User Manual
ADCP-75-114 • Issue 2C • January 2002
Page 17
©
2002,
ADC
Telecommunications,
Inc.
7.
Check
the
forward
path
RF
signal
level
at
the
DHU
RF
IN
port
and
verify
that
the
DHU
composite
input
signal
level
is
–20
dBm
(provides
maximum
DRU
output).
Re-adjust
FWD
LEVEL
ADJ
rotary
switches
to
add
or
remove
gain
if
required.
8.
Check
the
reverse
path
RF
signal
level
at
the
antenna
and
verify
that
the
signal
level
is
correct
per
the
system
design.
Re-adjust
REV
LEVEL
ADJ
rotary
switches
to
add
or
remove
gain
if
required.
9.
Reconnect
the
alarm
system
or
notify
the
alarm
system
provider
that
unit
turn-up
is
complete.
3.3 Forward Path Level Adjustment
The
level
of
the
composite
RF
output
signal
from
the
donor
antenna
will
vary
depending
on
the
gain
of
the
antenna,
the
number
of
channels
present,
and
the
level
of
the
channels.
For
maximum
output
at
the
DRU,
the
forward
path
signal
level
must
be
adjusted
to
provide
a
–20
dBm
composite
maximum
input
signal
level
at
the
DHU
input
port.
Use
the
following
procedure
to
adjust
the
RIU
to
provide
the
required
forward
path
signal
level
at
the
DHU:
1.
Connect
a
power
meter
to
the
antenna
cable.
The
required
signal
levels
and
test
points
are
shown
in
Figure
13.
DIRECTIONAL
ANTENNA TO/FROM
CELL SITE BTS
16655-B
REMOTE
INTERFACE
UNIT
FORWARD
(DOWNLINK)
REVERSE
(UPLINK)
+13 dBm FOR 800 MHz
+16 dBm for 1900 MHz
(COMPOSITE MAX)
-40 dBm
(COMPOSITE
MAX)
DIGITAL
HOST
UNIT
OPTICAL LINK
OPTICAL LINK
DIGITAL
REMOTE
UNIT
DIRECTIONAL ANTENNA
TO/FROM HANDSETS
MEASURE RF LEVEL
OF A SINGLE CARRIER
AT ANTENNA OUTPUT
CHECK SYSTEM DESIGN
SPECIFICATIONS FOR RF LEVEL
REQUIRED AT DONOR ANTENNA
-20 dBm
COMPOSITE MAX
INPUT TO DHU
-30 dBm
(COMPOSITE MAX
INPUT TO RIU)
Figure 13. Signal Levels and Test Points
2.
Measure
the
power
level
of
the
composite
output
signal
from
the
antenna.
If
the
power
level
exceeds
–29
dBm,
use
an
external
attenuator
to
reduce
the
signal
level
until
it
falls
within
the
range
of
–29
to
–60
dBm.
3.
Subtract
–20
(the
composite
input
signal
level
required
at
the
DHU
to
maximize
the
output
signal
at
the
DRU)
from
the
level
measured
in
step
2.
The
difference
equals
the
amount
of
gain
required
to
raise
the
forward
path
signal
to
–20
dBm.
4.
Disconnect
the
power
meter
from
the
antenna
cable
and
connect
the
antenna
cable
connector
to
the
RIU.
5.
Using
a
small
screwdriver,
adjust
the
FWD
LEVEL
ADJ
rotary
switches
to
insert
the
gain
required
to
provide
a
–20
dBm
signal
at
the
DHU.
The
RIU
provides
a
forward
path
signal
adjustment
range
of
from
+9
dB
to
+40
dB.
Refer
to
Figure
14
for
a
description
of
how
the
rotary
switches
work
and
to
Table
4
for
the
adjustment
settings.