IEEE 802.15.1 (a.k.a. Bluetooth)

1. IEEE 802.15.1 (a.k.a. Bluetooth)

2. Bluetooth: • King Harold Blatand, or Bluetooth, a Viking and King of Denmark 940-981, united Denmark & Norway • 1994 – Ericsson study on a wireless technology to link mobile phones and accessories

3. Bluetooth working group history • February 1998: The Bluetooth SIG is formed • promoter company group: Ericsson, IBM, Intel, Nokia, Toshiba • May 1998: Public announcement of the Bluetooth SIG • July 1999: 1.0A spec (>1,500 pages) is published • December 1999: ver. 1.0B is released • December 1999: The promoter group increases to 9 • 3Com, Lucent, Microsoft, Motorola • March 2001: ver. 1.1 is released • Aug 2001: There are 2,491+ adopter companies • Nov. 2003: ver. 1.2 is released • Nov. 2004: ver. 2.0 is released

5. Bluetooth positioning • Bluetooth: • Wireless voice and data for mobile devices • IrDA: • Wirelss data cable replacement for devices in line of sight • HomeRF: • Networking mobile data and voice devices to a PC anywhere in the home • IEEE 802.11 and Hiperlan 2: • Wireless enterprise networking in the office • DECT: • Wireless voice at home and in the office

6. Bluetooth GSM GPRS UMTS Bandwidth DECT WLAN IrDA WLAN UMTS Dect GPRS IR GSM Bluetooth Coverage Bluetooth positioning

7. Bluetooth positioning

8. Usage Models • Headset – hands free cell phone (road, office, car) • 3 in 1 Phone – intercom (no charge), portable phone (fixed line charge), cellular • Office-->LAN/PSTN Home-->PSTN • Internet Bridge – Network access point, for mobile internet browsing • Automatic Synchronizer – Background syncs between PC & PDA, Phone & PC, etc. • Instant Postcard – digital camera send to cell phone • Interactive Conference – Exchange business cards & data in meetings • Wireless Workplace – Peripherals connect to your PC or LAN without wires

9. 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 Core Bluetooth Products

10. Other 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

11. Future Usage Scenarios • Home Automation • Home Entertainment/Games • Electronic Commerce/M-Commerce • Industrial Control • Surveillance • Access Control • Location Based Services • Current Trials: Shopping Malls, Train Stations • ……

12. Key Success Factors • Interoperability (assured by BQB) • Mass Production at Low Cost • Ease of Use • End User Experience

13. Bluetooth Qualification Body (BQB) • A person authorized to provide qualification services for products • Bluetooth Qualification Test Facility (BQTF) • Preparation – Testing – Assessment & Listing – Qualified Products List (QPL) • Stats (as of 02/01/04): • Qualified Products: 1368 • BQBs Worldwide: 35 • BQTFs Worldwide: 25 • Only 4 of each in US

14. Bluetooth Profiles • Profiles implement usage models • Profiles will use 1 or more protocols • Qualification based on set of profiles provided

15. Profiles & Services • An application that provides a capability to another device, e.g. printing, LAN Access, synchronization, etc. • Bluetooth profiles define core services • Programmers can write new services

18. Example...

19. Baseband

20. Bluetooth Technical Features • 2.4 GHz ISM Open Band • Globally free available frequency • 79 MHz of spectrum = 79 channels • Frequency Hopping & Time Division Duplex (1600 hops/second) • 10-100 Meter Range • Class I – 100 meter (300 feet) • Class II – 20 meter (60 feet) • Class III – 10 meter (30 feet)

21. Frequency Hopping among Piconets • Typically, FH scheme uses carriers spacing of 1 MHz with up to 79 different frequencies. • f = 2402 + k ; k = 0…78 • So, with FH, there are 79 logical channels (theoretically). • When two piconets choose the same 1MHz-band, collision occurs.

22. 78 Frequency 0 Time Frequency hopping

23. Frequency Hopping Sequences • Each time, the FH kernel selects a segment of 64 adjacent channels, and then hops to 32 of them without repetition in a random order • Next, a different 32-hop sequence is chosen from another segment of 64 adjacent channels

24. Interference • Frequency hopping • Short range • Power control • FEC and ARQN • Short packets and fast acknowledgements • Other equipment in ISM band e.g. WLAN, micro-wave oven, etc. • Adaptive Frequency Hopping (AFH) is proposed in IEEE 802.15.1.

25. Bluetooth Link types • Synchronous Connection Oriented (SCO) • Circuit switched typically used for voice • Symmetric, synchronous service • Slot reservation at fixed intervals • Point-to-point • Asynchronous Connectionless Link (ACL) • Packet switched • Symmetric or asymmetric, asynchronous service • Polling mechanism between master and slave(s) • Point-to-point and point-to-multipoint

26. Packet Types Data/voice packets Control packets Voice data ID* Null Poll FHS DM1 HV1 HV2 HV3 DV DH1 DH3 DH5 DM1 DM3 DM5

27. Packet Format 54 bits 72 bits 0 - 2744 bits Access code Header Payload header Data Voice CRC No CRC No retries ARQ FEC (optional) FEC (optional) 625 µs master slave

28. m Max 7 active slaves s s s Packet Header 54 bits • Addressing (3) • Packet type (4) • Flow control (1) • 1-bit ARQ (1) • Sequencing (1) • HEC (8) Access code Payload Header Purpose 16 packet types (some unused) Broadcast packets are not ACKed For filtering retransmitted packets Verify header integrity total 18 bits Encode with 1/3 FEC to get 54 bits

29. 3.75ms (HV3) 2.5ms (HV2) 1.25ms (HV1) Voice Packets (HV1, HV2, HV3) 240 bits 54 bits 72 bits = 366 bits Access code Header 30 bytes Payload HV1 + 1/3 FEC 10 bytes 20 bytes HV2 + 2/3 FEC HV3 30 bytes

30. 625 µs 2/3 FEC DM1 1 17 2 DH1 2 1 27 Data rate calculation: DM1 and DH1 72 bits 240 bits 54 bits = 366 bits Access code 30 bytes Header Payload 625 µs 1 2

31. 1875 µs 2/3 FEC DM3 2 121 2 DH3 2 2 183 Data rate calculation: DM3 and DH3 54 bits 72 bits = 1626 bits 1500 bits Access code 187 bytes Header Payload 1875 µs 1 2 4 3

32. 3125 µs 2/3 FEC DM5 2 224 2 DH5 2 2 339 Data rate calculation: DM5 and DH5 54 bits 72 bits = 2870 bits 2744 bits Access Code 343 bytes Header Payload 625 µs 3125 µs 1 2 4 3 5 6

33. Summary of Bluetooth Packet Types ACL SCO

34. Bluetooth v2.0 Enhanced Data Rate (EDR) • EDR achieves higher data throughput by using Phase Shift Keying (PSK) modulation, instead of Gaussian Frequency Shift Keying (GFSK) modulation.

35. m s m s s • Piconet • Master can connect to 7 slaves • Each piconet has max capacity =1 Mbps • hopping pattern is determined by the master s Bluetooth Physical link • Point to point link • master - slave relationship • radios can function as masters or slaves

36. S4 S1 M1 S3 S2 Piconet capacity One ACL link (432 kbps symmetric or 721/56 kbps asymetric) or Three simultaneous SCO links (64 kbps) or A combination of voice/data

37. m s s s Piconet Management • Attach and detach slaves • Master-slave switch • Establishing SCO links • Handling of low power modes ( Sniff, Hold, Park) Paging req Master Slave response

38. Connection Setup • Inquiry - scan protocol • to learn about the clock offset and device address of other nodes in proximity

39. Baseband: Connection state • Active mode: • Bluetooth unit listens for each master transmission. • Slaves not addressed can sleep through a transmission. • Periodic master transmissions used for sync. • Sniff mode • Unit does not listen to every master transmission. • Master polls such slaves in specified sniff slots. • For ACL mode only. • Hold mode • Master and slave agree on a time duration for which the slave is not polled. • The physical link is only active during slots that are reserved for the operation of the synchronous link types SCO. • Park mode • Slave gives up AM_ADDR. • Listens periodically for a beacon transmission to synchronize and uses PM_ADDR/AR_ADDR for unparking.

40. Low power mode (Sniff) Sniff offset Sniff duration Slave Sniff period Master • Traffic reduced to periodic sniff slots

41. Low power mode (hold) Hold offset Slave Hold duration Master

42. Low power mode (Park) Slave Beacon instant Master Beacon interval • Power saving + keep more than 7 slaves in a piconet • Give up active member address, yet maintain synchronization • Communication via broadcast LMP messages

43. Master Active Slave Parked Slave Standby Piconet formation • Page - scan protocol • to establish links with nodes in proximity

44. Intra-piconet communication The master controls all traffic on the piconet SCO link - reservation The master allocates capacity for SCO links by reserving slots in pairs. ACL link – polling scheme The slave transmits in the slave-to-master slot only when it has been addressed by its MAC address in the previous master-to-slave slot. Therefore no collisions.

45. Piconet MAC protocol : Polling FH/TDD f5 f1 f4 f3 f2 f6 m s1 s2 625 sec 1600 hops/sec

46. Multi slot packets FH/TDD f1 f5 f4 f6 m s1 s2 625 µsec Data rate depends on type of packet

47. ACL ACL ACL ACL ACL ACL SCO SCO SCO SCO SCO SCO Physical Link Types • Synchronous Connection Oriented (SCO) Link • slot reservation at fixed intervals • Asynchronous Connection-less (ACL) Link • Polling access method m s1 s2

48. S4 S1 M1 S3 S2 Piconet capacity One ACL link (432 kbps symmetric or 721/56 kbps asymetric) or Three simultaneous SCO links (64 kbps) or A combination of voice/data

49. Device 1 Device 2 L2CAP L2CAP Data link LMP LMP Baseband Baseband Physical Baseband: Summary • TDD, frequency hopping physical layer • Device inquiry and paging • Two types of links: SCO and ACL links • Multiple packet types (multiple data rates with and without FEC)

50. Networking