This system with this kind of RF delivery switch has a
high flexibility of changing modulation schemes or
carrier frequency assignments for individual zones,
because optical fiber is transparent for all radio
frequency signals.
Followings are the advantages in introducing the DS.
I) The DS allows the CS to switch radio zones on a
traffic demand basis, and to have the potential ‘pool’ of
modem and RF units for concentrated traffic.
2) Since all modulators, demodulators and receiving
power monitors are concentrated into CS, radio channel
controls, such as seamless hand-off and so on, are
easily made, whilst maintaining communication with
the same modem unit.
3) The system can be easily and quickly upgraded or
renewal, because there is no need to replace existing BS
equipments.
On the other hand, one of the key advantages of
controlling several radio zones in the CS is to enable the
system to choose the radio zone with better quality by
the zone-diversity, which realizes a seamless hand-over
procedure between two adjacent radio zones.