Functions - Ericsson CME 20 R6.1 Reference Manual

Operation and Maintenance Support
Passive RU
Replaceable unit (RU)
Sub-RU
24.2

Functions

24.2.1 Local/Remote Mode
Each Main RU and associated Sub-RUs can be put or removed from
operation locally on site via the local/remote mode function. An RU in
local mode does not have communication with the BSC over the A-bis
interface and is therefore not in operation.
On the cabinet there is a visual indication of current local/remote mode
status for CMRU. There is also a button to toggle between the two
modes.
When a Main RU, which has a direct signalling link to the BSC, is put
into operation for the first time (after manufacture), this must be done
manually using the local/remote button.
When an RU switches from remote mode to local mode, the BSC is
informed by raising a class 1 external condition. Communication with
the BSC is then terminated by disconnecting the A-bis OML and RSL
on layer 2.
When an RU switches from local to remote mode, the RU accepts the
A-bis OML and RSL re-establishment on layer 2. The external
condition originally reported to the BSC is ceased internally, but not
reported to the BSC.
24.2.2 Remote Operational Indication
The operational indicator associated with the micro RBS RU is under
BSC control when the RU is in remote mode.
154 (306)
This is a means of describing the RBS in a
function-oriented way, and a logical model
of the RBS in terms of MOs is built in the
BSC. All O&M actions are based on this
logical model structure created in the BSC.
An MO does not necessarily have a one-
to-one relationship with a physical unit in
the RBS, and the MO comprises both
hardware and software
An RU with a very low level of
intelligence. It is independent of the
processor system and has no connection
for O&M communication.
The smallest unit that can be handled on
site or in a repair center. Information
about the RU can be retrieved via OMT or
BSC.
A sub—replaceable unit is always
connected to a superior Main RU. This
connection is used for retrieval of
equipment information. A Sub-RU
normally does not have a processor.
© Ericsson Radio Systems AB
— All Rights Reserved —
EN/LZT 123 2697 R5A
1998-08-13