310 likes | 330 Views
Presented by Selim Dursun. Bluetooth. What is bluetooth? Introduction Overview Specifications & Layers Profiles Ad-hoc networking Qualification Products & Future Usage. What is bluetooth?.
E N D
Bluetooth • What is bluetooth? • Introduction • Overview • Specifications & Layers • Profiles • Ad-hocnetworking • Qualification • Products & Future Usage
What is bluetooth? • Bluetooth wireless technology is an open specification for a low-cost, low-power, short-range radio technology for ad-hoc wireless communication of voice and dataanywhere in the world.
Intoduction • 1994Ericsson getsinterested in wirelessconnectionsfrommobiletelephonesto other deviceslikePDAsand accessorieslikeHeadsets • FormingtheSIG(SpecialInterestGroup)with4othermembers(IBM,Intel,Nokia,Toshiba)in orderto developawirelessstandard for communicationbetweenmobiledevices
Introdution • Todayover 2000members • 2main priorities: • Cheap • Lower energyconsumption • IEEE802.15committeestandardizesthephysicaland linklayer • SIGstillenhancesBluetooth • two versionsin futurepossible (SIGvsIEEE)
Overview • Originally conceived as a cable replacement technology • Other usage models begantodevelop: • Personal Area Network (PAN) • Ad-hoc networks • Data/voice access points • Wireless telematics
Overview • Advantages • Bluetooth: interoperable • IrDA:line ofsightneeded,point-to-point • WLAN:higher power consumption • Disadvantages • Bluetooth: onlyupto1Mbps • IrDA:muchcheaper,faster (upto16Mbps) • WLAN:faster (upto11Mbps) WLANandBluetoothinterfere eachother(bothare usingthe ISMband)
Specifications & Layers • specification protocol stack
Layers • Bluetooth Radio • Baseband • LMP(LinkManagerProtocol) • HCI(HostControllerInterface) • L2CAP(LogicalLinkControl andAdaptation Protocol) • RFCOMM(RadioFrequency Communication) • SDP(Service DiscoveryProtocol)
Bluetooth Radio • the lowest defined layer of the Bluetooth specification • operating inthe 2,4GHzISMBand • accomplishesspectrumspreading byfrequency hopping(FHSS)from2.402GHzto2.480GHz
Bluetooth Radio • 3 different power classes • PowerClass1:long range (100m,100mW) • PowerClass2:midrange (10m,1-2,5mW) • PowerClass3:shortrange (0.1-10m,1mW) • signalstrength adjustment
Baseband • the physical layer of the Bluetooth that provides • Errorcorrection • Flowcontrol • Hopping sequence • Security • hopping through 79channels • dataisdividedinpackets • accesscode:e.g.timing synchronization • header:e.g.packetnumbering,flowcontrol,slave address • payload:voice,dataorboth
Baseband • Connection Modes describes the set of rules by which all bluetooth devices must abide in order to establish a link a communicate with one another • STANDBY: not connected in a piconet • ACTIVE:active participation on the channel • PowerSaving Modes • SNIFF:slave listensto the channel atareducedrate(decreasing ofdutycycle) leastpowerefficient • HOLD:datatransferisheldforaspecifictime period, mediumpowerefficient • PARK:synchronizedto the piconetbutdoesnotparticipate intraffic
Baseband • SecurityModes • non-secure • encryption enforcedby application layer • encryption enforcedby linklayer • For devices • trusted device • untrusted device • For services • require authorization and authentication • require authentication • open to all devices
Audio • two codecs:PCMandCVSD • both at64kbit/s • synchronousconnection oriented(SCO)links • time-critical • no retransmission • errorsappearasbackgroundnoise
LMP (LinkManagerProtocol) • providesauthentication,linksetupandlinkconfiguration including powersurveillance • takesplace asaservice provider • communication with LMPDUs(protocol dataunits)
HCI (HostControllerInterface) • providesacommandinterface to baseband controllerandlinkmanager • also to hardware status,control andeventregister • Bluetooth definedHostControllerTransportLayers: • UART (HCIoverserialinterface) • RS232(HCIoverserialinterface) • USB(HCIoverUSBinterface e.g.USBdongle)
L2CAP (LogicalLinkControl andAdaptation Protocol) • providesaconnection-orientedandconnectionlessservice to upperlayer • protocolswith quality-of-service functionsusing multiplexing,segmentation andreassembly • two linktypesdefinedinBasebandlayer: • 1.SCO(synchronousconnection-oriented) • 2.ACL(asynchronousconnection-less) BUT ONLYACLissupportedby L2CAP (SCOnotplanned)
RFCOMM (RadioFrequency Communication) • Providesemulation ofserialports • Supportsupto 60simultaneousconnections • Differentiatesbetween two device types: • Type 1:communication endpoints(e.g.printer or headsets) • Type 2:deviceswhich are partofcommunication(e.g.modems) • Butinthe protocol itselfno distinction ismade, some information isfortype 1otherfortype 2
SDP (Service DiscoveryProtocol) • discoverswhichservicesare available • identifiesthe characteristicsofthe services • uses a request/response model where each transaction consists of one request protocol data unit (PDU) and one response PDU • SDPisusedwithL2CAP • isoptimizedforthedynamicnature of bluetooth • SDPdoesnot definemethodsforaccessingservices
Profiles • how bluetooth isused • describe howimplementationsforaspecificuse mustbe written • definesoptionsineach protocol • definesparameterranges • profilesare usedto solve interoperabilityproblemsbetween differentmanufacturers’ products
Ad-hoc-networking • piconet • decentral, onemasterupto7slaves • upto255parked slaves • point to point or point to multipoint conn • unique bluetoothdeviceaddress • scatternet • overlappingoftwopiconets, up to 10 • differenthoppingsequences • peer to peer (P2P) network
Ad-hoc-networking • a: piconet with a single slave • b: piconet with a multi slave • c: scatternet
Qualification • aimsinteroperabilitybetween all bletooth devices • no licensefees • bluetoothdevicesmustsupportsameprofiles • bluetoothlogo guaranteesinteroperability
Qualification • no line ofsight required • you can use it everywhere • bluetoothchip • integrated • powermanagement • not reallycheap • Automaticad-hocnetworking(invisible) e.g.automaticdata synchronisation
Notebook PCs & desktop computers Printers PDAs Other handheld devices Cell phones Wireless periperals: Headsets Cameras Access Points CD Player TV/VCR/DVD Telephone Answering Devices Cordless Phones Cars Products
Products • 2004 Toyota Prius – hands free calls • Toshiba Washer & Dryer – downloads the washer/dryer software for new clothes! • Nokia N-gage • Digital Pulse Oximetry System
Future Usage • Home Automation • Home Entertainment/Games • Electronic Commerce/M-Commerce • Industrial Control • Surveillance • Access Control • Location Based Services • Current Trials: Shopping Malls, Train Stations
Thats All ! Thanks for listening...