8.5 Paging

36.4133GPPEvolved Universal Terrestrial Radio Access Network (E-UTRAN)Release 17S1 Application Protocol (S1AP)TS

8.5.1 General

The purpose of the Paging procedure is to enable the MME to page a UE in the specific eNB.

8.5.2 Successful Operation

Figure 8.5.2-1: Paging procedure

The MME initiates the paging procedure by sending the PAGING message to the eNB.

At the reception of the PAGING message, the eNB shall perform paging of the UE in cells which belong to tracking areas as indicated in the List of TAIs IE.

The CN Domain IE shall be transferred transparently to the UE.

The Paging DRX IE may be included in the PAGING message, and if present the eNB shall use it according to TS 36.304 [20].

A list of CSG IDs may be included in the PAGING message.

If included, the E-UTRAN may use the list of CSG IDs to avoid paging the UE at CSG cells whose CSG ID does not appear in the list.

For each cell that belongs to any of the TAs indicated in the List of TAIs IE, the eNB shall generate one page on the radio interface.

The Paging Priority IE may be included in the PAGING message, and if present the eNB may use it according to TS 23.401 [11] and TS 23.272 [17].

If the UE Radio Capability for Paging IE is included in the PAGING message, the eNB may use it to apply specific paging schemes. If the Enhanced Coverage Restricted IE is included in the PAGING message, the eNB shall, if supported, use it as defined in TS 23.401 [11].

If the Assistance Data for Recommended Cells IE is included in the Assistance Data for Paging IE it may be used, together with the Paging Attempt Information IE if also present according to TS 36.300 [14].

If the Assistance Data for CE capable UEs IE is included in the Assistance Data for Paging IE, it may be used for paging the indicated CE capable UE, together with the Paging Attempt Information IE according to TS 36.300 [14].

If the Next Paging Area Scope IE is included in the Paging Attempt Information IE it may be used for paging the UE according to TS 36.300 [14].

If the Paging eDRX Information IE is included in the PAGING message, the eNB shall, if supported, use it according to TS 36.304 [20]. If the Paging Time Window IE is included in the Paging eDRX Information IE, the eNB shall take this information into account to determine the UE’s paging occasion according to TS 36.304 [20]. The eNB should take into account the reception time of the PAGING message on the S1-MME interface to determine when to page the UE.

If the Extended UE Identity Index Value IE is included in the PAGING message, the eNB shall, if supported, use it to identify the paging resources to be used according to TS 36.304 [20]. The MME shall, if supported, include the Extended UE Identity Index Value IE in the PAGING message.

If the NB-IoT Paging eDRX Information IE is included in the PAGING message, the eNB shall, if supported, use it according to TS 36.304 [20]. If the NB-IoT Paging Time Window IE is included in the NB-IoT Paging eDRX Information IE, the eNB shall take this information into account to determine the UE’s paging occasion according to TS 36.304 [20]. The eNB should take into account the reception time of the PAGING message on the S1-MME interface to determine when to page the UE.

If the NB-IoT UE Identity Index Value IE is included in the PAGING message, the eNB shall, if supported, use it to identify the paging resources to be used according to TS 36.304 [20].

If the CE-Mode-B Restricted IE is included in the PAGING message and the Enhanced Coverage Restricted IE is not set to restricted, the eNB shall use it as defined in TS 23.401 [11].

If the Data Size IE is included in the PAGING message, the eNB shall, if supported, use it to decide whether to initiate Mobile Terminated EDT procedures towards the UE as described in TS 36.300 [14].

If the WUS Assistance Information IE is included in the PAGING message, the eNB shall, if supported, use it to determine the WUS group for the UE, as specified in TS 36.304 [20].

If the NB-IoT Paging DRX IE is included in the PAGING message, the eNB shall use it according to TS 36.304 [20].

If the Paging Cause IE is included in the PAGING message, the eNB shall, if supported, transfer it to the UE according to TS 36.331 [21].

8.5.3 Unsuccessful Operation

Not applicable.

8.5.4 Abnormal Conditions

Not applicable.