User Manual

OPTICAL MASTER UNIT
PRODUCT DESCRIPTION AND USER’S MANUAL
© Axell Wireless Ltd 3
1.3.2 Cascading OMUs
Up to four OMUs can be cascaded and operate up to 24 repeaters as one system: one Master OMU
and three Slave OMUs.
This type of topology requires only one Control module and one modem (at the Master OMU). All
OMUs and hosted Repeaters are managed as a single system via the Master OMU.
Figure 3. Four OMUs cascaded in one system
1.3.3 Expansion using Multi-color Laser System
The number of Repeaters supported by each OMU can be expanded using multi-colored laser
systems.
A laser system with two colors can operate one repeater for each fibre optic converter in an OMU-
Repeater system – one color is used for the uplink and one for the downlink. A laser system with
three or more colors can operate two or more repeaters per fibre optic converter. One color is used for
the downlink which is the same for all repeaters, and in the uplink each repeater has its own color.
The connection from one repeater to the next is done via so called add-drop couplers.
The difference in distance between the repeaters and the OMU can be compensated for automatically.
Two repeaters are connected to the same converter in the OMU via the same fibre but the wavelength
for the uplink differs between the units. Slave 1: 1550 ± 3 nm, Slave 2: 1510 ± 3 nm. The downlink
signal is the same for both repeaters.
Figure 4. Dual-color Fiber connections to two Repeaters
BTS
RepeatersOMU Units