8 M2AP Procedures

36.4433GPPEvolved Universal Terrestrial Radio Access Network (E-UTRAN)M2 Application Protocol (M2AP)Release 17TS

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

8.1 List of M2AP Elementary procedures

In the following tables, all Eps are divided into Class 1 and Class 2 Eps (see subclause 3.1 for explanation of the different classes):

Table 2: Class 1 procedures

Elementary Procedure	Initiating Message	Successful Outcome	Unsuccessful Outcome
Elementary Procedure	Initiating Message	Response message	Response message
MBMS Session Start	MBMS SESSION START REQUEST	MBMS SESSION START RESPONSE	MBMS SESSION START FAILURE
MBMS Session Stop	MBMS SESSION STOP REQUEST	MBMS SESSION STOP RESPONSE
MBMS Session Update	MBMS SESSION UPDATE REQUEST	MBMS SESSION UPDATE RESPONSE	MBMS SESSION UPDATE FAILURE
MBMS Scheduling Information	MBMS SCHEDULING INFORMATION	MBMS SCHEDULING INFORMATION RESPONSE
Reset	RESET	RESET ACKNOWLEDGE
M2 Setup	M2 SETUP REQUEST	M2 SETUP RESPONSE	M2 SETUP FAILURE
eNB Configuration Update	ENB CONFIGURATION UPDATE	ENB CONFIGURATION UPDATE ACKNOWLEDGE	ENB CONFIGURATION UPDATE FAILURE
MCE Configuration Update	MCE CONFIGURATION UPDATE	MCE CONFIGURATION UPDATE ACKNOWLEDGE	MCE CONFIGURATION UPDATE FAILURE
MBMS Service Counting	MBMS SERVICE COUNTING REQUEST	MBMS SERVICE COUNTING RESPONSE	MBMS SERVICE COUNTING FAILURE

Table 3: Class 2 procedures

Elementary Procedure	Message
Error Indication	ERROR INDICATION
MBMS Service Counting Results Report	MBMS SERVICE COUNTING RESULTS REPORT
MBMS Overload Notification	MBMS OVERLOAD NOTIFICATION

The following applies concerning interference between Elementary Procedures:

– The Reset procedure takes precedence over all other Eps.

8.2 MBMS Session Start

8.2.1 General

The purpose of the MBMS Session Start procedure is to request the eNB to notify Ues about an upcoming MBMS Session of a given MBMS Bearer Service and to establish an MBMS E-RAB and an MBMS-service-associated logical M2-connection. The MBMS Session Start procedure is triggered by the MCE.

The procedure uses MBMS-Service-associated signalling.

8.2.2 Successful Operation

Figure 8.2.2-1. MBMS Session Start procedure. Successful operation.

The MCE initiates the procedure by sending an MBMS SESSION START REQUEST message. If the eNB accepts the MBMS session start request, the eNB responds with the MBMS SESSION START RESPONSE message. The eNB shall select and join the IP multicast (identified by the IP multicast address and the IP address of the multicast source as described by the TNL Information IE or, if present, the Alternative TNL Information IE) to enable the reception of MBMS data.

If the MBMS SESSION START REQUEST message contains the MBMS Session Identity IE, the eNB shall use it for broadcast of the MBMS Session Identity on the air interface.

If the MBMS SESSION START REQUEST message contains the SC-PTM information IE, the eNB shall use SC-PTM for the related MBMS service in the relevant cells. The eNB shall establish or modify the resources according to the values of the Allocation and Retention Priority IE (priority level and pre-emption indicators) and the resource situation as follows:

– The eNB shall consider the priority level of the requested session, when deciding on the resource allocation.

– The priority levels and the pre-emption indicators may (individually or in combination) be used to determine whether the session has to be started unconditionally and immediately. If the requested session is marked as “may trigger pre-emption” and the resource situation requires so, the eNB may trigger the pre-emption procedure which may then cause the forced release of a lower priority session which is marked as “pre-emptable”. Whilst the process and the extent of the pre-emption procedure is operator-dependent, the pre-emption indicators shall be treated as follows:

1. If the Pre-emption Capability IE is set to “may trigger pre-emption”, then this allocation request is allowed to trigger a pre-emption procedure.

2. If the Pre-emption Capability IE is set to “shall not trigger pre-emption”, then this allocation request is not allowed to trigger a pre-emption procedure.

3. If the Pre-emption Vulnerability IE is set to “pre-emptable”, then this session shall be included in the pre-emption process.

4. If the Pre-emption Vulnerability IE is set to “not pre-emptable”, then this session shall not be included in the pre-emption process.

5. If the Priority Level IE is set to “no priority” the given values for the Pre-emption Capability IE and Pre-emption Vulnerability IE shall not be considered. Instead the values “shall not trigger pre-emption” and “not pre-emptable” shall prevail.

– The E-UTRAN pre-emption process shall keep the following rule: E-UTRAN shall only pre-empt sessions with lower priority, in ascending order of priority.

The eNB shall report to the MCE, in the MBMS SESSION START RESPONSE message the result of the requested MBMS E-RAB.

8.2.3 Unsuccessful Operation

Figure 8.2.3-1. MBMS Session Start procedure. Unsuccessful operation.

If the eNB is not capable of correctly processing the request (e.g. the MBMS resources could not be established at all in any cell), the MCE shall be informed by the MBMS SESSION START FAILURE message.

8.2.4 Abnormal Conditions

In case the SC-PTM information IE is received, but does not contain any cell of the eNB, the MCE shall be informed by the MBMS SESSION START FAILURE message.

8.3 MBMS Session Stop

8.3.1 General

The purpose of the MBMS Session Stop procedure is to release the corresponding MBMS E-RAB and the MBMS-service-associated logical M2-connection. The MBMS Session Stop procedure is triggered by the MCE.

The procedure uses MBMS-Service-associated signalling.

8.3.2 Successful Operation

Figure 8.3.2-1. MBMS Session Stop procedure. Successful operation.

The MCE initiates the procedure by sending a MBMS SESSION STOP REQUEST message. Upon receipt of the MBMS SESSION STOP REQUEST message, the eNB shall respond with the MBMS SESSION STOP RESPONSE message. The eNB shall disable the reception from the IP backbone of the particular MBMS bearer service, release the affected resources and remove the MBMS bearer context.

8.3.3 Abnormal Conditions

Void.

8.4 MBMS Scheduling Information

8.4.1 General

The purpose of the MBMS Scheduling Information Procedure is to provide MCCH related information, and optional session suspension decision to the eNB.

The procedure uses non MBMS-Service-associated signalling.

8.4.2 Successful Operation

Figure 8.4.2-1. MBMS Scheduling Information procedure. Successful operation.

The MCE initiates the procedure by sending the MBMS SCHEDULING INFORMATION message to the eNB. The eNB shall store the MBSFN Area Configuration Item IE, apply the MCCH update from the modification period defined in the MCCH Update Time IE, and transmit the MCCH according to the MCCH configuration for the given MBSFN area indicated by the MCE. If an empty PMCH Configuration List IE is contained in this message for an MBSFN area, the eNB shall update the content of the corresponding MCCH so as not to include PMCH related information over the corresponding MCCH. If the Modulation and Coding Scheme 2 IE is included, the eNB shall ignore the Modulation and Coding Scheme IE and use the Modulation and Coding Scheme 2 IE instead. If the received PMCH Configuration IE contains the MCH Scheduling Period Extended IE, the eNB shall take its value into account instead of the value signalled in the MCH Scheduling Period IE. If the received PMCH Configuration IE contains the MCH Scheduling Period Extended 2 IE, the eNB shall take its value into account instead of the value signalled in the MCH Scheduling Period IE. The eNB shall schedule the MBMS services in the MCCH according to the order defined in the MBMS Session List per PMCH IE. If the MBMS Suspension Notification List IE is included in this message for an MBSFN area, the eNB shall broadcast the suspension decision over the air interface from the radio frame defined by the SFN IE, until the end of the Modification Period just before the "MCCH Update Time".

If the MBMS SCHEDULING INFORMATION message contains the Subframe Allocation Extended IE included in the MBSFN Subframe Configuration IE, the eNB shall, if supported, store it and take it into account.

8.4.3 Abnormal Conditions

Void.

8.5 Reset

8.5.1 General

The purpose of the Reset procedure is to initialise or re-initialise the eNB or part of eNB M2AP MBMS-service-related contexts, in the event of a failure in the MCE or vice versa. This procedure does not affect the application level configuration data exchanged during, e.g., the M2 Setup procedure.

The procedure uses non MBMS-service-associated signalling.

8.5.2 Successful Operation

8.5.2.1 Reset Procedure Initiated from the MCE

Figure 8.5.2.1-1. Reset procedure initiated from the MCE. Successful operation.

In the event of a failure at the MCE, which has resulted in the loss of some or all transaction reference information, a RESET message shall be sent to the eNB.

At reception of RESET message the eNB shall release all allocated resources on M2 and M1/Uu related to MBMS-service association(s) indicated explicitly or implicitly in the RESET message and remove the indicated MBMS-service contexts including MBMS M2AP IDs.

After the eNB has released all assigned M2 and M1 resources and MBMS-service contexts for all indicated MBMS-service association(s), the eNB shall respond with the RESET ACKNOWLEDGE message. The eNB does not need to wait for the release of radio resources to be completed before returning the RESET ACKNOWLEDGE message.

If the RESET message contains the MBMS-Service-associated logical M2-connection list IE, then:

– The eNB shall use the MCE MBMS M2AP ID IE and/or the eNB MBMS M2AP ID IE to explicitly identify the MBMS service association(s) to be reset.

– The eNB shall in the RESET ACKNOWLEDGE message include, for each MBMS service association to be reset, the MBMS-Service-associated logical M2-connection Item IE in the MBMS-Service-associated logical M2-connection list IE. The MBMS-Service-associated logical M2-connection Item Ies shall be in the same order as received in the RESET message and shall include also unknown MBMS-Service-associated logical M2-connections. Empty MBMS-Service-associated logical M2-connection Item Ies, received in the RESET message, may be omitted in the RESET ACKNOWLEDGE message.

– If the MCE MBMS M2AP ID IE is included in the MBMS-Service-associated logical M2-connection Item IE for an MBMS service association, the eNB shall include the MCE MBMS M2AP ID IE in the corresponding MBMS-Service-associated logical M2-connection Item IE in the RESET ACKNOWLEDGE message.

– If the eNB MBMS M2AP ID IE is included in an MBMS-Service-associated logical M2-connection Item IE for an MBMS service association, the eNB shall include the eNB MBMS M2AP ID IE in the corresponding MBMS-Service-associated logical M2-connection Item IE in the RESET ACKNOWLEDGE message.

Interactions with other procedures:

If the RESET message is received, any other ongoing procedure (except another Reset procedure) on the same M2 interface related to a MBMS service association, indicated explicitly or implicitly in the RESET message, shall be aborted.

8.5.2.2 Reset Procedure Initiated from the eNB

Figure 8.5.2.2-1. Reset procedure initiated from the eNB. Successful operation.

In the event of a failure at the eNB, which has resulted in the loss of some or all transaction reference information, a RESET message shall be sent to the MCE.

At reception of RESET message the MCE shall release all allocated resources on M2 related to MBMS-service association(s) indicated explicitly or implicitly in the RESET message and the indicated MBMS-service contexts on M2 for the eNB.

After the MCE has released all assigned M2 resources and MBMS-service contexts for all the eNB indicated MBMS-service association(s), the MCE shall respond with the RESET ACKNOWLEDGE message.

If the RESET message contains the MBMS-Service-associated logical M2-connection list IE, then:

– The MCE shall use the MCE MBMS M2AP ID IE and/or the eNB MBMS M2AP ID IE to explicitly identify the MBMS service association(s) to be reset.

– The MCE shall in the RESET ACKNOWLEDGE message include, for each MBMS service association to be reset, the MBMS-Service-associated logical M2-connection Item IE in the MBMS-Service-associated logical M2-connection list IE. The MBMS-Service-associated logical M2-connection Item Ies shall be in the same order as received in the RESET message and shall include also unknown MBMS-Service-associated logical M2-connections. Empty MBMS-Service-associated logical M2-connection Item Ies, received in the RESET message, may be omitted in the RESET ACKNOWLEDGE message.

– If the MCE MBMS M2AP ID IE is included in the MBMS-Service-associated logical M2-connection Item IE for an MBMS service association, the MCE shall include the MCE MBMS M2AP ID IE in the corresponding MBMS-Service-associated logical M2-connection Item IE in the RESET ACKNOWLEDGE message.

– If the eNB MBMS M2AP ID IE is included in an MBMS-Service-associated logical M2-connection Item IE for an MBMS service association, the MCE shall include the eNB MBMS M2AP ID IE in the corresponding MBMS-Service-associated logical M2-connection Item IE in the RESET ACKNOWLEDGE message.

Interactions with other procedures:

If the RESET message is received, any other ongoing procedure (except another Reset procedure) on same M2 interface related to a MBMS service association, indicated explicitly or implicitly in the RESET message, shall be aborted.

8.5.3 Abnormal Conditions

8.5.3.1 Abnormal Condition at the MCE

If the RESET message includes the MBMS-Service-associated logical M2-connection list IE, but neither the MCE MBMS M2AP ID IE nor the eNB MBMS M2AP ID IE is present for a MBMS-Service-associated logical M2-connection Item IE, then the MCE shall ignore the MBMS-Service-associated logical M2-connection Item IE. The MCE may return the empty MBMS-Service-associated logical M2-connection Item IE in the MBMS-Service-associated logical M2-connection list IE in the RESET ACKNOWLEDGE message.

8.5.3.2 Abnormal Condition at the eNB

If the RESET message includes the MBMS-Service-associated logical M2-connection list IE, but neither the MCE MBMS M2AP ID IE nor the eNB MBMS M2AP ID IE is present for a MBMS-Service-associated logical M2-connection Item IE, then the eNB shall ignore the MBMS-Service-associated logical M2-connection Item IE. The eNB may return the empty MBMS-Service-associated logical M2-connection Item IE in the MBMS-Service-associated logical M2-connection list IE in the RESET ACKNOWLEDGE message.

8.5.3.3 Crossing of Reset Messages

If Reset procedure is ongoing in eNB and the eNB receives a RESET message from the peer entity on the same M2 interface related to one or several MBMS service associations previously requested to be reset, indicated explicitly or implicitly in the received RESET message, the eNB shall respond with RESET ACKNOWLEDGE message as described in 8.5.2.1.

If Reset procedure is ongoing in MCE and the MCE receives a RESET message from the peer entity on the same M2 interface related to one or several MBMS service associations previously requested to be reset, indicated explicitly or implicitly in the received RESET message, the MCE shall respond with RESET ACKNOWLEDGE message as described in 8.5.2.2.

8.6 M2 Setup

8.6.1 General

The purpose of the M2 Setup procedure is to exchange application level data needed for the eNB and MCE to interoperate correctly on the M2 interface and to configure MCCH related content on the BCCH for each of the cells controlled by the eNB which is foreseen to participate in MBMS service data transmission. This procedure shall be the first M2AP procedure triggered after the TNL association has become operational. The procedure uses non MBMS-service-associated signalling.

This procedure erases any existing application level configuration data in the eNB and the MCE and MCCH related BCCH data in all cells served by the eNB. This procedure also re-initialises the E-UTRAN M2AP MBMS service related contexts (if any) and erases all related signalling connections in the two nodes like a Reset procedure would do.

8.6.2 Successful Operation

Figure 8.6.2-1. M2 Setup procedure. Successful operation.

The eNB initiates the procedure by sending a M2 SETUP REQUEST message including the appropriate data to the MCE. The eNB shall include in the M2 SETUP REQUEST message the cell(s) which is (are) foreseen to participate in MBMS service data transmission.

The MCE responds with M2 SETUP RESPONSE message including the appropriate data. The MCE shall provide the MCCH related BCCH configuration (and, if required, the MCCH related BCCH extended configuration) for all cells indicated in the M2 SETUP REQUEST message.

The exchanged data shall be stored in the respective node, MCCH related BCCH configuration broadcasted as provided by the MCE in the respective cell(s), and used for the duration of the TNL association or until any further configuration update procedure is performed.

When this procedure is finished the M2 interface is operational, all affected cells are ready for MBMS service data transmission and other M2 messages can be exchanged.

If the M2 SETUP REQUEST message contains the eNB Name IE the MCE may use this IE as a human readable name of the eNB.

If the M2 SETUP RESPONSE message contains the MCE Name IE the eNB may use this IE as a human readable name of the MCE.

The eNB shall broadcast the MCCH related BCCH configuration only in those cells indicated in the Cell Information List IE contained in the M2 SETUP RESPONSE message for which the Cell Reservation Info IE within the MCCH related BCCH Configuration Item IE is not set to “reserved Cell”.

If the M2 SETUP RESPONSE message contains the Modification Period Extended IE within the MCCH related BCCH Configuration Item IE, the eNB shall take its value into account instead of the value signalled in the Modification Period IE.

If the M2 SETUP RESPONSE message contains the Repetition Period Extended IE within the MCCH related BCCH Configuration Item IE, the eNB shall take its value into account instead of the value signalled in the Repetition Period IE.

If the M2 SETUP RESPONSE message contains the MCCH related BCCH Extended Configuration Data per MBSFN Area IE, the eNB shall, if supported, broadcast and store the included corresponding configuration of MBSFN area(s) and use it for the duration of the TNL association or until any further configuration update procedure is performed. The eNB shall broadcast the MCCH related BCCH extended configuration only in those cells indicated in the Cell Information List IE contained in the M2 SETUP RESPONSE message for which the Cell Reservation Info IE within the MCCH related BCCH Extended Configuration Item IE is not set to "reserved Cell".

8.6.3 Unsuccessful Operation

Figure 8.6.2-1. M2 Setup procedure. Unsuccessful operation.

If the MCE cannot accept the setup it should respond with a M2 SETUP FAILURE message and appropriate cause value.

If the M2 SETUP FAILURE message includes the Time To Wait IE the eNB shall wait at least for the indicated time before reinitiating the M2 setup towards the same MCE.

8.6.4 Abnormal Conditions

Void.

8.7 eNB Configuration Update

8.7.1 General

The purpose of the eNB Configuration Update procedure is to update application level configuration data needed for the eNB and MCE to interoperate correctly on the M2 interface. This procedure does not affect existing MBMS-service-related contexts, if any.

The procedure uses non MBMS-service-associated signalling.

8.7.2 Successful Operation

Figure 8.7.2-1. eNB Configuration Update procedure. Successful operation.

The eNB initiates the procedure by sending an ENB CONFIGURATION UPDATE message to the MCE including an appropriate set of updated configuration data that it has just taken into operational use. The eNB CONFIGURATION UPDATE message may contain:

– the Global eNB ID IE,

– the eNB Name IE,

– the eNB MBMS Configuration data per cell IE.

If the Global eNB ID IE is not included in the ENB CONFIGURATION UPDATE message, the MCE shall interpret that the existing eNB ID is not changed.

If the eNB Name IE is not included in the ENB CONFIGURATION UPDATE message, the MCE shall interpret that the existing eNB name, if any, is not changed.

The MCE responds with the ENB CONFIGURATION UPDATE ACKNOWLEDGE message to acknowledge that it successfully updated the configuration data. If the ENB CONFIGURATION UPDATE message does not contain the information for an existing cell, the MCE shall interpret that the corresponding configuration data for that cell is not changed and shall continue to operate the M2 with the existing related configuration data for that cell.

If the ENB CONFIGURATION UPDATE ACKNOWLEDGE message contains the Cell Information List IE within the MCCH related BCCH Configuration Item IE or within the MCCH related BCCH Extended Configuration Item IE, the eNB shall broadcast that MCCH related BCCH configuration only in those cells indicated in the IE for which the Cell Reservation Info IE is not set to “reservedCell”. If the ENB CONFIGURATION UPDATE ACKNOWLEDGE message does not contain the Cell Information List IE within the MCCH related BCCH Configuration Item IE or within the MCCH related BCCH Extended Configuration Item IE, the eNB shall not broadcast that MCCH related BCCH configuration in any cell. If the ENB CONFIGURATION UPDATE ACKNOWLEDGE message contains the Modification Period Extended IE within the MCCH related BCCH Configuration Item IE, the eNB shall take its value into account instead of the value signalled in the Modification Period IE. If the ENB CONFIGURATION UPDATE ACKNOWLEDGE message contains the Repetition Period Extended IE within the MCCH related BCCH Configuration Item IE, the eNB shall take its value into account instead of the value signalled in the Repetition Period IE. If the ENB CONFIGURATION UPDATE ACKNOWLEDGE message does not contain the MCCH related BCCH Configuration Item IE or the MCCH related BCCH Extended Configuration Item IE for an existing MBSFN area, the eNB shall interpret that the corresponding configuration data for that MBSFN area is not changed and shall continue to operate the M2 with the existing related configuration data for that MBSFN area.

The eNB may update the configured MBMS Services Areas and the MBSFN Synchronisation Area per cell:

– If the eNB includes the E-UTRAN CGI IE for a cell within the ENB CONFIGURATION UPDATE message, the MCE shall assume that the eNB does neither broadcast MCCH related configuration in the BCCH nor any MBMS service data in that cell any more.

– If the eNB includes the eNB MBMS Configuration data Item IE for a cell within the ENB CONFIGURATION UPDATE message, the MCE may decide to include in the ENB CONFIGURATION UPDATE ACKNOWLEDGE message the MCCH related BCCH configuration or the MCCH related BCCH extended configuration for the related MBSFN area(s).

If the eNB CONFIGURATION UPDATE message contains the eNB Name IE, the MCE may use this IE as a human readable name of the eNB.

The updated configuration data shall be stored in both eNB and MCE and used for the duration of the TNL association or until any further update is triggered by the eNB or the MCE.

The eNB may initiate a further eNB Configuration Update procedure only after a previous eNB Configuration Update procedure has been completed.

8.7.3 Unsuccessful Operation

Figure 8.7.3-1. eNB Configuration Update procedure. Unsuccessful operation.

If the MCE cannot accept the update it shall respond with an ENB CONFIGURATION UPDATE FAILURE message and appropriate cause value.

If the ENB CONFIGURATION UPDATE FAILURE message includes the Time To Wait IE the eNB shall wait at least for the indicated time before reinitiating the ENB Configuration Update procedure towards the MCE. Both nodes shall continue to operate the M2 interface with their respective configuration data.

8.7.4 Abnormal Conditions

If the eNB after initiating eNB Configuration Update procedure receives neither an ENB CONFIGURATION UPDATE ACKOWLEDGE nor an ENB CONFIGURATION UPDATE FAILURE message, the eNB may reinitiate a further eNB Configuration Update procedure towards the same MCE, provided that the content of the new ENB CONFIGURATION UPDATE message is identical to the content of the previously unacknowledged ENB CONFIGURATION UPDATE message.

8.8 MCE Configuration Update

8.8.1 General

The purpose of the MCE Configuration Update procedure is to update application level configuration data needed for the eNB and MCE to interoperate correctly on the M2 interface and to re-configure MCCH related content on the BCCH for the MBSFN areas contributed by the eNB which is foreseen to participate in MBMS service data transmission. The procedure uses non MBMS-service-associated signalling. This procedure does not affect existing MBMS-service-related contexts, if any.

8.8.2 Successful Operation

Figure 8.8.2-1. MCE Configuration Update procedure. Successful operation.

The MCE initiates the procedure by sending an MCE CONFIGURATION UPDATE message to the eNB including an appropriate set of updated configuration data. The MCE CONFIGURATION UPDATE message may contain:

– the Global MCE ID IE,

– the MCE Name IE,

– the MCCH related BCCH Configuration data per MBSFN area IE.

If the Global MCE ID IE is not included in the MCE CONFIGURATION UPDATE message, the eNB shall interpret that the existing MCE ID is not changed.

If the MCE Name IE is not included in the MCE CONFIGURATION UPDATE message, the eNB shall interpret that the existing MCE name, if any, is not changed.

The eNB responds with the MCE CONFIGURATION UPDATE ACKNOWLEDGE message to acknowledge that it successfully updated the configuration data.

If the MCE CONFIGURATION UPDATE message contains the Cell Information List IE within the MCCH related BCCH Configuration Item IE, or within the MCCH related BCCH Extended Configuration Item IE, the eNB shall broadcast that MCCH related BCCH configuration only in those cells indicated in the IE for which the Cell Reservation Info IE is not set to “reservedCell”. If the MCE CONFIGURATION UPDATE message does not contain the Cell Information List IE within the MCCH related BCCH Configuration Item IE, or within the MCCH related BCCH Extended Configuration Item IE, the eNB shall not broadcast that MCCH related BCCH configuration in any cell. If the MCE CONFIGURATION UPDATE message contains the Modification Period Extended IE within the MCCH related BCCH Confiruation Item IE, the eNB shall take its value into account instead of the value signalled in the Modification Period IE. If the MCE CONFIGURATION UPDATE message contains the Repetition Period Extended IE within the MCCH related BCCH Confiruation Item IE, the eNB shall take its value into account instead of the value signalled in the Repetition Period IE. If the MCE CONFIGURATION UPDATE message does not contain the MCCH related BCCH Configuration Item IE, or the MCCH related BCCH Extended Configuration Item IE, for an existing MBSFN area, the eNB shall interpret that the corresponding configuration data for that MBSFN area is not changed and shall continue to operate the M2 with the existing related configuration data for that MBSFN area.

If the MCE CONFIGURATION UPDATE message contains the MCE Name IE, the eNB may use this IE as a human readable name of the MCE.

The updated configuration data shall be stored in both eNB and MCE and used for the duration of the TNL association or until any further update is triggered by the MCE or the eNB.

The MCE may initiate a further MCE Configuration Update procedure only after a previous MCE Configuration Update procedure has been completed.

If the MCE CONFIGURATION UPDATE message contains the Subcarrier Spacing MBMS IE within the MCCH related BCCH Configuration Item IE, the eNB shall, if supported, store this value and use it in MBMS operation.

8.8.3 Unsuccessful Operation

Figure 8.8.3-1. MCE Configuration Update procedure. Unsuccessful operation.

If the eNB cannot accept the update it shall respond with an MCE CONFIGURATION UPDATE FAILURE message and appropriate cause value.

If the MCE CONFIGURATION UPDATE FAILURE message includes the Time To Wait IE the MCE shall wait at least for the indicated time before reinitiating the MCE Configuration Update procedure towards the eNB. Both nodes shall continue to operate the M2 interface with their respective configuration data.

8.8.4 Abnormal Conditions

If the MCE neither receives an MCE CONFIGURATION UPDATE ACKNOWLEDGE nor an MCE CONFIGURATION UPDATE FAILURE message, the MCE may reinitiate MCE Configuration Update procedure towards the same eNB provided that the content of the new MCE CONFIGURATION UPDATE message is identical to the content of the previously unacknowledged MCE CONFIGURATION UPDATE message.

8.9 Error Indication

8.9.1 General

The Error Indication procedure is initiated by a node to report detected errors in one incoming message, provided they cannot be reported by an appropriate failure message.

If the error situation arises due to reception of a message utilising MBMS-service-associated signalling, then the Error Indication procedure uses MBMS-service-associated signalling. Otherwise the procedure uses non MBMS-service-associated signalling.

8.9.2 Successful Operation

Figure 8.9.2-1. Error Indication procedure, MCE originated. Successful operation.

Figure 8.9.2.1-2. Error Indication procedure, eNB originated. Successful operation.

When the conditions defined in clause 10 are fulfilled, the Error Indication procedure is initiated by an ERROR INDICATION message sent from the receiving node.

The ERROR INDICATION message shall contain at least either the Cause IE or the Criticality Diagnostics IE.

In case the Error Indication procedure is triggered by utilising MBMS-service-associated signalling the MCE MBMS M2AP ID IE and the eNB MBMS M2AP ID IE shall be included in the ERROR INDICATION message. If one or both of MCE MBMS M2AP ID IE and the eNB MBMS M2AP ID IE are not correct, the cause shall be set to appropriate value e.g. “Unknown or already allocated MCE MBMS M2AP ID”, “Unknown or already allocated eNB MBMS M2AP ID” or “Unknown or inconsistent pair of MBMS M2AP ID”.

8.9.3 Abnormal Conditions

Void.

8.10 MBMS Session Update

8.10.1 General

The purpose of the MBMS Session Update procedure is to inform the eNB about changing characteristics of the MBMS session.

The procedure uses MBMS-Service-associated signalling.

8.10.2 Successful Operation

Figure 8.10.2-1. MBMS Session Update procedure. Successful operation.

The MCE initiates the procedure by sending a MBMS SESSION UPDATE REQUEST message.

If the MBMS Service Area IE is included in the MBMS SESSION UPDATE REQUEST message, the eNB shall check the involvement of its cells in the new service area, update correspondingly the MBMS context and resources, join or leave the IP multicast if needed and send the MBMS SESSION UPDATE RESPONSE message.

If the TNL Information IE is included in the MBMS SESSION UPDATE REQUEST message, the eNB shall ignore the contained information.

If the MBMS SESSION UPDATE REQUEST message contains the MBMS Session Identity IE for an MBMS service, the eNB shall ignore the contained information.

If the MBMS SESSION UPDATE REQUEST message contains the SC-PTM information IE, the eNB shall check the SC-PTM related involvement of its cells in the new list of Cell identities, update correspondingly the MBMS context and resources, join or leave the IP multicast if needed and send the MBMS SESSION UPDATE RESPONSE message. If the ARP parameter is updated, the corresponding update of resources shall follow the principles described for the MBMS Session Start procedure. The eNB shall provide the MBMS session only in those cells included in the new list of Cell identities.

8.10.3 Unsuccessful Operation

Figure 8.10.3-1. MBMS Session Update procedure. Unsuccessful operation.

If the eNB fails to update the MBMS session, it shall return a MBMS SESSION UPDATE FAILURE message.

8.10.4 Abnormal Conditions

Void.

8.11 MBMS Service Counting

8.11.1 General

The purpose of the MBMS Service Counting procedure is to request the eNB to report the number of connected mode Ues that either are receiving the MBMS service(s) or are interested in the reception of the MBMS service(s).

The procedure uses non MBMS-Service-associated signalling.

8.11.2 Successful Operation

Figure 8.11.2-1. MBMS Service Counting procedure. Successful operation.

The MCE initiates the procedure by sending the MBMS SERVICE COUNTING REQUEST message to the eNB.

After receiving the MBMS SERVICE COUNTING REQUEST message successfully, the eNB shall respond the MCE with the MBMS SERVICE COUNTING RESPONSE message, apply the MCCH update from the modification period defined in the MCCH Update Time IE, and perform counting as specified in TS 36.300 [3].

8.11.3 Unsuccessful Operation

Figure 8.11.3-1. MBMS Service Counting procedure. Unsuccessful operation.

If the eNB is not capable of correctly processing the request, it shall return a MBMS SERVICE COUNTING FAILURE message.

8.11.4 Abnormal Conditions

If the eNB has received a MBMS SERVICE COUNTING REQUEST message for a MBSFN Area ID and MCCH Update Time pair, the eNB shall ignore subsequent MBMS SERVICE COUNTING REQUEST messages containing the same MBSFN Area ID and MCCH Update Time, and a different MBMS Counting Request Session IE.

8.12 MBMS Service Counting Results Report

8.12.1 General

The purpose of the MBMS Service Counting Results Report procedure is for the eNB to provide the counting results to the MCE.

The procedure uses non MBMS-Service-associated signalling.

8.12.2 Successful Operation

Figure 8.12.2-1. MBMS Service Counting Results Report procedure. Successful operation.

The eNB initiates the procedure by sending an MBMS SERVICE COUNTING RESULTS REPORT message.

The MBMS SERVICE COUNTING RESULTS REPORT message contains the counting results according to the counting configuration in the respective MBMS SERVICE COUNTING REQUEST message.

8.12.3 Abnormal Conditions

If, for a given MBSFN area, the MBMS SERVICE COUNTING RESULTS REPORT message contains one or more TMGIs corresponding to the configuration of one MBMS SERVICE COUNTING REQUEST message and some other TMGIs not part of this configuration, the MCE shall ignore the result corresponding to those other TMGIs.

8.13 MBMS Overload Notification

8.13.1 General

The purpose of the MBMS Overload Notification procedure is to enable the eNB to notify the MCE about MBMS overload status.

The procedure uses non MBMS-Service-associated signalling.

8.13.2 Successful Operation

Figure 8.13.2-1. MBMS Overload Notification procedure. Successful operation.

The eNB initiates the procedure by sending an MBMS OVERLOAD NOTIFICATION message to the MCE.

If a PMCH Overload Status IE is set to “Overload”, the MCE shall consider that the corresponding PMCH is overloaded, i.e. the user plane data for ongoing sessions could not be transported over the air interface in the scheduling period. If a PMCH Overload Status IE is set to “Normal”, the MCE shall consider that the corresponding PMCH is not overloaded.

8.13.3 Abnormal Conditions

Void.