Introduction to extended data
Bluetooth (? Bluetooth) is a wireless technical standard, which can realize short-distance data exchange between fixed equipment, mobile equipment and personal area network of buildings (using UHF radio waves in ISM band of 2.4-2.485 GHz). Bluetooth technology was first invented by telecom giant Ericsson in 1994 as a substitute for RS232 data line. Bluetooth can connect multiple devices, which overcomes the problem of data synchronization.
A Bluetooth master device can communicate with at most seven devices in a piconet (a temporary computer network using Bluetooth technology), although not all devices can reach this maximum.
Devices can change roles through protocols, and slave devices can also be changed into master devices (for example, headphones initiate a connection request to a mobile phone. Naturally, the master device is the initiator of the connection, but it may run as a slave device later. )
Data can be transmitted between the master device and other devices at any time (except the rarely used broadcast mode). The master device can select the slave device to access; Usually, you can quickly switch between devices by rotating.
basic requirement
Personal computers without built-in Bluetooth can communicate with Bluetooth devices through Bluetooth adapters. Some desktops and recent laptops have built-in Bluetooth radios, while others need an external adapter to realize Bluetooth communication, usually a small USB dongle.
Unlike the early IrDA, which needed separate adapters to connect various devices, Bluetooth can realize communication between computers and multiple devices through one adapter. Apple began to adopt Bluetooth technology in 20 12 years: MacOSX v 10.2.
Regarding the Microsoft platform, Windows XP Service Pack 2 and SP3 versions provide native support for Bluetooth 1. 1, 2.0 and 2.0+EDR. Earlier versions required users to install Bluetooth adapter drivers instead of directly supporting Bluetooth.
Microsoft's own Bluetooth dongle (included in its Bluetooth computer equipment) has no external driver and needs to install Windows XP Service Pack 2. Windows Vista RTM/SP 1 or Windows Vista with wireless function package? SP2 is compatible with Bluetooth 2. 1+EDR. Windows 7 is compatible with Bluetooth 2. 1+EDR and extended query response (EIR).
Windows XP and Windows Vista/Windows 7 Bluetooth stacks provide native support for the following Bluetooth protocols: PAN, SPP, DUN, HID, HCRP. Windows XP stack can be replaced by a third-party stack that supports other protocols or updates the Bluetooth version. Windows Vista/Windows 7 Bluetooth stack supports third-party protocols and does not need to replace Microsoft stack.
Linux has two commonly used Bluetooth stacks, BlueZ and Affix. Most Linux kernel programs contain the BlueZ stack, which was first developed by Qualcomm. Affix stack was proposed by Nokia. FreeBSD has supported Bluetooth since version 5.0. NetBSD has supported Bluetooth since version 4.0. Its Bluetooth stack is also connected to the OpenBSD port.
The short-link broadcasting technology (later renamed Bluetooth) was originally developed by Nils Rydbeck, CTO of Ericsson Mobile Company in Lund, Sweden, for the purpose of two inventions:1989 (SE 8902098-6 published by Dr. Johan Ullman on June 2, 0989 and 1992 published on July 24, 0989).
Nils Rydbeck handed over the work specified in the specification to Tord Wingren, and handed over the development work to Jaap Haartsen and Sven Mattisson. They work for Ericsson in Lund, Sweden. This specification is based on frequency hopping technology.
References:
Bluetooth-Baidu encyclopedia