Specs

Here are some specification details from the Bluetooth Web site

• The devices in a piconet share a common communication data channel. The channel has a total capacity of 1 megabit per second (Mbps). Headers and handshaking information consume about 20 percent of this capacity.

In the United States and Europe, the frequency range is 2,400 to 2,483.5 MHz, with 79 1-MHz radio frequency (RF) channels. In practice, the range is 2,402 MHz to 2,480 MHz. In Japan, the frequency range is 2,472 to 2,497 MHz with 23 1-MHz RF channels.

• A data channel hops randomly 1,600 times per second between the 79 (or 23) RF channels. • Each channel is divided into time slots 625 microseconds long.

• A piconet has a master and up to seven slaves. The master transmits in even time slots, slaves in odd time slots.

• Packets can be up to five time slots wide.

• Data in a packet can be up to 2,745 bits in length.

• There are currently two types of data transfer between devices: SCO (synchronous connection oriented) and ACL (asynchronous connectionless).

• In a piconet, there can be up to three SCO links of 64,000 bits per second each. To avoid timing and collision problems, the SCO links use reserved slots set up by the master.

• Masters can support up to three SCO links with one, two or three slaves.

• Slots not reserved for SCO links can be used for ACL links.

• One master and slave can have a single ACL link.

• ACL is either point-to-point (master to one slave) or broadcast to all the slaves.

• ACL slaves can only transmit when requested by the master