microcells - Maxwell

• Sometimes the problem is not excessive traffic,
but a “hole” in the system coverage caused by
propagation difficulties, such as a tall building or
hill that casts a radio shadow.
• Obviously cell sites should be chosen to minimize
these problems, but it is not always possible to
eliminate them completely.
• In that case a repeater can be used, as shown in
Figure 3.12. The repeater simply amplifies signals
from the cell site and from the mobiles.
• It can connected to the main site by a microwave
link, but often the repeater simply receives and
transmits at the same frequencies, avoiding
feedback by careful location of directional trnsmit
and receive antennas.