Section: 5.9.2 Location Change Reporting Procedure 5.9.2.1 General
Content: The PDN GW may request for each PDN connection independently whether the MME shall report changes of ECGI/eNodeB ID/TAI (by using the "MS Info Change Reporting Action" parameter) and/or the UE entering/leaving a Presence Reporting Area (by using the "Presence Reporting Area Action" parameter) and/or whether the MME shall report changes of user CSG information (by using "CSG Information Reporting Action" parameter) to the PDN GW. This reporting (any combination of "MS Info Change Reporting Action" and/or "Presence Reporting Area Action" and/or "CSG Information Reporting Action") may be controlled by the PDN GW at the following procedures: - Attach, - Tracking Area Update (when inducing a Modify Bearer procedure to the PDN GW), - Inter-RAT Mobility to E-UTRAN (when inducing a Modify Bearer procedure to the PDN GW), - Dedicated bearer activation, - PDN GW initiated bearer modification with bearer QoS update, - PDN GW initiated bearer modification without bearer QoS update, - UE requested PDN connectivity, - UE requested bearer resource modification. The "Presence Reporting Area Action" and "Presence Reporting Area Information" parameters apply to all procedures listed above but, within this specification, their usage has only been described in the message flows related with the Attach and the UE requested PDN connectivity procedures. The reporting of UE entering/leaving a Presence Reporting Area is further described in clause 5.9.2.2. The PDN GW may also request the MME to stop any of the above mentioned types of reporting. The MME shall obey the last explicit instruction received from the PDN GW or source MME. During both mobility management and session management procedures, the MME shall indicate to the PDN GW the support of reporting location changes (using the MS Info Change Reporting support indication): - If ECGI/eNodeB ID/TAI information is permitted to be sent to the PDN GW according to MME operator's policy, - If CSG information is permitted to be sent to the PDN GW according to MME operator's policy. The MME may be configured to report ECGI/eNodeB ID/TAI changes only when one or more E-RAB(s) are established. Otherwise the MME shall report ECGI/eNodeB ID/TAI changes as soon as detected. If the level of support changes during a mobility management procedure then the MME shall indicate the current level of support to the S-GW and shall in addition provide ECGI/eNodeB ID/TAI even if the PDN GW has not requested this information. This could for example happen during MME change when the level of support indicated by the old MME is not the same as in the new MME. NOTE 1: The inclusion of ECGI/eNodeB ID/TAI will trigger a Modify Bearer Request message from S-GW to the PDN GW and therefore this will make sure that the new level of support reaches the PDN GW. At change of Serving Node (MME/S4-SGSN), the old Serving Node provides the new serving node with "MS Info Change Reporting Action" as previously requested by the PDN GW. The new Serving Node takes the "MS Info Change Reporting Action" immediately into account with the exception that, at mobility between a S4-SGSN and a MME, the new MME (respectively S4-SGSN) does not take into account the "MS Info Change Reporting Action" received from the S4-SGSN (respectively MME) but assumes that no location information change reporting is requested for the target RAT. At a change of RAT type between EUTRAN and UTRAN or between EUTRAN and GERAN, if location information change reporting is required in the target RAT, the PDN GW shall request "MS Info Change Reporting Action" from the new Serving Node (MME or S4-SGSN). Upon inter-RAT mobility, if the target MME/S4-SGSN supports location information change reporting, the target MME/S4-SGSN shall include the User Location Information in the Create Session Request / Modify Bearer Request, regardless of whether location Information change reporting had been requested in the previous RAT by the PDN GW. The PDN GWPDN GW shall not request the MME to report location changes if it has not received the indication for corresponding support from the MME. NOTE 2: For E-UTRAN access, homogeneous support of reporting changes of UE presence in a Presence Reporting Area in a network is assumed: When the PCRF configuration indicates that reporting changes of UE presence in a Presence Reporting Area is supported for E-UTRAN, this means it is supported by all the PDN GWPDN GW, all MME and all the SGW including the MME and SGW working in network sharing mode. If change of UE presence in Presence Reporting Area reporting is not supported, the PCRF may instead activate location information change reporting at cell, eNodeB or tracking area level. The following procedure shall be used for location change reports to the PDN GWPDN GW where the report is not combined with other mobility management or session management signalling. The procedure shall only apply when the MME has been explicitly requested to report location changes. The following procedure can be used for MO Exception Data Counter reporting where the report is not combined with other mobility management or session management signalling. The MME only includes the MO Exception data counter if the RRC establishment cause is set to "MO exception data" and the UE is accessing via the NB-IoT RAT. The MME maintains the MO Exception Data Counter for Serving PLMN Rate Control purposes (see clause 4.7.7.2). The MME may immediately send the MO Exception Data Counter to the Serving GW. Alternatively, in order to reduce signalling, the MME may send the MO Exception Data Counter to the Serving GW as described in TS 29.274[ 3GPP Evolved Packet System (EPS); Evolved General Packet Radio Service (GPRS) Tunnelling Protocol for Control plane (GTPv2-C); Stage 3 ]  [43]. The SGW and PDN GWPDN GW indicate each use of this RRC establishment cause by the related counter on its CDR. NOTE 3: Due to the increased signalling load, it is recommended that ECGI/eNodeB ID/TAI or CSG reporting is only applied for a limited number of subscribers. Figure 5.9.2.1-1 represents the ECGI change triggering a report of change in ECGI, and/or the User CSG information change triggering a report of change in user CSG information. The figure also shows the reporting of a TAI change and/or when a UE enters or leaves a Presence Reporting Area. Figure 5.9.2.1-1: Notification of the ECGI, TAI and/or user CSG information changes 1a. the MME has received an ECGI information Update from the eNodeB. 1b. The MME detects that the user CSG information has changed by comparing with the MME stored user CSG information, or 1c. The MME detects that the TAI of the UE has changed, or 1d. The MME detects that the UE has entered or left a Presence Reporting Area defined for this UE. NOTE 4: It is possible that these changes are triggered at same time. 2. If the MME has been requested to report location changes to the PDN GWPDN GW for the UE (under the conditions specified in clause 5.9.2), the MME shall send the Change Notification message to the SGW indicating the new ECGI, TAI and/or user CSG information. The MME stores the notified user CSG information. If the MME has been requested to report a change of UE presence in Presence Reporting Area (under the conditions specified in clause 5.9.2), the MME shall send the Change Notification message including the Presence Reporting Area Information comprising the area identifier(s) and indication(s) on whether the UE is inside or outside the area(s). If MME decides to reactivate one or more of the inactive Presence Reporting Area(s), the Presence Reporting Area Information in this message also comprises the reactivated PRA identifier(s), and indication(s) on whether the UE is inside or outside the reactivated area(s). 3. The SGW forwards the Change Notification message to the PDN GWPDN GW. If dynamic PCC is deployed, and location changes need to be conveyed to the PCRF, then the PDN GWPDN GW shall send this information to the PCRF as defined in TS 23.203[ Policy and charging control architecture ]  [6]. If Presence Reporting Area Information has been received, the PDN GWPDN GW shall forward the Presence Reporting Area Information to the PCRF, to the OCS or to both as defined in TS 23.203[ Policy and charging control architecture ]  [6]. 4. The PDN GW sends the Change Notification Ack to the SGW. 5. The SGW forwards the Change Notification Ack to the MME.