User Manual

DELTANODE FIBER DAS MANUAL
©DeltaNode Solutions 2012
14
Revision 12-03
2.1.3 POI – The Point of Interconnect
Basically this is a 1U high unit that contains 4 1:8 splitters and some attenuators. This is a coupling field
used to tie together the signals between the BIUs and the FOIs in a multiple band or multiple operator
system.
POI
DIU-304
COMMON 1 2 3 4 5 6 7 8
COMMON 1 2 3 4 5 6 7 8
COMMON 1 2 3 4 5 6 7 8
COMMON 1 2 3 4 5 6 7 8
A
B
C
D
Each of the 4 fields has a COMMON port and ports 1-8. If you are using it as a combiner 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 port.
Using it as a splitter means you connect the combined signal to the COMMON port and you can then
receive 8 ports with equal signal strengths on ports 1-8 (minus insertion loss).
RF Performance
Parameter
Value
Unit
Insertion loss COMMON to any port 1:8
Nominal
35
dB
IM3 performance
> 50
dB
Return loss performance
> 20
dB
Maximum signal input level
20
dBm
Isolation between ports in same strip
> 15
dB
Isolation between ports in different strips
> 60
dB
Table 5: Specification of the POI
2.1.4 FOI – The Fiber Optic Interface unit
The FOI is the unit responsible for converting the RF signals in the
downlink to fiber-optical laser that can be transmitted on the fiber to the
remote. It is also responsible for receiving the laser light transmitted by
the Remote Unit and convert it back to RF signals that will then usually go
into the POI and then later in to the BIU.
The fiber-optic interface can either be a single fiber interface (with WDM)
or a dual head with separate Rx and Tx connectors. This is ordered as
needed when the Master Unit is specified.
Each FOI can serve up to 4 Remote Units on a single fiber. The drawback is
that 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.
Figure 3: Fiber optic interface