6-1. Bluetooth Architecture Overview NDSL Lab. CSIE, CGU - 1 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 NDSL Lab. CSIE, CGU - 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) • The stone’s inscription (“runes”) say: Harald controlled Denmark and Norway Harald thinks “notebooks” and “cellular phones” should seamlessly communicate NDSL Lab. CSIE, CGU - 3 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 NDSL Lab. CSIE, CGU - 4 Bluetooth Background B lu etooth S IG 代 表 性 成 員 ( 按 產 業 別 分 類 ) 半導體 F u jitsu H ew lettP a ck a rd H ita chi S em i IB M Intel L S I L ogic M itsu bishi M otorola NEC P hilsa r P ra irieC om m P hilips S a m su ng S ilicon W a ve TI T oshiba … E tc. 電信 A lca tel A T & T W ireless B ritish T elecom D a ew oo T elecom E ricsson F ra nce T elecom H ita chi L G T elecom M otorola N ok ia N T T D oK oM o T a iw a n T elcom S ym bia n S print P C S Q u a lcom m 電腦與周邊 消費性電子 A cer C a non C om pa q D ell C om pu ter G a tew a y 2 0 0 H ita chi IB M NCR NEC P a lm R icoh S eik o E pson C a non C a sio F u ji P hoto H ita chi L G E lectronics N ok ia P hilips R a dio S ha ck S a m su ng S a nyo S ha rp S ony T oshiba 網路 3 C om B roa dcom H a rris H ita chi Intel L u cent N ortel N etw ork s S iem ens A G X ircom 汽車和其他 BMW B ritish A irw a ys F edera l E xpress F ord H a rris Saab T ek tronix T hom son T ok yo G a s C o. V olvo 資 料 來 源 : B lu etooth S IG , 2 0 0 0 年 1 月 NDSL Lab. CSIE, CGU - 5 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 NDSL Lab. CSIE, CGU - 6 Usage Model (Ultimate Headset) NDSL Lab. CSIE, CGU - 7 Usage Model (Ultimate Headset) • Keep your hands free for – Car – Office – Road NDSL Lab. CSIE, CGU - 8 Usage Model (Automatic Synchronizer) • Background Synchronization – PDA – Cellular Phone – Notebook NDSL Lab. CSIE, CGU - 9 Usage Model (Three in One Phone) • Intercom (Walki Talki) • Cordless • Cellular NDSL Lab. CSIE, CGU - 10 Usage Model (Three in One Phone) • Office (No telephone charge) • Home (Fixed line charge) • Outdoor (Mobile phone charge) NDSL Lab. CSIE, CGU - 11 Usage Model (Remote Control &Transmission) NDSL Lab. CSIE, CGU - 12 Usage Model (Conference Scenario) • Conference Table – Share and exchange data NDSL Lab. CSIE, CGU - 13 Usage Model (killer application) NDSL Lab. CSIE, CGU - 14 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 NDSL Lab. CSIE, CGU - 15 Mobile = Battery life • Low power consumption* – – – Standby current < 0.3 mA 3 months Voice mode 8-30 mA 75 hours Data mode average 5 mA (0.3-30mA, 20 kbit/s, 25%) 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 NDSL Lab. CSIE, CGU - 16 Bluetooth Specifications Applications IP SDP RFCOMM Applications Data Audio L2CAP Link Manager Baseband RF Firmware Bluetooth chip (Single chip with RS-232, USB or PC card interface) NDSL Lab. CSIE, CGU - 17 Bluetooth Certifications T e T c h n o l o g Ce ecrtific h n aotio l n o y g y C e rtific a tio n Application Framework Certification Applications v C a rd vCal S e rvic e UDP IP SDP v C a rd vCal IrO B E X PPP Data A u d io C trl A u d io C trl Audio UDP RFCOMM IrO B E X WAP PPP WAP TS0710 TS0710 L2CAP A U D IA OU D I O A p p lic a tio n F ra m e w o rk L a y e r C e rtific a tio n C la s s e s A pLpo lic a tio n F ra m e w o rk C e rtific a tio n C la s s w e r In te rfa c e T yp e L a y e r C e rtific C la s s a tio n C la s s e s T C P /IP T C P /IP L 2C A P S till Im g S till Im g H ID H ID v C a rd v C al S e rvic e UDP PPP v C a rd IrO B E X v C al W AP UDP S till Im a g e s PPP IrO B E X A u d io C trl W AP RFCOMM S till Im a g e s T C P /IP H ID A u d io C trl RFCOMM T C P /IP H ID IrO B E X IrO B E X PT Pyp P e RFCOMM IrO B E X RFCOMM IrO B E X T C P /IP PPP H ID RFCOMM R2F C O M M L CAP 2T C P /IP L CAP 2 H ID L CAP 2 L C2A P L CAP 2 L CAP 2 L CAP 2 L CAP HCI: Host Controller Interface L o w er In terface BL BM RF BB RF C ertificatio n C lass yp e BT a s ic L a yA uedrio CCelass rtific a tio n CAla sses D ata u d io LL2M CAP Baseband RF B T .v C a rd B T .vaC aln C la s s C e rtific tio B T .U D P B T .P P P B T .v C a rd B T .O B E X B T .v C al B T .W A P B T .U D P B T .S Im g B T .P P P B T .O B E X B T .A u dio C trl B T .W A P B T .T S 0 7 1 0 B T .S Im g B T .T C P /IP B T .H ID B T .A u dio C trl B T .T S 0 7 1 0 B T .T C P /IP B T .H ID B a s ic L a y e r C e rtific a tio n C la s s e s S e rvic e Link Manager B T .O B E X B T .O BLEoX w e r In te rfa c e B T .P P P C la s s B T .T S 0 7 1 0 B T .O B E X B T .T S 0 7 1 0 B T .O B E X B T .T C P /IP B T .P P P B T .H ID B T .T S 0 7 1 0 B T .T 2 S 0710 B T .L C A P -A B T .T 2 C P /IP B T .L C A P -D B T .H 2 ID B T .L C A P -D 2 B T .L C2A P -D B T .L C A P -A 2 B T .L C A P -D 2 B T .L C A P -D 2 B T .L C A P -D 2 L CAP S e rvic e LM BB RF2 L CAP A u n it th a t s u p p orts b o th LM E xa m p le : B T .B B -A ,D BB RF LM BTByp e RF A ir LM a u d io a n d BB RF A ir .LM L oBwTer In-A terface B T .LM -D B T .B B -A C lass B T .B B -D B T .R F B T .R F A u d io D ata B T .LM -A B T .LM -D d a ta g e ts th e c er tific atio n c las s A a n d D . B T .B B -A B T .B B -D B T .R F B T .R F - D ata 2 2 B T .L CCAertificatio P -A BnT .L C A P -D C lass B T .LM -A B T .LM -D B T .B B -A B T .B B -D A u d io D ata B T .R B T .R 2 F 2 F B T .L C A P -A B T .L C A P -D B T .LM -A B T .LM -D B T .B B -A B T .B B -D B T .R F B T .R F A u n it th a t s u p p orts b o th a u d io a n d d a ta g e ts th e c er tific atio n c las s A a n d D . E xa m p le : B T .B B -A ,D Basic Layer Certification NDSL Lab. CSIE, CGU - 18 Host Control Interface (HCI) (1/3) Program Profile Spec Audio L2CAP Host HCI (Host control Interface) HCI (Host control Interface) Audio LMP Bluetooth chip Baseband RF NDSL Lab. CSIE, CGU - 19 Bluetooth Host HCI (2/3) Host Drives and Applications Bluetooth HCI driver Bluetooth HCI Transport driver (USB, PC Card, PCI) HCI HCI : Host Controller Interface provides a common interface between the bluetooth host and the bluetooth module. Transport Bus HCI Transport Firmware Bluetooth Host Controller Link Manager Bluetooth Baseband Bluetooth Radio Bluetooth Module NDSL Lab. CSIE, CGU - 20 HCI (3/3) – All HCI transactions are framed in packets: – Commands – Event – Data (ACL) – Data (SCO) NDSL Lab. CSIE, CGU - 21 Bluetooth Products • Blue-Dongle • Blue-Connect • BluePort • Bluetooth printer • Bluetooth Modem • Etc., NDSL Lab. CSIE, CGU - 22 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 NDSL Lab. CSIE, CGU - 23 BT Trend (2/2) Cost $30 BB RF 2-chip Headset Version $10 BB+RF Full Bluetooth Performance 2000 Single-chip Data Only Version 2001 $4 Host+BB+RF Single-chip 2003 ? Soft. modem Host+RF Year NDSL Lab. CSIE, CGU - 24 Bluetooth Module • CPU core : ARM, 8051, MIPS, etc., HOST RF Transceiver NDSL Lab. CSIE, CGU - 25 Bluetooth Module • Software modem is possible nowaday HOST NDSL Lab. CSIE, CGU - 26 RF Transceiver NDSL Lab. CSIE, CGU - 27 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 NDSL Lab. CSIE, CGU - 28 ISM Unlicensed Band • 79 channels in 2.4GHz (in USA and most Europe) Guard band Licensed band Guard band 2.402-2.480 GHz 79 hopping channels 2.4 2.402 GHz Licensed band 2.48 2.483 ISM unlicensed band NDSL Lab. CSIE, CGU - 29 Frequency Range • 2.4GHz ISM Frequency Range C o u n tr y E u rope* & U S A Ja pa n S pa in F ra nce F re q u e n c y R an g e 2 4 0 0 – 2 4 8 3 .5 M H z 2471 – 2497 M Hz 2445 – 2475 M Hz 2 4 4 6 .5 – 2 4 8 3 .5 M H z R F C h an n e ls f= 2 4 0 2 + k M H z f= 2 4 7 3 + k M H z f= 2 4 4 9 + k M H z f= 2 4 5 4 + k M H z k = 0 ,… ,7 8 k = 0 ,… ,2 2 k = 0 ,… ,2 2 k = 0 ,… ,2 2 1MHz . . . 79 12 3 83.5 MHz NDSL Lab. CSIE, CGU - 30 Transmit Power • transmit power and range 0 dbm (up to 20dbm with power control) 10-100 m Power Class 1 2 3 Max Output 100mW (20dBm) 2.5mW (4dBm) 1mW (0dBm) Min Output 1mW (0dB) 0.25mW (-6dBm) N/A Power Control -4db/time Max twice Optional Optional 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 NDSL Lab. CSIE, CGU - 31 Frequency Hopping 78 Frequency 0 Time NDSL Lab. CSIE, CGU - 32 FHSS Data Source Transmitter d(t) Digital Modulator Hopping Code Generator Front-end Filter + Frequency synthesizer + Data Detector ^ d(t) Receiver Local hopping code generator Frequency synthesizer NDSL Lab. CSIE, CGU - 33 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-f fo fo+f NDSL Lab. CSIE, CGU - 34 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 NDSL Lab. CSIE, CGU - 35 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% NDSL Lab. CSIE, CGU - 36 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 NDSL Lab. CSIE, CGU - 37 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) S P M sb M P S P sb S S » Unique hopping pattern/ID • Scatternet – High capacity system » Minimal impact with up to 10 piconets within range – Radios can share piconets! NDSL Lab. CSIE, CGU - 38 Piconet vs. Scatternet • A scatternet contains two piconets Piconet Scatternet Slave Master Master Piconet Slave Slave Slave Slave NDSL Lab. CSIE, CGU - 39 Piconet and Scatternet point-to-point (piconet) multi-point (piconet) scatternet Master host Slave host NDSL Lab. CSIE, CGU - 40 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) BD_ADDR 16 8 24 NAP UAP LAP bits NDSL Lab. CSIE, CGU - 41 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 NDSL Lab. CSIE, CGU - 42 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 Slave Native CLK + Master clock BD_ADDR same hopping sequence 3, 56, 7, 23, 44, … offset Master BD_ADDR NDSL Lab. CSIE, CGU - 43 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 Slave CLKE paging + Slave clock BD_ADDR estimated slave’s hopping sequence 3, 56, 7, 23, 44, … Slave BD_ADDR NDSL Lab. CSIE, CGU - 44 ID a The Piconet IDd IDa IDd D IDa A P M IDe IDe E sb IDa IDb B IDb IDc S C ID a IDc S • 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 by Clock • Non-piconet devices are in standby • Piconet Addressing – Active Member Address (AMA, 3-bits) – Parked Member Address (PMA, 8-bits) IDa sb M or S P NDSL Lab. CSIE, CGU - 45 Basic Baseband Protocol Frame Frame (1.25 ms) fk Master Master One Slot Packet One Slot Packet Slave fk fk+1 fk+1 Three Slot Packet One Slot Packet Slave 625 us One Slot 625 us One Slot • 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) NDSL Lab. CSIE, CGU - 46 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 +/-10 s 220 s Slave guard time even (625s) Access code/Header Packet odd (625s) Payload even time slot guard time for hopping NDSL Lab. CSIE, CGU - 47 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 1-slot Packet (DH1) f(2k) f(2k+1) f(2k+2) f(2k+3) f(2k+4) 3-slot Packet (DH3) f(2k) f(2k+1) f(2k+2) f(2k+3) f(2k+4) 5-slot Packet (DH5) f(2k) f(2k+1) f(2k+2) f(2k+3) f(2k+4) even (625s) odd (625s) even (625s) odd (625s) NDSL Lab. CSIE, CGU - 48 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 NDSL Lab. CSIE, CGU - 49 Connection Procedure (2/3) ID packet FHS packet ID packet ID : GIAC/DIAC FHS : slave’s BD_ADDR, CLKN, Class of Devise(CoD), Page Scan Interval ID : DIAC ID packet FHS packet Data packet FHS : master’s BD_ADDR, CLKN, CoD, BCH parity, AMA NDSL Lab. CSIE, CGU - 50 ID Packet • Access Code 34bits 24bits BCH Parity Word LAP 24 bits 6bits Barker Sequence • During a connection – identifies the packet as being from or to a specific Master • Other modes – in inquiry to produce the Inquiry Access Code (IAC) NDSL Lab. CSIE, CGU - 51 FHS Packet Format • Used when 1. Master inquiries device during inquiry procedure, return from Slave 2. Master pages a Slave during page procedure, sent from Master 3. A device switches as Master NDSL Lab. CSIE, CGU - 52 Connection Procedure (3/3) Unconnected Standby tac h Standby De Ttypical=2s Connecting States Inquiry Page Ttypical=0.6s Active States Transmit data AMA Connected AMA Ttypical=2 ms Low Power States Releases AMA Address PARK PMA Ttypical=2 ms HOLD AMA NDSL Lab. CSIE, CGU - 53 Page and Inquire Scans Ttypical=11 ms 18 slots Ttypical=11 ms 18 slots Page Scan Page Scan Sleep Connected Ttypical=1.25 Ttypical=1.25 Inquire Scan Inquire Scan Standby Connected Ttypical=11 ms 18 slots Ttypical=11 ms 18 slots • A radio must be enabled to accept pages or inquires – Consumes 18 slots every 1.25 s (or so) for each scan slot is 0.625 ms NDSL Lab. CSIE, CGU - 54 Page and Inquire Scans • Inquiry scan: – 32 channels (of 79 channels) are assigned for inquiry procedure – 32 channels are divided as 2 trains (Trains A and B), each one contains 16 channels. • Page scan: – 32 channels (of 79 channels) are assigned for page procedure – 32 channels are divided as 2 trains (Trains A and B), each one contains 16 adjacent channels. – Train A : f(k-8), f(k-7), … f(k), f(k+1), … , f(k+7) – Train B : f(k-16), f(k-15), … f(k-9), f(k+8), … , f(k+15) • 3200 hop/sec • Broadcast ID packet (with specified GIAC or DIAC) NDSL Lab. CSIE, CGU - 55 Inquiring for Radios IDd IDa D A IDb B IDc C • Radio wants to find other radios in the area NDSL Lab. CSIE, CGU - 56 Inquiring for Radios IDd IDa D INQ A INQ IDb Inquire INQ B IDc C • Radio Wants to find other radios in the area – Radio A issues an Inquire (pages with the Inquire ID) » Radios B, C and D are doing an Inquire Scan NDSL Lab. CSIE, CGU - 57 Inquiring for Radios IDd IDa D A IDb IDb B IDc C • Radio Wants to find other radios in the area – Radio A issues an Inquire (pages with the Inquire ID) » Radios B, C and D are doing a Inquire Scan – Radio B recognizes Inquire and responds with an FHS packet » Has slave’s Device ID and Clock NDSL Lab. CSIE, CGU - 58 Inquiring for Radios IDd IDb IDa D INQ A INQ IDb Inquire INQ B IDc C • Radio Wants to find other radios in the area – Radio A issues an Inquire (pages with the Inquire ID) » Radios B, C and D are doing a Inquire Scan – Radio B recognizes Inquire and responds with an FHS packet » Has slave’s Device ID and Clock NDSL Lab. CSIE, CGU - 59 Inquiring for Radios IDd IDb IDa IDd D A IDc IDb B IDc C • Radio Wants to find other radios in the area – Radio A Issues an Inquire (again) – Radios C and D respond with FHS packets » As radios C & D respond simultaneously packets are corrupted and Radio A won’t respond » Each radio waits a random number of slots and listens NDSL Lab. CSIE, CGU - 60 Inquiring for Radios IDd IDb IDa D INQ A INQ IDb Inquire INQ B IDc C • Radio Wants to find other radios in the area – Radio A Issues an Inquire (again) NDSL Lab. CSIE, CGU - 61 Inquiring for Radios IDd IDb IDa D A IDc IDb B IDc C • Radio Wants to find other radios in the area – Radio A Issues an Inquire (again) – Radios C respond with FHS packets NDSL Lab. CSIE, CGU - 62 Inquiring for Radios IDd IDb IDa IDc D INQ A INQ IDb Inquire INQ B IDc C • Radio Wants to find other radios in the area – Radio A Issues an Inquire (again) NDSL Lab. CSIE, CGU - 63 Inquiring for Radios IDd IDb IDa IDc IDd D A IDb B IDc C • Radio Wants to find other radios in the area – Radio A Issues an Inquire (again) – Radios D respond with FHS packets NDSL Lab. CSIE, CGU - 64 Inquiring for Radios IDd IDb IDa IDc D A IDd IDb B IDc C • Radio Wants to find other radios in the area – Radio A Issues an Inquire (again) – Radios D respond with FHS packets – Radio A now has information of all radios within range NDSL Lab. CSIE, CGU - 65 Inquiry Procedure fk fk+1 fk fk+1 fk+4 IDa INQUIRER INQ INQ IDb INQ fk+1 IDb STANDBY FHS 625 s • Inquiry has unique device address (all BT radio use) – ID packet with dedicated or general access code – Unique set of “Inquiry” hop frequencies • Any device can inquire by paging the Inquiry address • Correlater hit causes slave to respond with FHS packet – Device ID – Clock – Etc. NDSL Lab. CSIE, CGU - 66 Inquiry Procedure 1.25ms Fully scan Train A:16*0.625ms=10ms (1) Train A will be scanned 256 times: 2.56s (2) Train B will be scanned 256 times: 2.56s Repeat scan Trains A and B two complete cycles: 2*(2.56+2.56)=10.24s 2 slots 1 2 3 15 16 repeat 256 times INQUIRER train A A A A A B A A A 10 ms 16 slots = 10ms STANDBY scan fk A sleep RAND1 fk fk+1 A A fk+1 sleep RAND2 fk+2 A FHS A FHS Listen 11.25 ms (18 slots) • 32 channels are allocated as inquiry procedure – They are divided as two trains : A Train and B Train (16 channels for each) • Multiple slaves are expected to respond – Correlater hit causes slave to » respond with FHS packet » Wait a random number of slots » Wait for another Inquiry page and repeat • Master should end up with a list of slave FHS packets in area NDSL Lab. CSIE, CGU - 67 Inquire Summary • Inquiring radio Issues inquiry packet with Inquire ID (GIAC or DIAC access code) • Any radio doing an Inquire scan will respond with an FHS packet – FHS packet gives Inquiring radio information to page » Device ID » Clock IDa – If there is a collision then radios wait a random number of slots before responding to the page inquire • After process is done, Inquiring radio has Device IDs and Clocks of all radios in range • Slave listens one of 16 channels for sufficient time (e.g., 18 slots=11.25ms) NDSL Lab. CSIE, CGU - 68 Master Paging a Slave IDa IDc A IDc C • Paging assumes master has slaves Device ID and an idea of its Clock NDSL Lab. CSIE, CGU - 69 Master Paging a Slave IDa IDc A Page IDc IDc C • Paging assumes master has slaves Device ID and an idea of its Clock – A pages C with C’s Device ID and CLKE NDSL Lab. CSIE, CGU - 70 Master Paging a Slave IDa IDc A IDc IDc C • Paging assumes master has slaves Device ID and an idea of its Clock – A pages C with C’s Device ID (DAC) – C Replies to A with C’s Device ID NDSL Lab. CSIE, CGU - 71 Master Paging a Slave IDa IDc A IDa IDc C • Paging assumes master has slaves Device ID and an idea of its Clock – A pages C with C’s Device ID – C Replies to A with C’s Device ID – A sends C its Device ID and Clock (FHS packet) NDSL Lab. CSIE, CGU - 72 Master Paging a Slave IDa IDc A ID a IDc C • Paging assumes master has slaves Device ID and an idea of its Clock – – – – A pages C with C’s Device ID C Replies to A with C’s Device ID A sends C its Device ID and Clock (FHS packet) A connects as a master to C NDSL Lab. CSIE, CGU - 73 Master Paging a slave fk fk+1 fk fk+1 fk+2 fk+2 fm FH S Master IDa IDc IDc IDc IDa IDc fk+1 Slave IDc 625 s • Master pages slave (packet has slave ID) at slave page frequency (1 of 32) – Master sends page train of 16 most likely frequencies in slave hop set » Slave ID sent twice a transmit slot on slave page frequency » Master listens twice at receive slot for a response – • If misses, master sends second train on remaining 16 frequencies Slave listens for 11.25 ms (page scan) – – – If correlater triggers, slave wakes-up and relays packet at response frequency Master responds with FHS packet (provides master’s Device ID and Clock) Slave joins piconet NDSL Lab. CSIE, CGU - 74 Paging Procedure 1.25ms FHS Pager train A A A A B B 10 ms Paged CONNECTION scan fk B Sleep (1.25 s) fk+1 B 11.25 ms • Each slave page scans on unique sequence of 32 channels fk – Master pages 16 most likely channels for entire sleep period (nominally 1.25 seconds) • If clocks are off, then second train sent on last 16 frequencies for entire sleep period NDSL Lab. CSIE, CGU - 75 Physical Link Definition • SYNCHRONOUS CONNECTIONORIENTED (SCO) LINK • • • • • • circuit switching symmetric, synchronous services slot reservation at fixed intervals For voice transmission Point-to-point connection No packet retransmission • ASYNCHRONOUS CONNECTIONLESS (ACL) LINK • • • • • • packet switching (a)symmetric, asynchronous services polling access scheme For data transmission (ex:program) Point-to-multipoint connection Packet retransmission NDSL Lab. CSIE, CGU - 76 Physical Link HV3 : 6 slots gap NDSL Lab. CSIE, CGU - 77 Packet Types/Data Rates Packet Types SEGMENT 1 2 TYPE 0000 0001 0010 0011 0100 0101 0110 0111 1000 1001 SCO link ACL link NULL POLL FHS DM1 NULL POLL FHS DM1 DM1 108.8 108.8 108.8 DH1 172.8 172.8 172.8 DH1 DM3 258.1 387.2 54.4 DH3 390.4 585.6 86.4 DM5 286.7 477.8 36.3 DH5 432.6 721.0 57.6 HV1 HV2 HV3 DV Data Rates (Kbps) TYPE symmetric asymmetric AUX1 3 1010 1011 1100 1101 DM3 DH3 4 1110 1111 DM5 DH5 NDSL Lab. CSIE, CGU - 78 Bluetooth Protocols Still Image WAE vCard/vCal WAP OBEX HID Service Discovery TCP/UDP Audio Printing RFCOMM IP TCS L2CAP Host Controller Interface NDSL Lab. CSIE, CGU - 79 THANK YOU Q&A NDSL Lab. CSIE, CGU - 80