15.6 Radio amateur and CB radio
Radio amateurs are allowed transmitting powers of up to
750W divided into two license classes.
CB radio, however, is limited to a maximum 4W of trans-
mitting power, even though sometimes, significantly higher
transmitting powers are used by illegally employing power
amplifiers.
15.7 Bluetooth - the end of all cables
The radio transmission system “Bluetooth” certainly will
find its way into almost all technical appliances during the
next years. Bluetooth is a new, very affordable, world-wide
standard using approx. 2,4GHz and a high data transfer
rate. Transmission is intended to be extremely resistant to
interference by using “frequency hopping”, and also very
secure by using automatic data encryption.
It will replace both the annoying connection cables used
for stereos, speakers, monitors, printers, PCs etc., as well
as enable communication between up to 8 devices like e.g.
UMTS cellphones or portable PCs. Just a few years
ahead, it will be pretty normal that the coffee maker will be
able to “talk” to the washing machine or the coke vending
machine...
Transmitting power and thus exposure to radiation is
extremely low
with bluetooth devices, as power is limited
to just 1mW. However, its range is also limited to only 10m.
Though, suitable amplifiers will also be available, exten-
ding the range to several 100m.
By the way, U.S. market researchers forecast
more than
1,4 billion
sold bluetooth devices for 2005 alone.
An amateur radio stati-
on. High RF power of up
to 750W is possible.
Ericsson Bluetooth:
From camera to cellpho-
ne via radio.
Bluetooth module in the
year 2000: Newer deve-
lopments are just a tenth
in size...
Ericsson Bluetooth
headset:
significantly
lower radiation exposure
compared to cellphones.
15.0 RF exposure in practice
56
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