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

3. 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

4. 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. 4

6. 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

7. 6 Bluetooth positioning Coverage Bandwidth WLAN Bluetooth GSM DECT WLAN IrDA GPRS UMTS GPRS GSM Dect Bluetooth IR UMTS

8. 7 Bluetooth positioning

9. 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

10. 9 Core Bluetooth Products 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

11. 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

12. 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 ……

13. 12 Key Success Factors Interoperability (assured by BQB) Mass Production at Low Cost Ease of Use End User Experience

14. 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

15. 14 Bluetooth Profiles Profiles implement usage models Profiles will use 1 or more protocols Qualification based on set of profiles provided

16. 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

17. 16

18. 17

19. 18 Example...

20. 19 Baseband

21. 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)

22. 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.

23. 22 Frequency hopping Time Frequency 0 78

24. 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

25. 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.

26. 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

27. 26 Packet Types Control packets Data/voice packets ID* Null Poll FHS DM1 Voice data HV1 HV2 HV3 DV DM1 DM3 DM5 DH1 DH3 DH5

28. 27 Packet Format 72 bits 54 bits 0 - 2744 bits Access code Header Payload Data Voice CRC No CRC No retries 625 µs master slave header ARQ FEC (optional)

29. 28 Access Code Synchronization DC offset compensation Identification Signaling Access code Header Payload 72 bits Purpose  Channel Access Code (CAC)  Device Access Code (DAC)  Inquiry Access Code (IAC) Types X

30. 29 Packet Header Addressing (3) Packet type (4) Flow control (1) 1-bit ARQ (1) Sequencing (1) HEC (8) Access code Header Payload 54 bits Purpose Encode with 1/3 FEC to get 54 bits Broadcast packets are not ACKed For filtering retransmitted packets 18 bits total s s m s 16 packet types (some unused) Max 7 active slaves Verify header integrity

31. 30 Voice Packets (HV1, HV2, HV3) Access code Header Payload 72 bits 54 bits 240 bits 30 bytes = 366 bits 10 bytes + 2/3 FEC + 1/3 FEC 20 bytes 30 bytes HV3 HV2 HV1 3.75ms (HV3) 2.5ms (HV2) 1.25ms ( HV1 )

32. 31 Data rate calculation: DM1 and DH1 Payload Access code Header 72 bits 54 bits 240 bits 30 bytes = 366 bits 2/3 FEC 1 17 2 DM1 1 27 2 DH1 625 µs 1 2 Di r SizeFreqRate  171600/2108.8  17108.8  27172.8  27172.8

33. 32 Data rate calculation: DM3 and DH3 Payload Access code Header 72 bits 54 bits 1500 bits 187 bytes = 1626 bits 2/3 FEC 2 121 2 DM3 2 183 2 DH3 1875 µs Di r SizeFreqRate  1211600/4387.2  17 54.4  183585.6  27 86.4 1 2 3 4

34. 33 Data rate calculation: DM5 and DH5 Payload Access Code Header 72 bits 54 bits 2744 bits 343 bytes = 2870 bits 2/3 FEC 2 224 2 DM5 2 339 2 DH5 3125 µs 625 µs 1 2 3 4 5 6 Di r SizeFreqRate  2241600/6477.8  17 36.3  339723.2  27 57.6

35. 34 ACL SCO Summary of Bluetooth Packet Types

36. 35 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.

37. 36 Bluetooth Physical link Point to point link – master - slave relationship – radios can function as masters or slaves ms s s m s Piconet –Master can connect to 7 slaves –Each piconet has max capacity =1 Mbps –hopping pattern is determined by the master

38. 37 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 M1 S1 S2 S4 S3

39. 38 Piconet Management Attach and detach slaves Master-slave switch Establishing SCO links Handling of low power modes ( Sniff, Hold, Park) req response Paging Master Slave s s m s

40. 39 Connection Setup Inquiry - scan protocol –to learn about the clock offset and device address of other nodes in proximity

41. 40 Inquiry on time axis Slave1 Slave2 Master Inquiry hopping sequence f1 f2

42. 41 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.

43. 42 Low power mode (Sniff) Master Slave Sniff period Sniff offset Sniff duration Traffic reduced to periodic sniff slots

44. 43 Low power mode (hold) Slave Hold duration Hold offset Master

45. 44 Low power mode (Park) Master Slave Beacon interval Beacon instant Power saving + keep more than 7 slaves in a piconet Give up active member address, yet maintain synchronization Communication via broadcast LMP messages

46. 45 Piconet formation Master Active Slave Parked Slave Standby Page - scan protocol –to establish links with nodes in proximity

47. 46 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.

48. 47 Piconet MAC protocol : Polling m s1s1 s2s2 625 sec f1 f2 f3 f4 1600 hops/sec f5 f6 FH/TDD

49. 48 Multi slot packets m s1s1 s2s2 625 µsec f1 f4 f5 f6 FH/TDD Data rate depends on type of packet

50. 49 Physical Link Types m s1s1 s2s2 SCO  Synchronous Connection Oriented (SCO) Link  slot reservation at fixed intervals Asynchronous Connection-less (ACL) Link –Polling access method SCO ACL

51. 50 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 M1 S1 S2 S4 S3

52. 51 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) Baseband L2CAP LMP Physical Data link Device 2Device 1

53. 52 Networking

54. 53 Addressing Bluetooth device address (BD_ADDR) –48 bit IEEE MAC address Active Member address (AM_ADDR) –3 bits active slave address –all zero broadcast address Parked Member address (PM_ADDR) –8 bit parked slave address

55. 54 Why Scatternets A group of overlapping piconets is called a scatternet  Users in a piconet share a 1 Mbps channel – individual throughput decreases drastically as more units are added  The aggregate and individual throughput of users in a scatternet is much greater than when each user participates on the same piconet  Collisions do occur when 2 piconets use the same 1 MHz hop channel simultaneously. As the number of piconets increases, the performance degrades gracefully

56. 55 Inter-piconet communication  A unit may particpate in more than one piconet on a TDM basis.  To participate on a piconet it needs the master’s identity and the clock offset.  While leaving the piconet it informs the master  The master can also multiplex as slave on another piconet. But all traffic in its piconet will suspended in its absence.

57. 56 Inter piconet communication Cell phone Cordless headset Cordless headset Cell phone Cordless headset Cell phone mouse

58. 57 Scatternet

59. 58 Scatternet, scenario 2 How to schedule presence in two piconets? Forwarding delay ? Missed traffic?

60. 59 Bluetooth Scatternets Scatternet Formation Problem – Assignment of roles to devices (Master / Slave / Bridge) – Independent devices, no prior knowledge → distributed – Formation time should be reasonable. – Assumption: all devices within transmission range of each other.

61. 60 Piconet interconnection 6 5 34 7 4 51 28 3 12 9 23 35 42 9 15 14 1 32 10 45 8

62. 61 Bluetooth Scatternets Properties desired – Reachability (basic) – Number of piconets (minimize) – Network diameter (minimize) – Degree (minimize; bounded) – Number of bridge nodes (minimize) – Number of roles (minimize) Various Trade-offs

63. 62

64. 63 Protocol Architecture Radio: –interface, frequency hopping, modulation, transmit power Baseband: –connection establishment in a piconet, addressing, packet format, timing, power control Link Management Protocol (LMP): –link setup, authentication, packet size Logical Link Control and Adaptation Protocol (L2CAP): –adapts upper-layer protocols to baseband, connectionless service, connection-oriented service Service Discovery Protocol (SDP): –device info (service, characteristic), service query

65. 64

66. How some companies view Bluetooth's future

67. 66 PPP Protocols and Usage Models RFCOMM TCP/IP Baseband L2CAP OBEX IrMC TCS-BIN Audio Sync Dial-up net. Usage Models File Transfer AT-commands FaxHeadset LAN Access Cordless Phone SDP LMP

68. 67 SONY / CASIO

69. 68 HP Print data from network: –maps, emails, web pages, … Print phone book & other phone data Print directly from camera

70. 69 Siemens Cable replacement Home Access Point Home Control

71. 70 CASIO Intelligent home: –Door lock, Light, Audio/Video, Electronic equipment, Automatic synchronisation,...

72. 71 Research on Bluetooth Coexistence with other wireless technologies Opportunistic Bluetooth overlay networks Cross layer integration ???