3 Definitions and abbreviations

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

3.1 Definitions

For the purposes of the present document, the following terms and definitions apply.

Alarm: A notification, of the form defined by the alarm reporting function (ITU-T X.733 [9]), of a specific event.

Active resource: An active resource in the context of redundancy is equivalent to a primary resource.

Alarm report: A specific type of event report used to convey alarm information.

Outstanding alarm condition: The state in which the conditions that originated an alarm are still present in the system.

Anomaly: An anomaly is a discrepancy between the actual and desired characteristics of an item (ITU-T M.20 [1]). In the context of the present document, the item may also be external to the NE (e.g. : environmental alarm detector).

Asymmetric redundancy: A redundancy where the primary and secondary resources have different capabilities, and therefore cannot exchange their roles (where the secondary may take the primary role, but the primary may not take the secondary role). Once the faulty primary resource is repaired and restored to service a change back needs to be performed.

Back up: A back up resource is a secondary resource providing redundancy to a primary resource.

Backed up: A backed up resource is a primary resource which has a secondary resource providing redundancy.

Change-back: A change back is the reverse change over in an asymmetric redundancy to restore the resources into their original roles.

Change-over: Change over is the action within a system capable of supporting redundancy which results in a secondary resource taking over the primary role. In a symmetric redundancy, the primary resource may take the secondary role.

Cleared Alarm: An alarm notification with the perceived severity set to cleared.

Cold standby: A secondary resource that requires initialisation activity before it can provide backup capability is defined as being in a cold standby state (ITU-T X.751 [14]).

Counter: Counters are a management abstraction of an underlying process, which may be associated with a defined internal event in management information. The current value of a counter is incremented when this event occurs (see note). It can take any values in its range. When a counter reaches its maximum value, it wraps around and counts upwards from 0; overflow information is not in general retained. An additional notification may be defined for counters with wrap behaviour.

NOTE: The rule that a counter value can increase only in single increments is a descriptive convention that simplifies the description of a counter threshold. It does not imply that it will always be possible to observe each increment in the counter’s range, since the events counted may occur in rapid succession.

Counter Threshold: A counter threshold contains information about the level(s) and other characteristics related to the thresholding mechanism for a counter.

Defect: A defect is a limited interruption in the ability of an item to perform a required function. It may or may not lead to maintenance action depending on the results of additional analysis (M.20 [1]). In the context of the present document, the item may also be external to the NE (e.g. : environmental alarm detector).

Duplex redundancy: A duplex redundancy is a redundancy in which a given function can be performed by two resources: a primary resource and secondary resource (also known as active and standby resources respectively).

Failure: A failure is the termination of the ability of an item to perform a required function (M.20 [1]). In the context of the present document, the item may also be external to the NE (e.g. : environmental alarm detector).

NOTE: After a failure, the item has a fault (M.20 [1]).

Fault: A fault is the inability of an item to perform a required function, excluding that inability due to preventive maintenance, lack of external resources or planned actions.

NOTE: A fault is often the result of a failure of the item itself, but may exist without prior failure (M.20 [1]).

Gauge: The gauge is the management abstraction of the value of a dynamic variable, such as the number of connections currently operated by a protocol machine or the rate of change of a traffic counter. There is no restriction on what the dynamic variable may represent, within the constraints set out below. The value of the gauge is subject to change in either direction. The value of the increment or decrement is unconstrained, except that a change that would take the gauge beyond its minimum or maximum value, will leave the gauge value at its minimum or maximum value respectively, until it is subsequently again within the gauge range values.

Gauge Threshold: A gauge threshold contains information about the level(s) and other characteristics related to the thresholding mechanism for a gauge.

Hot standby: A secondary resource that is able to provide backup capability for a primary resource without the need for initialisation activity is defined as being in a hot standby state (X.751 [14]).

Least Replaceable Unit (LRU): The smallest piece of equipment that can be replaced by field service personnel.

N+K redundancy: A redundancy where a given function can be performed by N primary resources and K secondary resources. When a failure occurs on one of the N primary resources, one of the K secondary resources may take over the role of that faulty primary resource.

Primary object: A primary object is a managed object that represents a primary resource.

Primary resource: A primary resource (in a system capable of supporting redundancy) is a resource that is performing a given function. On failure of a primary resource a secondary resource may take over the role of the faulty primary resource. A primary resource may also be referred to as an "active" or "backed up" resource.

Primary role: A primary object being backed up in a redundancy relationship is defined as being in the primary role.

Redundancy: The capability of a system to perform fault tolerant functionality by means of spare resources (or groups of resources).

Secondary object: A secondary object is a managed object that represents a secondary resource.

Secondary resource: A secondary resource (in a system capable of supporting redundancy) is a resource that may back up a primary resource. A secondary resource may take over the role of a primary resource on failure of that resource. A secondary resource may also be referred to as a "standby" or "back up" resource.

Secondary role: A secondary object backing up in a redundancy relationship is defined as being in the secondary role.

Standby resource: A standby resource in the context of redundancy is equivalent to a secondary resource.

Symmetric redundancy: A redundancy where the primary and secondary resources have the same capabilities, and therefore each of the resources can exchange their roles (primary and secondary). Once the faulty resource is repaired and restored to service there is no need to perform a change back.

Thresholding: Thresholding is the general mechanism (based on counters or gauges) to generate a defined notification from numeric changes in the value(s) of a counter(s) or gauge(s). The defined notification is generated as a result of a value change crossing the threshold level of a counter or gauge.

Threshold Level: A threshold level is a value which a threshold mechanism compares with the value of a counter or gauge, to determine whether a defined notification is to be generated.

3.2 Abbreviations

For the purposes of the present document, the following abbreviations apply, in addition to those listed in GSM 01.04 [16]:

AO Associated Object

ACSE Association Control Service Element

ASN.1 Abstract Syntax Notation (number) 1

BSC Base Station Controller

BSS Base Station System

BTS Base Transceiver Station

CASC Current Alarm Summary Control

CMIS Common Management Information Service

CMISE Common Management Information Service Element

CMIP Common Management Information Protocol

EFD Event Forwarding Discriminator

FTAM File Transfer Access and Management

GDMO Guidelines for the Definition of Managed Objects

LRU Least Replaceable Unit

MIB Management Information Base

MOC Managed Object Class

MORT Managed Object Referring to Test

MOS Management Operations Schedule

NE Network Element

OAM Operation, Administration and Maintenance

OMC Operations and Maintenance Centre

OS Operations System

OSI Open Systems Interconnection

PLMN Public Land Mobile Network

QOS Quality of Service

ROSE Remote Operation Service Element

SFTC Simple File Transfer Control

TARR Test Action Request Receiver

TMN Telecommunications Management Network

TO Test Object