Bluetooth Technology By, Ms.Vicky HSU Rajan Avudaiappan Computer Networks-I [A1604] SVU CS-426

Introduction Originally developed by: Ericsson Mobile Communication (Sweden) Initiated the study (1994) Low power, low cost radio interference between mobile phones and its accessories Eliminate cables between the devices Later IBM, INTEL, Nokia & Toshiba formed the “Bluetooth Special Internet Group (SIG)” [1998] Developed Bluetooth 1.0 Specification (1999) Promoter group: Microsoft, Motorola, 3Com and Lucent

Bluetooth History Harald Bluetooth Gormson Name of a king (Denmark, 10th century) To honor him for his contributions for communication technology

Bluetooth!! [i.e.] Bluetooth networking standard is: Bluetooth: a set of rules for radio frequencies & communication (Voice and Data application) [i.e.] Bluetooth: A physical standard for radio signals Part of radio spectrum with ISM devices (Industrial, Scientific and Medical Devices) Operates in 2.45 GHz range of RF spectrum A protocol standard communications

Bluetooth communication Uses different radio waves to communicate Perfect for short range communication Uses FHSS (Frequency Hopping Spread- Spectrum) Doesn’t interfere with other Support 8 connection [ < 10 meter ] Switches b/w 79 frequencies (random) or Channel

Bluetooth communication Bluetooth Device Changes frequencies - 1600 times / Sec (Disturbance could be avoided) Piconet It is a type of network connection (Generated by the Bluetooth devices) Bluetooth – Other Bluetooth devices able to connect automatically (in discoverable mode)

Bluetooth classification Based on the power levels Based on maximum transmission capacity Classification Power level Capacity Class I 20 dBm 100 m Class II 0-4 dBm 10 m Class III 0 dBm 1 m

Bluetooth operation ‘Radio channel’ is shared by devices (group) Bluetooth: Radio Bluetooth RF (Physical layer) Operates in the unlicensed ISM band (2.4 GHz) It makes use of a frequency hop transceiver To prevent interference and fading To make available of many FHSS carriers It makes use of a binary FM (to reduce transceiver complexity) Data rate - up to 1 Mbps ‘Radio channel’ is shared by devices (group) They are synchronized to a common clock & Frequency hopping pattern

Bluetooth operation Bluetooth: Radio ‘ Bluetooth Piconet ’ A type of network connection (Group of devices will occupying shared physical channel) Master (Synchronization reference) clock & device address - decide channel characteristics Slave devices (Devices - that connected with the master) ‘ Frequency Hopping ’ Devices use a explicit Frequency hopping pattern Algorithm ( Bluetooth specification address & master’s clock) Pseudo - Random sequence hopping pattern (ISM 79 freq.) ‘ Full Duplex ’ Uses Time - Division Duplex method Data transmission in the form of packets

Bluetooth operation Bluetooth: Link & Protocols ‘ Control Layers ’ Placed above the physical channel Layer of links and Channels Control Protocols ‘ Physical Links ’ Connection established between Two Piconet Bluetooth devices Master & Slave - possible Slave & Slave - impossible Can be used to transport more than one logical layer Supports synchronous, asynchronous traffic

Bluetooth operation Bluetooth: Link & Protocols Logical Links Data traffic in logical link is being multiplexed (into the physical link by occupying slots ) Link Manager Protocol (LMP) It is a control protocol (for baseband & physical layers) Link manager uses this LMP (to control device operations) Provide services to manage (for radio & baseband layers) Logical Link Control and Adaptation Protocol (L2CAP) Based above the baseband layer Provides abstraction to applications and services Multiplexing & De-multiplexing of many channels

Bluetooth Wireless Technology Bluetooth - for voice and data application Penetration  can penetrate solid objects like walls Bluetooth chip cost : (< $3 ~ $5) – Economically efficient Easy to use Security – Allows 3 diff. Modes Non-secure, Service level, Link level Max bandwidth : 1 Mbps (theoretically) : 721 Kbps Low power consumption Interference  very short time Good for Wireless Personal Area Network (WPAN)

Bluetooth Wireless Technology Quick synchronization between Bluetooth enabled devices Omni directional --> No line-of-sight requirement Ability to establish connection (between any portable devices and a wired network) Uses globally available unlicensed ISM radio band Frequency range : 902 - 928 MHz 2.4 – 2.484 GHz Need not require operator’s license from: Federal Communication Commission (FCC) Any other International Regulatory Board Adopt common frequency band Can use virtually anywhere (any country in the world)

Bluetooth Wireless Technology System consists of: Software, Hardware and interoperability requirements Bluetooth Baseband protocol Combination of “Circuit & Packet switching” Easy to embedded directly into: Existing component boards or an adapter devices Bluetooth equipment integrate easily in TCP/IP network It uses wireless LAN & IEEE standards for data transmissions Bluetooth frequency range used in: USA - 2402 MHz to 2480 MHz Europe - 2402 MHz to 2480 MHz Japan - 2472 to 2497 MHz

Bluetooth (IEEE standards) IEEE 802.15 Working group for Wireless Personal Area Networks (WPANs) Bluetooth technology follows “IEEE 802.15.1” standards Ver 1.0, 1.1, 1.2 & 2.0 1.2  Adaptive Frequency Hopping  Reduce interference

Technology Characteristics Uses small data packets Improve & Maximize interface capacity Minimize interference by: Quick Frequency Hopping Adaptive output power Forward Error Correction Specific method used by receivers Detect errors in the transmission Correct errors -> Ability to correct them Maximum availability of devices in a Piconet: 1 Master device 7 Slave devices

Technology Characteristics Service Support: Asynchronous, Synchronous Asynchronous Connectionless Link (ACL) Supports for data transfer Carry either user data or control data Efficiency is best Synchronous Connection Oriented (SCO) Link Real-time Voice support Multimedia Traffic Uses reserved bandwidth Maximum three SCO connection (64,000 bits/sec) is possible

Bluetooth Links Data & Voice transmitted as packets Errors detected at receiver side Notification  to the header of the return packet Only lost or erroneous packets need to be retransmitted ACL supports: (Data transmission) Symmetrical or Asymmetrical Packet Switched Point-to-multi point connections Symmetrical Connection Link Max. Data rate : 433.9 Kbps (in both direction) Asymmetrical Connection Link Max. Data rate: 723.2 Kbps (in one direction) 57.6 Kbps (in reverse direction)

Bluetooth Links SCO link supports: (voice transmission) Symmetrical Circuit Switched Point-to-Point connection Three synchronous channels of 64 Kbps They use either: Pulse Code Modulation Std. for encoding speech (Analog ~ Digital) - PSTN Continuously Variable Slope Delta Modulation (CVSD) Std. for encoding speech (Analog ~ Digital) More immunity to interference Best for Voice transmission than PCM over wireless link Appropriate voice-coding scheme is being selected (After communication between: link managers of the devices)

Host Controller Interface Baseband and link controller Bluetooth protocol stack Data & Control Voice Application OBEX WAP TCS SDP RFCOMM L2CAP Host Controller Interface Baseband and link controller Link manager Radio Two way voice Control

Bluetooth protocol stack TCS (Telephony Control Protocol) Gives information about telephony services  SDP (Service Discovery Protocol) Allows Bluetooth devices can find out what all are services supported by other Bluetooth devices WAP (Wireless Application Protocol) & OBEX (Object Exchange) Gives interfaces to the higher layer parts of other communication protocols RFCOMM (Radio Frequency Communication) It is the Bluetooth serial port emulator It provides serial interface services (RS 232)

Bluetooth protocol stack L2CAP (Logical Link Control and Adaptation Protocol) Multiplexes the data from higher-level layers and also alters between different packet sizes Makes virtual connection between hosts and keeps track of multiple concurrent sessions (Ex: file transfers) Breaks the application data into Bluetooth-size fragments for transmission, and it will do the reverse operation for the received data Host Controller Interface Controls communication between a separate host and a Bluetooth module Link Manager Handles and configures links with other devices

Bluetooth protocol stack Broadband and Link Controller It handles the physical links through radio as well as assembling of packets It also controls the frequency hopping Radio It uses for modulation and demodulation of data for transmission and reception

Bluetooth Protocols

Bluetooth Protocols

Bluetooth devices…(examples) Bluetooth Head phones Bluetooth PDAs Bluetooth Access points Bluetooth adapters Bluetooth projectors Bluetooth cameras Bluetooth printers Bluetooth car adapters Bluetooth mice, keyboard Bluetooth Handsets Bluetooth Modems Bluetooth Medical devices Bluetooth Flash cards Bluetooth projectors Bluetooth MP3 players Bluetooth mobile PCs

References www.bluetooth.com Bluetooth Demystified, Nathan J.Muller, McGraw-Hill, NY, USA 2000 Bluetooth- Connect without cables, By Jennifer Bray and Charles F Sturman, Prentice Hall PTR, Upper Saddle River, New Jersey 07458, 2001 Bluetooth Operation and Use, By Robert Morrow, McGraw-Hill, New York, 2002 http://www.baracoda.com/shared_docs/bluetooth_protocol.pdf http://www.cs.fsu.edu/~yasinsac/group/slides/carter3.pdf http://stephen.ksuettc.org/bluetooth.pdf http://www.rzo.free.fr/docs_jean/bluetooth.pdf www.cs.utk.edu/.../bluetooth/whatisbluetooth.gif www.palowireless.com/.../spec_stack.gif http://www.palowireless.com/infotooth/knowbase.asp http://www.ericsson.com/ericsson/corpinfo/publications/review/2000_04/files/2000046.pdf http://www.ieee802.org/15/ http://electronics.howstuffworks.com/bluetooth.htm

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