User Manual
ADCP-75-114 • Issue 2C • January 2002
Page 1
©
2002,
ADC
Telecommunications,
Inc.
1 DESCRIPTION
This
section
provides
a
complete
description
of
the
Remote
Interface
Unit
(RIU).
1.1 Primary Functions and Components
The
RIU,
shown
in
Figure
1,
serves
as
the
interfacing
unit
between
a
remote
BTS
and
the
Digivance
DHU.
The
RIU
provides
the
following
basic
functions:
•
RF
interface
to
the
BTS
(through
donor
antenna)
and
DHU
•
Gain
adjustments
to
the
forward
and
reverse
path
RF
signal
•
Duplexing
of
the
forward
and
reverse
path
RF
signals
•
Alarm
reporting
to
an
external
alarm
system
16650-A
FRONT PANEL
CABLE MANAGEMENT
TRAY
MOUNTING
BRACKET
(BOTH SIDES)
3.5 INCHES
(89 mm)
11.4 INCHES
(290 mm)
3.9 INCHES
(99 mm)
17.2 INCHES
(437 mm)
13.6 INCHES
(345 mm)
Figure 1. Remote Interface Unit
A
remote
interface
between
the
DHU
and
the
cell
site
BTS
via
a
donor
antenna
requires
specific
RF
input
and
output
signal
levels
(within
normal
operating
range)
at
the
DHU
and
antenna.
The
correct
levels
at
the
DHU
and
antenna
can
be
provided
using
the
Remote
Interface
Unit
(RIU).
The
RIU
is
an
accessory
item
that
is
used
to
adjust
both
the
forward
and
reverse
path
RF
signal
levels.
In
the
forward
path,
the
RIU
provides
gain
adjustments
in
1
dB
increments
over
a
range
of
+9
to
+40
dB.
In
the
reverse
path,
the
RIU
provides
gain
adjustments
in
1
dB
increments
over
a
range
of
+28
to
+59
dB
(800
Mhz)
or
+33
to
+64
dB
(1900
MHz).
The
RIU
connects
to
a
directional
antenna
through
a
duplexer
(internal)
which
provides
separate
forward
and
reverse
path
connections
for
the
DHU.
In
the
forward
path
(downlink),
the
recommended
composite
maximum
RF
input
signal
level
at
the
DHU
is
–20
dBm.
When
the
level
of
the
RF
input
signal
at
the
DHU
is
–20
dBm,
the
level
of
the
RF
output
signal
at
the
DRU
will
be
+13
dBm
(800
MHz)
or
+16
dBm
(1900
MHz).