Bluetooth was originally the king who unified Denmark in the 10 century. He unified Sweden, Finland and Denmark at that time. Naming this new technical standard after him means unifying the fragmented situation. Bluetooth technology uses advanced technologies such as FH (frequency hopping) and TDMA (time division multiple access) to link several digital devices (various mobile devices, fixed communication devices, computers and their terminal devices, various digital data systems, such as digital cameras, digital video cameras, and even various household appliances and automation devices) in a short distance at the lowest cost. Bluetooth technology will be a unified bridge for the interfaces of various peripheral devices in the network, which eliminates the connection between devices and replaces it with wireless connection.
Bluetooth is a short-range wireless communication technology. Electronic devices can be connected to each other through Bluetooth, which saves the traditional wires. Through the wireless receiver on the chip, electronic products equipped with Bluetooth technology can communicate with each other within ten meters, and the transmission speed can reach 1 megabyte per second. In the past, the transmission technology in infrared data association required the distance of electronic equipment in sight. Now, with Bluetooth technology, such troubles can be eliminated.
Bluetooth is a technical standard for short-range wireless digital communication jointly proposed by Toshiba, Ericsson, IBM, Intel and Nokia in May 1998. Its goal is to achieve the highest data transmission speed 1Mb/s (the effective transmission speed is 72 1kb/s) and the maximum transmission distance 10m. Users can use the ISM (Industrial, Scientific and Medical) band of 2.4GHz and set 79 channels on it with a bandwidth of 1MHz.
Advantages of Bluetooth technology: supporting voice and data transmission; Using radio technology, the transmission range is large, which can penetrate different substances and spread among them; Frequency hopping spread spectrum technology is adopted, which has strong anti-interference and is not easy to eavesdrop; In theory, there is no interference problem when using spectrum that is unrestricted in all countries; Low power consumption; Low cost. Disadvantages of Bluetooth: slow transmission speed. Technical performance parameters of Bluetooth: the effective transmission distance is 10cm~ 10m, and the increased transmission power can reach 100 m or even more. The transceiver operates at 2.45GHz and covers 79 channels (2.402GHz to 2.480GHz) at the interval of 1MHz. Data transmission technology adopts short packet, frequency hopping spread spectrum technology, 1600 times/second to prevent eavesdropping and avoid interference; Send one packet at a time, and the packet size ranges from 126 to 287 bit. The contents of the packet can be data containing different services, such as data or voice. For synchronous connection, the data transmission bandwidth in each direction can reach 32.6Kbps, which is close to 65,438+00 times the analog connection rate of a typical 56kb/s modem. For asynchronous connection, the data transmission rate in one direction can reach 7,265,438+0 KB/s for uploading or downloading, and the rate in the opposite direction is 57.6 KB/s; The data transmission channel is to set aside three concurrent synchronous voice channels, each with a bandwidth of 64 KB/s; Voice and data can also be mixed in one channel, providing 64kb/s synchronous voice connection and asynchronous data connection. Network connection uses encryption technology and password authentication to connect devices, and it can form a Bluetooth piconet with less than 7 other devices at the same time. 1 Bluetooth device can join 8 different piconets at the same time, and the transmission bandwidth of each piconet is 1Mb/s respectively. When more than two devices share a channel, a Bluetooth piconet can be formed, in which one device controls the transmission capacity.