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BLUETOOTH. THE STANDARD & ISSUES. Why:. Short range wireless links – substitute cables. On-the-fly connectivity for Handhelds’. What:. Low cost, power-efficient & Single chip. 79 channels – 1 MHz. interval. 1600 hops/sec. 1 Mbps - GFSK. CMOS – low cost , -70 dBm.
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BLUETOOTH THE STANDARD & ISSUES
Why: • Short range wireless links – substitute cables • On-the-fly connectivity for Handhelds’ What: • Low cost, power-efficient & Single chip • 79 channels – 1 MHz. interval • 1600 hops/sec. • 1 Mbps - GFSK • CMOS – low cost , -70 dBm
Interoperability: PROFILE Features and procedures for Inter-working Profiles Controller & Stack Settings Conformance ? BluetoothR Vendor Implementations
ARCHITECTURE COM emulation Discovery Processor-Chip comm. Logical link, Packet delivery Peers’ link management PHY, MAC processing On-chip integration Radio parameters
Bluetooth Communication Model: PICONET Master – Slave concept Park–mode : more devices in Piconet Unique PRN hopping sequences SCATTERNET Inter-Piconet communication Bridging-nodes : Time sharing of Piconets
CONNECTION ESTABLISHMENT INQUIRY Faster rate, inquiry signals A B ACK, DA, Clock offset Identical initial hopping sequence PAGING Page, DA (unicast) M S ACK => A : Master Unique PRN
PICONET Expansion Discovery (inquiry) / SCAN Low power modes : Hold, Sniff & Park More than 7 Active slaves possible Slave-Slave comm. not permitted
PICONET CHANNEL FH/TDD scheme : Slot = 625 u-sec. SYNC Link (SCO) Real-time voice apps Bi-directional slot reservation Vocoder : 10b / 1.25 ms. 16 30 33 79
ASYNC Link (ACL) M-S Data comm. : FEC + CRC MTD : Avoids slave collisions & meets QoS 16 17 10 3 33 79 Multi-slots improve channel efficiency
BLUETOOTH LINK MANAGEMENT L2CAP x SAR, Integrity checks Connection oriented <phase, local name> Connectionless : Broadcast, multicast Muxs’ Higher layer protocols using channels Channel identifier <Src, Protocol> SDP Discovery (SDP Queries) – x Invoking Client-Server protocol : service records <UUID, value> Attribute specific SDP query / Browse records v1.1 non-IP & L2CAP optimized functionality
LINK MANAGER LMP msgs : Environment/Link centric parameter adjustment LMP Handshake Authentication A B Shared Key Encryption Secret Key SECURE Out-of-Band Pairing : Secure SEED - PIN generation
ADV L2CAP, SDP & RFCOMM : Firm / Software Allows STACK portability High degree of Interoperability ISSUES Standardization of Control APIs HV1/2 reduces throughput Multi-slot ACL reduces channel hopping rate Discovery latency Affects PICONET capacity More B devices Profile management
REFERENCES • Bhagwat, P., “Bluetooth: technology for short-range wireless apps”, 2001, www.cs.colorado.edu/~rhan/CSCI_7143_002_Fall_2001/Papers /Bhagwat2001_Bluetooth.pdf