User Manual

Architecture
Nortel Networks Confidential
3–24
PE/DCL/DD/0063
411–9001–063
Standard 12.07/EN September 2000
GSM/BSS V12
3.2.6.3 Management of the O&M protocol
This function provides the level 2 and 3 layers of the O&M protocol concerning
CSWM/gateway dialogue. The gateway is fully an O&M slave. It manages a
level–3 message dictionary.
3.2.6.4 Management of the defense
The software part of the gateway defense system essentially concerns detection of
minor and major faults which lead, respectively, to a ”light” software reset of certain
functions or passage to HALT state. A software watchdog system is also active.
3.2.6.5 Switchover management
The software’s role in switchover management is to send command codes to a
hardware logic circuit which controls gateway activation and de–activation.
3.2.6.6 Initialization
Initialization consists of configuring all peripherals present on the gateway board,
the communication controllers, the position of the GSM TIME channel, the
cross–connect matrix, and the transfer of certain initialization data from the PROM
to the RAM.
3.2.6.7 Multitasking organization
Most of the functions are not related to one another and therefore operate
completely asynchronously. In order for these functions to take place
simultaneously for the external environment, an internal function, transparent to the
outside, is needed to manage multitasking, hierarchized organization.
3.2.7 BCF configurations
The BCF exists in simplex or duplex configuration.
The following table gives the number of boards in every configuration.
Boards Simplex BCF Duplex BCF
CSWM 1 2 (1 active/1 passive)
PCMI 1 1 to 3
DSC 1 1 to 4
SYNC 1 2 (1 active/1 passive)
GTW 1 2 (1 active/1 passive)
Table 3–2 BCF configurations