A.2 Probable causes

12.113GPPFault management of the Base Station System (BSS)TS

The probable cause is a parameter contained in the alarm notification. It specifies the most probable cause of the alarm. The syntax of the probable cause parameter is defined in ITU-T X.721 [6], and the semantics (use and meaning) in X.733.

The actual value assignments for the possible (and recommended) probable causes for the scope of GSM fault management are defined in X.721/X.733, M.3100 and this annex.

In a network element, the managed objects which generate alarm notifications shall in their respective MOCs’ definitions include the relevant alarm notifications defined in ITU-T X.721 or, alternatively, the general packages equipmentRelatedAlarmPackage and/or functionalRelatedAlarmPackage defined in GSM 12.20 [22]. Further, they should include the list of the probable cause values that they use in their behaviour definitions.

The syntax for the definition of the probable causes is a choice of two ASN.1 types: ‘global value’ and ‘local value’.

– The global value type probable cause is defined as a unique object identifier. A list of global values is defined by ITU-T X.721. Additional global values may be defined and registered following the standard procedures defined in ITU-T X.208.

– The local value type probable cause is defined as an integer. To assure the interoperability within the TMN networks, the ITU-T M.3100 [2] has defined standard values for the local value probable cause to be used within the TMN application context, and all additional probable causes defined in any other specifications must use the global value type. The TMN application context defined in ITU-T M.3100 has (by definition) all the capabilities of the Systems management application context defined by ITU-T X.701 [5] and, in addition, the ITU-T M.3100 definition of the local value type probable cause.

Further, some of the generic probable causes defined in X.721/X.733 and M.3100 are suitable for use in GSM/BSS alarm notifications, but these probable causes alone are insufficient to support all the needs of a GSM/BSS network element. Therefore, some more GSM/BSS specific probable causes have been defined in this annex, of the global value type as specified in M.3100.

Finally, all probable causes identified as relevant for use within the scope of GSM fault management, referring to X.721/733, M.3100 or GSM 12.11 definitions, are listed in the table below. The columns 2-4 identify in which specifications these probable causes are defined. The formal value assignments are specified in the ASN.1 module; see section A.3.

Where the probable cause is defined in M.3100 as well as X.721/X.733 or GSM 12.11, then the present document recommends the use of the probable cause from either the X.721/X.733 or GSM 12.11 specification.

Table 4: Probable causes

Probable Cause

GSM 12.11

X.721/

X.733

M.3100

Example Object Classes
(See notes 1 and 2)

Alarm Type
(see note 3)

A-bis to BTS interface failure

X

lapdLink, pcmCircuit

EQP

A-bis to TRX interface failure

X

lapdLink, pcmCircuit

EQP

Antenna problem

X

X

bts, equipmentMOC

EQP

Battery breakdown

X

bts, basebandTransceiver,

radioCarrier, equipmentMOC

EQP

Battery charging fault

X

X

bts, basebandTransceiver,

radioCarrier, equipmentMOC

EQP

Clock synchronisation problem

X

bsc, bts, transcoder,

equipmentMOC

EQP

Combiner problem

X

bts, equipmentMOC

EQP

Disk problem

X

X

bsc, bts, transcoder,

equipmentMOC

EQP

Equipment failure

X

bsc, bts, transcoder,

equipmentMOC

EQP

Excessive receiver temperature

X

radioCarrier

EQP

Excessive transmitter output power

X

radioCarrier

EQP

Excessive transmitter temperature

X

radioCarrier

EQP

Frequency hopping degraded

X

bts, frequencyHoppingSystem

EQP

Frequency hopping failure

X

X

bts, frequencyHoppingSystem

EQP

Frequency redefinition failed

X

bts, frequencyHoppingSystem

EQP

I/O device error

X

X

bsc, bts, transcoder,

equipmentMOC

EQP

Line interface failure

X

bsc, bts, transcoder, pcmCircuit equipmentMOC

EQP

Link failure

X

bsc, bts, transcoder, pcmCircuit,

lapdLink , equipmentMOC

EQP

Loss of synchronisation

X

X

bts, btsSiteManager, transcoder

EQP

Lost redundancy

X

X

bts

EQP

Mains breakdown with battery back-up

X

bts, basebandTransceiver,

radioCarrier, equipmentMOC

EQP

Mains breakdown without battery back-up

X

bts, basebandTransceiver,

radioCarrier, equipmentMOC

EQP

Power supply failure

X

X

bts, basebandTransceiver,

radioCarrier, equipmentMOC

EQP

Processor problem

X

bsc, bts, transcoder,

equipmentMOC

EQP

Receiver antenna fault

X

X

radioCarrier

EQP

Receiver failure

X

X

X

radioCarrier

EQP

Receiver multicoupler failure

X

radioCarrier

EQP

Receiver problem

X

bsc, bts, transcoder,

equipmentMOC

EQP

Reduced transmitter output power

X

radioCarrier

EQP

Signal quality evaluation fault

X

X

bts, basebandTransceiver,

radioCarrier

EQP

Timeslot hardware failure

X

lapdlink, transcoder,

pcmCircuit, channel

EQP

Timing problem

X

bsc, bts, transcoder,

equipmentMOC

EQP

Transceiver problem

X

X

bsc, bts, transcoder,

equipmentMOC

EQP

Transcoder problem

X

bsc, bts, transcoder,

equipmentMOC

EQP

Transcoder or rate adapter problem

X

transcoder, equipmentMOC

EQP

(continued)

Table 4 (continued): Probable causes

Probable Cause

GSM 12.11

X.721/

X.733

M.3100

Example Object Classes
(See notes 1 and 2)

Alarm Type
(see note 3)

Transmitter antenna failure

X

radioCarrier

EQP

Transmitter antenna not adjusted

X

radioCarrier

EQP

Transmitter failure

X

radioCarrier

EQP

Transmitter low voltage or current

X

radioCarrier

EQP

Transmitter off frequency

X

radioCarrier

EQP

Transmitter problem

X

bsc, bts, transcoder,

equipmentMOC

EQP

Application subsystem failure

X

X

replaceableSoftwareUnit

PROC

Configuration or customisation error

X

X

replaceableSoftwareUnit

PROC

Corrupt data

X

replaceableSoftwareUnit

PROC

CPU cycles limit exceeded

X

replaceableSoftwareUnit,

equipmentMOC

PROC

Database inconsistency

X

X

replaceableSoftwareUnit

PROC

File error

X

X

replaceableSoftwareUnit

PROC

File system call unsuccessful

X

replaceableSoftwareUnit

PROC

Input parameter out of range

X

replaceableSoftwareUnit

PROC

Invalid parameter

X

X

replaceableSoftwareUnit

PROC

Invalid pointer

X

replaceableSoftwareUnit

PROC

Message not expected

X

replaceableSoftwareUnit

PROC

Message not initialised

X

replaceableSoftwareUnit

PROC

Message out of sequence

X

replaceableSoftwareUnit

PROC

Out of memory

X

X

replaceableSoftwareUnit,

equipmentMOC

PROC

Software error

X

X

replaceableSoftwareUnit

PROC

Software program abnormally

terminated

X

replaceableSoftwareUnit

PROC

Storage capacity problem

X

replaceableSoftwareUnit,

equipmentMOC

PROC

System call unsuccessful

X

replaceableSoftwareUnit

PROC

Timeout expired

X

X

replaceableSoftwareUnit

PROC

Underlying resource unavailable

X

X

replaceableSoftwareUnit,

equipmentMOC

PROC

Variable out of range

X

replaceableSoftwareUnit

PROC

Version mismatch

X

X

replaceableSoftwareUnit,

equipmentMOC

PROC

Watch dog timer expired

X

replaceableSoftwareUnit,

equipmentMOC

PROC

Cooling system failure

X

X

btsSiteManager, bts, bsc, transcoder

ENV

Enclosure door open

X

btsSiteManager, bts, bsc, transcoder

ENV

External equipment failure

X

X

btsSiteManager, bts, bsc, transcoder

ENV

External power supply failure

X

btsSiteManager, bts, bsc, transcoder

ENV

External transmission device failure

X

btsSiteManager, bts, bsc, transcoder

ENV

Fan failure

X

btsSiteManager, bts, bsc, transcoder

ENV

Fire detected

X

btsSiteManager, bts, bsc, transcoder

ENV

Flood detected

X

btsSiteManager, bts, bsc, transcoder

ENV

High humidity

X

bts, btsSiteManager, bsc, transcoder

ENV

High temperature

X

bts, btsSiteManager, bsc, transcoder

ENV

Humidity unacceptable

X

bts, btsSiteManager, bsc, transcoder

ENV

Intrusion detected

X

btsSiteManager, bts, bsc, transcoder

ENV

Low humidity

X

bts, btsSiteManager, bsc, transcoder

ENV

Low temperature

X

bts, btsSiteManager, bsc, transcoder

ENV

Smoke detected

X

btsSiteManager, bts, bsc, transcoder

ENV

Temperature unacceptable

X

bts, btsSiteManager, bsc, transcoder

ENV

(continued)

Table 4 (concluded): Probable causes

Probable Cause

GSM 12.11

X.721/

X.733

M.3100

Example Object Classes
(See notes 1 and 2)

Alarm Type
(see note 3)

Bandwidth reduced

X

X

btsSiteManager, bts, bsc, transcoder

QOS

Congestion

X

X

btsSiteManager, bts, bsc, transcoder

QOS

Excessive BER

X

btsSiteManager, bts, bsc, transcoder

QOS

Excessive response time

X

X

btsSiteManager, bts, bsc, transcoder

QOS

Excessive retransmission rate

X

X

btsSiteManager, bts, bsc, transcoder

QOS

Reduced alarm reporting

X

eventForwardingDiscriminator

QOS

Reduced event reporting

X

eventForwardingDiscriminator

QOS

Reduced logging capability

X

X

log

QOS

System resources overload

X

X

btsSiteManager, bts, bsc, transcoder

QOS

Threshold crossed

X

btsSiteManager, bts, bsc, transcoder

QOS

Broadcast channel failure

X

X

bts

COM

Call establishment error

X

bsc

COM

Connection establishment error

X

X

bsc, bts, transcoder

COM

Framing error

X

pcmCircuit, radioCarrier, bts,

transcoder

COM

Invalid message received

X

X

btsSiteManager, bts, bsc, transcoder

COM

Invalid MSU received

X

bsc

COM

LAPD link protocol failure

X

lapdLink, btsSiteManager, bts, bsc, transcoder

COM

Local alarm indication

X

pcmCircuit

COM

Local node transmission error

X

X

bsc

COM

Loss of frame

X

pcmCircuit, radioCarrier

COM

Loss of signal

X

pcmCircuit, radioCarrier

COM

Remote alarm indication

X

pcmCircuit

COM

Remote node transmission error

X

X

bsc

COM

Routing failure

X

X

btsSiteManager, bts, bsc, transcoder

COM

SS7 protocol failure

X

bsc

COM

Transmission error

X

btsSiteManager, bts, bsc, transcoder,

lapdLink, equipmentMOC, radioCarrier

COM

NOTE 1: In this column, for each probable cause there is a list of one or more managed object classes defined in GSM 12.20 [22] that should use that probable cause. This, however, does not put any limitation on the use of the probable causes. In other words, any managed object can use any of the above probable causes, as long as it includes the correct notifications.

NOTE 2: The object class "equipmentMOC" stands for any manufacturer-defined MOC derived from the "gsmEquipment" MOC (defined in 12.20), or it is equivalent to the "gsmEquipment" MOC, if directly used for instantiation.

NOTE 3: In this column, an alarm type is associated with each probable cause. According to ITU-T X.733, there are five alarm types: Communications alarm (COM); Quality of Service alarm (QOS); Processing Error alarm (PROC); Equipment alarm (EQP); Environmental alarm (ENV).