Ericsson, Nokia, IBM, Toshiba, Intel, 3Com, Motorola, Lucent and Microsoft.
And other big companies. Bluetooth is an industry standard, but it is not an international standard. Bluetooth system consists of radio unit, link control unit, link management support unit and host terminal interface. Bluetooth radio works in ISM band of 2.4 GHz. Bluetooth radio waves can realize wireless communication from 10 m to 100 m according to the transmission capacity of the antenna. Bluetooth protocol adopts circuit switching and packet switching technology. Bluetooth protocol stack supports asynchronous connectionless (ACL) link of data and synchronous directional (SCO) link of up to three voices. In addition, Bluetooth also supports the combined link of asynchronous data and synchronous voice, which is called DV packet type. Various voice channels support 64 Kb/s bidirectional synchronous channels. Asynchronous channels support up to 723.2 Kb/s uplink and 57.6 Kb/s downlink (and vice versa) or 433.9 Kb/s peer-to-peer link. The protocol stack is mainly composed of link managers and controllers of baseband and link layer as physical layers.