Section: 5.5.3.2.3 EMM common procedure initiation
Content: If the network receives a TRACKING AREA UPDATE REQUEST message containing the Old GUTI type IE, and the network does not follow the use of the most significant bit of the <MME group id> to distinguish the node type as specified in 3GPP TS 23.003[ Numbering, addressing and identification ]  [2], clause 2.8.2.2.2, the network shall use the Old GUTI type IE to determine whether the mobile identity included in the Old GUTI IE is a native GUTI or a mapped GUTI. During the tracking area updating procedure, the MME may initiate EMM common procedures, e.g. the EMM authentication and security mode control procedures. The MME may be configured to skip the authentication procedure even if no EPS security context is available and proceed directly to the execution of the security mode control procedure as specified in clause 5.4.3, during a tracking area updating procedure for a UE that has only a PDN connection for emergency bearer services or for RLOS. The MME shall not initiate an EMM authentication procedure before completion of the tracking area updating procedure, if the following conditions apply: a) the UE initiated the tracking area updating procedure after handover or inter-system handover to S1 mode; b) the target cell is a shared network cell; and - the UE has provided its GUTI in the Old GUTI IE or the Additional GUTI IE in the TRACKING AREA UPDATE REQUEST message, and the PLMN identity included in the GUTI is different from the selected PLMN identity of the target cell; or - the UE has mapped the P-TMSI and RAI into the Old GUTI IE and not included an Additional GUTI IE in the TRACKING AREA UPDATE REQUEST message, and the PLMN identity included in the RAI is different from the selected PLMN identity of the target cell.