection establishment
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Bluetooth
RFBaseband
Link Manager
L2CAP
TCP/IP HID RFCOMM
Applications
Data
Con
trolAudio
PROTOCOL STACK: RF & baseband
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Bluetooth
z FH spread spectrumz broadband on average / narrowband instantaneously
z filter rejection: avoiding most of the interferencez multiple access scheme: FH-CDMA
FILTER AND SURVIVE
SIGNAL SPREADING
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Bluetooth
z FH parameters
z 79 carriers, spaced at 1 MHz2.402 + k MHz, k = 0, …, 78
z lower guard space: 1.5 MHz
z upper guard space: 3 MHzz 1600 hops/s nominal hop rate
BLUETOOTH RADIO PARAMETERS
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Bluetooth
z Modulation parameters
z 1 Ms/s FSK modulation: 0.28 < h < 0.35z Gaussian shaping GFSK: BT = 0.5
z 1 Mb/s nominal bit rate
z 20dB spectral bandwidth: 1 MHz
BLUETOOTH RADIO PARAMETERS
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Bluetooth
z Time slottedz Time division duplex (TDD)z Tslot = Tdwell
THE BLUETOOTH CHANNEL
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Bluetooth
625 µs
t
t
A
B
f(2k) f(2k+1) f(2k+2)
FH/TDD CHANNEL
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Bluetooth
slave
slave
master
master
slave
slave
slave
slave
PICONET CHANNELS
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Bluetooth
z Only roles during piconet existencez Any unit can become master, but
only one per piconetz Master defines piconet channelz Master controls traffic on channelz Master provides QoS
MASTER-SLAVE CONCEPT
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Bluetooth
time
Freq.
EXPLOITING 79 MHz OF SPECTRUM
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Bluetooth
MULTI-SLOT PACKETS
f(k)
625 µs
f(k+1) f(k+2) f(k+3) f(k+4)
f(k+3) f(k+4)f(k)
f(k)
f(k+5)
f(k+5)
f(k+5)
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Bluetooth
PAYLOAD FORMAT
168 8
L_CH
2 1
FLOW LENGTH
5
L_CH
2 1
FLOW LENGTH
9
reserved
4
{ CRC
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Bluetooth
PHYSICAL LINKS
z Multi-media supportz synchronous servicesz asynchronous servicesz isochronous services
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Bluetooth
PHYSICAL LINKS
z Synchronous servicesz circuit switchingz point-to-pointz no delay variations, error tolerant
z Asynchronous servicesz packet switchingz point-to-multipointz delay tolerant, no errors
z Isochronous servicesz point-to-pointz delay & error tolerant
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Bluetooth
PHYSICAL LINKS
z Mixing services on air interfacez time slotted channelz packet scheduling by masterz control over quality of service
z Synchronous Connection-Oriented (SCO) Linkz symmetric, synchronous servicesz slot reservation with fixed interval
z Asynchronous Connection-Less (ACL) Linkz (a)symmetric, asynchronous servicesz polling access scheme
z isochronous service via master scheduling
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Bluetooth
MASTER
SLAVE 1
SLAVE 2
SLAVE 3
ACLSCO SCO SCO SCOACLACL ACL
MIXING SERVICESTsco
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Bluetooth
z DM1*, DH1**
z DM3, DH3
z DM5, DH5
ACL PACKETS
625 µs
* DM1 is a common packet** DH packet: uncoded DM packet: 2/3-rate coded; shortened (15,10) Hamming code
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Bluetooth
PROFILES
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protocols
unit A unit B
profiles
applications
PROFILES & PROTOCOLS
applications
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Bluetooth
Generic Access Profile
Service DiscoveryApplication Profile
TCS-BIN-based Profiles
Cordless PhoneProfile
Intercom Profile
Serial Port Profile
Dial-up NetworkingProfile
Fax Profile
Generic Object ExchangeProfile
Headset Profile
LAN Access Profile
File TransferProfile
Object Push Profile
SynchronizationProfile
BLUETOOTH PROFILES
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Bluetooth
IMPLEMENTATION ISSUES
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Bluetooth
BLUETOOTH IMPLEMENTATION
z low-cost
z low-power
z HW/SW separation
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Bluetooth
radio baseband
host
control
BLUETOOTH IMPLEMENTATION
z radio: analog circuitry
z baseband: dedicated logic
z control: general purpose processor
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Bluetooth
IMPLEMENTATION: low cost
z main stream technology
z single-chip solution
z simplicity
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Bluetooth
IMPLEMENTATION: low power
z low voltage
z smart partitioning
z smart processing
z single chip
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CROSS-INDUSTRY COLLABORATION
z Promotersz 3COMz Ericssonz IBMz Intelz Lucentz Microsoftz Motorolaz Nokiaz Toshiba
z 2000+ adopters
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Bluetooth
SOLVED