8 Creation of Trace Records

3GPP52.008GSM subscriber and equipment traceRelease 17Telecommunication managementTS

Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM

As has already been stated, the sequence of events for the creation of a trace record is as follows:

1) Trace is activated for a particular IMSI or IMEI.

2) The subscriber undertakes such action as to cause an invoking event to start.

3) The compilation of a trace record commences in the NEF as described in the Trace Type and under the control of the traceRecord attribute recordCriteria. This allows trace records to be produced at times other than when the invoking event ends, e.g. after a specific event has occurred.

4) If a further invoking event occurs trace data related to this event is collected in the same trace record.

5) All invoking events end or the recordCriteria attribute is satisfied, (see 3) above), or for the BSS only, an MSC INVOKE TRACE message is received with the BSS record type field set to "No BSS Trace" and the message relates to an ongoing trace.

6) The record is forwarded to the OSF or local filestore (depending on priority).

In certain circumstances it may be undesirable for the invoking event to have to end before the record is forwarded to the OSF or local filestore. Examples of these circumstances may be:

1) The operator requires to know a subscriber’s whereabouts at the moment he starts making a call.

2) The operator requires to know when a handover occurs, as soon as it occurs.

3) The buffer in the NEF may be too full to contain any more trace record data.

This is resolved through the use of the attribute recordCriteria in the traceControl object. When this attribute is set to anything other than noCriteria, records are forwarded to either the filestore or the OSF as soon as the specified criteria is satisfied.

8.1 Trace Record Control

8.1.1 General

The trace record collection and generation processes are controlled by the traceControl managed object class. There shall be one, and only one, instance of this object class for each NEF that supports the trace function. This object carries out the following functions:

1) to cause the data to be collected in the NEF as defined by the Trace Type;

2) to define the criteria by which records are generated;

3) to generate the trace record notifications.

The system management functions are:

– Create traceControl;

– Delete traceControl;

– Get Attribute;

– Set Attribute.

The notifications are:

– stateChange;

– objectCreation;

– objectDeletion;

– attributeValueChange;

– traceReport.

8.1.2 Attributes

There is one instance of this object class in each NEF that supports the trace function. It contains the following attributes:

Name	M/O	Value‑Set
traceControlId	RDN	Single
administrativeState	M	Single
operationalState	M	Single
recordCriteria	M	Single
eventTypes	O	Single

traceControlId

This attribute is a unique identifier for the traceControl MOI in the NEF and is used as an RDN.

administrativeState

This attribute defines the administrative state of the traceControl MOI in the NEF (Recommendation X.731 [16]).

operationalState

This attribute defines the operational status of the traceControl MOI in the NEF (Recommendation X.731 [16]).

recordCriteria

This attribute, if set, defines the criteria by which trace records are generated in the NEF. It may have one or more of the following values:

noCriteria	The NEF will not output trace records of the event type.

event	The NEF will output a trace record every time a particular recordable event occurs, the nature of that event being defined in the attribute eventTypes.

In all cases, a trace record will be produced at the end of the invoking event, or if other criteria are set by the manufacturer, when these criteria are met.

eventTypes

This attribute defines a set of recordable events, the appearance of any will trigger a trace record to be output, assuming the "event" value is set in the recordCriteria attribute.

8.1.3 Other Trace Record Criteria

Regardless of the trace record criteria set by the operator, there are circumstances under which a trace record may be generated, with the criteria being set by the manufacturer. These will usually be due to a lack of resources such as "Buffer Full" or "Processor Overload".