Gestetner B147, Service Manual

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BLUETOOTH
B147/B149/B190 6-126 SM
6.19 BLUETOOTH
6.19.1 SPECIFICATIONS
Bluetooth wireless provides radio links between mobile computers, mobile phones
and other portable handheld devices.
Bluetooth contains the following features.
•
Cheaper compared to the IEEE802.11b wireless LAN.
•
Many protocols for infrared transmission (IrDA) can be used with Bluetooth.
• A Bluetooth device can connect to other Bluetooth devices without any settings.
Standard applied: Bluetooth 1.1 (Bluetooth Special Interest Group)
Data transfer rates: 1 Mbps
Bandwidth: 2.4GHz Frequency Hopping Spread Spectrum (FHSS)
Piconet . Bluetooth devices communicate with each other device in the ad hoc
mode. This network is called a “Piconet”. A Piconet may contain a maximum of 8
Bluetooth devices.
There is one master device and seven slave devices in a Piconet. The master
device controls the hopping frequency and timing, as well as storing the ID codes
of the slave devices. The master and slave devices can be swapped. Once the
master device leaves the Piconet, a slave device becomes the new master.
Machines with the Bluetooth option become potential slave devices to connect to
the PC.
FHSS (Frequency Hopping Spread Spectrum). The Bluetooth device divides
2402 to 2480 MHz into 79 channels of 1 MHz width, and changes the channel 1600
times per second. If other devices in the LAN are using the same radio band,
Bluetooth can avoid interference from the other devices.
Time
Freque
ncy
Channel 1
Channel 2
Channel 3
B146D587.WMF