User's Manual
ADCP-75-110 • Issue 2B • July 2001
Page 1
©
2001,
ADC
Telecommunications,
Inc.
1 SYSTEM FUNCTIONAL OVERVIEW AND UNIT DESCRIPTION
This
section
provides
an
overview
of
the
Digivance
Indoor
Coverage
Solution
(ICS),
a
description
of
the
functions
and
features
provided
by
the
units
that
comprise
the
system,
a
listing
of
terms
used
and
their
definition,
and
a
table
of
specifications.
1.1 System Functional Overview
The
Digivance
ICS
is
a
digitally
distributed
antenna
system
that
provides
in-building
coverage
for
analog
(AMPS)
or
digital
(TDMA
or
CDMA)
cellular
phone
systems
operating
within
the
800
and
1900
MHz
frequency
bands.
Large
buildings
typically
interfere
with
the
transmission
or
reception
of
cellular
phone
system
signals
by
imposing
high
attenuation
losses
on
RF
signals.
The
Digivance
ICS
is
designed
to
overcome
the
attenuation
losses
that
make
cellular
communications
within
buildings
or
structures
difficult
or
impossible.
With
the
Digivance
ICS,
cellular
phone
RF
signals
can
be
distributed
to
the
interior
areas
of
any
building
or
structure
to
eliminate
dead
spots
and
improve
reception.
1.1.1 Basic System Components
The
basic
components
of
the
Digivance
ICS
and
their
functions
are
shown
in
Figure
1.
The
basic
system
consists
of
the
Digital
Host
Unit
(DHU),
Digital
Remote
Unit
(DRU),
and
when
additional
capacity
or
longer
fiber
runs
are
required,
the
Digital
Expansion
Unit
(DEU).
In
addition,
two
accessory
items,
the
Local
Interface
Unit
(LIU)
and
the
Remote
Interface
Unit
(RIU)
may
be
used
as
needed
to
interface
the
DHU
with
the
cellular
system
Base
Transceiver
Station
(BTS).
1.1.2 Interface With BTS
The
DHU
interfaces,
either
locally
or
remotely,
with
the
BTS.
As
referenced
in
this
publication,
the
BTS
could
be
either
a
microcell
or
a
cell
site
base
station.
When
the
BTS
(microcell)
is
co-located
with
the
DHU,
a
local
interface
over
coaxial
cable
is
possible.
An
interface
device,
such
as
the
LIU,
may
be
required
to
provide
the
proper
input
and
output
RF
signal
levels
between
the
BTS
and
the
DHU.
When
the
BTS
(cell
site
base
station)
is
not
co-
located
with
the
DHU,
a
remote
interface
using
a
donor
antenna
is
required.
An
interface
device
such
as
the
RIU
is
required
to
provide
the
proper
input
and
output
RF
signal
levels
between
the
donor
antenna
and
the
DHU.
The
DHU
interfaces,
as
described
in
the
preceding
paragraph,
with
the
BTS.
In
the
forward
path,
the
DHU
receives
RF
signals
from
the
BTS.
The
DHU
digitizes
the
RF
signals
and
then
converts
them
to
digital
optical
signals
for
transport
to
the
DEUs
and
DRUs.
In
the
reverse
path,
the
DHU
receives
digital
optical
signals
from
the
DRUs
and
DEUs.
The
DHU
converts
the
optical
signals
back
to
the
original
RF
signal
format
for
transmission
to
the
BTS.