Warning: include(../header.html): failed to open stream: No such file or directory in /home/alex/mobilealmanac.com/htdocs/gloss/item.php on line 19
Warning: include(): Failed opening '../header.html' for inclusion (include_path='.:/usr/local/lib/php') in /home/alex/mobilealmanac.com/htdocs/gloss/item.php on line 19
Bluetooth
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 like personal digital assistants (PDAs), mobile phones, laptops, PCs, printers and digital cameras via a secure, low-cost, globally available short range radio frequency.
The name Bluetooth was born from the 10th century king of Denmark, King Harold Bluetooth (whose surname is sometimes written as Bluetooh), who engaged in diplomacy which led warring parties to negotiate with each other. The inventors of the Bluetooth technology thought this a fitting name for their technology which allowed different devices to talk to each other.[1]. The name of the king in Danish was Harald Blåtand and the Bluetooth logo is based on the H and B runes.
Introduction
Bluetooth is a radio standard primarily designed for low power consumption, with a short range (power class dependent: 1 meter, 10 meters, 100 meters) and with a low-cost transceiver microchip in each device.
Bluetooth lets these devices communicate with each other when they come in range, even if they are not in the same room, as long as they are within up to 100 meters of each other, dependent on the power class of the product.
The Bluetooth specification was first developed by Ericsson (now Sony Ericsson), and was later formalized by the Bluetooth Special Interest Group (SIG). The SIG was formally announced on May 20, 1999. It was established by Sony Ericsson, IBM, Intel, Toshiba and Nokia, and later joined by many other companies as Associate or Adopter members. Bluetooth is also known as IEEE 802.15.1.
Bluetooth 1.0 and 1.0B
Versions 1.0 and 1.0 B had numerous 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
In version 1.1:
many errata found in the 1.0B specifications were fixed.
added support for non-encrypted channels.
Received Signal Strength Indicator (RSSI)
[edit]
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 using 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.
[edit]
Bluetooth 2.0
This version is backwards compatible with 1.x. The main enhancement is the introduction of Enhanced Data Rate (EDR) of 2.1 Mbit/s. 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.
Return to the cell phone glossary
Warning: include(../footer.html): failed to open stream: No such file or directory in /home/alex/mobilealmanac.com/htdocs/gloss/item.php on line 41
Warning: include(): Failed opening '../footer.html' for inclusion (include_path='.:/usr/local/lib/php') in /home/alex/mobilealmanac.com/htdocs/gloss/item.php on line 41