User's Manual
User Handbook L-RU Revision C
CONFIDENTIAL
PROPRIETARY
Reg. No.: User Handbook 1100182-C.DOC Page 9 of 29
2.1 General System Performance
Optical link:
• 0 to 6 dB optical attenuation
• Mono-mode fiber
Plug-and-play function:
• Self-leveling system in UL and DL
• Fixed output power levels of RU in DL
• Fixed output power levels of RU in UL for laser protection
• ALC of MU in DL for auto-leveling of composite input power for varying num-
ber of carriers
• ALC of MU in UL for auto-leveling of parallel optical links and compensating
for various optical link losses
• Commissioning effort reduced to a minimum
• Operating under ETSI requirements
Application:
• RU and MU build up an end-to-end RF system connected via a pair of optical fiber.
See User Handbook of Master Unit (L-MU series) for additional information about
MU.
• The system MU-RU and its plug-and-play functionality is designed to operate for
typical DAS applications with nominal UL input signal strengths (into RU RF in/out
port) in the range of -55 dBm to -35 dBm.
• As every distributed RF-over-fiber system, ClearFill Space1 introduces signal de-
lays in DL and in UL due to the use of single-mode optical fibers between MU and
RU. This delay has to be taken into account by cellular network planning/operation
for appropriate setting of BTS/NodeB search windows. This also applies for remote
BTS/NodeB’s which may be connected to a ClearFill Space1 system over-the-air
using an off-air repeater with donor antenna. Establishing a connection between
mobile / handheld device and BTS/NodeB may fail due to of improper setting of
search window / range.