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EP-4740518-A1 - USER EQUIPMENT BEHAVIOR FOR PLMN AND RAT SELECTION DURING SUSPENDED NAS SIGNALING

EP4740518A1EP 4740518 A1EP4740518 A1EP 4740518A1EP-4740518-A1

Abstract

Techniques pertaining to user equipment (UE) behavior for public land mobile network (PLMN) and radio access technology (RAT) selection during suspended non-access stratum (NAS) signaling in mobile communications are described. An apparatus (e.g., a UE) enters an Evolved Packet System (EPS) Mobility Management idle (EMM-IDLE) mode with suspend indication or a 5th Generation Mobility Management idle (5GMM-IDLE) mode with suspend indication. While in the EMM-IDLE mode with suspend indication or the 5GMM-IDLE mode with suspend indication, the UE behaves in a same way as in an EMM-IDLE mode or a 5GMM-IDLE over a 3rd Generation Partnership Project (3GPP) access.

Inventors

  • PUNEET, Puneet
  • NIEMI, Marko

Assignees

  • MediaTek Singapore Pte. Ltd.

Dates

Publication Date
20260513
Application Date
20240611

Claims (10)

  1. A method, comprising: entering, by a processor of a user equipment (UE) , an Evolved Packet System (EPS) Mobility Management idle (EMM-IDLE) mode with suspend indication or a 5 th Generation Mobility Management idle (5GMM-IDLE) mode with suspend indication; and behaving, by the processor, in a same way as in an EMM-IDLE mode or a 5GMM-IDLE over a 3 rd Generation Partnership Project (3GPP) access while in the EMM-IDLE mode with suspend indication or the 5GMM-IDLE mode with suspend indication.
  2. The method of claim 1, wherein the behaving comprises performing a procedure as in the EMM-IDLE mode or the 5GMM-IDLE mode over the 3GPP access.
  3. The method of claim 2, wherein the performing of the procedure comprises performing a public land mobile network (PLMN) selection procedure.
  4. The method of claim 2, wherein the performing of the procedure comprises performing an N1 or S1 capability updated procedure.
  5. The method of claim 1, wherein the entering of the EMM-IDLE mode with suspend indication or the 5GMM-IDLE mode with suspend indication comprises entering the EMM-IDLE mode with suspend indication or the 5GMM-IDLE mode with suspend indication responsive to a network suspending a non-access stratum (NAS) signaling connection in an EMM connected (EMM-CONNECTED) or 5GMM connected (5GMM-CONNECTED) mode.
  6. An apparatus implementable in a user equipment (UE) , comprising: a transceiver configured to communicate wirelessly; and a processor coupled to the transceiver and configured to perform operations comprising: entering an Evolved Packet System (EPS) Mobility Management idle (EMM-IDLE) mode with suspend indication or a 5 th Generation Mobility Management idle (5GMM-IDLE) mode with suspend indication; and behaving in a same way as in an EMM-IDLE mode or a 5GMM-IDLE over a 3 rd Generation Partnership Project (3GPP) access while in the EMM-IDLE mode with suspend indication or the 5GMM-IDLE mode with suspend indication.
  7. The apparatus of claim 6, wherein the behaving comprises performing, via the transceiver, a procedure as in the EMM-IDLE mode or the 5GMM-IDLE mode over the 3GPP access.
  8. The apparatus of claim 7, wherein the performing of the procedure comprises performing a public land mobile network (PLMN) selection procedure.
  9. The apparatus of claim 7, wherein the performing of the procedure comprises performing an N1 or S1 capability updated procedure.
  10. The apparatus of claim 6, wherein the entering of the EMM-IDLE mode with suspend indication or the 5GMM-IDLE mode with suspend indication comprises entering the EMM-IDLE mode with suspend indication or the 5GMM-IDLE mode with suspend indication responsive to a network suspending a non-access stratum (NAS) signaling connection in an EMM connected (EMM-CONNECTED) or 5GMM connected (5GMM-CONNECTED) mode.

Description

USER EQUIPMENT BEHAVIOR FOR PLMN AND RAT SELECTION DURING SUSPENDED NAS SIGNALING CROSS REFERENCE TO RELATED PATENT APPLICATION (S) The present disclosure claims the priority benefit of Indian Patent Application No. 202321045845, filed 07 July 2023, respectively, the content of which herein being incorporated by reference in its entirety. TECHNICAL FIELD The present disclosure is generally related to mobile communications and, more particularly, to user equipment (UE) behavior for public land mobile network (PLMN) and radio access technology (RAT) selection during suspended non-access stratum (NAS) signaling in mobile communications. BACKGROUND In wireless communications such as mobile communications under the current 3rd Generation Partnership Project (3GPP) specification, suspension of NAS signaling connection can be initiated by a network in an Evolved Packet System (EPS) Mobility Management connected (EMM-CONNECTED) or 5th Generation Mobility Management connected (5GMM-CONNECTED) mode when user plane Cellular Internet of Things (CIoT) EPS optimization is used. Resumption of the suspended NAS signaling connection may be initiated by a UE. Upon indication from lower layers that a radio resource control (RRC) connection has been suspended, the UE is to enter an EMM idle (EMM-IDLE) mode with suspend indication or 5GMM idle (5GMM-IDLE) mode with suspend indication. The UE is to not consider the NAS signaling connection released, and the UE is to not consider a secure exchange of NAS messages terminated. According to the 3GPP specification, the UE can perform a PLMN selection procedure, and an N1/S1 capability update procedure can be performed in the EMM-IDLE mode and 5GMM-IDLE mode. If the UE is in the EMM-CONNECTED mode or 5GMM-CONNECED mode, the UE would release the connection locally. If the UE has either persistent protocol data unit (PDU) session or persistent EPS bearer context, the UE is to wait until the radio bearer associated with the persistent EPS bearer context or the persistent PDU session has been released. When the UE is in the EMM-IDLE mode with suspend indication  or the 5GMM-IDLE mode with suspend indication, the UE and network would be considered as NAS signaling not released. However, the UE behavior is not defined as to whether or not the PLMN selection procedure or N1/S1 capability update procedure is allowed in the EMM-IDLE mode with suspend indication or the 5GMM-IDLE mode with suspend indication. Moreover, the UE behavior is also not defined as to how the PLMN selection procedure or N1/S1 capability update procedure can be performed in the EMM-IDLE mode with suspend indication or the 5GMM-IDLE mode with suspend indication. Therefore, there is a need for solutions of UE behavior for PLMN and RAT selection during suspended NAS signaling in mobile communications. SUMMARY The following summary is illustrative only and is not intended to be limiting in any way. That is, the following summary is provided to introduce concepts, highlights, benefits, and advantages of the novel and non-obvious techniques described herein. Select implementations are further described below in the detailed description. Thus, the following summary is not intended to identify essential features of the claimed subject matter, nor is it intended for use in determining the scope of the claimed subject matter. An objective of the present disclosure is to propose solutions or schemes that address the issue (s) described herein. More specifically, various schemes proposed in the present disclosure are believed to provide solutions pertaining to UE behavior for PLMN and RAT selection during suspended NAS signaling in mobile communications. It is believed that implementations of one or more of the schemes proposed herein may address or otherwise alleviate the issues described above. For instance, under the proposed schemes, when in an EMM-IDLE mode with suspend indication or an 5GMM-IDLE mode with suspend indication, a UE may behave the same as in an idle mode. In one aspect, a method may involve a UE entering an EMM-IDLE mode with suspend indication or a 5GMM-IDLE mode with suspend indication. The method may also involve the UE behaving in a same way as in an EMM-IDLE mode or a 5GMM-IDLE over a 3GPP access while in the EMM-IDLE mode with suspend indication or the 5GMM-IDLE mode with suspend indication. In another aspect, an apparatus may include a transceiver configured to communicate wirelessly and a processor coupled to the transceiver. The processor may enter an EMM-IDLE mode with suspend indication or a 5GMM-IDLE mode with suspend indication.  The processor may also behave in a same way as in an EMM-IDLE mode or a 5GMM-IDLE over a 3GPP access while in the EMM-IDLE mode with suspend indication or the 5GMM-IDLE mode with suspend indication. It is noteworthy that, although the description provided herein may be in the context of certain radio access technologies, networks, and network topologies suc