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6-1. Bluetooth Architecture Overview

6-1. Bluetooth Architecture Overview. Agenda. Who is Bluetooth? History and Background What does Bluetooth do for you? Usage Model What is Bluetooth? Compliance, compatibility What does Bluetooth do? Technical points Architectural Overview of Bluetooth. Who is Bluetooth?.

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6-1. Bluetooth Architecture Overview

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  1. 6-1. Bluetooth Architecture Overview

  2. Agenda • Who is Bluetooth? • History and Background • What does Bluetooth do for you? • Usage Model • What is Bluetooth? • Compliance, compatibility • What does Bluetooth do? • Technical points • Architectural Overview of Bluetooth

  3. 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) • The stone’s inscription (“runes”) say: • Harald controlled Denmark and Norway • Harald thinks “notebooks” and “cellular phones” should seamlessly communicate

  4. Bluetooth Background • 1997. - Designed by Ericsson • 1998.2 - Established the Special interest group (form SIG 1) • Ericsson, Nokia, IBM, Toshiba,Intel • 1998.5 - Bluetooth Consortium is established formally. • 1999.7 - Bluetooth v1.0beta • Core Specification and Foundation Profile • 1999.12 -Lucent、3Com、Motorola、Microsoft(form SIG 2) • 2001.2 - Bluetooth v1.1 • 2002 – IEEE 802.15 WPAN • IEEE 802.15.1 Wireless Personal Area Networks (Bluetooth) • IEEE 802.15.2 Coexistence • IEEE 802.15.3 WPAN Higher Rate • IEEE 802.15.4 WPAN Low Rate

  5. Bluetooth Background

  6. What does Bluetooth do for you? • three major applications Landline Cable Replacement Data/Voice Access Points (internet access) most important in voice applications Personal Ad-hoc Networks

  7. Usage Model (Ultimate Headset)

  8. Usage Model (Ultimate Headset) • Keep your hands free for • Car • Office • Road

  9. Usage Model (Automatic Synchronizer) • Background Synchronization • PDA • Cellular Phone • Notebook

  10. Usage Model (Three in One Phone) • Intercom (Walki Talki) • Cordless • Cellular

  11. Usage Model (Three in One Phone) • Office (No telephone charge) • Home (Fixed line charge) • Outdoor (Mobile phone charge)

  12. Usage Model (Remote Control &Transmission)

  13. Usage Model (Conference Scenario) • Conference Table • Share and exchange data

  14. Usage Model (killer application)

  15. Key Characteristics • Low cost • Market consideration • Low power consumption • Portable device consideration • Short Range • Unlicensed Used • ISM band used • Robust operation • Fast frequency hopping • Short packet length • Multiple links • Mixed voice and data • Sized 0.5 squire inches

  16. Mobile = Battery life • Low power consumption* • Standby current < 0.3 mA Þ 3 months • Voice mode 8-30 mA Þ 75 hours • Data mode average 5 mA (0.3-30mA, 20 kbit/s, 25%) Þ 120 hours • Low Power Architecture • Programmable data length (else radio sleeps) • Hold and Park modes 60 µA (rough) • Devices connected but not participating • Hold retains AMA address, Park releases AMA, gets PMA address • Device can participate within 2 ms

  17. IP Bluetooth Specifications Applications SDP RFCOMM Applications Control Data Audio L2CAP Firmware Link Manager Bluetooth chip Baseband (Single chip with RS-232, USB or PC card interface) RF

  18. Applications IP SDP RFCOMM Control Data Audio L2CAP Link Manager Baseband RF Bluetooth Certifications Application Framework Certification HCI: Host Controller Interface Basic Layer Certification

  19. Host Control Interface (HCI) (1/3) Program Profile Spec Audio L2CAP Host HCI (Host control Interface) HCI (Hostcontrol Interface) Audio LMP Bluetooth chip Baseband RF

  20. Bluetooth Host HCI (2/3) Host Drives and Applications HCI : Host Controller Interface provides a common interface between the bluetooth host and the bluetooth module. Bluetooth HCI driver Bluetooth HCI Transport driver (USB, PC Card, PCI) Transport Bus HCI HCI Transport Firmware Bluetooth Host Controller Link Manager Bluetooth Baseband Bluetooth Radio Bluetooth Module

  21. HCI (3/3) • All HCI transactions are framed in packets: • Commands • Event • Data (ACL) • Data (SCO)

  22. Bluetooth Products • Blue-Dongle • Blue-Connect • BluePort • Bluetooth printer • Bluetooth Modem • Etc.,

  23. BT Trend (1/2) • 2 chips solution • RF transceiver • Baseband BB chip • integrated single chip (BB+RF) solution will be provided • Chip design house co-work with software design company to provide total solution of bluetooth technology

  24. BT Trend (2/2) Cost $30 Headset Version BB RF $10 2-chip BB+RF $4 ? Single-chip Full Bluetooth Performance Soft. modem Host+BB+RF Data Only Version Host+RF Single-chip Year 2000 2001 2003

  25. Bluetooth Module • CPU core : ARM, 8051, MIPS, etc., HOST RF Transceiver

  26. Bluetooth Module • Software modem is possible nowaday HOST

  27. RF Transceiver

  28. Bluetooth Specifications • 2.4 GHz ISM Unlicensed band • Microwave ovens also use this band • Frequency Hopping Spread Spectrum • Avoid interference • 23/79 channels • 1 MHz per channel • 1 Mbps link rate (GFSK modulation) • Fast frequency hopping and short data packets avoids interference • Nominally hops at 1600 times a second (vs. 2.5 hops/sec in IEEE 802.11) • 625us per hop (366us for data only) • 3200 times a second during inquiry and paging modes • Multiple uncoordinated networks may exist and cause interference • CVSD (Continuous Variable Slope Delta Modulation) voice coding (FEC) enables operation at high bit error rates

  29. ISM Unlicensed Band • 79 channels in 2.4GHz (in USA and most Europe) Guard band Guard band Licensed band Licensed band 2.402-2.480 GHz 79 hopping channels 2.4 GHz 2.402 2.48 2.483 ISM unlicensed band

  30. Frequency Range • 2.4GHz ISM Frequency Range 1MHz . . . 79 1 2 3 83.5 MHz

  31. Transmit Power • transmit power and range • 0 dbm (up to 20dbm with power control) • 10-100 m • Power 1mW (class 3) • 3% power of cellular phone • 10meters of transmission distance or 100m by PA • Power 100mW(class 1) • 100 meters of transmission distance

  32. Frequency Hopping 78 Frequency 0 Time

  33. Data Source Digital Modulator + d(t) Transmitter Hopping Code Generator Frequency synthesizer ^ Front-end Filter Data Detector d(t) + Receiver Local hopping code generator Frequency synthesizer FHSS

  34. Modulation and Symbol Rate • Symbol Rate : 1M symbols/sec (1MHz) • GFSK (Gaussian Frequency Shift Keying) • Binary One (1) : Positive frequency deviation • Binary Zero (0) : Negative frequency deviation • Maximum frequency deviation • Between 140kHz and 175kHz Magnitude frequency fo fo-f fo+f

  35. Adaptive Frequency Hopping • When no interference is detected, hop over the entire frequency band • If interference is detected at a level which cause packet error • Actively avoid these frequency hop locations. • This technique is currently legal for Class 3 Bluetooth units. • Hop locations must be maintained

  36. Interference Simulations • 1 Bluetooth piconet + 1 WLAN unit • PER (Packet Error Rate) without adaptation =11% • PER with adaptation = 0% • 5 Bluetooth piconets separated by 5 meters + 1 WLAN unit • PER without adaptation =15% • PER with adaptation = 8.4%

  37. Radio 2 WG • Radio 2 WG mandated to be backward compatible and interoperable with Radio 1 • 5.8G ISM band • is optional extensions for providing additional capabilities for applications • Higher data rates: • Multimedia (streaming audio/video) • High speed image transfer • High speed transfer of large files to (e.g.) printers • Data rate alignment with 2.5/3G cellar networks • 10M-12Mbps goal

  38. 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+ active slaves per piconet • Each piconet has maximum capacity (1 Msps and 1 Mbps) • Unique hopping pattern/ID • Scatternet • High capacity system • Minimal impact with up to 10 piconets within range • Radios can share piconets!

  39. Piconet vs. Scatternet • A scatternet contains two piconets Scatternet Piconet Slave Master Master Piconet Slave Slave Slave Slave

  40. Piconet and Scatternet point-to-point (piconet) multi-point (piconet) scatternet Master host Slave host

  41. Device Addressing (1/2) • Every Bluetooth device has unique 48-bit Bluetooth Device Address (BD_ADDR) which is assigned by SIG • The BD_ADDR is used to control the system functions : • Hopping sequence • Channel access code • Encryption key • The BD_ADDR contains 3 parts: • 24-bit Lower Address Part (LAP) • Used to identify unique BT device (reduce overhead) • 8-bit Upper Address Part (UAP) • Used to determine the hopping sequence • 16-bit Non-significant Address Part (NAP) 16 8 24 bits NAP UAP LAP BD_ADDR

  42. Device Addressing (2/2) • AM_ADDR (Active Member Address) • Each slave is assigned a 3-bit address • 7 slaves in a piconet is available • 000 : for broadcasting packets (I.e. master address) • An exception is FHS (Frequency Hopping Synchronization) packet which may use “000” address but is not a broadcast message • Slaves that are disconnected or parked give up their AM_ADDRs • PM_ADDR (Parked Member Address) • Slaves that enter the park mode will obtain a 8-bit PM_ADDR • At most 256 slaves are in park mode in a piconet

  43. Slave Native CLK Master clock same hopping sequence 3, 56, 7, 23, 44, … + BD_ADDR offset Master BD_ADDR Clock Synchronization • CLKN(Native Clock) • Exist in each bluetooth device • The counter can not be frozen and adjusted • Clock resolution : 312.5us (half slot time : used for paging/inquiry procedures) • slave follows its master CLKN to hop in a piconet • Master need inform the slave its CLKN and BD_ADDR • Slave adds offset into its CLKN to synchronize with master

  44. Clock Synchronization • CLKE(Estimated Clock) • Is used when master pages a known slave device (has been inquired) • Master uses the slave’s BD_ADDR to estimate the slave’s CLKN estimated slave’s hopping sequence 3, 56, 7, 23, 44, … Slave CLKE Slave clock + BD_ADDR paging Slave BD_ADDR

  45. or The Piconet • All devices in a piconet hop together • In forming a piconet, master gives slaves its clock and device ID(BD_ADDR) via FHS packet • Hopping pattern determined by device ID(48-bit) • Phase in hopping pattern determined byClock • Non-piconet devices are in standby • Piconet Addressing • Active Member Address(AMA, 3-bits) • Parked Member Address (PMA, 8-bits)

  46. Basic Baseband Protocol • Spread spectrum frequency hopping radio • Hops every packet • Packets are 1, 3 or 5 slots long • Frame consists of two packets • Transmit followed by receive • Nominally hops at 1600 times a second (1 slot packets) (1.25 ms)

  47. Time Division Duplex (TDD) • Master : even numbered slots • Slave : odd numbered slots • The Slot Number ranges from 0- 227-1. f(2k) f(2k+1) f(2k+2) Master 220 ms +/-10 ms Slave guard time Packet time slot even (625s) odd (625s) even Access code/Header Payload guard time for hopping

  48. Multi-slot Packets • Different packet overhead will result in different throughput • DH1 : 172.8Kbps in Sym. and Asyn. modes • DH3 : 390.4Kbps in Sym. mode; 387.2 and 54.4Kbps in Asyn. Mode • DH5 : 433.9Kbps in Sym. mode; 721 and 57.6Kbps in Aysn. • DH : without FEC f(2k+1) f(2k+2) f(2k+3) f(2k+4) f(2k) 1-slot Packet (DH1) f(2k+1) f(2k+2) f(2k+3) f(2k+4) f(2k) 3-slot Packet (DH3) f(2k+1) f(2k+2) f(2k+3) f(2k+4) f(2k) 5-slot Packet (DH5) even (625s) odd (625s) even (625s) odd (625s)

  49. Connection Procedure (1/3) • 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/Sniff/Hold • Low Power connected states

  50. Connection Procedure (2/3) ID : GIAC/DIAC ID packet FHS : slave’s BD_ADDR, CLKN, Class of Devise(CoD), Page Scan Interval FHS packet ID packet ID : DIAC ID packet FHS : master’s BD_ADDR, CLKN, CoD, BCH parity, AMA FHS packet Data packet

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