B.3 Description of record fields

12.053GPPSubscriber Related Call and Event DataTS

This subclause contains a brief description of each field of the call and event records described in the previous subclause.

B.3.1 Additional Charging Information

This field consists of two parts, a charge indicator and additional charging parameters. The charge indicator is derived from the information contained within the ISUP "backward call indicator" and may be used to store a charge indicator (charge/no charge) received from another network node. The additional charging parameters are non-standard and intended to permit the inclusion of further charging information received from Intelligent Network and/or Value Added Service nodes.

B.3.2 AoC parameters / change of AoC parameters

The AoC parameter field contains the set of charge advice (AoC) parameters sent to the MS on call set-up. If further sets of parameters are sent during the call, as a result of a tariff switch-over for example, then this may be recorded in the Change of AoC Parameter field including the time at which the change occurred.

It should be noted that the Change of AoC Parms. field is optional and not required if partial records are generated on tariff switch-over.

The AoC parameters are defined in GSM 02.24 [12].

B.3.3 Basic Service / change of service / ISDN Basic Service

The basic service field contains the code of the basic service employed on call set-up. Any alteration to the basic service during the connection may be recorded in the change of service field including the time at which the change took place.

The change of service field is optional and may be omitted if partial records are created whenever the basic service is changed.

The coding of basic services is defined in detail in GSM 09.02 [17].

In the case of the transit record the GSM basic service employed is generally not available. However, if the device on which the call originates/terminates is connected via ISDN digital subscriber signalling then the appropriate ISDN basic service code may be recorded in the record. One possible example includes the direct connection of an ISDN PABX to an MSC/VLR.

B.3.4 Call duration

This field contains the relevant call duration in seconds. For incomplete calls (call attempts) the relevant duration is the call holding time from the seizure to the release of the traffic channel. For complete (answered) calls this is the chargeable duration from answer to release of the traffic channel. For partial records this is the duration of the individual partial record and not the cumulative duration of the call.

It should be noted that the time stamps may be expressed in terms of tenths of seconds or even milliseconds and, as a result, the calculation of the call duration may result in the rounding or truncation of the measured duration to a whole number of seconds.

Whether or not rounding or truncation is to be used is considered to be outside the scope of the present document subject to the following restrictions:

1) A call duration of zero seconds shall not be accepted.

2) The same method of truncation/rounding shall be applied to both single and partial records.

If CAMEL is invoked for the call and a control relationship is existing, the call might continue after a RELEASE or a DISCONNECT from the called party side received by the gsmSSF. The call duration of the incoming leg is stored in the main body of the call record. For each outgoing leg the call duration is stored in the respective ‘CAMELInformation’ module. If a call leg does not reach answer status and attempt charging is enabled a ‘CAMELInformation’ module containing the holding time is generated.

An example of how to use the call duration and the timestamps is given in Figure B.0. It shows a CAMEL controlled mobile originated follow-on scenario. The uppermost arrow  marks the over all duration of the call that is to be measured and stored in the main body of the respective MOC record. The duration before t5 (incoming leg) or t4 (outgoing leg) needs not to be stored since the call is answered later on. The call duration in the first outgoing leg module contains the time interval from t4 to t6 (period ). The call duration measurement of the second outleg is started with t9 and ended with t10 (interval ).

Since the last outgoing leg is not answered, the respective module contains the holding time starting with t11 and ending with t13 (period ).

(The timestamps t1, t2, t3, t7, t8 and t12 are mentioned for completion reasons only.)

Point in time

Signalling message sent/received

trigger detection point encountered

Duration logging

t1

SETUP; TDP(control)

t2

IAM

seizure of outg. leg 1

t3

ACM

t4

ANSWER

start of call duration (outg. leg 1)

t5

CONNECT

start of call duration (inc. leg)

t6

RELEASE; EDP(control)

stop of call duration (outg. leg 1)

t7

IAM

seizure of outg. leg 2

t8

ACM

t9

ANSWER

start of call duration (outg. leg 2)

t10

RELEASE; EDP(control)

stop of call duration (outg. leg 2)

t11

IAM

seizure of outg. leg 3

start of holding time (outg. leg 3)

t12

ACM

t13

RELEASE; EDP(control)

stop of holding time (outg. leg 3)

Figure B.0: Call duration measurement in follow-on scenarios

B.3.5 Call reference

This field uniquely identifies a call or transaction on one side of the interface (i.e. ‘A’ or ‘B’ side) and is derived from the transaction identifier of GSM 04.08 [16]. It is also used to identify all partial records and transactions belonging to the same connection.

For the avoidance of doubt, there is no global call reference defined within GSM and the call reference field cannot be used to combine, for example, the MOC and MTC records of a mobile‑to‑mobile connection.

B.3.5.1 Network call reference

Whenever CAMEL is applied, this field is used for correlation of call records outputted from the originating MSC (when applicable), the GMSC and the terminating MSC, and a network optional call record from the gsmSCF.

B.3.6 Calling / called / connected / translated number

In general a CCITT E.164 [2] number but may also include other numbering plans e.g. X.121. Each of these fields includes the type of number and number plan as specified in detail in GSM 04.08 [16]. Where appropriate, these fields may also contain the presentation and screening information also specified in GSM 04.08 [16].

The called number is the number received from the mobile station on mobile originated call set-up as defined in GSM 04.08 [16]. Similarly, the calling number is the number received from the network on mobile terminated call set-up. In case of CAMEL initiated CF, the called (forwarded-to) number is returned by CAMEL.

The translated number is the result of any digit translation performed by the MSC on the called number received from the mobile station on mobile originated call set-up.

The connected number is the number of the actual party reached as defined in GSM 04.08 [16]. Although this is normally identical to the called number it may differ.

The following examples are intended to explain the use of these fields:

Example 1: Called Number = Connected Number

Normal call from a mobile subscriber to a mobile subscriber or to a PSTN subscriber.

Example 2: Called Number != Connected Number

In case of routing to a PABX with Automatic Call Distribution or to an ISDN Basic Access with several devices attached. The connected number is that of the party actually reached. N.B. The recording of the actual number connected may be limited by the capability of intermediate signalling connections.

Example 3: MTC record for Call Forwarding ("A" -> "B" -> "C")

In case of call forwarding, the connected number recorded in the MTC record of the "B" subscriber is that of the forwarded-to party or "C" subscriber. The calling party field contains the number of the "A" subscriber.

Example 4: Translated Number

This field is only present if digit translation is applied by the MSC to the called number received from the mobile station. Examples include abbreviated dialling codes and service numbers.

B.3.7 CAMEL call leg information

This field contains a set of CAMEL information IEs according to the number of outgoing CAMEL call legs.

B.3.8 CAMEL information

This field contains a list of parameters with information related to one CAMEL outgoing call leg.

As a network option, parameters that are identical to the corresponding values in the top level structure of the record are not recorded again. That means whenever a value is not mentioned in this set the value provided in the basic record is valid instead. This might lead to an empty or even absent structure, if no parameter was modified.

B.3.9 CAMEL initiated CF indicator

The purpose of this field is to destinguish CAMEL call forwarding service scenarios from standard GSM call forwarding scenarioes.

From the BCSM’s point of view this field is set to ‘CF’ whenever the O_CSI was applied after terminating CAMEL call processing had been taken place changing the call destination. For the avoidance of doubt: this flag does not depend on other modified call parameter(s) (e.g.: redirection information, e.t.c.) received in the CAP_CONNECT message of the T_CSI service.

This flag also indicates that another record might be generated, one containing the charging information related to the terminating CAMEL service and one containing the charging information related to the originating CAMEL service.

B.3.10 Cause for termination

This field contains a generalised reason for the release of the connection including the following:

– normal release;

– CAMEL initiated call release;

– partial record generation;

– partial record call re-establishment;

– unsuccessful call attempt;

– abnormal termination during the stable phase.

A more detailed reason may be found in the diagnostics field.

B.3.11 Data volume

This field includes the number of 64 octet segments transmitted during the use of data services if known (see B.1.3 Packet Data Services).

B.3.12 Diagnostics

This field includes a more detailed technical reason for the release of the connection and may contain one of the following:

– a MAP error from GSM 09.02 [17];

– a Cause from GSM 04.08 [16];

– a Cause from GSM 09.78 [23];

– a Cause from ISUP Q.767.

The diagnostics may also be extended to include manufacturer and network specific information.

B.3.13 Free format data

This field contains charging information sent by the gsmSCF in the FCI message as defined in GSM 09.78. This data is transferred transparently in the CAMEL sections of the relevant call records. ‘Free format data‘ sent to the legID=1 is always stored in the top level of the respective record. ‘Free format data‘ sent to the legID >1 is stored in the appropriate CAMEL call leg information field.

If the FCI is received more then once during one continuing incoming/outgoing CAMEL call leg, the information of the last FCI received is stored in the relevant record.

In the event of partial output the currently valid ‘Free format data’ is stored in the partial record.

B.3.14 Equipment id.

This field contains a local identifier used to distinguish between equipment of the same equipment type e.g. the number of the conference circuit employed if more than one is available.

B.3.15 Equipment type

This field contains the type of common equipment employed e.g. conference circuit for multi-party service.

B.3.16 Event time stamps

These fields contain the event time stamps relevant for each of the individual record types.

The call records may contain three significant call handling time stamps:

– The time at which the resource in question was seized (Seizure time)

– The time at which the call was answered or at which charging commences. (Answer time)

– The time at which the resource was released (Release time)

For both Mobile Originated and Mobile Terminated calls, the Seizure time is the time at which the traffic channel is allocated i.e. the time at which the ASSIGN COMMAND message is sent to the MS.

For Mobile Originated calls the Answer time is the time at which the CONNECT message is sent to the calling party. For Mobile Terminated calls the time at which the CONNECT message is received from the called party. However, if the subscriber has subscribed to the advice of charge charging level service, then the answer time shall be derived from the time at which the FACILITY message is received from the MS containing the acknowledgement of receipt of the AOC parameters. Similarly, if the AOC parameters are changed during the call then the change time recorded for a subscriber with AOC charging level is the receipt of the FACILITY message from the MS. For a subscriber with AOC information level the change time recorded is the time at which the FACILITY is sent to the MS. Finally, in case of call re-establishment (see subclause B.1.5) the answer time is the time at which the new traffic channel is allocated by the MSC i.e. when the ASSIGN COMMAND is sent to the MS.

The Release time is the time at which the connection is released by either party i.e. a DISCONNECT or RELEASE is sent by the network or a DISCONNECT is received from the MS. In the case of a radio link failure, the release time is the time at which the failure was detected by the MSC.

For unsuccessful call attempts the Seizure time is mandatory. The Release time is optional and the call duration recorded is the call holding time i.e. the difference between the two.

For successful calls the Answer time is mandatory and both the Seizure and Release times are optional. The call duration recorded is the chargeable duration i.e. the difference between the Answer and Release time stamps.

The event records include the following time stamps:

– HLR-int time: The receipt of a MAP_SEND_ROUTING_INFO request by the HLR.

– Loc.Upd. time: The receipt of a MAP_UPDATE_LOCATION_AREA request by the VLR or the receipt of a MAP_UPDATE_LOCATION request by the HLR.

– SS-Action: The receipt of a supplementary service request by the VLR.

e.g. MAP_REGISTER_SS, MAP_INVOKE_SS

– SMS-MO: The receipt of an RP_DATA message from the MS containing an SMS_SUBMIT PDU.

– SMS-MT: The transmission of an RP_DATA message to the MS containing anSMS_DELIVER PDU.

It should be noted that the events listed above are only examples in order to demonstrate the principles and that the list is by no means exhaustive.

All time-stamps include a minimum of date, hour, minute and second.

B.3.17 HSCSD parameters / Change of HSCSD parameters

The basic HSCSD parameters are negotiated between the MS and the network at call setup time. They comprise of the following parameters:

– the FNUR (Fixed Network User Rate) (optionally)

– the total AIUR (Air Interface User Rate) requested by the MS (for non-transparent HSCSD connections only)

– a list of the channel codings accepted by the MS

– the maximum number of traffic channels accepted by the MS (this is noted in the channels requested field)

– the channel coding and the number of traffic channels actually used for the call.

In case the network or user initiated modification procedure takes place during the call, the AIUR requested, the channel coding used and the number of traffic channel requested/used might be recorded in the Change of HSCSD parameters field including the time at which the change occurred and which entity requested the change.

It should be noted that the Change of HSCSD Parameters field is optional and not required if partial records are generated when a Change of HSCSD Parameters takes place.

B.3.18 Incoming/ outgoing trunk group

The incoming trunk group describes the trunk on which the call originates as seen from the MSC. For mobile originated calls this will generally be a BSS trunk. Similarly, the outgoing trunk group describes the trunk on which the call leaves the MSC.

B.3.19 Interrogation result

This field contains the result of the HLR interrogation attempt as defined in the MAP (GSM 09.02 [17]).

NOTE: This field is only provided if the attempted interrogation was unsuccessful.

B.3.20 Level of CAMEL service

This field describes briefly the complexity of CAMEL invocation.

– ‘Basic’ means that CAMEL feature is invoked during the setup phase (e.g.: to modify the destination) of the call only.

– ‘Online charging’ means that CAMEL supported AoC parameter were sent to the mobile station (SCI is received from the gsmSCF).

– The flag ‘call duration supervision’ is set whenever the call duration supervision is applied in the gsmSSF of the VPLMN (apply charging message is received from the gsmSCF).

B.3.21 Location / change of location

The location field contains a combination of the location area code (LAC) and cell identity (CI) of the cell in which the served party is currently located. Any change of location may be recorded in the change of location field including the time at which the change took place.

The change of location field is optional and not required if partial records are generated when the location changes.

The LAC and CI are both 2 octet quantities and coded according to GSM 04.08 [16].

B.3.22 Message reference

This field contains a unique message reference number allocated by the mobile station when transmitting a short message to the service centre. This field corresponds to the TP-Message-Reference element of the SMS_SUBMIT PDU defined in GSM 03.40 [15].

B.3.23 Mobile station classmark / change of classmark

This MS classmark field contains the mobile station classmark employed by the served MS on call set-up as defined in GSM 04.08 [16] (see mobile station classmark 2). Any alteration in the classmark during the connection may be recorded in the change of classmark field and will include the time at which the change took place.

It should be noted that the change of classmark field is optional and not required if partial records are created when the classmark is altered.

B.3.24 Entity number

This field contains the CCITT E.164 [2] number assigned to the entity (MSC, VLR, HLR etc.) that produced the record. For further details concerning the structure of MSC and location register numbers see GSM 03.03 [14].

B.3.25 Number of forwarding

This field, if provided via ISUP signalling, contains the number of times a call has been forwarded prior to the interrogation of the HLR and is defined in GSM 09.02 [17].

B.3.26 Old /new location

These fields contain the location of a mobile subscriber before and after a location update. In case of VLR location update the location information consists of a VMSC number and location area code. In case of HLR location update the field contains the VMSC number and the VLR number.

B.3.27 Radio channel requested / rad. channel used / change of rad. channel / speech version supported / speech version used

The radio channel requested field contains the type of channel requested by the user. The following values are permitted:

– full rate;

– half rate;

– dual mode half rate preferred;

– dual mode full rate preferred.

The radio channel used field indicates the type of traffic channel actually employed for the connection i.e. either full rate (Bm) or half rate (Lm) as described in GSM 05.01. Any change in the type of channel used may be recorded in the change of radio channel used field including the time at which the change occurred and the speech version used after the change of radio channel.

The speech version supported field contains the speech version supported by the MS with the highest priority. The speech version used field contains the speech codec version assigned for that call. The coding is according GSM 08.08 speech version identifier with the extension bit 8 set to 0.

It should be noted that the change of radio channel field is optional and not required if partial records are generated.

B.3.28 Record extensions

The field enables network operators and/ or manufacturers to add their own extensions to the standard record definitions. This field contains a set of "management extensions" as defined in CCITT X.721 [5].

B.3.29 Record type

The field identifies the type of the record e.g. mobile originated, mobile terminated etc.

B.3.30 Routing number / roaming number

The routing number field of the HLR interrogation record contains either a mobile station roaming number or, in case of call forwarding, a forwarded-to number.

The roaming number field of the MOC record contains the mobile subscriber roaming number as defined in GSM 03.03 [14] and coded according to GSM 09.02 [17].

B.3.31 Sequence number

This field contains a running sequence number employed to link the partial records generated for a particular connection (see A.1.2 Partial records).

B.3.32 Served IMEI

This fields contains the international mobile equipment identity (IMEI) of the equipment served. The term "served" equipment is used to describe the ME involved in the transaction recorded e.g. the called ME in case of an MTC record.

The structure of the IMEI is defined in GSM 03.03 [14].

B.3.33 Served IMSI

This fields contains the international mobile subscriber identity (IMSI) of the served party. The term "served" party is used to describe the mobile subscriber involved in the transaction recorded e.g. the calling subscriber in case of an MOC record.

The structure of the IMSI is defined in GSM 03.03 [14].

B.3.34 Served MSISDN

This fields contains the mobile station ISDN number (MSISDN) of the served party. The term "served" party is used to describe the mobile subscriber involved in the transaction recorded e.g. the called subscriber in case of an MTC record. In case of multi-numbering the MSISDN stored in a MOC record will be the primary MSISDN of the calling party.

The structure of the MSISDN is defined in GSM 03.03 [14].

B.3.35 Service centre address

This field contains a CCITT E.164 [2] number identifying a particular service centre e.g. short message service centre (see GSM 03.40 [15]).

B.3.36 Short message service result

This field contains the result of an attempt to deliver a short message either to a service centre or to a mobile subscriber (see GSM 09.02 [17]). Note that this field is only provided if the attempted delivery was unsuccessful.

B.3.37 Supplementary service(s)

The supplementary service field in the Supplementary Service record type contains the code of the supplementary service on which the action was performed.

The supplementary services field in the MOC / MTC records contains the codes of the supplementary services invoked as a result of, or during, a connection.

The coding of supplementary service is described in detail in GSM 09.02 [17].

B.3.38 Supplementary service action

This field contains the type of supplementary service action requested by the subscriber or performed by the network. Possible values include:

– registration;

– erasure;

– activation;

– deactivation;

– interrogation;

– invocation.

For further details see GSM 02.04.

B.3.39 Supplementary service action result

This field contains the result of an attempted supplementary service action (see GSM 09.02 [17]). Note that this field is only provided if the SS-action was at least partially unsuccessful.

B.3.40 Supplementary service parameters

This field contains the parameters associated with a supplementary service action requested by the subscriber. For further details of the parameters involved see the GSM 02.8n series of documents.

B.3.41 Transparency indicator

This field indicates whether the basic service was employed in transparent or non-transparent mode. It should also be noted that this field is only relevant for those services which may be operated in both transparent and non-transparent modes.

B.3.42 Update result

This field contains the result of the location update request as defined in the MAP (GSM 09.02 [17]). Note that this field is only provided if the attempted update was unsuccessful.