Reference Manual

Function Change
function change if the normal application software is valid, thus there is
always one application software available. If the normal application is
corrupt (or unavailable), the base application software is automatically
selected instead.
36.2.2 Software File Relation
Each Main RU visible via the A-bis interface is offered every software
file within the appropriate file package. The file revision of the offered
software file is compared with that of the software files already held in
non-volatile memory in order to determine whether download is
necessary or not. Download is carried out only when the file offered
has a different revision than the one held in RBS memory.
As an alternative to the above, unconditional download is also
supported. In this case, there are no conditions on File Revision, and so
forth, for the download.
36.2.3 Software File Download
The CMRU accepts the download of software files intended for all
Main RUs in the RBS.
A DMRU never accepts direct download of software files via A-bis,
since this must be done via the CMRU.
This arrangement means that only the files actually needed by each Main
RU are downloaded. Each individual file is downloaded only once, thus
minimising the software download time required. Note that this is an
improvement compared to the general A-bis concept; downloading a
software file several times, once for each Main RU needing it.
Loading software to a Main RU is allowed in any state, even while
operational.
The transfer of a software file is initiated and performed via the A-bis
interface. The CMRU stores the transferred software file in non-volatile
memory.
During software download to the central Main RU, appropriate software
files are transferred internally to the distributed Main RUs.
Only the software files, appropriate to a specific Distributed Main RU,
which are not already loaded on that RU are transferred. The software
files transferred are stored directly in the non volatile memory of a
Distributed Main RU.
36.2.4 Start Required
On completion of the internal distribution of software files, the RBS
informs the BSC that a restart of the RBS is necessary to activate the
new software.
36.2.5 Software Start
The activation of new software is ordered via the A-bis interface. When
the order is received, the software is copied from non-volatile memory
into volatile memory, where it is executed.
EN/LZT 720 0008 R1A
2001-06-26
275 (421)
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