Tech Tip
172
Networking Fundamentals
piconet
a Bluetooth network.
Also called a Personal
Area Network (PAN).
many miles, but there is no single standard that allows devices manufactured by
different companies to communicate with the other.
USB Wireless
Wireless USB is a standard for devices that connect through the USB port of
a PC. Wireless USB is most often used to support the transfer of data between the
PC and devices such as cameras, printers, mobile phones, DVD players, televisions,
external hard drives, and AV receivers. Wireless USB provides data speeds of up
to 480 Mbps at a maximum range of 3 meters and up to 100 Mbps at a maximum
range of 10 meters.
Bluetooth
Bluetooth is a short-range, wireless system that is designed for limited distances.
Typical Bluetooth devices have an effective range of 30 meters or less. Look at the
following table to see approximate values based on output wattage of the device.
Class Power Approximate Range
Class 1 100 mW 100 m
Class 2 2.5 mW 10 m
Class 3 1 mW 1 m
The abbreviation “mW” represents “milliwatt” or “1/1000 of a watt.” As you
can see, most Bluetooth devices have a very limited range.
The Bluetooth standard has evolved over the years in an effort to increase its
data rates. Look at the maximum data rates for each Bluetooth standard listed in
the following table.
Bluetooth Standard Maximum Data Rate
1.0 1 Mbps
2.0 3 Mbps
3.0 24 Mbps
As always when working with radio wave devices, expect that practical data rates will be
much lower than the data rate printed for the standard, except in ideal conditions.
Bluetooth uses 79 channels that use the frequency hopping spread spectrum
transmission technique, starting at 2.4 GHz. The Bluetooth standard was developed
separately from the IEEE network standards. It was never intended as a networking
standard designed to carry massive amounts of information. Bluetooth was
designed for appliances such as telephones, laptops, palm tops, digital cameras,
personal digital assistants, headsets, printers, keyboards, and mice.
A Bluetooth network is referred to as a piconet or a Personal Area Network
(PAN). A piconet is a very small network. Bluetooth became recognized by the
IEEE organization and was incorporated into the IEEE 802.15 Working Group