ADC Telecommunications Inc. DVICS800-1 Manual Do Utilizador
ADCP-75-110
•
Issue B
•
March 2001
Page 23
©
2001, ADC Telecommunications, Inc.
Determine
the Amount of Building Attenuation: If a donor antenna will provide the RF link
to
the BTS, determine if there is enough signal isolation between the donor antenna and the in-
building
system to avoid a feedback loop and signal degradation. This step can often be
accomplished
during the preliminary walkthrough.
Discuss
Installation with Building Management and Engineering: Discuss all initially
anticipated
Digivance ICS coverage areas (including any obviously desirable cable routings,
equipment
installations, power and mechanical requirements) with the authorized client and
building
personnel for an initial approval/confirmation. This gives a good estimate of the
extent
of the system work needed. Occasionally, some of the system design work can be
accomplished
at this point.
2.10.2 Phase Two - System Design
Determine
forward and reverse path loss and then design for unity gain on the uplink
and
maximum power out of the DRU on the downlink: The overall purpose of the
Digivance
ICS is to transparently overcome attenuation losses, not to provide additional gain
beyond
what is required to bring the signal to unity gain. Complete the following steps to
make
this determination:
1. Determine
the in-building reverse path (uplink) losses at typical operating frequencies
and
distances from the subscriber handset (terminal) to the DRU. This information will
be
used to determine the optimal uplink signal level to the outside world.
2. Determine
the typical composite cell site Effective Radiated Power (ERP) into the
system.
Calculate the interface adjustment required to feed the required downlink signal
level
to the DHU in order to drive the DRU output signal at the desired level.
Determine
the location of the DHU and its RF and AC power sources: Complete the
following
steps to make this determination:
1. Determine
where and how the DHU will be mounted.
2. Determine
the location of the DHU AC power source.
3. Determine
the RF source (LIU with BTS or RIU with BTS through donor antenna) for
the
DHU.
4. If
an LIU connection with the BTS is required, determine the distance to the DHU.
5. If
a RIU connection with the BTS is required, determine what type of antenna is needed
and
where it can be mounted.
6. Determine
the attenuation or amplification requirements for the DHU to BTS interface.