Bird Technologies Manual 7-9570-1-1
(Rough Draft)
08/19/16 Page 18
POI Module (Point of Interconnect Module)
The POI module contains four independent 1-to-8
splitter/combiners. The module is used in the Fiber
DAS system to tie together signals between BIU
modules and FOI modules in a multi-band or multi-
operator system. Each of the 4 independent split-
ter/combiners has a COMMON port and 8 in/out
ports (labeled 1-8). If you are using it as a com-
biner then you should connect the signals you want
to combine to the ports 1-8 and you will receive the
sum of the signals (minus insertion loss) on the
COMMON por t. Using it as a splitter then you
should connect the signal you want to split/distrib-
ute to the common port. Each of the 8 output ports
will then output the signal with equal signal
strength at each port (minus insertion loss).
The POI module is a stand alone module designed
to use 1 RU of rack space as shown in
Figure 11
.
The module is not designed to plug into the master
frame unit so it can be installed anywhere in the
rack that is convenient for the customer. It is typi-
cally installed just below the master frame unit in
most installations. This keeps the interconnect
cables (QMA style connectors) reasonably short.
The four independent splitter/combiner assemblies
that make up the POI module are labeled as A
through D.
FOI Module (Fiber Optic Interface Module)
The FOI module is responsible for converting RF
signals in the downlink direction (from the base sta-
tion) into optical signals that can be transmitted on
a fiber cable to the remote unit. It is also responsi-
ble for receiving optical signals in the uplink direc-
tion from the Remote Unit and converting them
back into RF signals which can be passed along to
the base station. The FOI module is shown in
Fig-
ure 12
.
The fiber-optic interface can either be a single fiber
interface (with WDM) or a dual fiber interface with
separate RX and TX connectors. The type of FOI
is ordered as needed when the Master Unit is
specified. Each FOI can serve up to 4 Remote
Units on a single fiber cable. The Remote Units
must have different optical wavelengths in the
uplinks to avoid interference. They can however,
share the same optical wavelength in the downlink.
FUNCTIONAL DESCRIPTION
The FOI is powered from the master frame back-
plane and communicates via Ethernet with the
other modules in the Master Unit. The FOI contains
several adjustable attenuators which can be used
to compensate for losses that occur before the FOI
(e.g. in the POI) and for losses that occur on the
fiber in the uplink. There are two sets of RF ports
on the FOI that can be used to connect signals
from two different strips in the POI. The FOI has a
dual fiber interface style with separate uplink and
downlink fiber optic connections.
There are two attenuators that can be set in the DL
path, this allows for balancing the input signals
from two different signal sources so that they can
share the dynamics of the laser properly. The RF
drive levels are measured and accessible in the
web interface so that they can be checked. In the
future alarm levels may be added to these test
points.
This interface is designed to work with SC-APC
connectors (7° angled physical connector) and sin-
Figure 11:
POI Module.
