BLUETOOTHBLUETOOTH

The Universal Radio Interface The Universal Radio Interface for ad hoc, Wireless for ad hoc, Wireless

ConnectivityConnectivity

By Jeffrey Adams

OutlineOutline

IntroductionIntroduction The Bluetooth Air InterfaceThe Bluetooth Air Interface NetworkingNetworking Authentication and EncryptionAuthentication and Encryption ConclusionConclusion

IntroductionIntroduction

1994 - Started by Ericsson1994 - Started by Ericsson• ““MC Link”MC Link”

1997 – Ericsson contacted others 1997 – Ericsson contacted others 1998 – Established SIG1998 – Established SIG

• NokiaNokia• IBMIBM• ToshibaToshiba• IntelIntel

Why is it called Bluetooth?Why is it called Bluetooth?

King of Denmark in the late 900sKing of Denmark in the late 900s Unite Denmark and part of Norway Unite Denmark and part of Norway

into a single kingdom into a single kingdom Introduced Christianity into Denmark Introduced Christianity into Denmark Jelling rune stone Jelling rune stone Svend Forkbeard Svend Forkbeard Communications industry Communications industry

The Bluetooth Air InterfaceThe Bluetooth Air Interface

IssuesIssues License-free bandLicense-free band Frequency HoppingFrequency Hopping Channel DefinitionChannel Definition Packet DefinitionPacket Definition Physical Link DefinitionPhysical Link Definition Interface ImmunityInterface Immunity

IssuesIssues

Worldwide OperableWorldwide Operable Supports voice and dataSupports voice and data PhysicalityPhysicality

License-free bandLicense-free band

2.45 GHz frequency band2.45 GHz frequency band• Allows for global availabilityAllows for global availability• Open to any radio systemOpen to any radio system

Range 2400 to 2483.5 MHzRange 2400 to 2483.5 MHz Range 2471 to 2497 MHzRange 2471 to 2497 MHz

Frequency HoppingFrequency Hopping

ProblemProblem SolutionSolution

• Divides the band into channelsDivides the band into channels• Radios hop from channel to channelRadios hop from channel to channel• Where hopping doesn’t solve the Where hopping doesn’t solve the

problem, there is error correctionproblem, there is error correction

Channel DefinitionChannel Definition

Frequency-hop/Frequency-hop/time-division-time-division-duplex (FH/TDD) duplex (FH/TDD) schemescheme

Channel Channel configurationconfiguration

Packet DefinitionPacket Definition

Packets are data exchanged between the Packets are data exchanged between the master and slavemaster and slave

Access Codes direct the packets to the Access Codes direct the packets to the proper master/slave groupproper master/slave group

Packets vary from single slots to multi-Packets vary from single slots to multi-slotsslots

Physical Link DefinitionPhysical Link Definition

Two types of linksTwo types of links• SCO LinkSCO Link

SymmetricalSymmetrical Circuit-switchedCircuit-switched Point-to-point connectionsPoint-to-point connections

• ACL linkACL link Symmetrical and AsymmetricalSymmetrical and Asymmetrical Packet-switchedPacket-switched Point-to-multipoint connectionsPoint-to-multipoint connections

Interface ImmunityInterface Immunity

Potential interference problems Potential interference problems SolutionsSolutions

• Frequency hoppingFrequency hopping• Forward error controlForward error control• ARQ scheme protectionARQ scheme protection• voice-encoding schemevoice-encoding scheme

NetworkingNetworking

PiconetsPiconets Establishing ConnectionsEstablishing Connections ScatternetScatternet Inter-piconet CommunicationInter-piconet Communication

PiconetsPiconets

2 or more Bluetooth units2 or more Bluetooth units Form into master/slave Form into master/slave

configurations with a clock to track configurations with a clock to track the hopping channelthe hopping channel

Master units control thingsMaster units control things

Establishing ConnectionEstablishing Connection

Wake-up sequenceWake-up sequence Packet access codePacket access code

ScatternetScatternet

Competition for channel spaceCompetition for channel space Help to alleviate this problemHelp to alleviate this problem Overlapping piconetsOverlapping piconets 1 MHz channel1 MHz channel

Inter-piconet CommunicationInter-piconet Communication

ProblemProblem Distinguishing the packet Distinguishing the packet

coordinates the hopcoordinates the hop Master units can hop piconets if need Master units can hop piconets if need

bebe

Authentication and EncryptionAuthentication and Encryption

Base level encryptionBase level encryption• Ciphering algorithmsCiphering algorithms

Challenge-response routineChallenge-response routine Stream cipherStream cipher Session key generationSession key generation

3 entities in the security algorithm3 entities in the security algorithm• Bluetooth unit addressBluetooth unit address• Private user keyPrivate user key• Random numberRandom number

Bluetooth DevicesBluetooth Devices

ConclusionConclusion

Bluetooth is wireless connectivityBluetooth is wireless connectivity Allows for ad hoc networkingAllows for ad hoc networking Much supported in industryMuch supported in industry

References and InformationReferences and Information

BLUETOOTH – The universal radio BLUETOOTH – The universal radio interface for ad hoc, wireless interface for ad hoc, wireless connectivity, Ericsson Review No.3 connectivity, Ericsson Review No.3 19981998

www.bluetooth.comwww.bluetooth.com www.bluetooth.orgwww.bluetooth.org www.ericsson.com/bluetoothwww.ericsson.com/bluetooth www.palowireless.com/bluetoothwww.palowireless.com/bluetooth