User's Manual

4 Commissioning
Page 29
Do not use a tool (e.g. pair of pliers) to tighten the N-type antenna connectors
as it might cause damage to the connector and lead to a malfunction of the
Remote Unit. It is sufficient to tighten the N-type antenna connectors by
hand.
) Note: Directly connect the base station signal to the Master Unit using a
coaxial cable to avoid coupling another signal into the system in the
DL direction than the single wanted signal transmitted by the base
station.
4.4. OPTICAL FIBER CABLE CONNECTION RULES
Optical signals are transmitted by use of optical fibers. The optical fiber is a single-
mode fiber. Type is E9/125 ยตm with the following minimum requirements.
Attenuation: <0.36 dB / km @ 1310 nm / <0.26 dB / km @ 1550 nm
Dispersion: <3.5 ps / nm km @ 1310 nm / <18.0 ps / nm km @ 1550 nm
Follow the procedure below before connecting the fiber cables to ensure optimized
performance. These procedures must be carried out carefully:
1. Remove fiber-optic protective caps.
2. Clean the end of the fiber-optic cable that will be inserted in the optical connectors
on the donor interface box with high-grade alcohol and lint-free cotton cleaning
swabs.
3. Blow out the laser receptacle with clean and dry compressed air to remove any
particulate matter.
4. Connect the fiber-optic cables by inserting the cable end into the laser receptacle
and aligning the key (on the cable end) with the keyed slot.
5. Measure attenuation and reflection with an appropriate measuring instrument. For
pigtails, a total value of < 0.4 dB (measured to a reference plug) can be assumed
due to the dead zone of the reflectometer. These measurements must be made
with a sufficient length of optical fiber, at the input and output of the device which
has to be measured.
6. Do not use any index matching gels or fluids of any kind in these connectors.
Gels are intended for laboratory use and attract dirt in the field.
Observe the following guidelines when connecting the optical fibers:
๎šƒ Do not bend the fiber-optic cable in a tight radius (< 4 cm) as this may cause
cable damage and interrupt transmission.
๎šƒ The specified bending radius of the optical fibers must not be exceeded.
๎šƒ The pigtails for the connection between Master and Remote Unit must have a
sufficient length. A protection for the feeding into units must be given.