IT 284 Unit 5

1. IT 284 Unit 5

2. Who Is Bluetooth? • Harald Blaatand “Bluetooth” II • King of Denmark 940-981 • Son of Gorm the Old (King of Denmark) and Thyra Danebod (daughter of King Ethelred of England) This is one of two Runic stones erected in his capitol city of Jelling (central Jutland) • This is the front of the stone depicting the chivalry of Harald. • The stone’s inscription (“runes”) say: • Harald controlled Denmark and Norway • Harald thinks notebooks and cellular phones should seamlessly communicate Source: Jim Kardach, Intel, [MobileDemo.ppt] 8Jun00 IEEE ComSoc http://grouper.ieee.org/groups/802/15/pub/2000/Jul00/00184r0P802-15_TG1-Bluetooth_IEEE-ComSoc-Pitch-8Jun00.ppt

3. A Comparison WLAN

4. Bluetooth vs. IrD • Bluetooth • Point to Multipoint • Data & Voice • Easier Synchronization due to omni-directional and no LOS requirement • Devices can be mobile • Range 10 m • IrD • Point to point • Intended for Data Communication • Infrared, LOS communication • Can not penetrate solid objects • Both devices must be stationary, for synchronization • Range 1 m

5. File Transfer Profile • Profile provides: • Enhanced client-server interactions: • -browse, create, transfer folders • - browse, pull, push, delete files

6. Other Products… • 2004 Toyota Prius & Lexus LS 430 • hands free calls • Digital Pulse Oximetry System • Toshiba Washer & Dryer • Nokia N-gage

7. Headset Profile • Profile provides: • Both devices must provide capability to initiate connection & accept/terminate calls. • Volume can be controlled from either device. • Audio gateway can notify headset of an incoming call.

8. Bluetooth Goals & Vision • Originally conceived as a cable replacement technology • Short-Range Wireless Solutions • Open Specification • Voice and Data Capability • Worldwide Usability • Other usage models began to develop: • Personal Area Network (PAN) • Ad-hoc networks • Data/voice access points

9. Special Interest Group

10. Technical features

11. Bluetooth FHSS • Employs frequency hopping spread spectrum • Reduce interference with other devices • Pseudorandom hopping • 1600 hops/sec- time slot is defined as 625 microseconds • Packet 1-5 time slots long

12. Time-Division Duplex Scheme • Channel is divided into consecutive slots (each 625 s) • One packet can be transmitted per slot • Subsequent slots are alternatively used for transmitting and receiving • Strict alternation of slots between the master and the slaves • Master can send packets to a slave only in EVEN slots • Slave can send packets to the master only in the ODD slots

13. Classification • Classification of devices on the basis of Power dissipated & corresponding maximum Range.

14. m s m s s s Typical Bluetooth Scenario • Bluetooth will support wireless point-to-point and point-to-multipoint (broadcast) between devices in a piconet. • Point to Point Link • Master - slave relationship • Bluetooth devices can function as masters or slaves • Piconet • It is the network formed by a Master and one or more slaves (max 7) • Each piconet is defined by a different hopping channel to which users synchronize to • Each piconet has max capacity (1 Mbps)

15. Master Active Slave Parked Slave Standby Piconet Structure • All devices in piconet hop together. • Master’s ID and master’s clock determines frequency hopping sequence & phase.

16. Ad-hoc Network – the Scatternet • Inter-piconet communication • Up to 10 piconets in a scatternet • Multiple piconets can operate within same physical space • This is an ad-hoc, peer to peer (P2P) network

17. S M P sb S S P P sb M S The Bluetooth network topology • Radio designation • Connected radios can be master or slave • Radios are symmetric (same radio can be master or slave) • Piconet • Master can connect to 7 simultaneous or 200+ inactive (parked) slaves per piconet • Each piconet has maximum capacity (1 Mbps) • Unique hopping pattern/ID • Scatternet • Piconets can coexist in time and space

18. Functional Overview • Standby • Waiting to join a piconet • Inquire • Ask about radios to connect to • Page • Connect to a specific radio • Connected • Actively on a piconet (master or slave) • Park/Hold • Low Power connected states

19. D A E B C or The Piconet • All devices in a piconet hop together • To form a piconet: master gives slaves its clock and device ID • Hopping pattern determined by device ID(48-bit) • Phase in hopping pattern determined by Clock • Non-piconet devices are in standby • Piconet Addressing • Active Member Address (AMA, 3-bits) • Parked Member Address (PMA, 8-bits)

20. The Bluetooth protocols Applications • A hardware/software description • An application framework Other TCS RFCOMM SDP Application Framework and Support Data Control Host Controller Interface Audio L2CAP Link Manager and L2CAP Link Manager Baseband Radio & Baseband RF

21. Bluetooth Protocol Stack

22. Baseband

23. 72 bits 54 bits 0 - 2744 bits Access Code Header Payload CRC Data header Voice ARQ No CRC FEC (optional) FEC (optional) Packet Structure

24. Channel Establishment • There are two managed situations • A device knows the parameters of the other • It follows paging process • No knowledge about the other • Then it follows inquiring &paging process • Two main states • Standby (no interaction) • Connection (working) • Park/Hold Connection State Machine

25. Link Manager Protocol

26. Link Manager Protocol • The Link Manager carries out link setup, authentication & link configuration. • Channel Control • All the work related to the channel control is managed by the master • The master uses polling process for this • The master is the first device which starts the connection • This role can change (master-slave role switch)

27. L2CAP • Service provided to the higher layer: • L2CAP provides connection-oriented and connectionless data services to upper layer protocols • Protocol multiplexing and demultiplexing capabilities • Segmentation & reassembly of large packets • L2CAP permits higher level protocols and applications to transmit and receive L2CAP data packets up to 64 kilobytes in length.

28. IP Control Applications Data SDP RFCOMM Middleware Protocol Group Audio L2CAP Link Manager Baseband RF Middleware Protocol Group • Additional transport protocols to allow existing and new applications to operate over Bluetooth. • Packet based telephony control signaling protocol also present. • Also includes Service Discovery Protocol.

29. Middleware Protocol Group (contd.) • Service Discovery Protocol (SDP) • Means for applications to discover device info, services and its characteristics. • TCP/IP • Network Protocols for packet data communication, routing. • RFCOMM • Cable replacement protocol, emulation of serial ports over wireless network.

30. Core Bluetooth Products • CD Player • TV/VCR/DVD • Access Points • Telephone Answering Devices • Cordless Phones • Cars • Notebook PCs & Desktop computers • Printers • PDAs • Other handheld devices • Cell phones • Wireless peripherals: • Headsets • Cameras

31. Security • Security Measures • Link Level Encryption & Authentication. • Personal Identification Numbers (PIN) for device access. • Long encryption keys are used (128 bit keys). • Further encryption can be done at the application layer.