Handbook

ClearFill Star CDMA
1100187 Rev. 1.0
Page 50 of 152
3.7.3 Example system architecture
3.7.4 System feeding
Adding Capacity by Growing Sectors on In-Building Solutions with ClearFill®Star: Unlike in
the Macro Network, it is recommended that capacity be grown by adding sectors to the in-
building system. The reason for this is increasing the number of sectors improves the ability
to locate users within a building. Also, adding sectors to a ClearFill®Star System is less
expensive than adding carriers.
Identifying the position of a user in a building is done by determining which base station
sector is serving them. So by adding sectors, you are able to more accurately determine
where a user is within a building or campus.
Each Base Station Interface (BSI) handles one sector and one carrier. Each Remote Radio
Head (RRH) handles one sector and one carrier. Each Point of Intercept (POI) handles a
carrier. Obviously to add either a carrier or a sector the base station needs additional
equipment. The base station for ClearFill®Star doesn’t need amplifiers or filters, but still has
MCR (Radio) and URC (Radio Controller) and CMU (Channel Elements).
If a sector is added to increase capacity, then while a POI is not needed, a BSI, MCR and
CMU is needed. If a carrier is added to increase capacity, an MCR is not needed, but a POI,
BSI and CMU is needed. So the difference between adding a sector rather than adding a
carrier is the need for a MCR (when adding a sector) versus the need for a POI (when
adding a carrier). The additional sectors help to pinpoint end user location within the
building. The need for a URC depends on the base station’s total number of carriers. A
URC does not need to be added when a sector is added.
A benefit of ClearFill®Star lies in its ability to use software to define the building or campus
area covered by a sector, or by a carrier. The CFS Network Management System can
change, via its GUI, which sector is radiated by any of the RRHs and/or what carrier is
radiated.
So as capacity needs change within the building or campus, the coverage footprint of
individual sectors or individual carriers may be modified.
3.7.4.1 POI
RFS offers RF Point-of-Interconnect devices (POIs) to ease the RF connectivity (splitting /
combining / RF leveling) between BSI and BTS.
The POI allows RF leveling by manually switchable attenuators to set:
 Nominal RF input power (downlink, forward) into the BSI (-57dBm)
 The signal into the BTS (uplink, reverse)
For example: The POI RFS CFS-POI-S1S2-819 (19” rack mount passive device) accepts a
simplexed (forward, reverse separate connectors) 850 or 1900 band signal and splits it into
two simplexed signals to connect with two BSIs (so-called twin BSI 19" rack). The 1900 MHz
version RFS CFS-POI-S1S2-19 accepts a simplexed (forward, reverse separate