Bluetooth technology specifies a two-way, short-range radio link that enables communication between PCs, mobile phones, PDAs, and other computing, electronic, and home theatre equipment. With Bluetooth, you can easily synchronize contact or calendar data between a PDA and laptop, talk on a hands-free phone, or print without cables. It is a cable replacement technology like infrared, but offers many advantages over infrared.
The Bluetooth specification focuses on keeping costs low, power consumption minimal, and the size small. Its low power consumption means it can be used in battery-powered devices. Bluetooth offers faster data rates and greater transmission distances compared with infrared and there are no line-of-site restrictions. It operates at the 2.4 GHz radio frequency, ensuring worldwide operability.
Bluetooth is named after a 10th century Danish king, Harald Blatand (Harld Bluetooth) who was known for uniting warring groups in current-day Norway, Sweden, and Denmark. It was originally developed by Ericsson, but is now managed by the Bluetooth Special Interest Group (SIG).
The Bluetooth SIG is an industry group with members from the telecommunications, computing, and chip manufacturing industries. To date over 2000 companies are members. The Bluetooth SIG oversees a qualification program to ensure compliance with the standard and interoperability with other Bluetooth devices. Any device bearing the Bluetooth logo has successfully completed interoperability testing.
Speed: The gross data rate supported by Bluetooth is 1 Mbps. Actual data rates are 432 kbps for full-duplex and 721 kbps for asymmetric
Frequency: Bluetooth uses the unlicensed ISM (Industrial, Scientific, and Medical) band at 2.4 GHz. In most countries, this band is available. In a few countries it is reserved for military use, but even these countries are moving to make the band available for general use. Because Bluetooth shares the same frequency range as 802.11b WLAN products, these two technologies cannot operate in the same space under some conditions.
Security: Bluetooth is designed to be as secure as wire using authentication and 128-bit encryption. Applications can also build their own security on top of the Bluetooth connection.
Architecture: With Bluetooth, up to 8 devices can be connected simultaneously. A piconet is the term for a collection of Bluetooth devices connected in an ad hoc fashion. All devices are peer units, but one device acts as a master and the other slaves for the duration of the piconet connection. Each piconet can support up to 3 full-duplex voice devices. Within a 10m area, there can be up to 10 piconets.
Bluetooth is becoming the preferred wireless technology in the WPAN (Wireless Personal Area Network). Personal applications include:
– Users can connect PCs to transfer files.
– Workers can collaborate on the same document using Microsoft NetMeeting.
– Users can connect to a printer without cables.
– Users can synchronize data between a handheld PDA and laptop.
– Users can listen to music via a wireless headset.
– Users can talk on their mobile phone with a wireless headset.
– Users can connect their laptops to the internet using their mobile phone’s GPRS or UMTS network.