User's Manual

Table Of Contents
Unit Descriptions - RF Path
CMA-331-AEN
Page 44
2.1.2 OIU
The OIU interfaces to the HEU/IHU, performs the RF to optic conversion of the received signal and distributes the wireless RF
services to the RAU units over the fiber optic infrastructure to the remote site. Each OIU supports up to 12 SM optic fibers (one
fiber
Figure 2-12. OIU Front Panel with Installed Modules
OIU hosts the following modules:
Module
Description
ACM
Auxiliary control module - provides interfaces for management of domestic modules via HCM;
Installed in HEUs’ in configurations with more than one HEU. See section
2.1.1.2.
OIM Optical interface module; converts the RF to three Optical links (see section 2.1.2.2)
FMM
Fiber main module; installed in an OIM slot at the main site; performs the RF-to-optic
conversion of the allocated service groups and transmits the cellular services along with 10
Gb Ethernet to the remote side where the FRM is installed.
OIX Optical interface expander; OIU to HEU interface module (see section 2.1.2.4).
Note: For configurations with one OIX an ETM (Expander termination module) is required for
terminating the unoccupied OIX slot. See section
2.1.1.6.
ETM
Expander termination module; For configurations with one RIX an ETM is required for
terminating the unused Expander slot. See section
2.1.1.6.