Fundamental Techniques

Fundamental Techniques

By denition, mobile radio terminal means any radio terminal that could be moved
during its operation. Depending on the radio channel, there can be three dierent
types of mobile communication. In general, however, a Mobile Station (MS)
or subscriber unit communicates to a xed Base Station (BS) which in turn communicates
to the desired user at the other end. The MS consists of transceiver,
control circuitry, duplexer and an antenna while the BS consists of transceiver and
channel multiplexer along with antennas mounted on the tower. The BS are also
linked to a power source for the transmission of the radio signals for communication
and are connected to a xed backbone network. Figure 1.2 shows a basic mobile
communication with low power transmitters/receivers at the BS, the MS and also

the Mobile Switching Center (MSC). The MSC is sometimes also called Mobile Telephone
Switching Oce (MTSO). The radio signals emitted by the BS decay as the
signals travel away from it. A minimum amount of signal strength is needed in
order to be detected by the mobile stations or mobile sets which are the hand-held
personal units (portables) or those installed in the vehicles (mobiles). The region
over which the signal strength lies above such a threshold value is known as the
coverage area of a BS. The xed backbone network is a wired network that links all
the base stations and also the landline and other telephone networks through wires.