The Bluetooth Technology The Bluetooth system is a
communication system which enables both voice
communication and data
communication to be done on the same system. In 1998, it was made an open standard, with five American/Japanese/European firms as "promoters." Pieces of equipment which have received authentication are assured of having mutual connectivity .
This abstract gives a summary description of the communications. The concept of the Bluetooth system is to provide a wireless connection between equipment and it can
potentially be applied to all kinds of electronic equipment. Some of the electronic equipments using Bluetooth system are: a chip set consisting of an RF transceiver LSI (ML 7050LA) and a base band controller LSI (ML7051LA), Bluetooth communication software.
The Bluetooth system is a wireless communication system which uses the 2.4 GHz band (ISM band) radio frequency which has been allocated for industrial/science and
engineering/medical use without the need for a license’s variety of electronic equipment, such as portable telephones, personal computers, etc., can be connected in a "cable-less" manner. The Bluetooth network is configured with two kinds of wireless stations:
master and slave stations. A service area called a Pico net is created, centered around the master and having a radius of approximately 10 meters. The master can be placed
in a state where it can have a maximum of seven slaves as active slaves regularly communicating on the Piconet.The ML7051LA base band controller LSI is developed
according to the SPA (Silicon Platform Architecture) concept. The Bluetooth communication
processing circuit is connected to the APB (AMBA Peripheral Bus) as a
peripheral block of this platform, in the same way as the UART (Universal Asynchronous Receiver Transmitter) block and the USB (Universal Serial Bus) block.
The Bluetooth communication processing circuitry is composed of ten kinds of small blocks. These blocks, through control by means of software, perform the functions
of wireless control, communication processing for each link, voice processing, and timing control, which are specified by the Bluetooth specifications. Bluetooth communication
is structured with software controlling the communication processing circuits described above. This processing software consists of the LC (Link Controller) and LMP (Link Manager. Master: when configuring a Pico net, first, an "inquiry" operation is performed. While periodically sending the "inquiry" signal, information gathering is done to collect the addresses, etc. of the slaves which exist on the periphery. Slave: to be accepted by the master, an "inquiry scan" operation is performed. While periodically switching the receiving frequency, it waits for the "inquiry" signal from the master. Upon receiving an "inquiry" signal, the address information, etc. of the slave is transmitted to the
master. Master: to transition the slave to the "connection" state, the "page" operation is performed. Within the "page" operation, the slave is notified of active member addresses, the master address, and clock phase information. While periodically switching the receiving frequency, the slave waits for the "page" signal from the master. Upon receiving a "page" signal, the master's address and clock-offset information are received. After this the master and slave can mutually exchange linked information and "connection" has been established. The slave obtains the information for frequency hopping and synchronizing the scrambler by calculating it based on the address and clock phase information which the slave receives from the master.