WHAT IS BLUETOOTH? Bluetooth is an open wireless protocol for exchanging data over short distance using short length radio waves from fixed and mobile devices creating a personal area network. It can connect several devices overcoming problems of synchronization. It is high speed ,low power microwave wireless link technology.
WHY THIS NAME? Danish Harald Blåtand was the King of Denmark between 940 and 985 AD. He united Denmark and Norway, so same way Bluetooth of today will unite the worlds of computers and telecom.
IMPLEMENTATION Bluetooth uses a radio technology called frequency hopping spread spectrum, which chops up data being sent and transmits it. It operates at 2.4 Ghz and is capable of transmitting voice and data. The effective range of bluetooth device is 32 feet(10 mts). It transfers at the rate of 1 Mbps which is 3 to 8 times the avg speed of parallel and serial ports. It is also known as IEEE 802.15 standards.
FREQUENCY HOPPING SPREADSPECTRUM In this modulation technique frequencies are switched repeatedly during radio transmission. It reduces interference with other devices 1600 hops/sec- time slot is defined as 625 microseconds Pseudorandom hopping
Bluetooth is a packet based protocol with master slave structure One master may communicate with upto 7 slaves in a piconet All devices share the masters clock The master clock ticks at312.5micro sec intervals Two clock ticks make up a slot of 625 micro sec
CNTD. The master transmits in even slots and receives in odd slots Where as the slave receives in even slots and transmits in odd slots Packets may be 1,3 or 5 slots long
CLASSIFICATION Classification of devices on the basis of Power dissipated & corresponding maximum Range. Class Max Power Range permitted( (dbm) (approx) mw) Class 1 100 20 ~100mts Class 2 2.5 4 ~10mts Class 3 1 0 ~1mt
TECHNICAL FEATURES Spread Spectrum (Frequency Hopping) &Connection Type Time Division Duplex (1600 hops/sec) 2.4 GHz ISM Open Band (79 MHz ofSpectrum spectrum = 79 channels)Modulation Gaussian Frequency Shift KeyingTransmission Power 1 mw – 100 mwData Rate 1 MbpsRange 30 ftSupported Stations 8 devicesData Security –Authentication Key 128 bit keyData Security –Encryption Key 8-128 bits (configurable)Module size 9 x 9 mm
TYPICAL BLUETOOTH SCENARIO• Bluetooth will support wireless point-to-point and point-to-multipoint (broadcast) between devices in a piconet.• Point to Point Link m s — Master - slave relationship — Bluetooth devices can function as masters or slaves• Piconet — It is the network formed by a Master and one or m more slaves (max 7) — Each piconet is defined by a different hopping channel to which users synchronize to s s s — Each piconet has max capacity (1 Mbps)
AD-HOC NETWORK• Inter-piconet communication• Up to 10 piconets in a scatternet• Multiple piconets can operate within same physical space• This is an ad-hoc, peer to peer (P2P) network
CHANNEL ESTABLISHMENT• There are two managed situations — A device knows the parameters of the other – It follows paging process — No knowledge about the other – Then it follows inquiring & paging process• Two main states and sub-states — Standby (no interaction) — Connection (working) — Seven more sub-states for attaching slaves & connection establishment
USES Bluetooth is a standard communication protocol primarily designed for low power consumption Short range wireless solutions World wide usability Transfer of data as well as voice Wireless networking between PCs in a confined space and where little bandwidth is require
CORE BLUETOOTH PRODUCTS• Notebook PCs & • CD Player Desktop computers • TV/VCR/DVD• Printers• PDAs • Access Points• Other handheld • Telephone Answering devices Devices• Cell phones • Cordless Phones• Wireless peripherals: • Cars • Headsets • Cameras
SUMMARY• A new global standard for data and voice• Eliminate Cables• Low Power, Low range, Low Cost network devices• Future Improvements — Master-Slave relationship can be adjusted dynamically for optimal resource allocation and utilization. — Adaptive, closed loop transmit power control can be implemented to further reduce unnecessary power usage.