Bluetooth is an industrial specification for wireless personal area networks (PANs), also known as IEEE 802.15.1. Bluetooth provides a way to connect and exchange information between devices such as personal digital assistants (PDAs), mobile phones, laptops, PCs, printers, digital cameras and video game consoles via a secure, globally unlicensed short-range radio frequency.
The name Bluetooth is derived from the cognomen of a 10th century king of Denmark, Harald Bluetooth. According to the inventors of the Bluetooth technology, Harald engaged in diplomacy which led warring parties to negotiate with each other, making Bluetooth a fitting name for their technology, which allows different devices to talk to each other.
Bluetooth
Bluetooth is in a variety of new products such as phones, printers, modems, and headsets, to name a few. Bluetooth is acceptable for situations when two or more devices are in close proximity with each other and don't require high bandwidth. Bluetooth is most commonly used with cell phones and handheld computing devices, either using a Bluetooth headset or transferring files from phones/PDAs to computers. Since Bluetooth uses short-range radio frequencies, it is not as effective for setting up networks that can be accessed from remote locations as with Wi-Fi.
Bluetooth also simplified the discovery and setup of services. Wi-Fi is more analogous to the traditional Ethernet network, and requires configuration to set up shared resources, transmit files, set up audio links (e.g. headsets and hands-free devices), whereas Bluetooth devices advertise all services they actually provide; this makes the utility of the service that much more accessible, without the need to worry about network addresses, permissions and all the other considerations that go with typical networks.
Bluetooth 1.0 and 1.0B
Versions 1.0 and 1.0 B had many problems and the various manufacturers had great difficulties in making their products interoperable. 1.0 and 1.0B also had mandatory Bluetooth Hardware Device Address (BD_ADDR) transmission in the handshaking process, rendering anonymity impossible at a protocol level, which was a major setback for services planned to be used in Bluetooth environments, such as Consumerium.
Bluetooth 1.1
Many errors found in the 1.0B specifications were fixed.
Added support for non-encrypted channels.
Received Signal Strength Indicator (RSSI)
Bluetooth 1.2
This version is backwards compatible with 1.1 and the major enhancements include
Adaptive Frequency-hopping spread spectrum (AFH), which improves resistance to radio frequency interference by avoiding the use of crowded frequencies in the hopping sequence
Higher transmission speeds in practice
extended Synchronous Connections (eSCO), which improves voice quality of audio links by allowing retransmissions of corrupted packets.
Host Controller Interface (HCI) support for 3-wire UART
HCI access to timing information for Bluetooth applications:
Bluetooth 2.0
This version is backwards compatible with 1.x. The main enhancement is the introduction of Enhanced Data Rate (EDR) of 3.0 Mbps. This has the following effects (Bluetooth SIG, 2004):
3 times faster transmission speed (up to 10 times in certain cases).
Lower power consumption through a reduced duty cycle.
Simplification of multi-link scenarios due to more available bandwidth.
Further improved BER (bit error rate) performance.
Future of Bluetooth
The next version of Bluetooth technology, currently code-named Lisbon, includes a number of features to increase security, usability and value of Bluetooth. The following features are defined:
Atomic Encryption Change - allows encrypted links to change their encryption keys periodically, increasing security, and also allowing role switches on an encrypted link.
Extended Inquiry Response - provides more information during the inquiry procedure to allow better filtering of devices before connection. This information includes the name of the device, and a list of services, with other information.
Sniff Subrating - reducing the power consumption when devices are in the sniff low-power mode, especially on links with asymmetric data flows. Human interface devices (HID) are expected to benefit the most, with mice and keyboards increasing the battery life from 3 to 10 times those currently used.
QoS Improvements - these will enable audio and video data to be transmitted at a higher quality, especially when best effort traffic is being transmitted in the same piconet.
Simple Pairing - this improvement will radically improve the pairing experience for Bluetooth devices, while at the same time increasing the use and strength of security. It is expected that this feature will significantly increase the use of Bluetooth.
Bluetooth technology already plays a part in the rising Voice over IP (VOIP) scene, with Bluetooth headsets being used as wireless extensions to the PC audio system. As VOIP becomes more popular, and more suitable for general home or office users than wired phone lines, Bluetooth may be used in Cordless handsets, with a base station connected to the Internet link.
The version of Bluetooth after Lisbon, code-named Seattle, has many of the same features, but is most notable for plans to adopt Ultra-wideband radio technology. This will allow Bluetooth use over UWB radio, enabling very fast data transfers, synchronizations and file pushes, while building on the very low power idle modes of Bluetooth. The combination of a radio using little power when no data is transmitted, and a high data rate radio used to transmit bulk data, could be the start of software radios. Bluetooth, given its worldwide regulatory approval, low power operation, and robust data transmission capabilities, provides an excellent signalling channel to enable the soft radio concept.
On 28 March 2006, the Bluetooth Special Interest Group (SIG) announced its selection of the WiMedia Alliance Multi-Band Orthogonal Frequency Division Multiplexing (MB-OFDM) version of Ultra-wideband (UWB) for integration with current Bluetooth wireless technology. UWB integration will create a version of the globally popular Bluetooth wireless technology with a high speed/high data rate option. This new version of Bluetooth technology will meet the high-speed demands of synchronizing and transferring large amounts of data as well as enabling high quality video and audio applications for portable devices, multi-media projectors and television sets, wireless VOIP. At the same time, Bluetooth technology will continue catering to the needs of very low power applications such as mice, keyboards and mono headsets, enabling devices to select the most appropriate physical radio for the application requirements, thereby offering the best of both worlds.
HOPE THIS ONE HELPS..=))
2006-10-07 01:23:32
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answer #6
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answered by ❀swe3tie✿ 4
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