Access network registration via different radio access technology

Abstract

Various aspects of the present disclosure relate to access network registration via different radio access technologies. An apparatus (e.g., user equipment (UE)) transmits, to a first network entity of a first access network associated with a first radio access technology, an identifier and a cause for a registration procedure with a second network entity of a second access network associated with a second radio access technology. The UE receives an indication of acceptance of registration with the second access network based at least in part on the registration procedure. The UE transmits, based at least in part on the acceptance of registration with the second access network, data to the first network entity of the first access network for routing to the second network entity of the second access network.

Description

ACCESS NETWORK REGISTRATION VIA DIFFERENT RADIO ACCESS TECHNOLOGYRELATED APPLICATION

[0001] This application claims priority to U.S. Provisional Application Serial No. 63 / 621,284 filed 16 January 2024 entitled “ACCESS NETWORK REGISTRATION VIA DIFFERENT RADIO ACCESS TECHNOLOGY,” the disclosure of which is incorporated by reference herein in its entirety.TECHNICAL FIELD

[0002] The present disclosure relates to wireless communications, and more specifically to interoperability between different radio access technologies (RATs).BACKGROUND

[0003] A wireless communications system may include one or multiple network communication devices, such as base stations, which may support wireless communications for one or multiple user communication devices, which may be otherwise known as user equipment (UE), or other suitable terminology. The wireless communications system may support wireless communications with one or multiple user communication devices by utilizing resources of the wireless communication system (e.g., time resources (e.g., symbols, slots, subframes, frames, or the like) or frequency resources (e.g., subcarriers, carriers, or the like). Additionally, the wireless communications system may support wireless communications across various radio access technologies including Third Generation (3G) radio access technology, Fourth Generation (4G) radio access technology, Fifth Generation (5G) radio access technology, among other suitable radio access technologies beyond 5G (e.g., Sixth Generation (6G)).SUMMARY

[0004] An article “a” before an element is unrestricted and understood to refer to “at least one” of those elements or “one or more” of those elements. The terms “a,” “at least one,” “one or more,” and “at least one of one or more” may be interchangeable. As used herein, including in the claims, “or” as used in a list of items (e.g., a list of items prefaced by a phrase such as “at least one of’ or “one or more of’ or “one or both of’) indicates an inclusive list such that, for example, a list of atAttorney Docket No. SMM920230184-WO-PCTleast one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Also, as used herein, the phrase “based on” shall not be construed as a reference to a closed set of conditions. For example, an example step that is described as “based on condition A” may be based on both a condition A and a condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase “based on” shall be construed in the same manner as the phrase “based at least in part on”. Further, as used herein, including in the claims, a “set” may include one or more elements.

[0005] Some implementations of the method and apparatuses described herein may further include a UE for wireless communication to trigger, via a first access network associated with a first radio access technology and via a first network equipment (NE) of a second access network associated with a second radio access technology, a registration procedure with a second NE of the second access network, the second radio access technology being different than the first radio access technology; transmit, via the first access network and to the first NE of the second access network associated with the second radio access technology, an indication of a cause for the registration procedure with the second NE of the second access network; and transmit, based at least in part on registering with the second access network in response to the registration procedure, data to the first NE of the second access network for routing to the second NE of the second access network.

[0006] In some implementations of the method and apparatuses for a UE described herein, the UE to trigger via the first NE of the second access network the registration procedure with the second NE of the second access network is based at least in part on the cause for the registration procedure; the cause for the registration procedure includes an emergency cause; the cause for the registration procedure includes a priority cause; the at least one processor is configured to cause the UE to: transmit, to the first NE, a first message to request a connection; receive, from the first NE, a second message indicating acceptance of the connection with the UE; transmit, to the first NE, a third message to establish a session for registration to the second NE of the second access network, the third message including the cause for the registration; receive, from the first NE, a fourth message indicating acceptance of establishment of the session for registration; transmit, to the second NE via the session, a register request message; and receive, from the second NE and via the session, a register message response.Attorney Docket No. SMM920230184-WO-PCT

[0007] In some implementations of the method and apparatuses for a UE described herein, the first radio access technology includes a Wireless Local Area Network (WLAN); the second radio access technology includes one or more of a 4G Long Term Evolution or a 5G New Radio (NR), and the second NE includes an Access and Mobility Management Eunction (AMF) or an Authentication Server Function (AUSF); the first NE of the second access network includes a Non- 3GPP Inter-Working Function (N3IWF); the at least one processor is further configured to cause the UE to perform, via the first NE of the second access network and with the second NE of the second access network, at least one Internet Key Exchange (IKE) message exchange according to an IKE protocol; the at least one processor is further configured to cause the UE to transmit the indication of the cause for the registration procedure as a private exchange type according to the IKE protocol; an IKE header of the at least one IKE message exchange indicates the private exchange type.

[0008] Some implementations of the method and apparatuses described herein may further include a processor for wireless communication to trigger, via a first access network associated with a first radio access technology and via a first NE of a second access network associated with a second radio access technology, a registration procedure for a UE with a second NE of the second access network, the second radio access technology being different than the first radio access technology; transmit, via the first access network and to the first NE of the second access network associated with the second radio access technology, an indication of a cause for the registration procedure with the second NE of the second access network; and transmit, based at least in part on registering with the second access network in response to the registration procedure, data to the first NE of the second access network for routing to the second NE of the second access network

[0009] In some implementations of the method and apparatuses for a processor described herein, the processor, to trigger via the first NE of the second access network the registration procedure with the second NE of the second access network is based at least in part on the cause for the registration procedure; the cause for the registration procedure includes an emergency cause; the cause for the registration procedure includes a priority cause; the at least one controller is configured to cause the processor to: transmit, to the first NE, a first message to request a connection; receive, from the first NE, a second message indicating acceptance of the connection with the UE; transmit, to the first NE, a third message to establish a session for registration to the second NE of the second access network, the third message including the cause for the registration;Attorney Docket No. SMM920230184-WO-PCTreceive, from the first NE, a fourth message indicating acceptance of establishment of the session for registration; transmit, to the second NE via the session, a register request message; and receive, from the second NE and via the session, a register message response.

[0010] In some implementations of the method and apparatuses for a processor described herein, the first radio access technology includes a WLAN; the second radio access technology includes one or more of a 4G Long Term Evolution or a 5G NR, and the second NE includes an AMF or an AUSF; the first NE of the second access network includes a N3IWF; the at least one controller is further configured to cause the processor to perform, via the first NE of the second access network and with the second NE of the second access network, at least one IKE message exchange according to an IKE protocol; the at least one controller is further configured to cause the processor to transmit the indication of the cause for the registration procedure as a private exchange type according to the IKE protocol; an IKE header of the at least one IKE message exchange indicates the private exchange type.

[0011] Some implementations of the method and apparatuses described herein may further include a method performed by a UE, the method including: triggering, via a first access network associated with a first radio access technology and via a first NE of a second access network associated with a second radio access technology, a registration procedure with a second NE of the second access network, the second radio access technology being different than the first radio access technology; transmitting, via the first access network and to the first NE of the second access network associated with the second radio access technology, an indication of a cause for the registration procedure with the second NE of the second access network; and transmitting, based at least in part on registering with the second access network in response to the registration procedure, data to the first NE of the second access network for routing to the second NE of the second access network.

[0012] In some implementations of the method and apparatuses described herein, the method performed by a UE further includes triggering via the first NE of the second access network the registration procedure with the second NE of the second access network is based at least in part on the cause for the registration procedure; the cause for the registration procedure includes an emergency cause; the cause for the registration procedure includes a priority cause; transmitting, to the first NE, a first message to request a connection; receiving, from the first NE, a second messageAttorney Docket No. SMM920230184-WO-PCTindicating acceptance of the connection with the UE; transmitting, to the first NE, a third message to establish a session for registration to the second NE of the second access network, the third message including the cause for the registration; receiving, from the first NE, a fourth message indicating acceptance of establishment of the session for registration; transmitting, to the second NE via the session, a register request message; and receiving, from the second NE and via the session, a register message response.

[0013] In some implementations of the method and apparatuses described herein, the method performed by a UE further includes where the first radio access technology includes a WLAN; the second radio access technology includes one or more of a 4G Long Term Evolution or a 5G NR, and the second NE includes an AMF or an AUSF; the first NE of the second access network includes a N3IWF; performing, via the first NE of the second access network and with the second NE of the second access network, at least one IKE message exchange according to an IKE protocol; transmitting the indication of the cause for the registration procedure as a private exchange type according to the IKE protocol; an IKE header of the at least one IKE message exchange indicates the private exchange type.

[0014] Some implementations of the method and apparatuses described herein may further include a UE for wireless communication to transmit, via a first access network associated with a first radio access technology and to a first NE of a second access network associated with a second radio access technology, a first message requesting a security association session with the first NE, the second radio access technology being different than the first radio access technology; receive a second message including a notification regarding the first NE and confirming the security association session between the UE and the first NE; and transmit, to the first NE of the second access network, a third message requesting a selected registration with a second NE of the second access network and including an access network parameter for the selected registration.

[0015] In some implementations of the method and apparatuses described herein, the UE is configured to receive, from the second NE of the second access network, a response confirming the selected registration with the second NE of the second access network; the first radio access technology includes a WLAN, and the second radio access technology includes one or more of a 4G Long Term Evolution or a 5G NR, and the second NE includes an AMF or an AUSF; the first NE of the second access network includes a N3IWF; the notification includes a notification of congestionAttorney Docket No. SMM920230184-WO-PCTat the first NE; the second message includes a back-off timer; the selected registration includes an indication of emergency registration; the selected registration includes an indication of priority registration; the access network parameter includes an establishment cause value, and the establishment cause value includes an indication of emergency; the access network parameter includes an establishment cause value, and the establishment cause value includes an indication of priority.

[0016] Some implementations of the method and apparatuses described herein may further include a processor for wireless communication to transmit, via a first access network associated with a first radio access technology and to a first NE of a second access network associated with a second radio access technology, a first message requesting a security association session with the first NE, the second radio access technology being different than the first radio access technology; receive a second message including a notification regarding the first NE and confirming the security association session between a UE and the first NE; and transmit, to the first NE of the second access network, a third message requesting a selected registration with a second NE of the second access network and including an access network parameter for the selected registration

[0017] In some implementations of the method and apparatuses described herein, the processor is configured to receive, from the second NE of the second access network, a response confirming the selected registration with the second NE of the second access network; the first radio access technology includes a WLAN, and the second radio access technology includes one or more of a 4G Long Term Evolution or a 5G NR, and the second NE includes an AMF or an AUSF; the first NE of the second access network includes a N3IWF; the notification includes a notification of congestion at the first NE; the second message includes a back-off timer; the selected registration includes an indication of emergency registration; the selected registration includes an indication of priority registration; the access network parameter includes an establishment cause value, and the establishment cause value includes an indication of emergency; the access network parameter includes an establishment cause value, and the establishment cause value includes an indication of priority.

[0018] Some implementations of the method and apparatuses described herein may further include a method performed by a UE, the method including transmitting, via a first access network associated with a first radio access technology and to a first NE of a second access networkAttorney Docket No. SMM920230184-WO-PCTassociated with a second radio access technology, a first message requesting a security association session with the first NE, the second radio access technology being different than the first radio access technology; receiving a second message including a notification regarding the first NE and confirming the security association session between the UE and the first NE; and transmitting, to the first NE of the second access network, a third message requesting a selected registration with a second NE of the second access network and including an access network parameter for the selected registration.

[0019] In some implementations of the method and apparatuses performed by a UE described herein, the method further includes receiving, from the second NE of the second access network, a response confirming the selected registration with the second NE of the second access network; the first radio access technology includes a WLAN, and the second radio access technology includes one or more of a 4G Long Term Evolution or a 5G NR, and the second NE includes an AMF or an AUSF; the first NE of the second access network includes a N3IWF; the notification includes a notification of congestion at the first NE; the second message includes a back-off timer; the selected registration includes an indication of emergency registration; the selected registration includes an indication of priority registration; the access network parameter includes an establishment cause value, and the establishment cause value includes an indication of emergency; the access network parameter includes an establishment cause value, and the establishment cause value includes an indication of priority.

[0020] Some implementations of the method and apparatuses described herein may further include a UE for wireless communication to transmit, to a first NE of a first access network associated with a first radio access technology, an identifier and a cause for a registration procedure with a second NE of a second access network associated with a second radio access technology; receive an indication of acceptance of registration with the second access network based at least in part on the registration procedure; and transmit, based at least in part on the acceptance of registration with the second access network, data to the first NE of the first access network for routing to the second NE of the second access network.

[0021] In some implementations of the method and apparatuses described herein, the UE is configured to transmit, to the first NE, a first message to request a connection; receive, from the first NE, a second message to accept the connection; transmit, to the first NE, a third message toAttorney Docket No. SMM920230184-WO-PCTestablish a session for registration to the second NE of the second access network, the third message including the identifier and the cause for the registration procedure; receive, from the first NE, an indication of acceptance to establish the session; transmit, to the second NE and via the session, a register message request; and receive, from the second NE and via the session, a register message response; the first access network includes a Trusted Non-3GPP Access Network (TNAN) and the second access network includes AUSF of a cellular network; the first NE includes a Trusted Non- 3GPP Gateway Function (TNGF); the identifier includes a Network Access Identifier (NAI); the cause for the registration procedure includes an emergency cause; the cause for registration includes a priority cause.

[0022] Some implementations of the method and apparatuses described herein may further include a processor for wireless communication to transmit, to a first NE of a first access network associated with a first radio access technology, an identifier and a cause for a registration procedure with a second NE of a second access network associated with a second radio access technology; receive an indication of acceptance of registration with the second access network based at least in part on the registration procedure; and transmit, based at least in part on the acceptance of registration with the second access network, data to the first NE of the first access network for routing to the second NE of the second access network.

[0023] In some implementations of the method and apparatuses described herein, the processor is configured to transmit, to the first NE, a first message to request a connection; receive, from the first NE, a second message to accept the connection; transmit, to the first NE, a third message to establish a session for registration to the second NE of the second access network, the third message including the identifier and the cause for the registration procedure; receive, from the first NE, an indication of acceptance to establish the session; transmit, to the second NE and via the session, a register message request; and receive, from the second NE and via the session, a register message response; the first access network includes a TNAN and the second access network includes CN of a cellular network; the first NE includes a TNGF; the identifier includes a NAI; the cause for the registration procedure includes an emergency cause; the cause for registration includes a priority cause.

[0024] Some implementations of the method and apparatuses described herein may further include a method performed by a UE, the method including transmitting, to a first NE of a firstAttorney Docket No. SMM920230184-WO-PCTaccess network associated with a first radio access technology, an identifier and a cause for a registration procedure with a second NE of a second access network associated with a second radio access technology; receiving an indication of acceptance of registration with the second access network based at least in part on the registration procedure; and transmitting, based at least in part on the acceptance of registration with the second access network, data to the first NE of the first access network for routing to the second NE of the second access network.

[0025] In some implementations of the method and apparatuses performed by a UE described herein, the method further includes transmitting, to the first NE, a first message to request a connection; receiving, from the first NE, a second message to accept the connection; transmitting, to the first NE, a third message to establish a session for registration to the second NE of the second access network, the third message including the identifier and the cause for the registration procedure; receiving, from the first NE, an indication of acceptance to establish the session; transmitting, to the second NE and via the session, a register message request; and receiving, from the second NE and via the session, a register message response; the first access network includes a TNAN and the second access network includes CN of a cellular network; the first NE includes a TNGF; the identifier includes a NAI; the cause for the registration procedure includes an emergency cause; the cause for registration includes a priority cause.

[0026] Some implementations of the method and apparatuses described herein may further include a UE for wireless communication to transmit, to a first NE of a first access network associated with a first radio access technology, a first message requesting a security association session with a second NE of a second access network associated with a second radio access technology; receive a second message including a notification and confirming the security association session between the UE and the second NE; and transmit, to the second NE, a third message requesting a selected registration with the second access network and including an access network parameter for the selected registration.

[0027] In some implementations of the method and apparatuses described herein, the UE is configured to receive, from the second NE, a response confirming the selected registration with the second NE; the first access network includes a TNAN and the second access network includes CN of a cellular network; the first NE includes a TNGF; the notification includes a notification of congestion; the second message includes a back-off timer; the selected registration includes anAttorney Docket No. SMM920230184-WO-PCTindication of emergency registration; the selected registration includes an indication of priority registration; the access network parameter includes an establishment cause value, and where the establishment cause value includes an indication of emergency; the access network parameter includes an establishment cause value, and where the establishment cause value includes an indication of priority.

[0028] Some implementations of the method and apparatuses described herein may further include a processor for wireless communication to transmit, to a first NE of a first access network associated with a first radio access technology, an identifier and a cause for a registration procedure with a second NE of a second access network associated with a second radio access technology; receive an indication of acceptance of registration with the second access network based at least in part on the registration procedure; and transmit, based at least in part on the acceptance of registration with the second access network, data to the first NE of the first access network for routing to the second NE of the second access network.

[0029] In some implementations of the method and apparatuses described herein, the processor is configured to transmit, to the first NE, a first message to request a connection; receive, from the first NE, a second message to accept the connection; transmit, to the first NE, a third message to establish a session for registration to the second NE of the second access network, the third message including the identifier and the cause for the registration procedure; receive, from the first NE, an indication of acceptance to establish the session; transmit, to the second NE and via the session, a register message request; and receive, from the second NE and via the session, a register message response; the first access network includes a TNAN and the second access network includes CN of a cellular network; the first NE includes a TNGF; the identifier includes a NAI; the cause for the registration procedure includes an emergency cause; the cause for registration includes a priority cause.

[0030] Some implementations of the method and apparatuses described herein may further include a method performed by a UE, the method including transmitting, to a first NE of a first access network associated with a first radio access technology, a first message requesting a security association session with a second NE of a second access network associated with a second radio access technology; receiving a second message including a notification and confirming the security association session between the UE and the second NE; and transmitting, to the second NE, a thirdAttorney Docket No. SMM920230184-WO-PCTmessage requesting a selected registration with the second access network and including an access network parameter for the selected registration.

[0031] In some implementations of the method and apparatuses for a UE described herein, the method further including receiving from the second NE, a response confirming the selected registration with the second NE; the first access network includes a TNAN and the second access network includes CN of a cellular network; the first NE includes a TNGF; the notification includes a notification of congestion; the second message includes a back-off timer; the selected registration includes an indication of emergency registration; the selected registration includes an indication of priority registration; the access network parameter includes an establishment cause value, and the establishment cause value includes an indication of emergency; the access network parameter includes an establishment cause value, and the establishment cause value includes an indication of priority.

[0032] Some implementations of the method and apparatuses described herein may further include a NE for wireless communication to receive, via a first access network associated with a first radio access technology, from a UE, and at the first NE of a second access network associated with a second radio access technology, a trigger for a registration procedure with a second NE of the second access network, the second radio access technology being different than the first radio access technology; receive, from the UE via the first access network, an indication of a cause for the registration procedure with the second NE of the second access network; and receive, based at least in part on registration of the UE with the second access network, data from the UE for routing to the second NE of the second access network.

[0033] In some implementations of the method and apparatuses described herein, the NE can be configured to receive, from the UE, a first message to request a connection; transmit, to the UE, a second message indicating acceptance of the connection with the UE; receive, from the UE, a third message to establish a session for registration to the second NE of the second access network, the third message including the cause for the registration procedure; and transmit, to the UE, a fourth message indicating acceptance of establishment of the session for registration; the cause for the registration procedure includes an emergency cause; the cause for the registration procedure includes a priority cause; the first radio access technology includes a WLAN; the second radio access technology includes one or more of a 4G Long Term Evolution or a 5G NR, and the secondAttorney Docket No. SMM920230184-WO-PCTNE includes an AMF or an AUSF; the first NE of the second access network includes a N3IWF; the at least one processor is further configured to cause the first NE to perform, with the UE, at least one IKE message exchange according to an IKE protocol; the at least one processor is further configured to cause the first NE to receive the indication of the cause for the registration procedure as a private exchange type according to the IKE protocol; an IKE header of the at least one IKE message exchange indicates the private exchange type.

[0034] Some implementations of the method and apparatuses described herein may further include a method performed by a NE, the method including receiving, via a first access network associated with a first radio access technology, from a UE, and at the first NE of a second access network associated with a second radio access technology, a trigger for a registration procedure with a second NE of the second access network, the second radio access technology being different than the first radio access technology; receiving, from the UE via the first access network, an indication of a cause for the registration procedure with the second NE of the second access network; and receiving, based at least in part on registration of the UE with the second access network, data from the UE for routing to the second NE of the second access network.

[0035] In some implementations of the method and apparatuses described herein for a NE, the method further includes receiving, from the UE, a first message to request a connection; transmitting, to the UE, a second message indicating acceptance of the connection with the UE; receiving, from the UE, a third message to establish a session for registration to the second NE of the second access network, the third message including the cause for the registration procedure; and transmitting, to the UE, a fourth message indicating acceptance of establishment of the session for registration; the cause for the registration procedure includes an emergency cause; the cause for the registration procedure includes a priority cause; the first radio access technology includes a WLAN; the second radio access technology includes one or more of a 4G Long Term Evolution or a 5G NR, and the second NE includes an AMF or an AUSF; the first NE of the second access network includes a N3IWF; performing, with the UE, at least one IKE message exchange according to an IKE protocol; receiving the indication of the cause for the registration procedure as a private exchange type according to the IKE protocol; an IKE header of the at least one IKE message exchange indicates the private exchange type.Attorney Docket No. SMM920230184-WO-PCT

[0036] Some implementations of the method and apparatuses described herein may further include a NE for wireless communication to receive, from a UE, via a first access network associated with a first radio access technology, and at the first NE of a second access network associated with a second radio access technology, a first message requesting a security association session with the first NE, the second radio access technology being different than the first radio access technology; transmit a second message including a notification regarding the first NE and confirming the security association session between the UE and the first NE; and receive, from the UE, a third message requesting a selected registration with a second NE of the second access network and including an access network parameter for the selected registration.

[0037] In some implementations of the method and apparatuses described herein, the NE is configured to transmit, to the second NE of the second access network, the selected registration; the first radio access technology includes a WLAN, and the second radio access technology includes one or more of a 4G Long Term Evolution or a 5G NR, and the second NE includes an AMF or an AUSF; the first NE of the second access network includes a N3IWF; the notification includes a notification of congestion at the first NE; the second message includes a back-off timer; the selected registration includes an indication of emergency registration; the selected registration includes an indication of priority registration; the access network parameter includes an establishment cause value, and the establishment cause value includes an indication of emergency; the access network parameter includes an establishment cause value, and the establishment cause value includes an indication of priority.

[0038] Some implementations of the method and apparatuses described herein may further include a method performed by a NE, the method including receiving, from a UE, via a first access network associated with a first radio access technology, and at the first NE of a second access network associated with a second radio access technology, a first message requesting a security association session with the first NE, the second radio access technology being different than the first radio access technology; transmitting a second message including a notification regarding the first NE and confirming the security association session between the UE and the first NE; and receiving, from the UE, a third message requesting a selected registration with a second NE of the second access network and including an access network parameter for the selected registration.Attorney Docket No. SMM920230184-WO-PCT

[0039] In some implementations of the method and apparatuses described herein for a NE, the method further including transmitting, to the second NE of the second access network, the selected registration; the first radio access technology includes a WLAN, and the second radio access technology includes one or more of a 4G Long Term Evolution or a 5G NR, and the second NE includes an AMF or an AUSF; the first NE of the second access network includes a N3IWF; the notification includes a notification of congestion at the first NE; the second message includes a back-off timer; the selected registration includes an indication of emergency registration; the selected registration includes an indication of priority registration; the access network parameter includes an establishment cause value, and the establishment cause value includes an indication of emergency; the access network parameter includes an establishment cause value, and the establishment cause value includes an indication of priority.

[0040] Some implementations of the method and apparatuses described herein may further include a / device / for wireless communication to receive, from a UE and at the first NE of a first access network associated with a first radio access technology, an identifier and a cause for a registration procedure with a second NE of a second access network associated with a second radio access technology; transmit an indication of acceptance of registration with the second access network based at least in part on the registration procedure; and receive, from the UE, data for routing to the second NE of the second access network.

[0041] In some implementations of the method and apparatuses described herein, the NE is configured to receive, from the UE, a first message to request a connection; transmit, to the UE, a second message to accept the connection; receive, from the UE, a third message to establish a session for registration to the second NE, the third message including the identifier and the cause for the registration procedure; and transmit, to the UE, an indication of acceptance to establish the session; the first access network includes a TNAN and the second access network includes CN of a cellular network; the first NE includes a TNGF; the identifier includes a NAI; the cause for the registration procedure includes an emergency cause; the cause for registration includes a priority cause.

[0042] Some implementations of the method and apparatuses described herein may further include a method performed by NE, the method including receiving, from a UE and at the first NE of a first access network associated with a first radio access technology, an identifier and a cause forAttorney Docket No. SMM920230184-WO-PCTa registration procedure with a second NE of a second access network associated with a second radio access technology; transmitting an indication of acceptance of registration with the second access network based at least in part on the registration procedure; and receiving, from the UE, data for routing to the second NE of the second access network.

[0043] In some implementations of the method and apparatuses described herein for a NE, the method further includes receiving, from the UE, a first message to request a connection; transmitting, to the UE, a second message to accept the connection; receiving, from the UE, a third message to establish a session for registration to the second NE, the third message including the identifier and the cause for the registration procedure; and transmitting, to the UE, an indication of acceptance to establish the session; the first access network includes a TNAN and the second access network includes CN of a cellular network; the first NE includes a TNGF; the identifier includes a NAI; the cause for the registration procedure includes an emergency cause; the cause for registration includes a priority cause.

[0044] Some implementations of the method and apparatuses described herein may further include a NE for wireless communication to receive, at the first NE associated with a first access network of a first radio access technology, a first message from a UE requesting a security association session with a second NE of a second access network associated with a second radio access technology; transmit a second message including a notification and confirming the security association session between the UE and the second NE; and receive, from the UE, a third message requesting a selected registration with the second NE and including an access network parameter for the selected registration.

[0045] In some implementations of the method and apparatuses described herein, the NE is configured to transmit, to the second NE, the selected registration; the first access network includes a TNAN and the second access network includes CN of a cellular network; the first NE includes a TNGF; the notification includes a notification of congestion; the second message includes a backoff timer; the selected registration includes an indication of emergency registration; the selected registration includes an indication of priority registration; the access network parameter includes an establishment cause value, and where the establishment cause value includes an indication of emergency; the access network parameter includes an establishment cause value, and where the establishment cause value includes an indication of priority.Attorney Docket No. SMM920230184-WO-PCT

[0046] Some implementations of the method and apparatuses described herein may further include a method performed by a NE, the method including receiving, at the first NE associated with a first access network of a first radio access technology, a first message from a UE requesting a security association session with a second NE of a second access network associated with a second radio access technology; transmitting a second message including a notification and confirming the security association session between the UE and the second NE; and receiving, from the UE, a third message requesting a selected registration with the second NE and including an access network parameter for the selected registration.

[0047] In some implementations of the method and apparatuses described herein, the method performed by a NE further includes transmitting, to the second NE, the selected registration; the first access network includes a TNAN and the second access network includes CN of a cellular network; the first NE includes a TNGF; the notification includes a notification of congestion; the second message includes a back-off timer; the selected registration includes an indication of emergency registration; the selected registration includes an indication of priority registration; the access network parameter includes an establishment cause value, and the establishment cause value includes an indication of emergency; the access network parameter includes an establishment cause value, and the establishment cause value includes an indication of priority.BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 illustrates an example of a wireless communications system in accordance with aspects of the present disclosure.

[0049] Figure 2 illustrates an example of a random access procedure between a UE and a NE, e.g., gNB.

[0050] Figures 3a, 3b illustrate an example procedure for registration via untrusted non-3GPP access.

[0051] Figure 4 illustrates an example of an IKE header in accordance with aspects of the present disclosure.

[0052] Figure 5 illustrates a procedure in accordance with aspects of the present disclosure.Attorney Docket No. SMM920230184-WO-PCT

[0053] Figures 6a, 6b, 6c illustrate an example procedure in accordance with aspects of the present disclosure.

[0054] Figures 7a, 7b, 7c illustrate an example procedure in accordance with aspects of the present disclosure.

[0055] Figures 8a, 8b, 8c illustrate an example procedure in accordance with aspects of the present disclosure.

[0056] Figures 9a, 9b, 9c illustrate an example procedure in accordance with aspects of the present disclosure.

[0057] Figure 10 illustrates an example of a UE in accordance with aspects of the present disclosure.

[0058] Figure 11 illustrates an example of a processor in accordance with aspects of the present disclosure.

[0059] Figure 12 illustrates an example of a NE in accordance with aspects of the present disclosure.

[0060] Figure 13 illustrates a flowchart of a method in accordance with aspects of the present disclosure.

[0061] Figure 14 illustrates a flowchart of a method in accordance with aspects of the present disclosure.

[0062] Figure 15 illustrates a flowchart of a method in accordance with aspects of the present disclosure.

[0063] Figure 16 illustrates a flowchart of a method in accordance with aspects of the present disclosure.

[0064] Figure 17 illustrates a flowchart of a method in accordance with aspects of the present disclosure.

[0065] Figure 18 illustrates a flowchart of a method in accordance with aspects of the present disclosure.Attorney Docket No. SMM920230184-WO-PCT

[0066] Figure 19 illustrates a flowchart of a method in accordance with aspects of the present disclosure.

[0067] Figure 20 illustrates a flowchart of a method in accordance with aspects of the present disclosure.DETAILED DESCRIPTION

[0068] Wireless networks can be implemented for access via specific RATs such as 3G, 4G, 5G, 6G, and combinations thereof. Implementations have been proposed for multi-RAT networks that enable instances of wireless networks to be accessible via multiple different RATs. For instance, in the context of 3GPP networks (e.g., 3G, 4G, 5G, 6G, etc.), implementations have been proposed to enable 3GPP networks to be accessible via non-3GPP RATs such as WLAN. In the context of 5G, for example, the N3IWF has been introduced that provides a gateway function for a UE to access a 5G network from a non-3GPP network. For instance, a UE may connect to an N3IWF via a non-3GPP network to register for connectivity to a 3GPP network. After successful registration with the 3GPP network the UE may transmit data to and receive data from the 3GPP network via connectivity to the non-3GPP network and utilizing the N3IWF.

[0069] While an N3IWF can provide functionality for enabling non-3GPP access to a 3GPP network, scenarios may occur where non-3GPP network to 3GPP network access may be denied. For instance, where an N3IWF used for connection to the 3GPP network via non-3GPP access is congested (e.g., experiencing network traffic above a threshold), UE registration with the 3GPP network may not be performed. Failure to register the UE with the 3GPP network can be particularly problematic in scenarios where a UE is attempting make emergency calls and / or high priority calls via non-3GPP network to 3GPP network access.

[0070] Accordingly, aspects of this disclosure are directed to enabling selected registrations such as emergency registration to be performed when a NE (e.g., N3IWF, TNGF) responsible for transcoding between a UE and an AMF of a 3 GPP network is congested due to its internal congestion construct. The described implementations, for instance, can be utilized in the context of untrusted non-3GPP networks as well as trusted non-3GPP networks. For example, for access to a 3GPP network via an untrusted non-3GPP network, an N3IWF may be utilized. For access to a 3GPP network via a trusted non-3GPP network, a TNGF may be utilized.Attorney Docket No. SMM920230184-WO-PCT

[0071] According to implementations, an exchange type is defined for the header of one or more IKE protocols to identify the purpose of 5G registration (e.g., emergency, high priority, etc.) in an untrusted non-3GPP access network. Further, a new extension to the NAI used by a UE to categorize and identify the purpose of 5G registration in a trusted non-3GPP access network is provided. The described implementations also allow a UE to maintain IKE security association (SA) and / or other state when the UE is denied access to a 3GPP network and to provide establishment cause for accessing a 3GPP network via untrusted or trusted non-3GPP access.

[0072] Thus, the described implementations can enable a UE to access a 3GPP network via a non-3GPP network in scenarios where a NE (e.g., N3IWF, TNGF) is congested. For instance, for at least some causes for registration (e.g., emergency, high priority, etc.) a NE providing non-3GPP to 3GPP network access can allow network registration with the 3GPP network to proceed when the NE exceeds a congestion threshold. Implementations can thus increase call reliability in congested scenarios and increase the likelihood of successful connection of some call types, such as for emergency and high priority calls.

[0073] Aspects of the present disclosure are described in the context of a wireless communications system.

[0074] Figure 1 illustrates an example of a wireless communications system 100 in accordance with aspects of the present disclosure. The wireless communications system 100 may include one or more network equipment NE 102, one or more UE 104, and CN 106. The wireless communications system 100 may support various radio access technologies. In some implementations, the wireless communications system 100 may be a 4G network, such as an LTE network or an LTE- Advanced (LTE-A) network. In some other implementations, the wireless communications system 100 may be a NR network, such as a 5G network, a 5G-Advanced (5G-A) network, or a 5G ultrawideband (5G-UWB) network. In other implementations, the wireless communications system 100 may be a combination of a 4G network and a 5G network, or other suitable radio access technology including Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20. The wireless communications system 100 may support radio access technologies beyond 5G, for example, 6G. Additionally, the wireless communications system 100 may support technologies, such as time division multiple access (TDMA), frequency division multiple access (FDMA), or code division multiple access (CDMA), etc.Attorney Docket No. SMM920230184-WO-PCT

[0075] The one or more NE 102 may be dispersed throughout a geographic region to form the wireless communications system 100. One or more of the NE 102 described herein may be or include or may be referred to as a network node, a base station, a network element, a network function, a NE, a radio access network (RAN), a NodeB, an eNodeB (eNB), a next-generation NodeB (gNB), or other suitable terminology. An NE 102 and a UE 104 may communicate via a communication link, which may be a wireless or wired connection. For example, an NE 102 and a UE 104 may perform wireless communication (e.g., receive signaling, transmit signaling) over a Uu interface.

[0076] An NE 102 may provide a geographic coverage area for which the NE 102 may support services for one or more UEs 104 within the geographic coverage area. For example, an NE 102 and a UE 104 may support wireless communication of signals related to services (e.g., voice, video, packet data, messaging, broadcast, etc.) according to one or multiple radio access technologies. In some implementations, an NE 102 may be moveable, for example, a satellite associated with a non-terrestrial network (NTN). In some implementations, different geographic coverage areas associated with the same or different radio access technologies may overlap, but the different geographic coverage areas may be associated with different NE 102.

[0077] The one or more UEs 104 may be dispersed throughout a geographic region of the wireless communications system 100. A UE 104 may include or may be referred to as a remote unit, a mobile device, a wireless device, a remote device, a subscriber device, a transmitter device, a receiver device, or some other suitable terminology. In some implementations, the UE 104 may be referred to as a unit, a station, a terminal, or a client, among other examples. Additionally, or alternatively, the UE 104 may be referred to as an Internet-of-Things (loT) device, an Internet-of- Everything (loE) device, or machine-type communication (MTC) device, among other examples.

[0078] A UE 104 may be able to support wireless communication directly with other UEs 104 over a communication link. For example, a UE 104 may support wireless communication directly with another UE 104 over a device-to-device (D2D) communication link. In some implementations, such as vehicle-to-vehicle (V2V) deployments, vehicle-to-everything (V2X) deployments, or cellular-V2X deployments, the communication link may be referred to as a sidelink. For example, a UE 104 may support wireless communication directly with another UE 104 over a PC5 interface.Attorney Docket No. SMM920230184-WO-PCT

[0079] An NE 102 may support communications with the CN 106, or with another NE 102, or both. For example, an NE 102 may interface with other NE 102 or the CN 106 through one or more backhaul links (e.g., SI, N2, N6, or other network interface). In some implementations, the NE 102 may communicate with each other directly. In some other implementations, the NE 102 may communicate with each other indirectly (e.g., via the CN 106). In some implementations, one or more NE 102 may include subcomponents, such as an access NE, which may be an example of an access node controller (ANC). An ANC may communicate with the one or more UEs 104 through one or more other access network transmission entities, which may be referred to as a radio heads, smart radio heads, or transmission-reception points (TRPs).

[0080] The CN 106 may support user authentication, access authorization, tracking, connectivity, and other access, routing, or mobility functions. The CN 106 may be an evolved packet core (EPC), or a 5G core (5GC), which may include a control plane entity that manages access and mobility (e.g., a mobility management entity (MME), an AMF) and a user plane entity that routes packets or interconnects to external networks (e.g., a serving gateway (S-GW), a packet data network (PDN) gateway (P-GW), or a user plane function (UPF)). In some implementations, the control plane entity may manage non-access stratum (NAS) functions, such as mobility, authentication, and bearer management (e.g., data bearers, signal bearers, etc.) for the one or more UEs 104 served by the one or more NE 102 associated with the CN 106.

[0081] The CN 106 may communicate with a packet data network over one or more backhaul links (e.g., via an SI, N2, N6, or other network interface). The packet data network may include an application server. In some implementations, one or more UEs 104 may communicate with the application server. A UE 104 may establish a session (e.g., a protocol data unit (PDU) session, or the like) with the CN 106 via an NE 102. The CN 106 may route traffic (e.g., control information, data, and the like) between the UE 104 and the application server using the established session (e.g., the established PDU session). The PDU session may be an example of a logical connection between the UE 104 and the CN 106 (e.g., one or more network functions of the CN 106).

[0082] In the wireless communications system 100, the NEs 102 and the UEs 104 may use resources of the wireless communications system 100 (e.g., time resources (e.g., symbols, slots, subframes, frames, or the like) or frequency resources (e.g., subcarriers, carriers)) to perform various operations (e.g., wireless communications). In some implementations, the NEs 102 and theAttorney Docket No. SMM920230184-WO-PCTUEs 104 may support different resource structures. For example, the NEs 102 and the UEs 104 may support different frame structures. In some implementations, such as in 4G, the NEs 102 and the UEs 104 may support a single frame structure. In some other implementations, such as in 5G and among other suitable radio access technologies, the NEs 102 and the UEs 104 may support various frame structures (i.e., multiple frame structures). The NEs 102 and the UEs 104 may support various frame structures based on one or more numerologies.

[0083] One or more numerologies may be supported in the wireless communications system 100, and a numerology may include a subcarrier spacing and a cyclic prefix. A first numerology (e.g., / r=0) may be associated with a first subcarrier spacing (e.g., 15 kHz) and a normal cyclic prefix. In some implementations, the first numerology (e.g., / r=0) associated with the first subcarrier spacing (e.g., 15 kHz) may utilize one slot per subframe. A second numerology (e.g., / r=l) may be associated with a second subcarrier spacing (e.g., 30 kHz) and a normal cyclic prefix. A third numerology (e.g., / r=2) may be associated with a third subcarrier spacing (e.g., 60 kHz) and a normal cyclic prefix or an extended cyclic prefix. A fourth numerology (e.g., / r=3) may be associated with a fourth subcarrier spacing (e.g., 120 kHz) and a normal cyclic prefix. A fifth numerology (e.g., / r=4) may be associated with a fifth subcarrier spacing (e.g., 240 kHz) and a normal cyclic prefix.

[0084] A time interval of a resource (e.g., a communication resource) may be organized according to frames (also referred to as radio frames). Each frame may have a duration, for example, a 10 millisecond (ms) duration. In some implementations, each frame may include multiple subframes. For example, each frame may include 10 subframes, and each subframe may have a duration, for example, a 1 ms duration. In some implementations, each frame may have the same duration. In some implementations, each subframe of a frame may have the same duration.

[0085] Additionally or alternatively, a time interval of a resource (e.g., a communication resource) may be organized according to slots. For example, a subframe may include a number (e.g., quantity) of slots. The number of slots in each subframe may also depend on the one or more numerologies supported in the wireless communications system 100. For instance, the first, second, third, fourth, and fifth numerologies (i.e., / r=0, / =l , / r=2, / r=3, / r=4) associated with respective subcarrier spacings of 15 kHz, 30 kHz, 60 kHz, 120 kHz, and 240 kHz may utilize a single slot per subframe, two slots per subframe, four slots per subframe, eight slots per subframe, and 16 slots perAttorney Docket No. SMM920230184-WO-PCTsubframe, respectively. Each slot may include a number (e.g., quantity) of symbols (e.g., Orthogonal Frequency Division Multiplexing (OFDM) symbols). In some implementations, the number (e.g., quantity) of slots for a subframe may depend on a numerology. For a normal cyclic prefix, a slot may include 14 symbols. For an extended cyclic prefix (e.g., applicable for 60 kHz subcarrier spacing), a slot may include 12 symbols. The relationship between the number of symbols per slot, the number of slots per subframe, and the number of slots per frame for a normal cyclic prefix and an extended cyclic prefix may depend on a numerology. It should be understood that reference to a first numerology (e.g., / r=0) associated with a first subcarrier spacing (e.g., 15 kHz) may be used interchangeably between subframes and slots.

[0086] In the wireless communications system 100, an electromagnetic (EM) spectrum may be split, based on frequency or wavelength, into various classes, frequency bands, frequency channels, etc. By way of example, the wireless communications system 100 may support one or multiple operating frequency bands, such as frequency range designations FR1 (410 MHz - 7.125 GHz), FR2 (24.25 GHz - 52.6 GHz), FR3 (7.125 GHz - 24.25 GHz), FR4 (52.6 GHz - 114.25 GHz), FR4a or FR4-1 (52.6 GHz - 71 GHz), and FR5 (114.25 GHz - 300 GHz). In some implementations, the NEs 102 and the UEs 104 may perform wireless communications over one or more of the operating frequency bands. In some implementations, FR1 may be used by the NEs 102 and the UEs 104, among other equipment or devices for cellular communications traffic (e.g., control information, data). In some implementations, FR2 may be used by the NEs 102 and the UEs 104, among other equipment or devices for short-range, high data rate capabilities.

[0087] FR1 may be associated with one or multiple numerologies (e.g., at least three numerologies). For example, FR1 may be associated with a first numerology (e.g., / r=0), which includes 15 kHz subcarrier spacing; a second numerology (e.g., / r=l), which includes 30 kHz subcarrier spacing; and a third numerology (e.g., / r=2), which includes 60 kHz subcarrier spacing. FR2 may be associated with one or multiple numerologies (e.g., at least 2 numerologies). For example, FR2 may be associated with a third numerology (e.g., / r=2), which includes 60 kHz subcarrier spacing; and a fourth numerology (e.g., / r=3), which includes 120 kHz subcarrier spacing.

[0088] According to implementations, one or more of the NEs 102 and the UEs 104 are operable to implement various aspects of the techniques described with reference to the presentAttorney Docket No. SMM920230184-WO-PCTdisclosure. For example, a UE 104 and an NE 102 can transmit and receive data via in intermediary non-3GPP access network (e.g., WLAN network) to enable the UE 104 to access a 3GPP access network associated with the NE 102 via the non-3GPP access network.

[0089] Figure 2 illustrates an example of a random access procedure 200 between a UE 104 and a NE 102, e.g., gNB. In a 3GPP access network, a UE establishes radio resource control (RRC) connection by using random access channel (RACH), where the UE attempts to obtain uplink (UL) resources by sending MSG #1 (preamble sequence). The gNB can respond with MSG#2 (random access response) on RACH and include a UE temporary identity and uplink resources. Upon obtaining the resource and a temporary identity, the UE can send a MSG#3 (connection request) to establish a connection and also send an establishment cause and the size of the NAS message to be transmitted. If the gNB is congested, the establishment cause can determine whether the gNB will make an exception that the UE can send the NAS message. For instance if the establishment cause is emergency, then the gNB is to assign a connection. The gNB can send contention resolution in MSG#4 and allow the UE a connection. The UE can then transmit the NAS emergency registration message, such as illustrated in the procedure 200.

[0090] Figures 3a, 3b illustrate an example procedure 300 for registration via untrusted non- 3GPP access. For instance, a connection procedure in non-3GPP access is different than in 3GPP and at the time of attempting to obtain network access which corresponds to the gNB, the purpose of the requested access may not be determined. For instance an untrusted non-3GPP access network (e.g., for 5G technology) allows a UE and / or other device to obtain access to a 5G core network. For example, in the procedure 300, the UE 104 utilizes connectivity to an untrusted non-3GPP access network 302 to register via untrusted access and a non-3GPP interworking function (N3IWF) 304 to the 5G network, e.g., the AMF 306 and / or the AUSF 308. See, e.g., Figure 4.12.2.2-1 in 3GPP technical specification (TS) 23.502.

[0091] To register to the network (e.g., a 5G network), the UE obtains an IP address and establishes an Internet Protocol security (IPsec) security association (SA) with a selected N3IWF for NAS message transmission. The N3IWF may reject the IPsec SA establishment if it receives an OVERLOAD START message from the network core AMF. There are however some exceptions in which the AMF is not to reject the IPsec establishment and therefore reject the UE registration toAttorney Docket No. SMM920230184-WO-PCTcore network (e.g., 5GCN). Examples of such exceptions are listed in 3GPP TS 24.501, subclause 4.7.2.2.

[0092] In addition to these exceptions, the UE may retry to access the network by retrying after a time interval that it may have received from the network; changing the universal integrated circuit card (UICC); switching off; and / or listing new network slices. In the untrusted non-3GPP access network, prior to message exchange between the N3IWF and the AMF for establishment of the first child SA, the N3IWF may also reject such an establishment due to its internal congestion and therefore the first child SA may not be established. Thus the UE may not be able to register for placing a call for those exception cases as described above. Currently a solution for this is missing in 3GPP.

[0093] The procedure 300 involves a UE 104, an untrusted non-3GPP access network 302, an N3IWF 304, an AMF 306, and an AUSF 308. In the procedure 300: At la. UE connects to untrusted non-3GPP access network and is allocated an Internet Protocol (IP) address; lb. UE selects an N3IWF and obtains its IP address; 2. IKE_SA_INIT; 3. IKE_AUTH Req (UE Id, without AUTH); 4. IKE_AUTH Res (Extensible Authentication Protocol (EAP)-Req / 5G-Start); 5. IKE_AUTH Req (EAP-Res / 5G-NAS / Access Network (AN)-Params, NAS-PDU [Registration Request]); 6a. AMF Selection; 6b. N2 msg (Registration Request); 7a. N2 msg (Identity Req. / Res.); 7b. IKE_AUTH Req / Res (EAP-Req / Res / 5G-NAS / NAS-PDU [Identity Req. / Res.]); 8a. Authentication, Authorization, and Accounting (AAA) Key Request (Subscription Concealed Identifier (SUCI) or Subscription Permanent Identifier (SUPI)); 8b. AAA msg (EAP / Authentication and Key Agreement (AKA)-Challenge); 8c. N2 msg (Auth. Request [EAP / AKA-Challenge]); 8d. IKE_AUTH Res (EAP-Req / 5G-NAS / NAS-PDU [Auth. Request [EAP / AKA-Challenge]]); 8e. IKE_AUTH Req (EAP-Res / 5G-NAS / NAS-PDU [Auth. Response [EAP / AKA-Challenge]]); 8f. N2 msg (Auth. Response [EAP / AKA-Challenge]); 8g. AAA msg (EAP / AKA-Challenge); and 8h. AAA Key Response (Security Anchor Function (SEAF) key, EAP-Success).

[0094] Further to the procedure 300, at 9a. N2 msg (Security Mode Command [EAP-Success]); 9b. IKE_AUTH Res (EAP-Req / 5G-NAS / NAS-PDU [NAS Security Mode Command [EAP- Success]]); 9c. IKE_AUTH Req (EAP-Res / 5G-NAS / NAS-PDU [Security Mode Complete]); 9d. N2 msg ([NAS Security Mode Complete]); 10a. Initial Context Setup Req (N3IWF key); 10b. IKE_AUTH Res (EAP-Success); I la. IKE_AUTH (with AUTH) at which point the IPsec SA isAttorney Docket No. SMM920230184-WO-PCTestablished; 1 lb. Initial Context Setup Res; 12. N2 msg (NAS Registration Accept); and 13. [NAS over IPsec] NAS Registration Accept. After this subsequent NAS messages are carried over the IPsec SA.

[0095] Accordingly, aspects of the present disclosure include solutions to enable registration with a 3GPP network in non-3GPP access scenarios when a non-3GPP access entity (e.g., N3IWF) may be congested. For instance, to establish a secure connection between a UE (and / or other device) and a NE capable of the IKEv2 such as N3IWF, for the purpose of NAS exchange between the UE and the network, communication can begin with four messages for IKE_SA_INIT and IKE_AUTH exchanges, such as according to Internet Engineering Task Force (IETF) Request for Comments (RFC) 7296.

[0096] The first pair of messages exchanged (e.g., IKE_SA_INIT) is to negotiate cryptographic algorithms and establish IKE SA, while the second pair of messages (e.g., IKE_AUTH) exchanged is to create the first child security association (SA) for the NAS signaling exchange. The IKE SA may not be established if there is an error related to creating the IKE SA such as an authentication error. See, e.g., IETF RFC 7296. If that is not the case the IKE SA may still be established even if the IKE_AUTH exchange fails for some reason. IETF RFC 7296 lists the following cases where the IKE SA is still established even if there is an error: NO_PROPOS AL_CHOSEN if None of the proposed crypto suites was acceptable; TS_UNACCEPTABLE if the policy does not allow the responder to accept the proposed traffic selectors; SINGLE_PAIR_REQUIRED if the traffic selectors specifying a single pair of addresses which are not acceptable;INTERNAL_ADDRESS_FAILURE if there is an error to assign an IP address; and FAILED_CP_REQUIRED if configuration is to be used for an identity.

[0097] Figure 4 illustrates an example of an IKE header 400 in accordance with aspects of the present disclosure. According to implementations a purpose of a network registration request can be determined at the time of establishing IKE SA and the first child SA for the signaling. An IKE header in the IKE protocol can have the format illustrated in the IKE header 400, such as specified according to IETF RFC 7296. The IKE header 400 includes an Exchange Type field 402 that can be used to identify a type of communication exchange that a UE is requesting with a 3GPP network via non-3GPP network access.Attorney Docket No. SMM920230184-WO-PCT

[0098] Table 1 identifies different exchange types that can be specified, such as via the Exchange Type field 402. Exchange Type (1 octet) - Indicates the type of exchange being used. This constrains the payloads sent in each message and orderings of messages in an exchange.Table 1: Different Exchange TypesExchange Type ValueRESERVED 0-33IKE_SA_INIT 34IKE_AUTH 35CREATE_CHILD_SA 36INFORMATIONAL 37RESERVED TO IANA 38-239Reserved for private use 240-255

[0099] The exchange types include a reserved value for private use 240-255. Therefore when accessing to the non-3GPP access network, the purpose of the access can be identified by adding 4 bits of establishment cause (e.g., as defined 3GPP TS 24.502 subclause 9.2.2) to the four least significant bits of Exchange type and defining a new exchange type for IKE_SA_INIT for establishing IKE SA and / or IKE_AUTH for establishing the first child SA in the IKE header.

[0100] Table 2 identifies different exchange types for a non-3GPP access information element.Attorney Docket No. SMM920230184-WO-PCTTable 2: Exchange type for non-3GPP access information element

[0101] Figure 5 illustrates a procedure 500 in accordance with aspects of the present disclosure. The procedure 500, for instance, involves a UE 104 and an N3IWF 304 and illustrates an example of denied registration due to congestion via untrusted non-3GPP access. For example, if the network is congested and the purpose of the registration is not high priority or emergency or any other status which may be able to access the network, upon establishment of IKE SA and as a response to IKE AUTH for establishing the first child SA, the N3IWF 304 may send a Notify message to the UE 104 of type CONGESTION with back-off timer as shown in the procedure 500.

[0102] Figures 6a, 6b, 6c illustrate an example procedure 600 in accordance with aspects of the present disclosure. The procedure 600, for instance, enables priority registration with a 3GPP network via untrusted non-3GPP network access. The procedure 600 includes numbered messages that can be utilized for priority registration as described herein. Further, the procedure 600 involves a UE 104, an untrusted non-3GPP access network 302, an N3IWF 304, an AMF 306, and an AUSF 308.

[0103] In the procedure 600: la. UE connects to untrusted non-3GPP access network 302 and is allocated an IP address; lb. UE selects an N3IWF 304 and obtains its IP address;2. IKE_SA_INIT(Header (HDR) [Exchange Type= Emergency]) in which an IKE header is used to indicate an exchange type of emergency; 3. IKE_AUTH Req (HDR [Exchange Type= Emergency], UE Id, without AUTH); 4. IKE_AUTH Res (EAP-Req / 5G-Start); 5. IKE_AUTH Req (EAP-Attorney Docket No. SMM920230184-WO-PCTRes / 5G-NAS / AN-Params, NAS-PDU [Registration Request]); 6a. AMF Selection; and 6b. N2 msg (Registration Request).

[0104] Further to the procedure 600 at 7a. N2 msg (Identity Req. / Res.); 7b. IKE_AUTH Req / Res (EAP-Req / Res / 5G-NAS / NAS-PDU [Identity Req. / Res.]); 8a. AAA Key Request (SUCI or SUPI); 8b. AAA msg (EAP / AKA-Challenge); 8c. N2 msg (Auth. Request [EAP / AKA-Challenge]); 8d. IKE_AUTH Res (EAP-Req / 5G-NAS / NAS-PDU [Auth. Request [EAP / AKA-Challenge]]); 8e. IKE_AUTH Req (EAP-Res / 5G-NAS / NAS-PDU [Auth. Response [EAP / AKA-Challenge]]); 8f. N2 msg (Auth. Response [EAP / AKA-Challenge]); 8g. AAA msg (EAP / AKA-Challenge); 8h. AAA Key Response (SEAF key, EAP-Success); 9a. N2 msg (Security Mode Command [EAP-Success]); and 9b. IKE_AUTH Res (EAP-Req / 5G-NAS / NAS-PDU [NAS Security Mode Command [EAP- Success]]).

[0105] Further to the procedure 600 at 9c. IKE_AUTH Req (EAP-Res / 5G-NAS / NAS-PDU [Security Mode Complete]); 9d. N2 msg ([NAS Security Mode Complete]); 10a. Initial Context Setup Req(N3IWF key); 10b. IKE_AUTH Res (EAP-Success); I la. IKE_AUTH Req / Res (with AUTH) at which point the IPsec SA is established; 1 lb. Initial Context Setup Res; 12. N2 msg (NAS Registration Accept); and 13. [NAS over IPsec] NAS Registration Accept. Subsequent NAS messages can be carried over the IPsec SA.

[0106] In the procedure 600 message 2 IKE_SA_INIT and / or message 3 as well as messages including for IKE_AUTH exchanges which are used for establishing the first child SA as well as exchanging the NAS messages can be used to implement the described implementations. For instance, for message 2: If the UE is establishing the IKE SA for the emergency purposes, the UE may use the new private encoding "240" and / or binary "11110000" as an exchange type to replace the conventional "34" which is represented as "00100010" in IKE_SA_INIT message. If the N3IWF is congested, it can determine from the new encoding of the exchange type in the header that the request for the establishing the IKE SA has an emergency purpose and may make the exception and may agree to establish the IKE SA and thereafter the first child SA. The procedure 600 shows the IKE_SA_INIT exchange with the new header in italics.

[0107] For message 3 and / or other messages for IKE_AUTH exchange: If the UE is establishing a first child SA for the emergency purposes, the UE may use the new private encodingAttorney Docket No. SMM920230184-WO-PCT"240" or binary "11110000" as exchange type to replace the traditional "35" which is represented as "00100011" in IKE_AUTH. If the N3IWF is congested, it can determine from the new encoding of the exchange type in the header that the request for the establishing the first child SA has emergency purpose and may make the exception and may agree to establish the first child SA. The UE and the network may use the same exchange type with identity "240" for the IKE_AUTH exchanges. The procedure 600 shows the IKE_AUTH exchanges with the new header in italics.

[0108] In implementations both IKE_SA_INIT and IK_AUTH exchanges may have exchange type dedicated for the establishment causes, see, e.g., Table 3.Table 3: Exchange type for non-3GPP access information element

[0109] In some scenarios it is recommended when establishing the IKE SA to maintain the SA even if the establishment of child SAs fails, e.g., according to IETF RFC 7296: A failed attempt to create a Child SA is not to tear down the IKE SA: there is no reason to lose the work done to set upAttorney Docket No. SMM920230184-WO-PCTthe IKE SA. The IKE SA may be established even if the N3IWF is busy and therefore the IKE_AUTH may use the private message type in the header and the exchange type dedicated for the establishment causes, such as illustrated in Table 4.Table 4: Exchange type for non-3GPP access information element

[0110] In implementations the above customized configurations are not limited and other configurations for customizing the exchange type in the header may be implemented.

[0111] Figures 7a, 7b, 7c illustrate an example procedure 700 in accordance with aspects of the present disclosure. The procedure 700, for instance, enables trusted non-3GPP priority registration according to implementations described herein. The procedure 700 includes numbered messages that can be utilized for priority registration as described herein. In trusted network scenarios since the NAS registration is performed prior to IP assignment (e.g., by using a layer 2 protocol such as IEEE 802.11) the category and / or the purpose of the connection to the access network for 5G registration may be indicated as a NAI that the UE provides to the trusted non-3GPP access network (e.g., TNAN) such as illustrated in the procedure 700. The procedure 700 involves a UE 104, a TNAN 702 including a Trusted Non-3GPP Access Point (TNAP) 704 and a TNGF 706, an AMF 306, and an AUSF 308.Attorney Docket No. SMM920230184-WO-PCT

[0112] In the procedure 700: Connectivity can be established via L2: Ethernet, 802.3, 802.11, Point-to-Point Protocol (PPP), etc.; 0. Trusted Non-3GPP Access Network Selection; 1. L2 connection; 2. L2 (EAP-Req / Identity); 3. L2 (EAP-Res / Identity) NAI=username@ category. realm where username identifies a UE, category can be used to specify an establishment cause for which the UE is requesting registration with a network (e.g., 5G network), and realm identifies an internet domain of a Network Access Server (NAS). Further to the procedure 700: 4. L2 (EAP-Req / 5G- Start); 5. L2 (EAP-Res / 5G-NAS / AN-Params [UE Id,5G- Globally Unique Temporary Identity (GUTI) or SUCI, Selected Public Land Mobile Network (PLMN) ID, Requested Network Slice Selection Assistance Information (NSSAI), Establishment cause], NAS-PDU [Registration Request]); 6a. AMF Selection; 6b. N2 msg (Registration Request); 7a. N2 msg (Identity Req. / Res.); and 7b. L2 (EAP-Req / Res / 5G-NAS / NAS-PDU [Identity Req. / Res.]).

[0113] Further to the procedure 700: At 8a. AAA Key Request (SUPI or SUCI); 8c. AAA Key Response (SEAF key, EAP-Success); accordingly, TNGF and TNAP keys are created. Further, at 9a. N2 msg (SMC Request [EAP-Success]); 9b. L2 (EAP-Req / 5G-NAS / NAS-PDU [SMC Request (EAP-Success)]); 9c. L2 (EAP-Res / 5G-NAS / NAS-PDU [SMC Complete]); 9d. N2 msg (SMC Complete); 10a. N2 Initial Ctx Setup Request (TNGF key); 10b. L2 (EAP-Req / 5G- Notification / TNGF Address); 10c. L2 (EAP-Res / 5G-Notification / ); lOd. AAA (TNAP key, EAP- Success); lOe. L2 (EAP-Success); 11. Security establishment using the TNAP key (e.g. 4-way handshake for WLAN); and 12. Local IP configuration.

[0114] In the procedure 700, for trusted network (NWt) connection between the UE 104 and the TNGF 706: 13a. IKE_SA_INIT; 13b. IKE_AUTH (IDi, SA, TSi, TSr, AUTH); 13c. IKE_AUTH (IDr, SA, TSi, TSr, AUTH); and 13d. Transmission Control Protocol (TCP) Connection. Further to the procedure 700: At 14. N2 Initial Ctx Setup Response; 15a. N2 msg (NAS Registration Accept); and 15b. [NAS over the NWt connection] NAS Registration Accept. Subsequent NAS messages between UE & TNGF can be carried over the NWt connection.

[0115] In the procedure 700, various messages can be used to implement the described implementations including message 3 for providing NAI to TNAN 702, message 13a for IKE_SA_INIT for establishing IKE SA, and messages 13b and 13c for IKE_AUTH exchanges which are for establishing the first child SA. For message 3 : the NAI message in this message may include subjects and / or values corresponding to establishment causes such as defined inAttorney Docket No. SMM920230184-WO-PCT3GPP TS 24.502 subclause 9.2.2. As an example the "category" in NAI may be replaced by: emergency; highPriority Access; mo-Signalling; mo-Data; mps-Priority Access; and / or mcs- Priority Access. This can enable the TNAN 702 to determine a purpose of the network connection for network (e.g., 5G) registration. Aspects of the procedure 700 introduced by the present disclosure include message content indicated in italics. Configuration for assigning the intention of the network connection in NAI is not limited the above example and can be expanded to different configurations.

[0116] Implementations described herein enable an IKE SA to be established even if the NE such as N3IWF is congested due to its internal congestion construct. In response to an IKE_AUTH request for establishing the first child SA, the NE may send a Notify message of the type CONGESTION and a payload for the value of the back-off timer in case the UE and / or the device may attempt to transmit a new IKE_AUTH exchange to register to the 5G network. Past a time interval, if the UE and / or the device does not initiate a new IKE_AUTH exchange for NAS registration, the NE such as N3IWF may terminate the IKE SA. This time interval may be less, equal to, or more than the back-off timer. The network may add additional time to a back-off timer prior to its termination in order to cover a period that the UE and / or the device may be out of coverage. The UE and the network may also keep the IKE SA without tearing it down within a specific time period.

[0117] The UE and / or the device may determine to place a high priority call, an emergency call, and / or a special call, and in such scenarios despite the Notify message with the type CONGESTED and the payload of the back-off timer, the UE and / or the device may initiate a new IKE_AUTH exchange with an appropriate NAS message to register and added access network (AN)-Parameters field (e.g., as defined in 3GPP TS 24.502) to indicate the purpose of the registration. The AN- Parameters field includes AN-Parameters types which may be "establishment cause for non-3GPP access," such as listed in 3GPP TS 24.502 subclause 9.2.2. For instance, upon receipt of establishment cause for emergency, the NE such as N3IWF may consider the emergency establishment cause and may forward the NAS message to the AMF by overriding the back-off timer due to internal congestion.

[0118] Figures 8a, 8b, 8c illustrate an example procedure 800 in accordance with aspects of the present disclosure. The procedure 800, for instance, represents a procedure for registration of a UEAttorney Docket No. SMM920230184-WO-PCTvia untrusted non-3GPP access. The procedure 800 involves a UE 104, an untrusted non-3GPP access network 302, an N3IWF 304, an AMF 306, and an AUSF 308. The procedure 800 includes numbered messages that can be utilized for priority registration as described herein.

[0119] In the procedure 800: At la. UE connects to untrusted non-3GPP access network and is allocated an IP address; lb. UE selects an N3IWF and obtains its IP address; 2. IKE_SA_INIT;3. IKE_AUTH Req (UE Id, without AUTH); 4. IKE_AUTH Res (EAP-Req / 5G-Start[Notify {CONGESTION, N3GPP_BACKOFF_TIMER}]); 5. IKE_AUTH Req (EAP-Res / 5G-NAS / AN- Params, NAS-PDU [Registration Request]); 6a. AMF Selection; and 6b. N2 msg (Registration Request). Further to the procedure 800: At 7a. N2 msg (Identity Req. / Res.); 7b. IKE_AUTH Req / Res (EAP-Req / Res / 5G-NAS / NAS-PDU [Identity Req. / Res.]); 8a. AAA Key Request (SUCI or SUPI); 8b. AAA msg (EAP / AKA-Challenge); 8c. N2 msg (Auth. Request [EAP / AKA-Challenge]); 8d. IKE_AUTH Res (EAP-Req / 5G-NAS / NAS-PDU [Auth. Request [EAP / AKA-Challenge]]); 8e. IKE_AUTH Req (EAP-Res / 5G-NAS / NAS-PDU [Auth. Response [EAP / AKA-Challenge]]); 8f. N2 msg (Auth. Response [EAP / AKA-Challenge]); 8e. IKE_AUTH Req (EAP-Res / 5G-NAS / NAS-PDU [Auth. Response [EAP / AKA-Challenge]]); 8f. N2 msg (Auth. Response [EAP / AKA-Challenge]); 8g. AAA msg (EAP / AKA-Challenge); and 8h. AAA Key Response (SEAF key, EAP-Success).

[0120] Further to the procedure 800: At 9a. N2 msg (Security Mode Command [EAP-Success]); 9b. IKE_AUTH Res (EAP-Req / 5G-NAS / NAS-PDU [NAS Security Mode Command [EAP- Success]]); 9c. IKE_AUTH Req (EAP-Res / 5G-NAS / NAS-PDU [Security Mode Complete]); 9d. N2 msg ([NAS Security Mode Complete]); 10a. Initial Context Setup Req (N3IWF key); 10b. IKE_AUTH Res (EAP-Success); and 1 la. IKE_AUTH (with AUTH). The IPsec SA is thus established. Further to the procedure 800: At 11b. Initial Context Setup Res; 12. N2 msg (NAS Registration Accept); and 13. [NAS over IPsec] NAS Registration Accept. Subsequent NAS messages can be carried over the IPsec SA.

[0121] In the procedure 800 message 4 and message 5 may be utilized to implement the described implementations. For instance, for message 4: If the NE such as N3IWF is congested, the IPsec SA or the child SA may still be created. The N3IWF may construct the IKE_AUTH response by setting the Notify message type in the Notify payload to 15,500 (e.g., as defined in section 3.10 in IETF RFC 7296) which indicates CONGESTION according to the private Notify message type, e.g., as specified in 3GPP TS 24.502 subclause 9.2.4.2. The Notification Data of the Notify payloadAttorney Docket No. SMM920230184-WO-PCTcan be set to the value of the N3GPP_BACK_TIMER. The Notify message can be inserted in the extensions field of the extensible authentication protocol (EAP)-Req / 5G-Start as defined in subclause 9.3.2.2.1 of 3GPP TS 24.502. The IKE-AUTH Resp can include EAP-Req / 5G-Start to indicate to the UE the initiation of EAP-5G. Furthermore the constructed Notify message with the CONGESTION error type and the value of the back-off timer may indicate to the UE to attempt the next IKE_AUTH exchange after the back-off timer. The N3IWF may transmit the IKE_AUTH response towards the UE.

[0122] Further, for message 5: The UE may generate an IKE_AUTH request including an EAP- Response / 5G-NAS packet which includes the AN -parameters and a registration request message. The UE may set AN-parameter type field value to "04H", meaning "establishment cause for non- 3GPP access" such as according to subclause 9.3.2.2.2 in 3GPP TS 24.502, where the "establishment cause for non-3GPP access" may be set to "0000" indicating emergency. In order for the UE to override the back-off timer interval, the "establishment cause for non-3GPP access" may be set according to a value rather than emergency value indicating an agreed reason to override the back-off timer interval.

[0123] In implementations after IKE SA establishment and at the time of first child SA establishment, in response to IKE_AUTH request for establishing the first child SA the N3IWF may not indicate that the network in congested. If the UE and / or the device performs a regular registration, the N3IWF may send a Notify message of type CONGESTED with a back off timer. The N3IWF and the UE may choose to tear down the IKE SA and / or the UE and the network may keep the IKE SA in order to avoid reestablishing it again after the back off timer's time interval.

[0124] In implementations if the UE and / or the device initiates a new IKE_AUTH exchange with appropriate NAS message to register the UE can add an access network (AN)-Parameters field such as defined in 3GPP TS 24.502 to include the purpose of the registration. As described in 3GPP TS 24.502, the AN-Parameters field includes AN-Parameters types which may be "establishment cause for non-3GPP access" which is listed in 3GPP TS 24.502 subclause 9.2.2.Upon receipt, for instance, of establishment cause for emergency, the NE such as N3IWF may, based on the emergency establishment cause, forward the NAS message to the AMF by overriding the back-off timer due to internal congestion.Attorney Docket No. SMM920230184-WO-PCT

[0125] In the procedure 800 message 5 may be used to implement the described implementations. For instance, using message 5, the UE may construct an IKE_AUTH request including an EAP-Response / 5G-NAS packet which includes the AN-parameters and a registration request message. The UE may set AN-parameter type field value to "04H", meaning "establishment cause for non-3GPP access" (e.g., according to 3GPP TS 24.502 subclause 9.3.2.2.2), where the "establishment cause for non-3GPP access" may be set to "0000" indicating emergency such as according to 3GPP TS 24.502 subclause 9.2.2. In order for the UE to override the back-off timer interval, the "establishment cause for non-3GPP access" may be set according to a value other than emergency value indicating an agreed reason to override the back-off timer interval.

[0126] One difference between the implementation described with reference to the procedure 800 and the implementation described with reference to the procedure 700 is that in the procedure 800 the timer which may be introduced is for the establishment of the first child after the IKE SA is established, and in such scenarios the N3IWF may not maintain the IKE SAs which are not used by establishing the first child SA.

[0127] Implementations also provide for solutions for NE congestions for trusted non-3GPP access networks. For instance, for a trusted non-3GPP access network where the NE is congested due to its internal congestion construct, the NE may establish preparations and / or security associations for communications between the UE and / or the device. Further, the NE may transmit towards the UE and / or the device a Notify message of the type CONGESTION and a payload for the value of the back-off timer. The UE and / or the device may determine to place a high priority call, an emergency call, and / or a special call. In such scenarios despite the Notify message with the type CONGESTED and the payload of the back-off timer, the UE and / or the device may initiate a message exchange with appropriate NAS message to register and add to the AN-Parameters field (e.g., as defined in 3GPP TS 24.502) indication of the purpose of the registration. As described in 3GPP TS 24.502, the AN-Parameters field includes AN-Parameters types which may be "establishment cause for non-3GPP access" which is listed in 3GPP TS 24.502 subclause 9.2.2. For instance, upon receipt of establishment cause for emergency, the NE may forward the NAS message to the AMF by overriding the back-off timer due to internal congestion.

[0128] Figures 9a, 9b, 9c illustrate an example procedure 900 in accordance with aspects of the present disclosure. The procedure 900, for instance, enables registration of a UE via a trusted non-Attorney Docket No. SMM920230184-WO-PCT3GPP access. The procedure 900 includes numbered messages that can be utilized for priority registration as described herein. The procedure 900 involves a UE 104, a TNAN 702 including a TNAP 704 and a TNGF 706, an AMF 306, and an AUSF 308. In the procedure 900: Eayer 2 connectivity can be utilized such as E2: Ethernet, 802.3, 802.11, PPP, etc.; 0. Trusted Non-3GPP Access Network Selection; 1. E2 connection; 2. E2 (EAP-Req / Identity); 3. E2 (EAP-Res / Identity) NAI=username@ priority .realm; 4. E2 (EAP-Req / 5G-Start [Notify {CONGESTION, N3GPP_BACKOFF_TIMER}]); 5. L2 (EAP-Res / 5G-NAS / AN-Params [UE Id,5G-GUTI or SUCI, Selected PLMN ID, Requested NSSAI, Establishment cause], NAS-PDU [Registration Request]); 6a. AMF Selection; 6b. N2 msg (Registration Request); 7a. N2 msg (Identity Req. / Res.); and 7b. L2 (EAP-Req / Res / 5G-NAS / NAS-PDU [Identity Req. / Res.]).

[0129] Further to the procedure 900: At 8a. AAA Key Request (SUPI or SUCI);8b. Authentication and Key Agreement; and 8c. AAA Key Response (SEAF key, EAP-Success). Thus TNGF and / or TNAP keys are created. At 9a. N2 msg (Security Mode Command (SMC) Request [EAP-Success]); 9b. L2 (EAP-Req / 5G-NAS / NAS-PDU [SMC Request (EAP-Success)]); 9c. L2 (EAP-Res / 5G-NAS / NAS-PDU [SMC Complete]); 9d. N2 msg (SMC Complete); 10a. N2 Initial Ctx Setup Request (TNGF key); 10b. L2 (EAP-Req / 5G-Notification / TNGF Address); 10c. L2 (EAP-Res / 5G-Notification / ); lOd. AAA (TNAP key, EAP-Success); lOe. L2 (EAP-Success); 11. Security establishment using the TNAP key (e.g. 4-way handshake for WLAN); and 12. Local IP configuration.

[0130] The procedure 900 also enables NWt connection between the UE 104 and the TNGF 706: 13a. IKEJNIT; 13b. IKE_AUTH (IDi, SA, TSi, TSr, AUTH); 13c. IKE_AUTH (IDr, SA, TSi, TSr, AUTH); and 13d. TCP Connection. Further to the procedure 900: At 14. N2 Initial Ctx Setup Response; 15a. N2 msg (NAS Registration Accept); and 15b. [NAS over the NWt connection] NAS Registration Accept. Subsequent NAS messages between UE 104 and TNGF 706 can be carried over the NWt connection.

[0131] In the procedure 900, various messages can be used to implement the described implementations including message 4 and message 5. For message 4: If the NE such as TNGF is congested, the security association for the connection between the UE and the TNGF can still be established. The TNGF may construct the L2 response by setting the Notify message type in the Notify payload to a value which means CONGESTION according to the private Notify messageAttorney Docket No. SMM920230184-WO-PCTtype, such as specified in 3GPP TS 24.502 subclause 9.2.4.2. The Notification Data of the Notify payload may be set to the value of the N3GPP_BACK_TIMER. The Notify message can be inserted in the extensions field of the EAP-Req / 5G-Start such as defined in 3GPP TS 24.502 subclause 9.3.2.2.I. The L2 response can include EAP-Req / 5G-Start to indicate to the UE the initiation of EAP-5G. Further, the constructed Notify message with the CONGESTION error type and the value of the back-off timer may indicate to the UE to attempt the next L2 exchange after the back-off timer. The TNGF may transmit the L2 response towards the UE.

[0132] For message 5: The UE may construct an L2 request including an EAP-Response / 5G- NAS packet which includes the AN-parameters and a registration request message. The UE may set AN-parameter type field value to "04H", meaning "establishment cause for non-3GPP access" such as according to 3GPP TS 24.502 subclause 9.3.2.2.2, where the "establishment cause for non-3GPP access" may be set to "0000" indicating emergency such as according to 3GPP TS 24.502 subclause 9.2.2. For the UE to override the back-off timer interval, the "establishment cause for non-3GPP access" may be set according to a value other than emergency value indicating an agreed reason to override the back-off timer interval.

[0133] In implementations a congested NE may not indicate to the UE and / or the device about the congestion in the L2 message. If the UE and / or the device initiates a message exchange with appropriate NAS message to register and adds in the AN-Parameters field (e.g., as defined in 3GPP TS 24.502) the purpose of the registration, the NE may forward the NAS message to the AMF by overriding the back-off timer due to internal congestion. Alternatively or additionally the network may respond to the NAS registration request by a Notify message of type CONGESTION with the pay load of back-off timer.

[0134] In the procedure 900, message 5 can be used to implement the described implementations. For instance, for message 5, the UE may construct an L2 request including an EAP-Response / 5G-NAS packet which includes the AN-parameters and a registration request message. The UE may set AN-parameter type field value to "04H", meaning "establishment cause for non-3GPP access" (e.g., according to 3GPP TS 24.502 subclause 9.3.2.2.2), where the "establishment cause for non-3GPP access" may be set to "0000" indicating emergency, e.g., according to 3GPP TS 24.502 subclause 9.2.2. For the UE to override the back-off timer interval,Attorney Docket No. SMM920230184-WO-PCTthe "establishment cause for non-3GPP access" may be set according to a value other than emergency value indicating an agreed reason to override the back-off timer interval.

[0135] One difference between and the previous implementation is that no timer may be defined for tearing down the IKE SA in some scenarios. A difference between this implementation and the previous implementation is that the timer may be introduced until the UE initiates sending the NAS message in message 5.

[0136] Figure 10 illustrates an example of a UE 1000 in accordance with aspects of the present disclosure. The UE 1000 may include a processor 1002, a memory 1004, a controller 1006, and a transceiver 1008. The processor 1002, the memory 1004, the controller 1006, or the transceiver 1008, or various combinations thereof or various components thereof may be examples of means for performing various aspects of the present disclosure as described herein. These components may be coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces.

[0137] The processor 1002, the memory 1004, the controller 1006, or the transceiver 1008, or various combinations or components thereof may be implemented in hardware (e.g., circuitry). The hardware may include a processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), or other programmable logic device, or any combination thereof configured as or otherwise supporting a means for performing the functions described in the present disclosure.

[0138] The processor 1002 may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a CPU, an ASIC, an FPGA, or any combination thereof). In some implementations, the processor 1002 may be configured to operate the memory 1004. In some other implementations, the memory 1004 may be integrated into the processor 1002. The processor 1002 may be configured to execute computer-readable instructions stored in the memory 1004 to cause the UE 1000 to perform various functions of the present disclosure.

[0139] The memory 1004 may include volatile or non-volatile memory. The memory 1004 may store computer-readable, computer-executable code including instructions when executed by the processor 1002 cause the UE 1000 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such as the memory 1004 or another type ofAttorney Docket No. SMM920230184-WO-PCTmemory. Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A non-transitory storage medium may be any available medium that may be accessed by a general-purpose or special-purpose computer.

[0140] In some implementations, the processor 1002 and the memory 1004 coupled with the processor 1002 may be configured to cause the UE 1000 to perform one or more of the functions described herein (e.g., executing, by the processor 1002, instructions stored in the memory 1004). For example, the processor 1002 may support wireless communication at the UE 1000 in accordance with examples as disclosed herein.

[0141] The UE 1000 may be configured to or operable to support a means for triggering, via a first access network associated with a first radio access technology and via a first NE of a second access network associated with a second radio access technology, a registration procedure with a second NE of the second access network, the second radio access technology being different than the first radio access technology; transmitting, via the first access network and to the first NE of the second access network associated with the second radio access technology, an indication of a cause for the registration procedure with the second NE of the second access network; and transmitting, based at least in part on registering with the second access network in response to the registration procedure, data to the first NE of the second access network for routing to the second NE of the second access network.

[0142] Additionally, the UE 1000 may be configured to support any one or combination of triggering via the first NE of the second access network the registration procedure with the second NE of the second access network is based at least in part on the cause for the registration procedure; the cause for the registration procedure includes an emergency cause; the cause for the registration procedure includes a priority cause; transmitting, to the first NE, a first message to request a connection; receiving, from the first NE, a second message indicating acceptance of the connection with the UE; transmitting, to the first NE, a third message to establish a session for registration to the second NE of the second access network, the third message including the cause for the registration; receiving, from the first NE, a fourth message indicating acceptance of establishment of the session for registration; transmitting, to the second NE via the session, a register request message; and receiving, from the second NE and via the session, a register message response.Attorney Docket No. SMM920230184-WO-PCT

[0143] Additionally, the UE 1000 may be configured to support any one or combination of where the first radio access technology includes a WLAN; the second radio access technology includes one or more of a 4G Long Term Evolution or a 5G NR, and the second NE includes an AMF or an AUSF; the first NE of the second access network includes a N3IWF; performing, via the first NE of the second access network and with the second NE of the second access network, at least one IKE message exchange according to an IKE protocol; transmitting the indication of the cause for the registration procedure as a private exchange type according to the IKE protocol; an IKE header of the at least one IKE message exchange indicates the private exchange type.

[0144] Additionally, or alternatively, the UE 1000 may support at least one memory (e.g., the memory 1004) and at least one processor (e.g., the processor 1002) coupled with the at least one memory and configured to cause the UE to trigger, via a first access network associated with a first radio access technology and via a first NE of a second access network associated with a second radio access technology, a registration procedure with a second NE of the second access network, the second radio access technology being different than the first radio access technology; transmit, via the first access network and to the first NE of the second access network associated with the second radio access technology, an indication of a cause for the registration procedure with the second NE of the second access network; and transmit, based at least in part on registering with the second access network in response to the registration procedure, data to the first NE of the second access network for routing to the second NE of the second access network.

[0145] Additionally, the UE 1000 may be configured to support any one or combination of the at least one processor is configured to trigger via the first NE of the second access network the registration procedure with the second NE of the second access network is based at least in part on the cause for the registration procedure; the cause for the registration procedure includes an emergency cause; the cause for the registration procedure includes a priority cause; the at least one processor is configured to cause the UE to: transmit, to the first NE, a first message to request a connection; receive, from the first NE, a second message indicating acceptance of the connection with the UE; transmit, to the first NE, a third message to establish a session for registration to the second NE of the second access network, the third message including the cause for the registration; receive, from the first NE, a fourth message indicating acceptance of establishment of the sessionAttorney Docket No. SMM920230184-WO-PCTfor registration; transmit, to the second NE via the session, a register request message; and receive, from the second NE and via the session, a register message response.

[0146] Additionally, the UE 1000 may be configured to support any one or combination of where the first radio access technology includes a WLAN; the second radio access technology includes one or more of a 4G Long Term Evolution or a 5G NR, and the second NE includes an AMF or an AUSF; the first NE of the second access network includes a N3IWF; the at least one processor is further configured to cause the UE to perform, via the first NE of the second access network and with the second NE of the second access network, at least one IKE message exchange according to an IKE protocol; the at least one processor is further configured to cause the UE to transmit the indication of the cause for the registration procedure as a private exchange type according to the IKE protocol; an IKE header of the at least one IKE message exchange indicates the private exchange type.

[0147] The UE 1000 may be configured to or operable to support a means for transmitting, via a first access network associated with a first radio access technology and to a first NE of a second access network associated with a second radio access technology, a first message requesting a security association session with the first NE, the second radio access technology being different than the first radio access technology; receiving a second message including a notification regarding the first NE and confirming the security association session between the UE and the first NE; and transmitting, to the first NE of the second access network, a third message requesting a selected registration with a second NE of the second access network and including an access network parameter for the selected registration.

[0148] Additionally, the UE 1000 may be configured to support any one or combination of receiving, from the second NE of the second access network, a response confirming the selected registration with the second NE of the second access network; the first radio access technology includes a WLAN, and the second radio access technology includes one or more of a 4G Long Term Evolution or a 5G NR, and the second NE includes an AMF or an AUSF; the first NE of the second access network includes a N3IWF; the notification includes a notification of congestion at the first NE; the second message includes a back-off timer; the selected registration includes an indication of emergency registration; the selected registration includes an indication of priority registration; the access network parameter includes an establishment cause value, and theAttorney Docket No. SMM920230184-WO-PCTestablishment cause value includes an indication of emergency; the access network parameter includes an establishment cause value, and the establishment cause value includes an indication of priority.

[0149] Additionally, or alternatively, the UE 1000 may support at least one memory (e.g., the memory 1004) and at least one processor (e.g., the processor 1002) coupled with the at least one memory and configured to cause the UE to transmit, via a first access network associated with a first radio access technology and to a first NE of a second access network associated with a second radio access technology, a first message requesting a security association session with the first NE, the second radio access technology being different than the first radio access technology; receive a second message including a notification regarding the first NE and confirming the security association session between the UE and the first NE; and transmit, to the first NE of the second access network, a third message requesting a selected registration with a second NE of the second access network and including an access network parameter for the selected registration.

[0150] Additionally, the UE 1000 may be configured to support any one or combination of the at least one processor is configured to receive, from the second NE of the second access network, a response confirming the selected registration with the second NE of the second access network; the first radio access technology includes a WLAN, and the second radio access technology includes one or more of a 4G Long Term Evolution or a 5G NR, and the second NE includes an AMF or an AUSF; the first NE of the second access network includes a N3IWF; the notification includes a notification of congestion at the first NE; the second message includes a back-off timer; the selected registration includes an indication of emergency registration; the selected registration includes an indication of priority registration; the access network parameter includes an establishment cause value, and the establishment cause value includes an indication of emergency; the access network parameter includes an establishment cause value, and the establishment cause value includes an indication of priority.

[0151] The UE 1000 may be configured to or operable to support a means for transmitting, to a first NE of a first access network associated with a first radio access technology, an identifier and a cause for a registration procedure with a second NE of a second access network associated with a second radio access technology; receiving an indication of acceptance of registration with the second access network based at least in part on the registration procedure; and transmitting, based atAttorney Docket No. SMM920230184-WO-PCTleast in part on the acceptance of registration with the second access network, data to the first NE of the first access network for routing to the second NE of the second access network.

[0152] Additionally, the UE 1000 may be configured to support any one or combination of transmitting, to the first NE, a first message to request a connection; receiving, from the first NE, a second message to accept the connection; transmitting, to the first NE, a third message to establish a session for registration to the second NE of the second access network, the third message including the identifier and the cause for the registration procedure; receiving, from the first NE, an indication of acceptance to establish the session; transmitting, to the second NE and via the session, a register message request; and receiving, from the second NE and via the session, a register message response; the first access network includes a TNAN and the second access network includes CN of a cellular network; the first NE includes a TNGF; the identifier includes a NAI; the cause for the registration procedure includes an emergency cause; the cause for registration includes a priority cause.

[0153] Additionally, or alternatively, the UE 1000 may support at least one memory (e.g., the memory 1004) and at least one processor (e.g., the processor 1002) coupled with the at least one memory and configured to cause the UE to transmit, to a first NE of a first access network associated with a first radio access technology, an identifier and a cause for a registration procedure with a second NE of a second access network associated with a second radio access technology; receive an indication of acceptance of registration with the second access network based at least in part on the registration procedure; and transmit, based at least in part on the acceptance of registration with the second access network, data to the first NE of the first access network for routing to the second NE of the second access network.

[0154] Additionally, the UE 1000 may be configured to support any one or combination of the at least one processor is configured to transmit, to the first NE, a first message to request a connection; receive, from the first NE, a second message to accept the connection; transmit, to the first NE, a third message to establish a session for registration to the second NE of the second access network, the third message including the identifier and the cause for the registration procedure; receive, from the first NE, an indication of acceptance to establish the session; transmit, to the second NE and via the session, a register message request; and receive, from the second NE and via the session, a register message response; the first access network includes a TNAN and theAttorney Docket No. SMM920230184-WO-PCTsecond access network includes CN of a cellular network; the first NE includes a TNGF; the identifier includes a NAI; the cause for the registration procedure includes an emergency cause; the cause for registration includes a priority cause.

[0155] The UE 1000 may be configured to or operable to support a means for transmitting, to a first NE of a first access network associated with a first radio access technology, a first message requesting a security association session with a second NE of a second access network associated with a second radio access technology; receiving a second message including a notification and confirming the security association session between the UE and the second NE; and transmitting, to the second NE, a third message requesting a selected registration with the second access network and including an access network parameter for the selected registration.

[0156] Additionally, the UE 1000 may be configured to support any one or combination of receiving from the second NE, a response confirming the selected registration with the second NE; the first access network includes a TNAN and the second access network includes CN of a cellular network; the first NE includes a TNGF; the notification includes a notification of congestion; the second message includes a back-off timer; the selected registration includes an indication of emergency registration; the selected registration includes an indication of priority registration; the access network parameter includes an establishment cause value, and the establishment cause value includes an indication of emergency; the access network parameter includes an establishment cause value, and the establishment cause value includes an indication of priority.

[0157] Additionally, or alternatively, the UE 1000 may support at least one memory (e.g., the memory 1004) and at least one processor (e.g., the processor 1002) coupled with the at least one memory and configured to cause the UE to transmit, to a first NE of a first access network associated with a first radio access technology, a first message requesting a security association session with a second NE of a second access network associated with a second radio access technology; receive a second message including a notification and confirming the security association session between the UE and the second NE; and transmit, to the second NE, a third message requesting a selected registration with the second access network and including an access network parameter for the selected registration.Attorney Docket No. SMM920230184-WO-PCT

[0158] Additionally, the UE 1000 may be configured to support any one or combination of the at least one processor is configured to receive, from the second NE, a response confirming the selected registration with the second NE; the first access network includes a TNAN and the second access network includes CN of a cellular network; the first NE includes a TNGF; the notification includes a notification of congestion; the second message includes a back-off timer; the selected registration includes an indication of emergency registration; the selected registration includes an indication of priority registration; the access network parameter includes an establishment cause value, and where the establishment cause value includes an indication of emergency; the access network parameter includes an establishment cause value, and where the establishment cause value includes an indication of priority.

[0159] The controller 1006 may manage input and output signals for the UE 1000. The controller 1006 may also manage peripherals not integrated into the UE 1000. In some implementations, the controller 1006 may utilize an operating system such as iOS®, ANDROID®, WINDOWS®, or other operating systems. In some implementations, the controller 1006 may be implemented as part of the processor 1002.

[0160] In some implementations, the UE 1000 may include at least one transceiver 1008. In some other implementations, the UE 1000 may have more than one transceiver 1008. The transceiver 1008 may represent a wireless transceiver. The transceiver 1008 may include one or more receiver chains 1010, one or more transmitter chains 1012, or a combination thereof.

[0161] A receiver chain 1010 may be configured to receive signals (e.g., control information, data, packets) over a wireless medium. For example, the receiver chain 1010 may include one or more antennas to receive a signal over the air or wireless medium. The receiver chain 1010 may include at least one amplifier (e.g., a low-noise amplifier (LNA)) configured to amplify the received signal. The receiver chain 1010 may include at least one demodulator configured to demodulate the receive signal and obtain the transmitted data by reversing the modulation technique applied during transmission of the signal. The receiver chain 1010 may include at least one decoder for decoding the demodulated signal to receive the transmitted data.

[0162] A transmitter chain 1012 may be configured to generate and transmit signals (e.g., control information, data, packets). The transmitter chain 1012 may include at least oneAttorney Docket No. SMM920230184-WO-PCTmodulator for modulating data onto a carrier signal, preparing the signal for transmission over a wireless medium. The at least one modulator may be configured to support one or more techniques such as amplitude modulation (AM), frequency modulation (FM), or digital modulation schemes like phase-shift keying (PSK) or quadrature amplitude modulation (QAM). The transmitter chain 1012 may also include at least one power amplifier configured to amplify the modulated signal to an appropriate power level suitable for transmission over the wireless medium. The transmitter chain 1012 may also include one or more antennas for transmitting the amplified signal into the air or wireless medium.

[0163] Figure 11 illustrates an example of a processor 1100 in accordance with aspects of the present disclosure. The processor 1100 may be an example of a processor configured to perform various operations in accordance with examples as described herein. The processor 1100 may include a controller 1102 configured to perform various operations in accordance with examples as described herein. The processor 1100 may optionally include at least one memory 1104, which may be, for example, an L1 / L2 / L3 cache. Additionally, or alternatively, the processor 1100 may optionally include one or more arithmetic-logic units (ALUs) 1106. One or more of these components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces (e.g., buses).

[0164] The processor 1100 may be a processor chipset and include a protocol stack (e.g., a software stack) executed by the processor chipset to perform various operations (e.g., receiving, obtaining, retrieving, transmitting, outputting, forwarding, storing, determining, identifying, accessing, writing, reading) in accordance with examples as described herein. The processor chipset may include one or more cores, one or more caches (e.g., memory local to or included in the processor chipset (e.g., the processor 1100) or other memory (e.g., random access memory (RAM), read-only memory (ROM), dynamic RAM (DRAM), synchronous dynamic RAM (SDRAM), static RAM (SRAM), ferroelectric RAM (FeRAM), magnetic RAM (MRAM), resistive RAM (RRAM), flash memory, phase change memory (PCM), and others).

[0165] The controller 1102 may be configured to manage and coordinate various operations (e.g., signaling, receiving, obtaining, retrieving, transmitting, outputting, forwarding, storing, determining, identifying, accessing, writing, reading) of the processor 1100 to cause the processor 1100 to support various operations in accordance with examples as described herein. For example,Attorney Docket No. SMM920230184-WO-PCTthe controller 1102 may operate as a control unit of the processor 1100, generating control signals that manage the operation of various components of the processor 1100. These control signals include enabling or disabling functional units, selecting data paths, initiating memory access, and coordinating timing of operations.

[0166] The controller 1102 may be configured to fetch (e.g., obtain, retrieve, receive) instructions from the memory 1104 and determine subsequent instruction(s) to be executed to cause the processor 1100 to support various operations in accordance with examples as described herein. The controller 1102 may be configured to track memory addresses of instructions associated with the memory 1104. The controller 1102 may be configured to decode instructions to determine the operation to be performed and the operands involved. For example, the controller 1102 may be configured to interpret the instruction and determine control signals to be output to other components of the processor 1100 to cause the processor 1100 to support various operations in accordance with examples as described herein. Additionally, or alternatively, the controller 1102 may be configured to manage flow of data within the processor 1100. The controller 1102 may be configured to control transfer of data between registers, ALUs 1106, and other functional units of the processor 1100.

[0167] The memory 1104 may include one or more caches (e.g., memory local to or included in the processor 1100 or other memory, such as RAM, ROM, DRAM, SDRAM, SRAM, MRAM, flash memory, etc. In some implementations, the memory 1104 may reside within or on a processor chipset (e.g., local to the processor 1100). In some other implementations, the memory 1104 may reside external to the processor chipset (e.g., remote to the processor 1100).

[0168] The memory 1104 may store computer-readable, computer-executable code including instructions that, when executed by the processor 1100, cause the processor 1100 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. The controller 1102 and / or the processor 1100 may be configured to execute computer-readable instructions stored in the memory 1104 to cause the processor 1100 to perform various functions. For example, the processor 1100 and / or the controller 1102 may be coupled with or to the memory 1104, the processor 1100, and the controller 1102, and may be configured to perform various functions described herein. In some examples, the processor 1100 may include multiple processors and the memory 1104 may include multipleAttorney Docket No. SMM920230184-WO-PCTmemories. One or more of the multiple processors may be coupled with one or more of the multiple memories, which may, individually or collectively, be configured to perform various functions herein.

[0169] The one or more ALUs 1106 may be configured to support various operations in accordance with examples as described herein. In some implementations, the one or more ALUs 1106 may reside within or on a processor chipset (e.g., the processor 1100). In some other implementations, the one or more ALUs 1106 may reside external to the processor chipset (e.g., the processor 1100). One or more ALUs 1106 may perform one or more computations such as addition, subtraction, multiplication, and division on data. For example, one or more ALUs 1106 may receive input operands and an operation code, which determines an operation to be executed. One or more ALUs 1106 may be configured with a variety of logical and arithmetic circuits, including adders, subtractors, shifters, and logic gates, to process and manipulate the data according to the operation. Additionally, or alternatively, the one or more ALUs 1106 may support logical operations such as AND, OR, exclusive-OR (XOR), not-OR (NOR), and not-AND (NAND), enabling the one or more ALUs 1106 to handle conditional operations, comparisons, and bitwise operations.

[0170] The processor 1100 may support wireless communication in accordance with examples as disclosed herein. The processor 1100 may be configured to or operable to support at least one controller (e.g., the controller 1102) coupled with at least one memory (e.g., the memory 1104) and configured to cause the processor to trigger, via a first access network associated with a first radio access technology and via a first NE of a second access network associated with a second radio access technology, a registration procedure for a UE with a second NE of the second access network, the second radio access technology being different than the first radio access technology; transmit, via the first access network and to the first NE of the second access network associated with the second radio access technology, an indication of a cause for the registration procedure with the second NE of the second access network; and transmit, based at least in part on registering with the second access network in response to the registration procedure, data to the first NE of the second access network for routing to the second NE of the second access network.

[0171] Additionally, the processor 1100 may be configured to or operable to support any one or combination of the at least one controller is configured to cause the processor to trigger via the first NE of the second access network the registration procedure with the second NE of the secondAttorney Docket No. SMM920230184-WO-PCTaccess network is based at least in part on the cause for the registration procedure; the cause for the registration procedure includes an emergency cause; the cause for the registration procedure includes a priority cause; the at least one controller is configured to cause the processor to: transmit, to the first NE, a first message to request a connection; receive, from the first NE, a second message indicating acceptance of the connection with the UE; transmit, to the first NE, a third message to establish a session for registration to the second NE of the second access network, the third message including the cause for the registration; receive, from the first NE, a fourth message indicating acceptance of establishment of the session for registration; transmit, to the second NE via the session, a register request message; and receive, from the second NE and via the session, a register message response.

[0172] Additionally, the processor 1100 may be configured to or operable to support any one or combination of where the first radio access technology includes a WLAN; the second radio access technology includes one or more of a 4G Long Term Evolution or a 5G NR, and the second NE includes an AMF or an AUSF; the first NE of the second access network includes a N3IWF; the at least one controller is further configured to cause the processor to perform, via the first NE of the second access network and with the second NE of the second access network, at least one IKE message exchange according to an IKE protocol; the at least one controller is further configured to cause the processor to transmit the indication of the cause for the registration procedure as a private exchange type according to the IKE protocol; an IKE header of the at least one IKE message exchange indicates the private exchange type.

[0173] The processor 1100 may support wireless communication in accordance with examples as disclosed herein. The processor 1100 may be configured to or operable to support at least one controller (e.g., the controller 1102) coupled with at least one memory (e.g., the memory 1104) and configured to cause the processor to transmit, via a first access network associated with a first radio access technology and to a first NE of a second access network associated with a second radio access technology, a first message requesting a security association session with the first NE, the second radio access technology being different than the first radio access technology; receive a second message including a notification regarding the first NE and confirming the security association session between a UE and the first NE; and transmit, to the first NE of the second accessAttorney Docket No. SMM920230184-WO-PCTnetwork, a third message requesting a selected registration with a second NE of the second access network and including an access network parameter for the selected registration.

[0174] Additionally, the processor 1100 may be configured to or operable to support any one or combination of the at least one controller is configured to cause the processor to receive, from the second NE of the second access network, a response confirming the selected registration with the second NE of the second access network; the first radio access technology includes a WLAN, and the second radio access technology includes one or more of a 4G Long Term Evolution or a 5G NR, and the second NE includes an AMF or an AUSF; the first NE of the second access network includes a N3IWF; the notification includes a notification of congestion at the first NE; the second message includes a back-off timer; the selected registration includes an indication of emergency registration; the selected registration includes an indication of priority registration; the access network parameter includes an establishment cause value, and the establishment cause value includes an indication of emergency; the access network parameter includes an establishment cause value, and the establishment cause value includes an indication of priority.

[0175] The processor 1100 may support wireless communication in accordance with examples as disclosed herein. The processor 1100 may be configured to or operable to support at least one controller (e.g., the controller 1102) coupled with at least one memory (e.g., the memory 1104) and configured to cause the processor to transmit, to a first NE of a first access network associated with a first radio access technology, an identifier and a cause for a registration procedure with a second NE of a second access network associated with a second radio access technology; receive an indication of acceptance of registration with the second access network based at least in part on the registration procedure; and transmit, based at least in part on the acceptance of registration with the second access network, data to the first NE of the first access network for routing to the second NE of the second access network.

[0176] Additionally, the processor 1100 may be configured to or operable to support any one or combination of the at least one controller is configured to cause the processor to transmit, to the first NE, a first message to request a connection; receive, from the first NE, a second message to accept the connection; transmit, to the first NE, a third message to establish a session for registration to the second NE of the second access network, the third message including the identifier and the cause for the registration procedure; receive, from the first NE, an indication of acceptance to establish theAttorney Docket No. SMM920230184-WO-PCTsession; transmit, to the second NE and via the session, a register message request; and receive, from the second NE and via the session, a register message response; the first access network includes a TNAN and the second access network includes CN of a cellular network; the first NE includes a TNGF; the identifier includes a NAI; the cause for the registration procedure includes an emergency cause; the cause for registration includes a priority cause.

[0177] The processor 1100 may support wireless communication in accordance with examples as disclosed herein. The processor 1100 may be configured to or operable to support at least one controller (e.g., the controller 1102) coupled with at least one memory (e.g., the memory 1104) and configured to cause the processor to transmit, to a first NE of a first access network associated with a first radio access technology, a first message requesting a security association session with a second NE of a second access network associated with a second radio access technology; receive a second message including a notification and confirming the security association session between a UE and the second NE; and transmit, to the second NE, a third message requesting a selected registration with the second access network and including an access network parameter for the selected registration.

[0178] Additionally, the processor 1100 may be configured to or operable to support any one or combination of the at least one controller is configured to cause the processor to receive, from the second NE, a response confirming the selected registration with the second NE; the first access network includes a TNAN and the second access network includes CN of a cellular network; the first NE includes a TNGF; the notification includes a notification of congestion; the second message includes a back-off timer; the selected registration includes an indication of emergency registration; the selected registration includes an indication of priority registration; the access network parameter includes an establishment cause value, and where the establishment cause value includes an indication of emergency; the access network parameter includes an establishment cause value, and where the establishment cause value includes an indication of priority.

[0179] Figure 12 illustrates an example of a NE 1200 in accordance with aspects of the present disclosure. The NE 1200 may be implemented in various ways such as described herein, including as an N3IWF. The NE 1200 may include a processor 1202, a memory 1204, a controller 1206, and a transceiver 1208. The processor 1202, the memory 1204, the controller 1206, or the transceiver 1208, or various combinations thereof or various components thereof may be examples of means forAttorney Docket No. SMM920230184-WO-PCTperforming various aspects of the present disclosure as described herein. These components may be coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces.

[0180] The processor 1202, the memory 1204, the controller 1206, or the transceiver 1208, or various combinations or components thereof may be implemented in hardware (e.g., circuitry). The hardware may include a processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), or other programmable logic device, or any combination thereof configured as or otherwise supporting a means for performing the functions described in the present disclosure.

[0181] The processor 1202 may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a CPU, an ASIC, an FPGA, or any combination thereof). In some implementations, the processor 1202 may be configured to operate the memory 1204. In some other implementations, the memory 1204 may be integrated into the processor 1202. The processor 1202 may be configured to execute computer-readable instructions stored in the memory 1204 to cause the NE 1200 to perform various functions of the present disclosure.

[0182] The memory 1204 may include volatile or non-volatile memory. The memory 1204 may store computer-readable, computer-executable code including instructions when executed by the processor 1202 cause the NE 1200 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such as the memory 1204 or another type of memory. Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A non-transitory storage medium may be any available medium that may be accessed by a general-purpose or special-purpose computer.

[0183] In some implementations, the processor 1202 and the memory 1204 coupled with the processor 1202 may be configured to cause the NE 1200 to perform one or more of the functions described herein (e.g., executing, by the processor 1202, instructions stored in the memory 1204). For example, the processor 1202 may support wireless communication at the NE 1200 in accordance with examples as disclosed herein.Attorney Docket No. SMM920230184-WO-PCT

[0184] The NE 1200 may be configured to or operable to support a means for receiving, via a first access network associated with a first radio access technology, from a UE, and at the first NE of a second access network associated with a second radio access technology, a trigger for a registration procedure with a second NE of the second access network, the second radio access technology being different than the first radio access technology; receiving, from the UE via the first access network, an indication of a cause for the registration procedure with the second NE of the second access network; and receiving, based at least in part on registration of the UE with the second access network, data from the UE for routing to the second NE of the second access network.

[0185] Additionally, the NE 1200 may be configured to or operable to support any one or combination of the method further including receiving, from the UE, a first message to request a connection; transmitting, to the UE, a second message indicating acceptance of the connection with the UE; receiving, from the UE, a third message to establish a session for registration to the second NE of the second access network, the third message including the cause for the registration procedure; and transmitting, to the UE, a fourth message indicating acceptance of establishment of the session for registration; the cause for the registration procedure includes an emergency cause; the cause for the registration procedure includes a priority cause; the first radio access technology includes a WLAN; the second radio access technology includes one or more of a 4G Long Term Evolution or a 5G NR, and the second NE includes an AMF or an AUSF; the first NE of the second access network includes a N3IWF; performing, with the UE, at least one IKE message exchange according to an IKE protocol; receiving the indication of the cause for the registration procedure as a private exchange type according to the IKE protocol; an IKE header of the at least one IKE message exchange indicates the private exchange type.

[0186] Additionally, or alternatively, the NE 1200 may support at least one memory (e.g., the memory 1204) and at least one processor (e.g., the processor 1202) coupled with the at least one memory and configured to cause the NE to receive, via a first access network associated with a first radio access technology, from a UE, and at the first NE of a second access network associated with a second radio access technology, a trigger for a registration procedure with a second NE of the second access network, the second radio access technology being different than the first radio access technology; receive, from the UE via the first access network, an indication of a cause for theAttorney Docket No. SMM920230184-WO-PCTregistration procedure with the second NE of the second access network; and receive, based at least in part on registration of the UE with the second access network, data from the UE for routing to the second NE of the second access network.

[0187] Additionally, the NE 1200 may be configured to support any one or combination of the at least one processor is configured to cause the NE to receive, from the UE, a first message to request a connection; transmit, to the UE, a second message indicating acceptance of the connection with the UE; receive, from the UE, a third message to establish a session for registration to the second NE of the second access network, the third message including the cause for the registration procedure; and transmit, to the UE, a fourth message indicating acceptance of establishment of the session for registration; the cause for the registration procedure includes an emergency cause; the cause for the registration procedure includes a priority cause; the first radio access technology includes a WLAN; the second radio access technology includes one or more of a 4G Long Term Evolution or a 5G NR, and the second NE includes an AMF or an AUSF; the first NE of the second access network includes a N3IWF; the at least one processor is further configured to cause the first NE to perform, with the UE, at least one IKE message exchange according to an IKE protocol; the at least one processor is further configured to cause the first NE to receive the indication of the cause for the registration procedure as a private exchange type according to the IKE protocol; an IKE header of the at least one IKE message exchange indicates the private exchange type.

[0188] The NE 1200 may be configured to or operable to support a means for receiving, from a UE, via a first access network associated with a first radio access technology, and at the first NE of a second access network associated with a second radio access technology, a first message requesting a security association session with the first NE, the second radio access technology being different than the first radio access technology; transmitting a second message including a notification regarding the first NE and confirming the security association session between the UE and the first NE; and receiving, from the UE, a third message requesting a selected registration with a second NE of the second access network and including an access network parameter for the selected registration.

[0189] Additionally, the NE 1200 may be configured to or operable to support any one or combination of the method further including transmitting, to the second NE of the second access network, the selected registration; the first radio access technology includes a WLAN, and theAttorney Docket No. SMM920230184-WO-PCTsecond radio access technology includes one or more of a 4G Long Term Evolution or a 5G NR, and the second NE includes an AMF or an AUSF; the first NE of the second access network includes a N3IWF; the notification includes a notification of congestion at the first NE; the second message includes a back-off timer; the selected registration includes an indication of emergency registration; the selected registration includes an indication of priority registration; the access network parameter includes an establishment cause value, and the establishment cause value includes an indication of emergency; the access network parameter includes an establishment cause value, and the establishment cause value includes an indication of priority.

[0190] Additionally, or alternatively, the NE 1200 may support at least one memory (e.g., the memory 1204) and at least one processor (e.g., the processor 1202) coupled with the at least one memory and configured to cause the NE to receive, from a UE, via a first access network associated with a first radio access technology, and at the first NE of a second access network associated with a second radio access technology, a first message requesting a security association session with the first NE, the second radio access technology being different than the first radio access technology; transmit a second message including a notification regarding the first NE and confirming the security association session between the UE and the first NE; and receive, from the UE, a third message requesting a selected registration with a second NE of the second access network and including an access network parameter for the selected registration.

[0191] Additionally, the NE 1200 may be configured to support any one or combination of the at least one processor is configured to cause the NE to transmit, to the second NE of the second access network, the selected registration; the first radio access technology includes a WLAN, and the second radio access technology includes one or more of a 4G Long Term Evolution or a 5G NR, and the second NE includes an AMF or an AUSF; the first NE of the second access network includes a N3IWF; the notification includes a notification of congestion at the first NE; the second message includes a back-off timer; the selected registration includes an indication of emergency registration; the selected registration includes an indication of priority registration; the access network parameter includes an establishment cause value, and the establishment cause value includes an indication of emergency; the access network parameter includes an establishment cause value, and the establishment cause value includes an indication of priority.Attorney Docket No. SMM920230184-WO-PCT

[0192] The NE 1200 may be configured to or operable to support a means for receiving, from a UE and at the first NE of a first access network associated with a first radio access technology, an identifier and a cause for a registration procedure with a second NE of a second access network associated with a second radio access technology; transmitting an indication of acceptance of registration with the second access network based at least in part on the registration procedure; and receiving, from the UE, data for routing to the second NE of the second access network.

[0193] Additionally, the NE 1200 may be configured to or operable to support any one or combination of the method further including receiving, from the UE, a first message to request a connection; transmitting, to the UE, a second message to accept the connection; receiving, from the UE, a third message to establish a session for registration to the second NE, the third message including the identifier and the cause for the registration procedure; and transmitting, to the UE, an indication of acceptance to establish the session; the first access network includes a TNAN and the second access network includes CN of a cellular network; the first NE includes a TNGF; the identifier includes a NAI; the cause for the registration procedure includes an emergency cause; the cause for registration includes a priority cause.

[0194] Additionally, or alternatively, the NE 1200 may support at least one memory (e.g., the memory 1204) and at least one processor (e.g., the processor 1202) coupled with the at least one memory and configured to cause the NE to receive, from a UE and at the first NE of a first access network associated with a first radio access technology, an identifier and a cause for a registration procedure with a second NE of a second access network associated with a second radio access technology; transmit an indication of acceptance of registration with the second access network based at least in part on the registration procedure; and receive, from the UE, data for routing to the second NE of the second access network.

[0195] Additionally, the NE 1200 may be configured to support any one or combination of the at least one processor is configured to cause the NE to receive, from the UE, a first message to request a connection; transmit, to the UE, a second message to accept the connection; receive, from the UE, a third message to establish a session for registration to the second NE, the third message including the identifier and the cause for the registration procedure; and transmit, to the UE, an indication of acceptance to establish the session; the first access network includes a TNAN and the second access network includes CN of a cellular network; the first NE includes a TNGF; theAttorney Docket No. SMM920230184-WO-PCTidentifier includes a NAI; the cause for the registration procedure includes an emergency cause; the cause for registration includes a priority cause.

[0196] The NE 1200 may be configured to or operable to support a means for receiving, at the first NE associated with a first access network of a first radio access technology, a first message from a UE requesting a security association session with a second NE of a second access network associated with a second radio access technology; transmitting a second message including a notification and confirming the security association session between the UE and the second NE; and receiving, from the UE, a third message requesting a selected registration with the second NE and including an access network parameter for the selected registration.

[0197] Additionally, the NE 1200 may be configured to or operable to support any one or combination of the method further including transmitting, to the second NE, the selected registration; the first access network includes a TNAN and the second access network includes CN of a cellular network; the first NE includes a TNGF; the notification includes a notification of congestion; the second message includes a back-off timer; the selected registration includes an indication of emergency registration; the selected registration includes an indication of priority registration; the access network parameter includes an establishment cause value, and the establishment cause value includes an indication of emergency; the access network parameter includes an establishment cause value, and the establishment cause value includes an indication of priority.

[0198] Additionally, or alternatively, the NE 1200 may support at least one memory (e.g., the memory 1204) and at least one processor (e.g., the processor 1202) coupled with the at least one memory and configured to cause the NE to receive, at the first NE associated with a first access network of a first radio access technology, a first message from a UE requesting a security association session with a second NE of a second access network associated with a second radio access technology; transmit a second message including a notification and confirming the security association session between the UE and the second NE; and receive, from the UE, a third message requesting a selected registration with the second NE and including an access network parameter for the selected registration.Attorney Docket No. SMM920230184-WO-PCT

[0199] Additionally, the NE 1200 may be configured to support any one or combination of the at least one processor is configured to cause the NE to transmit, to the second NE, the selected registration; the first access network includes a TNAN and the second access network includes CN of a cellular network; the first NE includes a TNGF; the notification includes a notification of congestion; the second message includes a back-off timer; the selected registration includes an indication of emergency registration; the selected registration includes an indication of priority registration; the access network parameter includes an establishment cause value, and where the establishment cause value includes an indication of emergency; the access network parameter includes an establishment cause value, and where the establishment cause value includes an indication of priority.

[0200] The controller 1206 may manage input and output signals for the NE 1200. The controller 1206 may also manage peripherals not integrated into the NE 1200. In some implementations, the controller 1206 may utilize an operating system such as iOS®, ANDROID®, WINDOWS®, or other operating systems. In some implementations, the controller 1206 may be implemented as part of the processor 1202.

[0201] In some implementations, the NE 1200 may include at least one transceiver 1208. In some other implementations, the NE 1200 may have more than one transceiver 1208. The transceiver 1208 may represent a wireless transceiver. The transceiver 1208 may include one or more receiver chains 1210, one or more transmitter chains 1212, or a combination thereof.

[0202] A receiver chain 1210 may be configured to receive signals (e.g., control information, data, packets) over a wireless medium. For example, the receiver chain 1210 may include one or more antennas to receive a signal over the air or wireless medium. The receiver chain 1210 may include at least one amplifier (e.g., a low-noise amplifier (LNA)) configured to amplify the received signal. The receiver chain 1210 may include at least one demodulator configured to demodulate the receive signal and obtain the transmitted data by reversing the modulation technique applied during transmission of the signal. The receiver chain 1210 may include at least one decoder for decoding the demodulated signal to receive the transmitted data.

[0203] A transmitter chain 1212 may be configured to generate and transmit signals (e.g., control information, data, packets). The transmitter chain 1212 may include at least oneAttorney Docket No. SMM920230184-WO-PCTmodulator for modulating data onto a carrier signal, preparing the signal for transmission over a wireless medium. The at least one modulator may be configured to support one or more techniques such as amplitude modulation (AM), frequency modulation (FM), or digital modulation schemes like phase-shift keying (PSK) or quadrature amplitude modulation (QAM). The transmitter chain 1212 may also include at least one power amplifier configured to amplify the modulated signal to an appropriate power level suitable for transmission over the wireless medium. The transmitter chain 1212 may also include one or more antennas for transmitting the amplified signal into the air or wireless medium.

[0204] Figure 13 illustrates a flowchart of a method 1300 in accordance with aspects of the present disclosure. The operations of the method may be implemented by a UE as described herein. In some implementations, the UE may execute a set of instructions to control the function elements of the UE to perform the described functions. It should be noted that the method described herein describes a possible implementation, and that the operations and the steps may be rearranged or otherwise modified and that other implementations are possible.

[0205] At 1302, the method may include triggering, via a first access network associated with a first radio access technology and via a first NE of a second access network associated with a second radio access technology, a registration procedure with a second NE of the second access network, the second radio access technology being different than the first radio access technology. The operations of 1302 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1302 may be performed by a UE as described with reference to Figure 10.

[0206] At 1304, the method may include transmitting, via the first access network and to the first NE of the second access network associated with the second radio access technology, an indication of a cause for the registration procedure with the second NE of the second access network. The operations of 1304 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1304 may be performed by a UE as described with reference to Figure 10.

[0207] At 1306, the method may include transmitting, based at least in part on registering with the second access network in response to the registration procedure, data to the first NE of theAttorney Docket No. SMM920230184-WO-PCTsecond access network for routing to the second NE of the second access network. The operations of 1306 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1306 may be performed a UE as described with reference to Figure 10.

[0208] Figure 14 illustrates a flowchart of a method 1400 in accordance with aspects of the present disclosure. The operations of the method may be implemented by a NE as described herein such as an N3IWF. In some implementations, the NE may execute a set of instructions to control the function elements of the NE to perform the described functions. It should be noted that the method described herein describes a possible implementation, and that the operations and the steps may be rearranged or otherwise modified and that other implementations are possible.

[0209] At 1402, the method may include receiving, via a first access network associated with a first radio access technology, from a UE, and at the first NE of a second access network associated with a second radio access technology, a trigger for a registration procedure with a second NE of the second access network, the second radio access technology being different than the first radio access technology. The operations of 1402 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1402 may be performed by a NE as described with reference to Figure 12.

[0210] At 1404, the method may include receiving, from the UE via the first access network, an indication of a cause for the registration procedure with the second NE of the second access network. The operations of 1404 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1404 may be performed by a NE as described with reference to Figure 12.

[0211] At 1406, the method may include receiving, based at least in part on registration of the UE with the second access network, data from the UE for routing to the second NE of the second access network. The operations of 1406 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1406 may be performed a NE as described with reference to Figure 12.

[0212] Figure 15 illustrates a flowchart of a method 1500 in accordance with aspects of the present disclosure. The operations of the method may be implemented by a UE as described herein.Attorney Docket No. SMM920230184-WO-PCTIn some implementations, the UE may execute a set of instructions to control the function elements of the UE to perform the described functions. It should be noted that the method described herein describes a possible implementation, and that the operations and the steps may be rearranged or otherwise modified and that other implementations are possible.

[0213] At 1502, the method may include transmitting, via a first access network associated with a first radio access technology and to a first NE of a second access network associated with a second radio access technology, a first message requesting a security association session with the first NE, the second radio access technology being different than the first radio access technology. The operations of 1502 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1502 may be performed by a UE as described with reference to Figure 10.

[0214] At 1504, the method may include receiving a second message including a notification regarding the first NE and confirming the security association session between the UE and the first NE. The operations of 1504 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1504 may be performed by a UE as described with reference to Figure 10.

[0215] At 1506, the method may include transmitting, to the first NE of the second access network, a third message requesting a selected registration with a second NE of the second access network and including an access network parameter for the selected registration. The operations of 1506 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1506 may be performed a UE as described with reference to Figure 10.

[0216] Figure 16 illustrates a flowchart of a method 1600 in accordance with aspects of the present disclosure. The operations of the method may be implemented by a NE as described herein such as an N3IWF. In some implementations, the NE may execute a set of instructions to control the function elements of the NE to perform the described functions. It should be noted that the method described herein describes a possible implementation, and that the operations and the steps may be rearranged or otherwise modified and that other implementations are possible.

[0217] At 1602, the method may include receiving, from a UE, via a first access network associated with a first radio access technology, and at the first NE of a second access networkAttorney Docket No. SMM920230184-WO-PCTassociated with a second radio access technology, a first message requesting a security association session with the first NE, the second radio access technology being different than the first radio access technology. The operations of 1602 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1602 may be performed by a NE as described with reference to Figure 12.

[0218] At 1604, the method may include transmitting a second message including a notification regarding the first NE and confirming the security association session between the UE and the first NE. The operations of 1604 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1604 may be performed by a NE as described with reference to Figure 12.

[0219] At 1606, the method may include receiving, from the UE, a third message requesting a selected registration with a second NE of the second access network and including an access network parameter for the selected registration. The operations of 1606 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1606 may be performed a NE as described with reference to Figure 12.

[0220] Figure 17 illustrates a flowchart of a method 1700 in accordance with aspects of the present disclosure. The operations of the method may be implemented by a UE as described herein. In some implementations, the UE may execute a set of instructions to control the function elements of the UE to perform the described functions. It should be noted that the method described herein describes a possible implementation, and that the operations and the steps may be rearranged or otherwise modified and that other implementations are possible.

[0221] At 1702, the method may include transmitting, to a first NE of a first access network associated with a first radio access technology, an identifier and a cause for a registration procedure with a second NE of a second access network associated with a second radio access technology. The operations of 1702 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1702 may be performed by a UE as described with reference to Figure 10.

[0222] At 1704, the method may include receiving an indication of acceptance of registration with the second access network based at least in part on the registration procedure. The operationsAttorney Docket No. SMM920230184-WO-PCTof 1704 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1704 may be performed by a UE as described with reference to Figure 10.

[0223] At 1706, the method may include transmitting, based at least in part on the acceptance of registration with the second access network, data to the first NE of the first access network for routing to the second NE of the second access network. The operations of 1706 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1706 may be performed a UE as described with reference to Figure 10.

[0224] Figure 18 illustrates a flowchart of a method 1800 in accordance with aspects of the present disclosure. The operations of the method may be implemented by a NE as described herein such as an TNAN. In some implementations, the NE may execute a set of instructions to control the function elements of the NE to perform the described functions. It should be noted that the method described herein describes a possible implementation, and that the operations and the steps may be rearranged or otherwise modified and that other implementations are possible.

[0225] At 1802, the method may include receiving, from a UE and at the first NE of a first access network associated with a first radio access technology, an identifier and a cause for a registration procedure with a second NE of a second access network associated with a second radio access technology. The operations of 1802 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1802 may be performed by a NE as described with reference to Figure 12.

[0226] At 1804, the method may include transmitting an indication of acceptance of registration with the second access network based at least in part on the registration procedure. The operations of 1804 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1804 may be performed by a NE as described with reference to Figure 12.

[0227] At 1806, the method may include receiving, from the UE, data for routing to the second NE of the second access network. The operations of 1806 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1806 may be performed a NE as described with reference to Figure 12.Attorney Docket No. SMM920230184-WO-PCT

[0228] Figure 19 illustrates a flowchart of a method 1900 in accordance with aspects of the present disclosure. The operations of the method may be implemented by a UE as described herein. In some implementations, the UE may execute a set of instructions to control the function elements of the UE to perform the described functions. It should be noted that the method described herein describes a possible implementation, and that the operations and the steps may be rearranged or otherwise modified and that other implementations are possible.

[0229] At 1902, the method may include transmitting, to a first NE of a first access network associated with a first radio access technology, a first message requesting a security association session with a second NE of a second access network associated with a second radio access technology. The operations of 1902 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1902 may be performed by a UE as described with reference to Figure 10.

[0230] At 1904, the method may include receiving a second message including a notification and confirming the security association session between the UE and the second NE. The operations of 1904 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1904 may be performed by a UE as described with reference to Figure 10.

[0231] At 1906, the method may include transmitting, to the second NE, a third message requesting a selected registration with the second access network and including an access network parameter for the selected registration. The operations of 1906 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1906 may be performed a UE as described with reference to Figure 10.

[0232] Figure 20 illustrates a flowchart of a method 2000 in accordance with aspects of the present disclosure. The operations of the method may be implemented by a NE as described herein such as an TNAN. In some implementations, the NE may execute a set of instructions to control the function elements of the NE to perform the described functions. It should be noted that the method described herein describes a possible implementation, and that the operations and the steps may be rearranged or otherwise modified and that other implementations are possible.Attorney Docket No. SMM920230184-WO-PCT

[0233] At 2002, the method may include receiving, at the first NE associated with a first access network of a first radio access technology, a first message from a UE requesting a security association session with a second NE of a second access network associated with a second radio access technology. The operations of 2002 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 2002 may be performed by a NE as described with reference to Figure 12.

[0234] At 2004, the method may include transmitting a second message including a notification and confirming the security association session between the UE and the second NE. The operations of 2004 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 2004 may be performed by a NE as described with reference to Figure 12.

[0235] At 2006, the method may include receiving, from the UE, a third message requesting a selected registration with the second NE and including an access network parameter for the selected registration. The operations of 2006 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 2006 may be performed a NE as described with reference to Figure 12.

[0236] The description herein is provided to enable a person having ordinary skill in the art to make or use the disclosure. Various modifications to the disclosure will be apparent to a person having ordinary skill in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not limited to the examples and designs described herein but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein.Attorney Docket No. SMM920230184-WO-PCT

Claims

What is claimed is:

1. A user equipment (UE) for wireless communication, comprising: at least one memory; and at least one processor coupled with the at least one memory and configured to cause the UE to: transmit, to a first network equipment of a first access network associated with a first radio access technology, an identifier and a cause for a registration procedure with a second network equipment of a second access network associated with a second radio access technology; receive an indication of acceptance of registration with the second access network based at least in part on the registration procedure; and transmit, based at least in part on the acceptance of registration with the second access network, data to the first network equipment of the first access network for routing to the second network equipment of the second access network.

2. The UE of claim 1 , wherein the at least one processor is configured to cause the UE to: transmit, to the first network equipment, a first message to request a connection; receive, from the first network equipment, a second message to accept the connection; transmit, to the first network equipment, a third message to establish a session for registration to the second network equipment of the second access network, the third message comprising the identifier and the cause for the registration procedure; receive, from the first network equipment, an indication of acceptance to establish the session; transmit, to the second network equipment and via the session, a register message request; and receive, from the second network equipment and via the session, a register message response.

3. The UE of claim 1, wherein the first access network comprises a Trusted Non-3GPP Access Network (TNAN) and the second access network comprises a core network (CN) of a cellular network.Attorney Docket No. SMM920230184-WO-PCT4. The UE of claim 3, wherein the first network equipment comprises a Trusted Non- 3 GPP Gateway Function (TNGF).

5. The UE of claim 1, wherein the identifier comprises a Network Access Identifier (NAI).

6. The UE of claim 1, wherein the cause for the registration procedure comprises an emergency cause.

7. The UE of claim 1, wherein the cause for registration comprises a priority cause.

8. A user equipment (UE) for wireless communication, comprising: at least one memory; and at least one processor coupled with the at least one memory and configured to cause the UE to: transmit, to a first network equipment of a first access network associated with a first radio access technology, a first message requesting a security association session with a second network equipment of a second access network associated with a second radio access technology; receive a second message comprising a notification and confirming the security association session between the UE and the second network equipment; and transmit, to the second network equipment, a third message requesting a selected registration with the second access network and comprising an access network parameter for the selected registration.

9. The UE of claim 8, wherein the at least one processor is configured to cause the UE to receive, from the second network equipment, a response confirming the selected registration with the second network equipment.Attorney Docket No. SMM920230184-WO-PCT10. The UE of claim 8, wherein the first access network comprises a Trusted Non-3GPP Access Network (TNAN) and the second access network comprises a core network (CN) of a cellular network.

11. The UE of claim 10, wherein the first network equipment comprises a Trusted Non- 3 GPP Gateway Function (TNGF).

12. The UE of claim 8, wherein the notification comprises a notification of congestion.

13. The UE of claim 8, wherein the second message comprises a back-off timer.

14. The UE of claim 8, wherein the selected registration comprises an indication of emergency registration.

15. The UE of claim 8, wherein the selected registration comprises an indication of priority registration.

16. The UE of claim 8, wherein the access network parameter comprises an establishment cause value, and wherein the establishment cause value comprises an indication of emergency.

17. The UE of claim 8, wherein the access network parameter comprises an establishment cause value, and wherein the establishment cause value comprises an indication of priority.

18. A processor for wireless communication, comprising: at least one controller coupled with at least one memory and configured to cause the processor to: transmit, to a first network entity of a first access network associated with a first radio access technology, an identifier and a cause for a registration procedure with a second network entity of a second access network associated with a second radio access technology; receive an indication of acceptance of registration with the second access network based at least in part on the registration procedure; andAttorney Docket No. SMM920230184-WO-PCTtransmit, based at least in part on the acceptance of registration with the second access network, data to the first network entity of the first access network for routing to the second network entity of the second access network.

19. The processor of claim 18, wherein the at least one controller is configured to cause the processor to: transmit, to the first network entity, a first message to request a connection; receive, from the first network entity, a second message to accept the connection; transmit, to the first network entity, a third message to establish a session for registration to the second network entity of the second access network, the third message comprising the identifier and the cause for the registration procedure; receive, from the first network entity, an indication of acceptance to establish the session; transmit, to the second network entity and via the session, a register message request; and receive, from the second network entity and via the session, a register message response.

20. A processor for wireless communication, comprising: at least one controller coupled with at least one memory and configured to cause the processor to: transmit, to a first network entity of a first access network associated with a first radio access technology, a first message requesting a security association session with a second network entity of a second access network associated with a second radio access technology; receive a second message comprising a notification and confirming the security association session between a UE and the second network entity; and transmit, to the second network entity, a third message requesting a selected registration with the second access network and comprising an access network parameter for the selected registration.Attorney Docket No. SMM920230184-WO-PCT

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