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BLUETOOTH TECHNOLOGY

BLUETOOTH TECHNOLOGY. A revolution in wireless communication. ROAD MAP. Introduction Basic Definitions Topology Protocols Link Management & Security Applications and Future. Introduction. Aim :- To replace cables between mobiles, PC cards, headsets, desktops and other devices.

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BLUETOOTH TECHNOLOGY

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  1. BLUETOOTH TECHNOLOGY A revolution in wireless communication

  2. ROAD MAP • Introduction • Basic Definitions • Topology • Protocols • Link Management & Security • Applications and Future

  3. Introduction • Aim :- To replace cables between mobiles, PC cards, headsets, desktops and other devices. • Developed by Special Interest Group (SIG) • Association of I.T majors like Intel, IBM, Nokia and Toshiba

  4. Slower than IR as time taken to discover the intended recipient Penetration of solid objects Omni directional Advantage of proximity so less time requirement No such feature Unidirectional with 30 degrees range Bluetooth Verses Infrared

  5. Data transfer rate 721 Kbps 30 feet range Mobility during data transfer Internet compatible (emulating EIA\ TIA 232) Rate is 4 Mbps Range very less Relatively stationary BT Verses IR

  6. Bluetooth Definitions • Piconet : Collection of devices connected via Bluetooth in ad hoc fashion. Limited to 8 units in a Piconet • Scatternet : Two or more independent unsynchronized Piconet.

  7. Definitions • Master : A device in Piconet whose clock and hopping sequence are used to synchronize all the devices. It also numbers the communication channels

  8. Definitions • Slave : All other devices in the Piconet except master • MAC : 3-bit media access control address used to differentiate between participating units

  9. Bluetooth technology • Implemented using short range transreceivers • Specifications comprises a system solution consisting of a hardware, a software & interoperability requirements • Uses globally available unlicensed ISM radio band of 2.4 GHz. • Frequency range 2.4 – 2.484 GHz

  10. BT technology • Advantage of using an unlicensed frequency band is that it is globally acceptable

  11. Types of Links • Asynchronous Connection Links (ACL) • Supports symmetrical, asymmetrical, packet-switched & point to multipoint links • Data Transfer Rate: 433.9 Kbps(sym.) • 732.2 Kbps in one, 57.6 Kbps in reverse(asymmetric)

  12. Types of Links • Synchronous Connection Oriented Links (SCO) • Provide symmetrical, circuit-switched & point to point connections

  13. Audio and Video • For voice coding 64 Kbps channels are required • Channels are derived through use of PCM or CVSDM • Video encoding decoding using MPEG –4 format • Radio links use freq. hopping spread spectrum techniques

  14. Spread Spectrum • Method of wireless communication that takes a narrow band signal and spreads it over a broader portion of the available frequency band. • CDMA applies the same concept

  15. Advantages of Spread Spectrum Technique • Prevents Interference : where transmission disruption by external source such as noise from electromagnetic devices. • Prevents Jamming : where stronger signal overwhelms the weaker one. • No reflection off solids. • No interception : where unauthorized users capture signal to determine the content.

  16. Performance Characteristics

  17. Bluetooth Topology • Ad-hoc connection where each Piconet is identified by a different hopping sequence • Synchronization in unlicensed ISM band not permitted but BT devices do it using TDM • Service discovery protocol allows wider applications ex: create LAN • Clustering avoided using technical safeguards.

  18. Bluetooth Protocols • Bluetooth Protocol Layers • Bluetooth Core Protocols (Baseband, LMP, L2CAP, SDP) • Cable Replacement Protocols (Radio Freq. Communication) • Telephony Control Protocols (TCSBIN, AT-Commands) • Adopted Protocols (PPP, TCP, OBEX, WAP, vCard, vCalender)

  19. LMP and SDP • LMP : responsible for link setup & control between Bluetooth devices, including the control and negotiations of baseband packet sizes • SDP : device information, services and characteristics of services can be queried.

  20. BLUETOOTH LINK MANAGEMENT

  21. Link Management • Peer to Peer communication using LMP • Link Manager • Messages Exchanged (PDU’s) • Within 30 seconds • PDU • 55 different types of PDU’s • 7 bit op code

  22. AUTHENTICATION • General Response Messages • LMP_accepted • LMP_not_accepted • Challenge- Response Scheme • Verifier sends(LMP_au_rand) • Response is a function of challenge ,Claimant ‘s (BD_ADDR)&Secret Key • Common Secret key is required for proper calculation

  23. PAIRING • When no Common Link Key: • 128 bit Initialization Key based on PIN and random no. • Calculation of Response on key • Verifier Approves the Link Key • Response not correct then Error • Code authentication failure (LMP_detach)

  24. Link Key is Created after authentication • Link Key Created may be either combination of Keys or one of the unit’s unit key(LMP_unit _key & LMP_comb_key) • Waiting Interval: • Increased exponentially

  25. ENCRYPTION • Is an Option. • Master’s Will in piconet • Master & Slave must Agree • Point to Point or also broadcast packet’s

  26. Master is configured to Transmit unencrypted packets and receive encrypted . Slave is configured To Transmit and Receive encrypted packets Master is configured to Transmit and Receive encrypted packets Master is configured to Transmit encrypted and receive unencrypted . Slave is configured To Transmit and Receive unencrypted . Master is configured to Transmit and Receive unencrypted . ENCRYPTIONStart Stop

  27. Clock Offset Request • Every Device has an Internal System Clock • Timing and frequncy determined by the master in Piconet. • Difference between slave’s and master’s. • Clock offset is updated on each time a packet is received.

  28. BLUETOOTH SECURITY • Built in Security • Frequency Hopping • Pseudorandom code sequence • Lasts 0.4 seconds • 75 channels in 2.4GHZ • Authentication preventing spoofing unwanted access • Encryption makes data unintelligible. • Inhibiting user-friendly hence 3 levels of security.

  29. Security Modes • Mode 1: • Absence of security (Bypassing Link –Level security functions) • Exchange of vCard and vCalenders • Mode 2: • Service Level Security for parallel applications • Mode 3: • Link Level Security • LM enforces security at connection set up. • Link Keys

  30. Key Length(8 and 128 bits) • 128 bit challenge and 32 bit response . • Depends on Level of Security • Maximum length limited by Hardware

  31. LAYOUT • FIELDS OF APPLICATION. • BLUETOOTH ADVANTAGE • SHORTCOMINGS OF THE TECHNOLOGY. • COMPARISON WITH IR & WLAN. • MISNOMERS. • RESEARCHES ON THE TECHNOLOGY. • FUTURE ASPECTS.

  32. APPLICATIONS • WAP enabled smart phones. • Electronic trading via handheld devices. • ad hoc Home/personal area network. • 3G Telephony.

  33. BLUETOOTH ADVANTAGE • Increased mobility in office by connecting various peripherals with BT. • Voice and data transmission possible • 721 kbps suffices most of the common uses. • Built in sufficient encryption and authentication. • Cheaper insatllation & maintainence.

  34. ERROR CORRECTION • 1/3 rate FEC (Forward Error Correction) • 2/3 rate FEC • ARQ unnumbered scheme (Automatic Repeat Request). • This reduces the available bandwidth.

  35. RADIATION THREATS • Penetration depth of RF is about 1.5 cm at 2450 MHz and about 2.5 cm at 900 MHz • It cannot generate enough heat to produce fire hazards. • Radiation not beamed but dispersed in all direction. • But in long run EM radiation can cause ill effects in some persons.

  36. LOOPHOLES IN SECURITY • Key initialization is not reliable. • Unit key can leak the information in traffic. • BT device address can be used to generate logs of transaction. • Battery draining denial of service scheme.

  37. BLUETOOTH v/s INFRAREDBT IrDA

  38. BLUETOOTH v\s WLAN WLAN BT

  39. IrDa Response • Infra com launches RED BEAMER technology. • Indirect and diffused IR will increase mobility of IR devices. • Transmission at only 56kbps.

  40. BLUETOOTH FACTS • Its not WLAN. Data throughput is much less in BT. • BT can jam WLAN as both use 2.4GHz RF. • Not designed to carry heavy traffic loads. • Not suitable in server-based applications.

  41. PIONEERS IN RESEARCH • IBM- Watch pad and cyber phones. • MS- Intelligent apps for Windows. • INTEL-wireless PC Cards, access points. • MOTOROLA & TOSHIBA-pc mobile interface via bluetooth. • GENERAL MOTORS- Better communication in cars. • NEC-launched BT enabled notebook.

  42. BLUETOOTH FUTURE • 100 million devices in use and around 2005 650 million devices will be deployed. • 19% vehicles will be bluetooth enabled by 2007.

  43. SOME PRODUCTS IN MARKET • Ericsson R520 Bluetooth/WAP/GPRS/Triband • Ericsson T36 Bluetooth/WAP/HSCSD/Triband • Alcatel OneTouch 700 GPRS, WAP, Bluetooth • TDK Bluetooth Product Range • Bluetooth-enabled Nokia 9110 linked to a FujiFilm digital camera • Ericsson Bluetooth GSM Headset • Ericsson Communicator

  44. REFRENCES • www.countersys.com/tech/bluetooth.html • www.bluetooth.com • www.cnet.com • www.motorola.com • www.palowireless.com • www.swedetrack.com • www.mobileinfo.com • www.computer.org • www.informit.com • www.erricsson.com • www.norwoodsystems.com

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