BLUETOOTH The Universal Radio Interface for ad hoc, Wireless Connectivity By Jeffrey Adams

Outline Introduction Introduction The Bluetooth Air Interface The Bluetooth Air Interface Networking Networking Authentication and Encryption Authentication and Encryption Conclusion Conclusion

Introduction Started by Ericsson Started by Ericsson “MC Link”“MC Link” 1997 – Ericsson contacted others 1997 – Ericsson contacted others 1998 – Established SIG 1998 – Established SIG NokiaNokia IBMIBM ToshibaToshiba IntelIntel

Why is it called Bluetooth? King of Denmark in the late 900s King of Denmark in the late 900s Unite Denmark and part of Norway into a single kingdom Unite Denmark and part of Norway 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 Interface Issues Issues License-free band License-free band Frequency Hopping Frequency Hopping Channel Definition Channel Definition Packet Definition Packet Definition Physical Link Definition Physical Link Definition Interface Immunity Interface Immunity

Issues Worldwide Operable Worldwide Operable Supports voice and data Supports voice and data Physicality Physicality

License-free band 2.45 GHz frequency band 2.45 GHz frequency band Allows for global availabilityAllows for global availability Open to any radio systemOpen to any radio system Range 2400 to MHz Range 2400 to MHz Range 2471 to 2497 MHz Range 2471 to 2497 MHz

Frequency Hopping Problem Problem Solution Solution 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 problem, there is error correctionWhere hopping doesn’t solve the problem, there is error correction

Channel Definition Frequency- hop/time-division- duplex (FH/TDD) scheme Frequency- hop/time-division- duplex (FH/TDD) scheme Channel configuration Channel configuration

Packet Definition Packets are data exchanged between the master and slave Packets are data exchanged between the master and slave Access Codes direct the packets to the proper master/slave group Access Codes direct the packets to the proper master/slave group Packets vary from single slots to multi- slots Packets vary from single slots to multi- slots

Physical Link Definition Two types of links Two types of links SCO LinkSCO Link Symmetrical Symmetrical Circuit-switched Circuit-switched Point-to-point connections Point-to-point connections ACL linkACL link Symmetrical and Asymmetrical Symmetrical and Asymmetrical Packet-switched Packet-switched Point-to-multipoint connections Point-to-multipoint connections

Interface Immunity Potential interference problems Potential interference problems Solutions Solutions Frequency hoppingFrequency hopping Forward error controlForward error control ARQ scheme protectionARQ scheme protection voice-encoding schemevoice-encoding scheme

Networking Piconets Piconets Establishing Connections Establishing Connections Scatternet Scatternet Inter-piconet Communication Inter-piconet Communication

Piconets 2 or more Bluetooth units 2 or more Bluetooth units Form into master/slave configurations with a clock to track the hopping channel Form into master/slave configurations with a clock to track the hopping channel Master units control things Master units control things

Establishing Connection Wake-up sequence Wake-up sequence Packet access code Packet access code

Scatternet Competition for channel space Competition for channel space Help to alleviate this problem Help to alleviate this problem Overlapping piconets Overlapping piconets 1 MHz channel 1 MHz channel

Inter-piconet Communication Problem Problem Distinguishing the packet coordinates the hop Distinguishing the packet coordinates the hop Master units can hop piconets if need be Master units can hop piconets if need be

Authentication and Encryption Base level encryption Base level encryption Ciphering algorithmsCiphering algorithms Challenge-response routine Challenge-response routine Stream cipher Stream cipher Session key generation Session key generation 3 entities in the security algorithm 3 entities in the security algorithm Bluetooth unit addressBluetooth unit address Private user keyPrivate user key Random numberRandom number

Bluetooth Devices

Conclusion Bluetooth is wireless connectivity Bluetooth is wireless connectivity Allows for ad hoc networking Allows for ad hoc networking Much supported in industry Much supported in industry

References and Information BLUETOOTH – The universal radio interface for ad hoc, wireless connectivity, Ericsson Review No BLUETOOTH – The universal radio interface for ad hoc, wireless connectivity, Ericsson Review No