User Manual

Users Guide - Andrew InCell™ Fiber Optic Distributed Antenna System
3-4
Composite Cable
The cable used between the CDU and each ERAU is typically a composite cable consisting of
two single-mode optical fibers and two copper conductors lines as shown in Figure 3-2. Andrew
composite cable is rugged, flexible and has a small diameter, making it very easy to install. One
optical fiber provides the downlink signal between the CDU and the ERAU; the second optical
fiber provides the uplink signal between the ERAU and the CDU. The composite cables use
industry standard SC/APC type connectors to interface with the ERAU and CDU. The two
copper lines are used to provide DC power and ground signals to the ERAU so that no additional
power planning is required. System installers are not required to install AC power, conduit and
transformers at each remote antenna location. With the CDU in the center of a system, remote
antennas could be spaced as far as 3 km apart using the composite cable.
The InCell™ System is designed to allow Enhanced Remote Antenna Units to be placed up to
1000’ from the central hub when using composite cables with 18 AWG copper wires. The 1000’
distance is a function of the voltage drop in the copper wires of the composite cable and is not a
limitation of the fiber optic elements. With the CDU in the center of a system, remote antennas
could be spaced as far as 3 km apart using the composite cable.
Andrew provides plenum rated composite cables for in-building installation as fully tested cable
assemblies and as bulk cable. The plenum cables meet demanding building codes for safety.
Tested cable assemblies are available in customer specified lengths, with optical and power
connectors installed. Bulk composite cable is also available on spools and requires system
installers to add crimp-on connectors for the copper lines and add SC/APC type connectors to the
fiber cables.
If the in-building location for each of the Enhanced Remote Antenna Units is pre-planned and the
distances are all known, then composite cables with connectorized ends and installation-ready wraps
can be ordered to specific lengths. The other option is to buy reels of composite cable and then
connectorize them in field. The connectors for the copper wires are fairly easy to crimp on, but the
SC/APC-connectors take much care and require the use of a non-fusion based splicing device and
well trained technicians to insure that reliable, low loss splices are made.