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Cell broadcasting
The frequency is recycled so that the frequency sent by the base station
should not interfere with each other by using a frequency different in each
base station. The one that each base station is used a frequency different in
each area and transmitted simultaneously is called Cell Broadcasting.
The transmission simultaneously using two or more frequencies different in
each base station. It seems cell broadcasting is similar to the content
of British Telecom applied patent. As for the transmission
simultaneously using a common one frequency to each base station, Adviser Group
has acquired the patent in Japan,
the United States, and the
People’s Republic of China.
Multicast and broadcasting
The multicast is a method to reproduce information by routers.
When for instance, a lot of users try to see content of concert, the
server that sends the content of the concert originally, one or two or more
contents are sent. The router delivered to the user who uses the
multicast reproduces. It forwards it to the other users by two or
more contents. As a result, the load to the server that sends the
content of the concert originally doesn't grow.
In the wireless, an infinite user can receive at the same time, and
information sent by the base station need not be reproduced.
What is the multicast in the wireless? When transmitting to two or
more specific users, it is sometimes called the multicast.
However, it is broadcasting as a transmission method.
Clipping Cast
Information
is transmitted to the cellular phone little by little by using time when the
use degree of the frequency is low such as nighttimes and early mornings.
Information shall be stored and accumulated by using memory of
cellular phone and reproduced. There are two methods, the method
of the transmission to an individual cellular user, the other method to
transmit by using the transmission simultaneously for a lot of cellular phone
users.
Frequency band and frequency
As
an explanation of the frequency of CDMA in Japan, the frequency band sometimes
called a frequency. For instance, the band of 1.228MHZ might be
called one frequency. However, because information on
the R･G･B signal etc. transmitted by an individual frequency, it is necessary to
divide an individual frequency with the frequency band.
Transmission simultaneously with
control channel
The base station uses the control channel to check positions of the cellular
phone in the area and the transmission simultaneously to these cellular
phones is always done. The transmission of information using the
free time of this control channel is called a short message.
However, there is a limit in the transmission volume of data to the
transmission simultaneously using the control channel. For
instance, the movie etc. cannot be transmitted.
To the transmission simultaneously using the traffic channel, the
transmission volume of data is not limited. The movie and the
musical program, etc. can be transmitted.
In the transmission simultaneously with the traffic
channel, using a
frequency different in each base station is the British Telecom method （cell
broadcasting）. The method to use a common
one frequency to each base station is the content of the patent that Adviser
Group acquired in Japan,
the United States, and China.
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