Content for TS 29.122 Word version: 17.4.0

1… 4.4… 4.4.3… 4.4.5… 4.4.7 4.4.8… 4.4.12… 5… 5.6… 5.8… 5.10… 5.12… 6…

4.4 Procedures over T8 reference point 4.4.1 Introduction 4.4.2 Monitoring Procedures
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4.4 Procedures over T8 reference point Word‑p. 24

4.4.1 Introduction Word‑p. 24

All procedures that operate across the T8 reference point, as specified in TS 23.682, are specified in the following subclauses.

4.4.2 Monitoring Procedures Word‑p. 24

4.4.2.1 General Word‑p. 24

These procedures are used to perform event monitoring functions via the T8 interface, which include:

Monitoring event configuration as specified in subclause 4.4.2.2;
Reporting of monitoring event as specified in subclause 4.4.2.3;
Network initiated notification of monitoring event cancellation as specified in subclause 4.4.2.4 ; and
Network initiated notifications of applied parameter configuration, as specified in subclause 4.4.2.5.

4.4.2.2 Monitoring Events Configuration Word‑p. 24

In order to subscribe to a new monitoring event configuration, the SCS/AS shall send an HTTP POST message to the SCEF targeting the resource "Monitoring Event Subscriptions". The body of the HTTP POST message shall include:

SCS/AS Identifier;
Monitoring Type;
Notification Destination Address; and
One of External Identifier, MSISDN or External Group Identifier. The External Identifier or the MSISDN identifies the subscription of an individual UE and the External Group Identifier points to a group of UEs.
In addition, the HTTP POST request may include:
- Maximum Number of Reports;
- Monitoring Duration indicated by the property "monitorExpireTime";
- Group Reporting Guard Time.
- Additional Monitoring Type(s), if the subscription request targets multiple event(s).

If the Subscription_modification feature is supported, the SCS/AS may send an HTTP PUT message in order to update an existing monitoring event subscription. The HTTP PUT request targets the resource "Individual Monitoring Event Subscription" replacing all properties in the existing configuration.

For one-time monitoring type of requests, the SCS/AS shall include the Maximum Number of Reports with a value set to 1 and not include the Monitoring Duration in the HTTP request message sent to the SCEF.

If the Partial_group_cancellation feature is supported, the SCS/AS may send an HTTP PATCH message in order to cancel certain UE(s) within an active group. The HTTP PATCH request targets the resource "Individual Monitoring Event Subscription" updates with the corresponding "excludedExternalIds" and/or "excludedMsisdns" attributes in the existing configuration.

Upon receipt of the HTTP POST, PUT or PATCH request message, if the SCS/AS is authorized to perform such request, the SCEF shall check whether the parameters (e.g. Maximum Number of Reports, Monitoring Duration, Maximum Latency, Maximum Response Time, Suggested number of downlink packets in POST or PUT request message) in the HTTP request body are within the range defined by operator policies. If one or more of these parameters are not within the range, the SCEF shall:

either reject the request message by sending an HTTP response to the SCS/AS with a status code set to 403 Forbidden and may include the "PARAMETER_OUT_OF_RANGE" error in the "cause" attribute of the "ProblemDetails" structure and indicate which parameters are out of the range in the "invalidParams" attribute of the "ProblemDetails" structure; or
modify the parameters which are not within the range by selecting different values which are in the range.

For individual UE configuration requests, the SCEF shall also check whether the Idle Status Indication is included for UE reachability event. If the Idle Status Indication is received in the request but not supported by the network, the SCEF may reject the request message by sending an HTTP response to the SCS/AS with a status code set to 403 Forbidden and may include the "IDLE_STATUS_UNSUPPORTED" error in the "cause" attribute of the "ProblemDetails" structure.

If the SCEF receives an HTTP POST request to create a subscription resource for a monitoring event, but without an indication of the support for the feature corresponding to the requested monitoring event, the SCEF shall reject the request by sending a "400 Bad Request" HTTP error response with the application error "EVENT_FEATURE_MISMATCH".

If the SCEF receives an HTTP POST request to create a subscription resource for a monitoring event that it does not support, the SCEF shall reject the request by sending a "500 Internal Server Error" HTTP error response with the application error "EVENT_UNSUPPORTED".

After validation, the SCEF shall store the parameters and

may assign an SCEF Reference ID related to the created monitoring event subscription resource; and based on operator policies, shall
- map the accuracy into permissible granularity for location reporting event;
- map the location area into a list of cells, eNodeB(s) and/or RAI(s)/TAI(s) and derive the corresponding MME(s)/SGSN(s), for number of UEs present in a geographic area event.

In order to delete a previous active configured monitoring event subscription at the SCEF, the SCS/AS shall send an HTTP DELETE message to the SCEF targeting the resource "Individual Monitoring Event Subscription" which is previously received in the response to the request that has created the monitoring events subscription resource. The SCEF shall detemine the SCEF Reference ID related to the active monitoring subscription resource.

4.4.2.2.2 Monitoring Events Configuration via HSS Word‑p. 25

4.4.2.2.2.1 General Word‑p. 25

The following monitoring events are applicable for the monitoring event configuration via HSS for an individual UE or a group of UEs:

Loss of connectivity;
UE reachability;
Location Reporting;
Change of IMSI-IMEI(SV) Association;
Roaming Status;
Communication Failure;
PDN connectivity status;
Availability after DDN Failure; and
API support capability.

Only one-time reporting is supported if the "reachabilityType" attribute sets to "SMS" for the event "UE reachability" or if the "locationType" attribute sets to "LAST_KNOWN_LOCATION" for the event "Location Reporting" in the monitoring event request.

4.4.2.2.2.2 Configuration Request for an individual UE Word‑p. 26

Upon receipt of a configuration request from the SCS/AS for an individual UE, the SCEF shall interact with the HSS via S6t, as specified in TS 29.336.

Upon receipt of a successful response from the HSS,

if it is a one-time monitoring request and the monitoring event report is received, the SCEF shall delete the associated configuration, send an HTTP response message to the SCS/AS with a "200 OK" status code and including the received monitoring event report(s) (more than one report may be provided if the "enNB" is supported).
otherwise, the SCEF shall,
- for an HTTP POST request, create a new "Individual Monitoring Event Subscription" resource addressed by the URI that contains the SCS/AS identifier and an SCEF-created subscription identifier, and send an HTTP response to the SCS/AS with a "201 Created" status code, containing the final suggested configuration parameter(s) (if modified), indication(s) of the discarded parameter(s) (if discarded), the monitoring event report(s) (more than one report may be provided if the "enNB" is supported), if received, and a location header field containing the URI of the created resource.
- for an HTTP PUT request, update the active "Individual Monitoring Event Subscription" resource addressed by the request URI and send an HTTP response to the SCS/AS with a "200 OK" status code, containing the final suggested configuration parameter(s) (if modified), indication(s) of the discarded parameter(s) (if discarded) and the monitoring event report(s) (more than one report may be provided if the "enNB" is supported), if received, or a "204 No Content" status code.
- for an HTTP DELETE request, delete the active "Individual Monitoring Event Subscription" resource addressed by the request URI and send an HTTP response to the SCS/AS with a "204 No Content" status code, or a "200 OK" status code and including the monitoring event report(s) (more than one report may be provided if the "enNB" is supported), if received.
If the SCEF receives a response with an error code from the HSS, the SCEF shall not create, update nor delete the concerned resource and respond to the SCS/AS with a corresponding failure code as described in subclause 5.2.6.

4.4.2.2.2.3 Configuration Request for a group of UEs Word‑p. 26

Upon receipt of a request from the SCS/AS including an External Group Identifier, then the monitoring configuration is for a group of UEs. The SCEF shall interact with the HSS via S6t as specified in TS 29.336.

Upon receipt of a successful response from the HSS indicating that group processing is in progress and before beginning the processing of individual UEs, the SCEF shall,

for an HTTP POST request, create a new "Individual Monitoring Event Subscription" resource addressed by a URI that contains the SCS/AS identity and an SCEF-created subscription identifier, store the number of UEs received in the response message from the HSS within the resource and send an HTTP response to the SCS/AS with "201 Created" status code and a location header field containing the URI of the created resource, in order to acknowledge the SCS/AS of the successful group processing request.
for an HTTP PUT request, update the active "Individual Monitoring Event Subscription" resource addressed by the request URL and send an HTTP response with "200 OK" status code to acknowledge the SCS/AS of the successful group processing request, or a "204 No Content" status code.
for an HTTP DELETE request, delete the active "Individual Monitoring Event Subscription" resource addressed by the request URI and send an HTTP response to the SCS/AS with "204 No Content" status code.

If the SCEF receives a response with an error code from the HSS, the SCEF shall not create, update nor delete the concerned resource and respond to the SCS/AS with a corresponding failure code as described in subclause 5.2.6.

Upon receipt of the processing result of the individual UEs from the HSS, the SCEF shall behave as follows:

if no Group Reporting Guard Time is received, the SCEF shall send an HTTP POST request message to the SCS/AS including a reference to the related monitoring subscription, a list of configuration failure result if received for the group members, and the "monitoringEventReports" attribute including a list of monitoring event reports if received for the group members;
otherwise, the SCEF shall accumulate all of the configuration results and/or monitoring event reports received from the HSS for the group members until the Group Reporting Guard Time expires. Then the SCEF shall send an HTTP POST request message to the SCS/AS including a reference to the related monitoring subscription, and a list of configuration failure result if received for the group members, and the "monitoringEventReports" attribute including a list of monitoring event reports at the Group Reporting Guard Time.
If the Partial_group_cancellation feature is supported,
- upon the cancellation of UE(s) within the active group identified by the "excludedExternalIds" and/or "excludedMsisdns" attributes is successful, the SCEF shall,
  - if the maximum number of reports applies to the monitoring event configuration of the cancelled UE(s), set the stored number of reports of the indicated UE(s) to the maximum number of reports;
  - still consider the rest of UE(s) as applicable within the active group based monitoring subscription to the group based Monitoring Event Report identified by the External Group Identifier;
  - determine whether the reporting for the group based event subscription is completed or not. If completed, the SCEF shall delete the corresponding "Individual Monitoring Event Subscription" resource with procedures as described in subclause 4.4.2.3.
If the cancellation of UE(s) within the active group is unsuccessful, the SCEF shall respond with proper error code indicating the error and should return the appropriate additional error information in the POST response body.

The SCS/AS shall send an HTTP response to acknowledge the SCEF about the handling result of the received HTTP POST request.

4.4.2.2.3 Monitoring Events Configuration directly via MME/SGSN Word‑p. 27

The monitoring event "Number of UEs in a geographic area" is applicable for the monitoring event configuration via MME/SGSN. Only one-time reporting is supported for this event with the value of Maximum Number of Reports indicated by "maximumNumberOfReports" set to 1.

Upon receipt of an HTTP POST request from the SCS/AS, the SCEF shall

resolve the location area to the involved SGSN(s)/MME(s) by local configuration;
interact with the HSS via the S6t interface as specified in TS 29.336 if the External Group ID(s) is included; and
interact with the SGSN(s)/MME(s) via the T6a/b inteface as specified in TS 29.128.

After collecting responses from the SGSN(s)/MME(s), if the SCEF does not receive any successful response from the involved SGSN(s)/MME(s), the SCEF shall respond to the SCS/AS with a corresponding failure code as described in subclause 5.2.6; otherwise the SCEF should send a response with 200 OK status code to acknowledge the SCS/AS with one aggregated report in the requested area by including the total count of the number of UEs in the "ueCount" attribute and the External Identifier(s) (if available) or the MSISDN(s) (if available) associated with the External Group ID.

4.4.2.2.4 Monitoring Events Configuration via PCRF Word‑p. 28

4.4.2.2.4.1 General Word‑p. 28

The following monitoring events: the location reporting event and communication failure event are applicable for the monitoring event configuration via PCRF for an individual UE.

If monitoring event configuration via PCRF is used for a subscription resource, the Subscription_modification feature cannot be supported.

Only the location reporting event is applicabe for the monitoring event configuration via PCRF for a group of UEs.

Only one-time reporting is supported for the monitoring event configuration via PCRF.

HTTP PUT is not supported for the monitoring event configuration via PCRF. If it is received, the SCEF shall reject the HTTP PUT message with 403 Forbidden during monitoring and may indicate the "OPERATION_PROHIBITED" error in the "cause" attribute of the "ProblemDetails" structure.

4.4.2.2.4.2 Configuration Request for an individual UE Word‑p. 28

Upon receipt of an HTTP POST request from the SCS/AS for an individual UE, the SCEF shall:

interact with the PCRF via the Rx inteface by using an existing AF session or establishing a new AF session as specified in TS 29.214;

NOTE 1:
The SCEF can derive the service information over the Rx interface based on SCS/AS ID for communication failure event.
after receiving the AAA message from the PCRF, create a resource which represents the monitoring event configuration addressed by a URI that contains the SCS/AS identifier and an SCEF-created subscription identifier; and
send a corresponding status code to acknowledge the SCS/AS of the successful processing of the request in the HTTP response message.

Then the SCEF shall wait for the reporting from the PCRF as specified in TS 29.214.

During configuration resource deletion, the SCEF shall also terminate the AF session if it was established and used only for event monitoring.

4.4.2.2.4.3 Configuration Request for a group of UEs Word‑p. 28

Upon receipt of an HTTP POST request from the SCS/AS for a group of UEs, the SCEF shall:

interact with all PCRFs in the same PLMN via Nta application of Nt interface as specified in TS 29.154;
after collecting ECA message from all PCRFs, create a resource which represents the monitoring event configuration, addressed by a URI that contains the SCS/AS identifier and an SCEF-created subscription identifier; and
send a corresponding status code to acknowledge the SCS/AS of the successful processing of the request in the HTTP response message.

Then the SCEF shall wait for the reporting from the PCRF(s) as specified in TS 29.154.

4.4.2.3 Reporting of Monitoring Event Procedure Word‑p. 28

Upon receipt of a Monitoring Event Report from the HSS or the MME/SGSN as defined in subclause 5.6.3 or subclause 5.6.8 of TS 23.682, from the PCRF as defined in subclause 5.6.5 or from the IWK-SCEF as defined in subclause 5.6.8 of TS 23.682, the SCEF shall determine the monitoring event subscription associated with the corresponding Monitoring Event Report.

If the monitoring event subscription refers to a Monitoring Event Configuration for a single UE or to a group-based Monitoring Event configuration, and no Group Reporting Guard Time was set, then the SCEF shall send an HTTP POST message including a link to the SCEF-created subscription resource and the received Monitoring Event Report to the identified destination. If the monitoring event subscription refers to a group-based Monitoring Event Configuration and Group Reporting Guard Time was provided during the Monitoring Event configuration procedure, then the SCEF shall accumulate all of the received Monitoring Event reports for the group of UEs until the Group Reporting Guard Time expires or the monitoring duration indicated by the property "monitorExpireTime" is reached.

Upon expiration of Group Reporting Guard Time or expiration of the monitoring duration, the SCEF shall send an HTTP POST message to the identified destination including a link to the SCEF-created subscription resource and the list of accumulated Monitoring Event Reports for each UE identified by either its External Identifier or MSISDN. The destination URL of the HTTP POST message is provided by the SCS/AS during the Monitoring Event Configuration procedure.

If the monitoring event subscription refers to a one-time monitoring request or a continuous monitoring request, but the maximum number of reports is reached, the SCEF shall consider the reporting as completed, delete the corresponding "Individual Monitoring Event Subscription" resource and send an HTTP POST message including the subscription identifier and a cancellation indication to the identified destination. The cancellation indication shall set to "true" indicating to cancel the configured monitoring subscription. The destination URL of the HTTP POST is provided by the SCS/AS during the Monitoring Event Configuration procedure. In addition, the SCEF shall interact with the HSS to delete the event configuration if the latter was performed via the HSS whereas event reports were performed via the SGSN/MME. The SCEF determines that the reporting for a group is completed by comparing the total number of received reports with the number of UEs of the group (received from the HSS during event configuration for a group of UEs) multiplied by the maximum number of reports.

If the Partial_group_cancellation feature is supported and one or more MSISDN(s) or External Identifier(s) within the active group based monitor subscription has been cancelled, the rest of UE(s) within the active group based monitoring subscription are still applicable to the group based Monitoring Event Report identified by the External Group Identifier.

When the monitoring duration indicated by the property "monitorExpireTime" is reached, the SCEF shall delete the related event subscription and event configuration locally. The SCS/AS shall no longer address the corresponding "Individual Monitoring Event Subscription" resource.

4.4.2.4 Network-initiated Explicit Monitoring Event Deletion Procedure Word‑p. 29

Upon receipt of an SCEF Reference ID for the event to be deleted from the HSS as defined in TS 29.336, the SCEF shall determine the subscription identifier associated with the indicated active monitoring subscription. Then the SCEF shall delete the related resource "Individual Monitoring Event Subscription", send an HTTP POST message including the subscription identifier and a cancellation indication to the identified destination. The cancellation indication shall set to "true" indicating to cancel the configured monitoring subscription. The destination URL of the HTTP POST is provided by the SCS/AS during the Monitoring Event Configuration procedure.

If the Partial_group_cancellation feature is supported, upon receipt of one or more MSISDN(s) or External Identifier(s) for the group member(s) to be cancelled within the active group based event subscription from the HSS as defined in TS 29.336, the SCEF shall,

if the maximum number of reports applies to the monitoring event configuration, set the stored number of reports of the indicated UE(s) to the maximum number of reports;
include the MSISDN(s) or External Identifier(s) to be cancelled in the MonitoringNotification Request to the destination URL provided by the SCS/AS during the Monitoring Event Configuration procedure; and
determine whether the reporting for the group based event subscription is completed or not. If completed, the SCEF shall delete the corresponding "Individual Monitoring Event Subscription" resource with procedures as described in subclause 4.4.2.3.

4.4.2.5 Network initiated notification of applied parameter configuration |R16| Word‑p. 30

For "LOSS_OF_CONNECTIVITY" and "UE_REACHABILITY" events, if the "Enhanced_param_config" feature is supported and the SCEF receives the currently applied parameter configuration from the HSS, the SCEF shall notify the SCS/AS via an HTTP POST message including the parameter changes in the "appliedParam" attribute.