17 January, 2003
BLUETOOTH (WIRELESS)
6-101
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iptions
6.14.3 COMMUNICATION USING BLUETOOTH
Piconet
Bluetooth devices communicate with each other in the ad hoc mode. This network
is called the “Piconet.” The Piconet may contain a maximum of 8 Bluetooth devices.
There is one master device and can be seven slave devices in the Piconet. The
master device controls the hopping frequency and timing, as well as storing the ID
codes of the slave devices. The master and one of the slave devices can be
swapped. Once the master device leaves the Piconet, a slave device becomes the
new master.
Machines with the Bluetooth option are potential slave devices to connect to a PC.
Frequency Hopping Spread Spectrum (FHSS)
The Bluetooth device divides the band ranging from 2,402 to 2,480 MHz into 79
channels of the 1-MHz width, and changes the channel 1,600 times per second.
The Bluetooth device can avoid interference from other Bluetooth devices in the
LAN while they are using the same radio band.
Time
F
req
uen
cy
Channel 1
Channel 2
Channel 3
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