CN112470500B

CN112470500B - Apparatus and method for system interworking

Info

Publication number: CN112470500B
Application number: CN201980049248.8A
Authority: CN
Inventors: 刘建华
Original assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Current assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Priority date: 2019-05-13
Filing date: 2019-05-13
Publication date: 2023-03-28
Anticipated expiration: 2039-05-13
Also published as: WO2020227897A1; CN112470500A

Abstract

An apparatus and method for system interworking capable of providing good communication performance and high reliability are provided. A method for system interworking of User Equipment (UE) includes receiving an indication from a network node, wherein the indication includes an indication of whether a UE capability Identification (ID) allocated or used in a current system will be used in another system, and performing the indication.

Description

Apparatus and method for system interworking

Technical Field

The present disclosure relates to the field of communication systems, and more particularly, to an apparatus and method for system interworking.

Background

Universal Terrestrial Radio Access Network (UTRAN) is a Radio Access Network of Universal Mobile Telecommunications System (UMTS), wherein the UTRAN consists of Radio Network Controllers (RNCs) and node bs (i.e., radio base stations). The node B communicates wirelessly with the mobile terminal, and the RNC controls the node B. The RNC is further connected to a Core Network (CN). Evolved UTRAN (E-UTRAN) is an evolution of UTRAN towards a high data rate, low delay and packet optimized radio access network. Furthermore, the E-UTRAN consists of interconnected Evolved Node bs (enodebs) further connected to an Evolved Packet Core (EPC) network. E-UTRAN is also known as Long Term Evolution (LTE) and is standardized in the third Generation Partnership project (3 rd Generation Partnership project,3 GPP).

To allow for a wide range of User Equipment (UE) implementations, different UE capabilities are specified. The UE capabilities are divided into a number of parameters which are transmitted from the user equipment at connection setup and during an ongoing connection if/when the UE capabilities change. The UE capabilities may then be used by the network to select the configuration supported by the UE.

In existing systems, when registration or registration updates, the capabilities of the terminal are reported to the access network, which then sends the capabilities of the terminal to the core network for storage. When the terminal initiates a connection establishment request, the access network requests the capability information of the terminal from the core network, and then provides configuration for the terminal according to the capability information of the terminal.

As the terminal supports more and more features, the capability information of the terminal will become larger and larger, which brings huge signaling overhead. In addition, the core network needs to store the capability information of all terminal registrations, which also brings more challenges to the core network. In current System interworking, different network architectures are possible for a UE Capability Management Function (UCMF) deployed in a Fifth Generation System (5 GS) and an Evolved Packet System (EPS), and the UE cannot determine whether a UE Capability Identity (ID) is used in a source System and is also used in a target System.

Therefore, there is a need for an apparatus and method for system interworking to handle UE capability IDs during interworking with different systems.

Disclosure of Invention

An object of the present disclosure is to propose an apparatus and method for system interworking to handle a UE capability Identity (ID) during interworking with a different system capable of providing good communication performance and high reliability.

In a first aspect of the disclosure, a User Equipment (UE) for system interworking includes a memory, a transceiver, and a processor coupled with the memory and the transceiver. The processor is configured to control the transceiver to receive an indication from a network node, wherein the indication comprises an indication whether a UE capability Identification (ID) allocated or used in a current system is to be used in another system, and the processor is configured to perform the indication.

In a second aspect of the present disclosure, a method of a UE for system interworking includes receiving an indication from a network node, wherein the indication includes an indication whether a UE capability ID allocated or used in a current system is to be used in another system, and performing the indication.

In a third aspect of the disclosure, a network node for system interworking includes a memory, a transceiver, and a processor coupled with the memory and the transceiver. The processor is configured to control the transceiver to transmit an indication to a UE, wherein the indication includes an indication of whether a UE capability ID allocated or used in a current system will be used in another system.

In a fourth aspect of the present disclosure, a method of a network node for system interworking includes sending an indication to a UE, wherein the indication includes an indication of whether a UE capability ID allocated or used in a current system will be used in another system.

In a fifth aspect of the disclosure, a system for system interworking includes a first network node. How to handle the UE capability Identification (ID) is determined based on the behavior of the first network node.

In a sixth aspect of the disclosure, a method for system interworking includes determining how to handle a UE capability Identification (ID) based on a behavior of a first network node.

In a seventh aspect of the disclosure, a non-transitory machine-readable storage medium has stored thereon instructions which, when executed by a computer, cause the computer to perform the above-described method.

In an eighth aspect of the disclosure, a terminal device comprises a processor and a memory for storing a computer program. The processor is configured to execute a computer program stored in the memory to perform the above-described method.

In a ninth aspect of the disclosure, a network node comprises a processor and a memory for storing a computer program. The processor is configured to execute a computer program stored in the memory to perform the above-described method.

Drawings

In order to more clearly illustrate embodiments of the present disclosure or related art, the following drawings, which will be described in the embodiments, are briefly introduced. It should be apparent that the drawings are merely some examples of the disclosure and that other drawings may be derived by those of ordinary skill in the art without undue experimentation.

Fig. 1 is a block diagram of a user equipment and a network node for system interworking in accordance with an embodiment of the present disclosure.

Fig. 2 is a flowchart illustrating a method of a user equipment for system interworking according to an embodiment of the present disclosure.

Fig. 3 is a flow chart illustrating a method for system interworking by a network node according to an embodiment of the present disclosure.

Fig. 4 is a schematic diagram of an exemplary illustration of a network architecture according to an embodiment of the disclosure.

Fig. 5 is a schematic diagram of an exemplary illustration of an Evolved Packet System (EPS) Radio Access Capability Signaling optimization (RACS) architecture according to an embodiment of the present disclosure.

Fig. 6 is a schematic diagram of an exemplary illustration of a 5GS to EPS handover using an N26 interface according to an embodiment of the disclosure.

Fig. 7 is a schematic diagram of an exemplary illustration of the operation between a next generation radio access network (NG-RAN) and an access and mobility management function (AMF) according to an embodiment of the present disclosure.

Fig. 8 is a schematic diagram of an exemplary illustration of the operation between a next generation radio access network (NG-RAN) and an access and mobility management function (AMF) according to an embodiment of the present disclosure.

Fig. 9 is a schematic diagram of an exemplary illustration of the operation between a next generation radio access network (NG-RAN) and an access and mobility management function (AMF) according to an embodiment of the present disclosure.

Fig. 10 is a schematic diagram of an exemplary illustration of the operation between a next generation radio access network (NG-RAN) and an access and mobility management function (AMF) according to an embodiment of the present disclosure.

Fig. 11 is a schematic diagram of an exemplary illustration of the operation between a next generation radio access network (NG-RAN) and an access and mobility management function (AMF) according to an embodiment of the present disclosure.

Fig. 12 is a schematic diagram of an exemplary illustration of 5 GS-to-EPS idle mode mobility using an N26 interface according to an embodiment of the disclosure.

Fig. 13 is a schematic diagram of an exemplary illustration of a mobility procedure from 5GS to EPS without an N26 interface according to an embodiment of the present disclosure.

Fig. 14 is a block diagram of a system for wireless communication in accordance with an embodiment of the present disclosure.

Detailed Description

Embodiments of the present disclosure are described in detail below with reference to the accompanying drawings with technical contents, structural features, and objects and effects achieved. In particular, the terminology in the embodiments of the present disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure.

Fig. 1 illustrates that in some embodiments, a User Equipment (UE) 10 and a network node 20 for system interworking in accordance with embodiments of the present disclosure are provided. The UE10 may include a processor 11, a memory 12, and a transceiver 13. The network node 20 may comprise a processor 21, a memory 22 and a transceiver 23. The

processor

11 or 21 may be used to implement the proposed functions, procedures and/or methods described in this specification. The layers of the radio interface protocol may be implemented in the

processor

11 or 21. The memory 12 or 22 is operatively coupled with the

processor

11 or 21 and stores various information to operate the

processor

11 or 21. The

transceiver

13 or 23 is operatively coupled with the

processor

11 or 21, and the

transceiver

13 or 23 transmits and/or receives radio signals.

The

processor

11 or 21 may comprise an Application Specific Integrated Circuit (ASIC), other chipset, logic circuit and/or data processing device. The memory 12 or 22 may include Read Only Memory (ROM), random Access Memory (RAM), flash memory, memory cards, storage media, and/or other storage devices. The

transceiver

13 or 23 may include a baseband circuit to process radio frequency signals. When an embodiment is implemented in software, the techniques described herein may be implemented with modules (e.g., procedures, functions, and so on) that perform the functions described herein. These modules may be stored in memory 12 or 22 and executed by

processor

11 or 21. The memory 12 or 22 may be implemented within the

processor

11 or 21 or external to the

processor

11 or 21, where these may be communicatively coupled to the

processor

11 or 21 in various ways as is known in the art.

According to sidelink technologies developed under third generation partnership project (3 GPP) releases 14, 15, 16 and beyond, communication between UEs involves vehicle-to-all device (V2X) communication, including vehicle-to-vehicle (V2V), vehicle-to-pedestrian (V2P), and vehicle-to-infrastructure/network (V2I/N). The UEs communicate directly with each other through a sidelink interface such as a PC5 interface or the like.

In some embodiments, the processor 11 is configured to control the transceiver 13 to receive an indication from the network node 20, wherein the indication comprises an indication whether a UE capability ID allocated or used in a current system is to be used in another system, and the processor 11 is configured to perform the indication.

In some embodiments, the current system is one of a fifth generation system (5 GS) and an Evolved Packet System (EPS) and the other system is the other of the 5GS and the EPS. The processor 11 is arranged to perform a registration procedure in the 5GS and the processor 11 is arranged to perform an attach procedure in the EPS. The UE capability ID is a Public Land Mobile Network (PLMN) assigned capability ID.

In some embodiments, the indication further comprises whether an interface exists or is co-located between a UE Capability Management Function (UCMF) and a UE capability management Unit (UCME) of network node 20. In some embodiments, the indication is provided in a registration accept message, a UE configuration update message, or a downlink non-access stratum (NAS) message.

In some embodiments, the processor 11 is configured to determine whether to include the UE capability ID in the tracking area update procedure according to the indication, or the processor 11 is configured to determine to include the UE capability ID in the tracking area update procedure.

In some embodiments, the processor 11 is configured to determine whether to include the UE capability ID in the attach request procedure based on the indication, the processor 11 is configured to determine to include the UE capability ID in the attach request procedure, or the processor 11 is configured to determine not to include the UE capability ID in the attach request procedure.

In some embodiments, the processor 21 is configured to control the transceiver 23 to send an indication to the UE10, wherein the indication comprises an indication whether the UE capability ID allocated or used in the current system is to be used in another system.

In some embodiments, the current system is one of a fifth generation system (5 GS) and an Evolved Packet System (EPS) and the other system is the other of the 5GS and the EPS. In some embodiments, the access and mobility management function (AMF) of the network node 20 instructs the UE and the next generation radio access network (NG-RAN) of the network node 20 how to handle the UE capability ID.

In some embodiments, the AMF or UE Capability Management Function (UCMF) of the network node 20 indicates to the UE whether the UE capability ID allocated or used in the current system will be used in another system. The UE capability ID is a Public Land Mobile Network (PLMN) assigned capability ID.

In some embodiments, the indication further comprises an AMF or UCMF indicating whether the UE10 is interfaced or co-located between the UCMF and a UE capability management Unit (UCME) of the network node 20. In some embodiments, the indication is provided in a registration accept message, a UE configuration update message, or a downlink non-access stratum (NAS) message.

In some embodiments, the AMF indicates the information to the NG-RAN using a non-UE specific NG application protocol (NGAP) message. The AMF or UCMF indicates information to the NG-RAN using a UE-specific NGAP message. The AMF or UCMF indicates information to the NG-RAN, which indicates the information to the UE.

In some embodiments, if the NG-RAN knows that the target evolved node b, eNB, and the target Mobility Management Entity (MME) support radio access capability signaling optimization (RACS) based on local configuration or an indication from the AMF or UCMF; alternatively, if the NG-RAN knows that the target eNB and/or target MME can handle the UE capability ID; or if the NG-RAN knows that the target eNB and/or target MME supports RACS and receives an indication from the AMF or UCMF whether the UE capability ID allocated or used in the current system will be used in another system; or, if the NG-RAN has received an indication from the AMF or UCMF that the UE radio access capability is not included in the source-to-target transparent container; the NG-RAN does not include UE radio access capability in the source-to-target transparent container.

In some embodiments, the NG-RAN is configured to send the UE capability ID to a target evolved universal terrestrial radio access network (E-UTRAN) in a source-to-target transparent container. The NG-RAN is used to indicate whether the AMF includes UE radio access capability in the source-to-target transparent container.

In some embodiments, the AMF determines whether to include the UE capability ID in the MME UE context based on: whether the target MME and/or E-UTRAN support RACS and/or whether UCMF and UCME have interfaces or are collocated for communication with each other; the AMF determines whether to include a UE capability ID in an MME UE context based on an indication from the NG-RAN and/or based on whether the target MME and/or E-UTRAN support RACS and/or whether UCMF and UCME have an interface or co-location to communicate with each other; alternatively, the AMF determines whether to include the UE capability ID in the MME UE context, rather than based on NG-RAN behavior and/or based on whether the target MME and/or E-UTRAN support RACS and/or whether UCMF and UCME have an interface or co-location to communicate with each other.

In some embodiments, if the target MME and/or E-UTRAN support RACS and/or UCMF and UCME have an interface or co-location to communicate with each other, the AMF includes the UE capability ID in the MME UE context.

In some embodiments, the target MME includes the UE capability ID in the handover request step. Specifically, the target MME includes the UE capability ID in the handover request step based on the E-UTRAN capabilities of RACS, and if the E-UTRAN supports RACS, the target MME includes the UE capability ID.

In some embodiments, if the target MME of network node 20 receives the UE capability ID from UE10, but the target MME does not have associated UE radio access capability, the target MME appears as the target MME including the UE capability ID in the context request step to operate with the AMF of network node 20, and the target MME retrieves the UE radio access capability from the UCME of network node 20 to provide the UE capability ID.

In some embodiments, the target MME informs the AMF to provide the associated UE radio access capability in the context request step, and the AMF provides the associated UE radio access capability to the target MME.

In some embodiments, the target MME of network node 20 sends a context request message to the AMF of network node 20, which provides the UE context to the target MME to include the UE capability ID.

In some embodiments, the target MME includes a request indication in the context request step, and if not, the AMF provides the UE capability ID based on whether the target MME and/or the E-UTRAN of the network node 20 support RACS and/or whether UCMF and UCME of the network node 20 have an interface or co-location to communicate with each other.

In some embodiments, if the target MME of the network node does not have an associated UE radio access capability for the UE capability ID, the target MME retrieves the UE radio access capability from the UCME of the network node 20 and provides the UE capability ID to the UCME. If the UE capability ID is not received from the UE10, the target MME retrieves the UE radio access capability from UCME and provides the UE capability ID to UCME.

In some embodiments, how to handle the UE capability ID is determined based on the behavior of the AMF. In some embodiments, determining how to process the UE capability ID includes determining whether the UE capability ID allocated or used in the current system is to be used in another system, the current system being one of a fifth generation system (5 GS) and an Evolved Packet System (EPS), and the other system being the other of the 5GS and the EPS. In some embodiments, the behavior of the AMF includes the AMF instructing the NG-RAN how to handle the UE capability ID, the AMF instructing the user equipment how to handle the UE capability ID, and/or the AMF does not instruct the NG-RAN how to handle the UE capability ID, and the NG-RAN determines how to handle the UE capability ID based on local configuration information.

Fig. 2 illustrates a method 200 of a user equipment for system interworking, according to an embodiment of the present disclosure. The method 200 comprises the following steps: block 202, receiving an indication from a network node, wherein the indication comprises an indication whether a UE capability Identification (ID) allocated or used in a current system is to be used in another system; and block 204, performing the indication.

In some embodiments, the current system is one of a fifth generation system (5 GS) and an Evolved Packet System (EPS) and the other system is the other of the 5GS and the EPS.

In some embodiments, the method further comprises performing a registration procedure in the 5GS and performing an attach procedure in the EPS. The UE capability ID is a Public Land Mobile Network (PLMN) assigned capability ID.

In some embodiments, the indication further comprises whether an interface exists or is co-located between a UE Capability Management Function (UCMF) and a UE capability management Unit (UCME) of the network node. In some embodiments, the indication is provided in a registration accept message, a UE configuration update message, or a downlink non-access stratum (NAS) message.

In some embodiments, the method further comprises determining whether to include the UE capability ID in a tracking area update procedure or determining to include the UE capability ID in a tracking area update procedure in accordance with the indication. In some embodiments, the method further comprises determining whether to include the UE capability ID in an attach request procedure, determining to include the UE capability ID in an attach request procedure, or determining not to include the UE capability ID in an attach request procedure in accordance with the indication.

Fig. 3 illustrates a method 300 of a network node for system interworking, in accordance with an embodiment of the present disclosure. The method 300 includes: block 302, an indication is sent to a user equipment, wherein the indication includes an indication whether a UE capability ID allocated or used in a current system is to be used in another system.

In some embodiments, the AMF or UE Capability Management Function (UCMF) of the network node 20 indicates to the UE whether the UE capability ID allocated or used in the current system will be used in another system. The UE capability ID is a Public Land Mobile Network (PLMN) assigned capability ID. In some embodiments, the indication further comprises the AMF or UCMF indicating whether the UE10 is interfaced or co-located between the UCMF and a UE capability management Unit (UCME) of the network node 20. In some embodiments, the indication is provided in a registration accept message, a UE configuration update message, or a downlink non-access stratum (MAS) message. In some embodiments, the AMF indicates the information to the NG-RAN using a non-UE specific NG application protocol (NGAP) message. The AMF or UCMF indicates information to the NG-RAN using a UE-specific NGAP message. The AMF or UCMF indicates information to the NG-RAN, which indicates the information to the UE.

In some embodiments, the AMF determines whether to include the UE capability ID in the MME UE context based on: whether the target MME and/or E-UTRAN support RACS and/or whether UCMF and UCME have interfaces or are collocated for communication with each other; the AMF determines whether to include a UE capability ID in an MME UE context based on an indication from the NG-RAN and/or based on whether the target MME and/or the E-UTRAN support RACS and/or whether UCMF and UCME have an interface or co-location to communicate with each other; alternatively, the AMF determines whether to include the UE capability ID in the MME UE context, rather than based on NG-RAN behavior and/or based on whether the target MME and/or E-UTRAN support RACS and/or whether UCMF and UCME have an interface or co-location to communicate with each other.

In some embodiments, the target MME informs the AMF in the context request step that the associated UE radio access capability is provided, the AMF providing the associated UE radio access capability to the target MME. In some embodiments, the target MME of network node 20 sends a context request message to the AMF of network node 20, which provides the UE context to the target MME to include the UE capability ID.

Fig. 4 is a schematic diagram of an exemplary illustration of a network architecture according to an embodiment of the disclosure. Fig. 4 illustrates that in some embodiments, in the UE capability optimization mechanism, a UE capability ID is introduced to present a set of UE radio access capabilities. The mapping relation of UE capability ID and radio access capability is managed in UCMF, which is a new network entity in 5 GS. The network architecture is shown in fig. 4.

Fig. 5 is a schematic diagram of an exemplary illustration of an Evolved Packet System (EPS) radio access capability signaling optimization (RACS) architecture, according to an embodiment of the disclosure. The same or similar mechanism as in fig. 4 is also introduced in EPS. Fig. 5 shows that, in some embodiments, UCMF has the same functionality in EPS AS in 5GS, linking MME and AS, optionally via SCEF. For the UCMF-MME interface, there are different alternatives A, B and C. In alternative a, UCMF as specified for 5GS is used for EPS and MME is connected in the same way as AMF in 5GS, i.e. SBI is used. In alternative B, the UCMF functional entity as specified for 5GS (possibly named UCME in EPS architecture) connects MME using EPS legacy type interface/protocol. In alternative C, UCMF connects MME via RACS-IWF, using SBI UCMF to RACS-IWF, and EPS legacy type interface RACS-IWF to MME, as specified for 5 GS. For alternative a, the 5GS and EPS use unified UCMF, and the UE capability IDs of the 5GS and EPS are managed in the UCMF. For alternative B, the UCMF used in 5GS and another network entity (e.g. UCME in EPS) are different entities. The two entities may be deployed in different places and have no interface to communicate UE capability ID information to each other, or may be co-located or have interfaces to communicate capability ID information to each other.

In some embodiments, when the UE performs interworking between the 5GS and the EPS, the UE needs to determine whether the capability ID allocated or used in the source system or the source RAT can be used in the target system or the target RAT. The UE then determines whether the capability ID is indicated in the first NAS message of the target system or RAT.

Fig. 6 is a schematic diagram of an exemplary illustration of a 5GS to EPS handover using an N26 interface according to an embodiment of the disclosure. Fig. 6 illustrates a solution for inter-system handoff using an N26 interface provided in some embodiments. N26 is the interface between the AMF and the MME, over which the UE context can be forwarded during the handover procedure. The present embodiment takes the 5GS to EPS as an example, and is also applicable to the process from EPS to 5 GS. In 5GS, the UE performs a registration procedure, and in EPS, the UE performs an attach procedure. The 5GS to EPS handover in single registration mode with N26 interface includes the operation as shown in fig. 6. At operation 0 (i.e., step 0), during the UE registration procedure, the AMF instructs the UE and NG-RAN how to handle the UE capabilities. The details are as follows. The indicated information may be that the AMF or the UCMF indicates to the UE that the capability ID allocated in the source system or the used capability ID is used or not used in the target system, for example, in the EPS in this embodiment. The assigned capability ID is a PLMN assigned capability ID. The indicated information may be that the AMF or the UCMF indicates to the UE whether there is an interface or co-location between the UCMF and the UCME. The messages and procedures shown in fig. 7 to 11 may be that the AMF or UCMF indicates information to the UE in a registration accept message, or a UE configuration update message, or any other NAS message from the AMF to the UE. The messages and procedures may be that the AMF indicates the information to the NG-RAN using a non-UE specific NGAP message, e.g. in a NG Setup RESPONSE (NG Setup RESPONSE) message during the NG Setup procedure, as shown in the following call flow in fig. 7. The AMF or UCMF indicates said information to the NG-RAN using a UE-specific NGAP message, for example an INITIAL CONTEXT SETUP REQUEST (INITIAL CONTEXT SETUP REQUEST) or a UE CONTEXT MODIFICATION REQUEST (UE CONTEXT MODIFICATION REQUEST) message during the following call flow as shown in fig. 10 and 11.

Fig. 6 illustrates that in some embodiments, the AMF or UCMF indicates the information to the NG-RAN, and the NG-RAN indicates the information to the UE. In operation 1, the NG-RAN decides that the UE can be handed over to E-UTRA. The NG-RAN sends a handover request (target eNB ID, direct forwarding path availability, source to target transparent container, intersystem handover indication) message to the AMF. If the NG-RAN knows that the target eNB/MME supports RACS, based on, for example, local configuration or an indication from AMF or UCMF; alternatively, if the NG-RAN knows that the target eNB/MME can handle the UE capability ID; or, if the NG-RAN knows that the target eNB/MME supports RACS, and receives in the indication from the AMF or UCMF an assigned capability ID in the source system or an indication that the used capability ID is used or not used in the target system; or if the NG-RAN has received the UE radio capability in the indication from the AMF or UCMF not included in the source-to-target transparent container; the NG-RAN does not include UE radio access capability in the source-to-target transparent container. Optionally, the NG-RAN may include the capability ID to the target E-UTRAN in a source to target transparent container. Further, the NG-RAN may indicate whether the AMF includes UE radio capability in the source-to-target transparent container.

Figure 6 shows that in operation 2, the amf determines from the "target eNB identifier" IE that the type of handover is to E-UTRAN in some embodiments. In operation 2, the AMF sends a forward relocation request with the following modifications and description. The AMF determines whether to include the UE capability ID in the MME UE context based on the following information. If 1) and/or 2) is yes, the AMF includes the UE capability ID in the MME UE context. 1) Whether the target MME and/or E-UTRAN support RACS. 2) Whether UCMF and UCME have an interface or co-location for communicating with each other. Operations 4 and 5 are shown in fig. 6. At operation 6, a handover request is provided with the following modifications. In this step, the MME may include a UE capability ID. Furthermore, the MME includes the UE capability ID in this step based on the RACS's E-UTRAN capabilities; if the E-UTRAN supports RACS, the MME includes the UE capability ID. Operations 7 through 17 are shown in fig. 6. In operation 18, the ue initiates a tracking area update procedure. The UE determines whether the capability ID is included in this step based on the information received in step 0 (i.e., operation 0). If the UE receives an indication that the capability ID allocated in the source system or used in the target system or that there is an interface or co-location between UCMF and UCME in step 0, the UE includes the capability ID in this step.

Fig. 12 is a schematic diagram of an exemplary illustration of 5GS to EPS idle mode mobility using an N26 interface according to an embodiment of the disclosure. Fig. 12 illustrates that, in some embodiments, a solution is provided when a UE is in idle mode mobility using an N26 interface. In this embodiment, the MME may receive a UE capability ID from the UE or the AMF. The present embodiment takes the case from 5GS to EPS, and is also applicable to the process from EPS to 5 GS. In 5GS, the UE performs a registration procedure, and in EPS, the UE performs an attach procedure. In operation 0 (i.e., step 0), optionally, as described in operation 0 (step 0) of the embodiment shown in fig. 6, the UE receives information from the AMF or the UCMF.

Fig. 12 shows that in some embodiments, at operations 1 to 3 (i.e. steps 1 to 3), the UE initiates the tracking area update procedure. The UE determines whether the capability ID is included in the step based on the information received in step 0 (i.e., operation 0). If the UE receives an indication that the capability ID allocated in the source system or used in the target system, or that there is an interface or co-location between UCMF and UCME, in step 0, the UE includes the capability ID in said step. Alternatively, the UE will always include the capability ID in this step.

Fig. 12 illustrates that, in operations 4 through 6 (i.e., steps 4 through 6), if the MME receives a UE capability ID from the UE, but the MME does not have associated UE radio access capabilities, the MME may behave as follows in some embodiments. 1) The MME includes the UE capability ID in the context request in step 4 to the AMF. Optionally, the MME informs the AMF to provide the associated capabilities. The AMF provides the associated capabilities to the MME. 2) The MME retrieves the UE radio access capabilities from the UCME and provides the UE capability ID.

Fig. 12 illustrates an alternative embodiment from operations 4 to 6 in some embodiments, the MME sending a context request message to the AMF, which provides the UE context, including the UE capability ID, to the MME. Optionally, the MME may include a request indication in step 4, and if not, the AMF provides the ID based on either or both of: 1) Whether the target MME and/or E-UTRAN support RACS; 2) Whether UCMF and UCME have an interface or co-location for communicating with each other.

Fig. 13 is a schematic diagram of an exemplary illustration of a mobility procedure from 5GS to EPS without an N26 interface according to an embodiment of the present disclosure. Fig. 13 shows that in some embodiments, a solution is provided when there is no UE mobility for the N26 interface. In this embodiment, the MME may receive a UE capability ID from the UE. The present embodiment takes the case from 5GS to EPS, and is also applicable to the process from EPS to 5 GS. In 5GS, the UE performs a registration procedure, and in EPS, the UE performs an attach procedure.

Fig. 13 shows that in some embodiments, the UE receives information from the AMF or UCMF in operation 0 (i.e., step 0), optionally as described in step 0 (i.e., operation 0) of the embodiment shown in fig. 6. Operations 1 to 4 (i.e., steps 1 to 4) are shown in fig. 13. In operations 5 to 7 (i.e., steps 5 to 7), the UE initiates an attach request procedure. 1 to 3 there are three alternatives. In alternative 1, the UE determines whether to include the capability ID in step based on the information received in step 0. If the UE receives an indication that the capability ID allocated or used in the source system is used in the target system or that there is an interface or co-location between UCMF and UCME in step 0, the UE includes the capability ID in this step. In alternative 2, the UE always includes the capability ID in this step. In alternative 3, the UE does not include the capability ID in this step. In some embodiments, if the MME does not have an associated UE radio access capability for the UE capability ID, the MME retrieves the UE radio access capability from the UCME, providing the UE capability ID to the UCME. If the UE capability ID is not received from the UE, the MME may retrieve and provide the UE capability ID to UCME.

In summary, the embodiments of the present disclosure provide an apparatus and method for a UE to process capability or UE capability ID during interworking with different systems. The network indicates to the UE whether the assigned capability ID can be used for another system or another RAT. The UE determines a method of reporting the capability, for example, whether to report a capability ID allocated in the current system or RAT. The network makes decisions and the like based on network architecture and/or operator policies and the like. The present embodiments also provide for the behavior of the source RAN during interworking, the behavior of the source Core Network (CN) node during interworking, and the behavior of the target CN node during interworking. The solution may be applied to inter-RAT mobility, e.g. UE moving between NR-RAN to EUTRAN, 3GPP RAT to non-3 GPP RAT. The solution can also be applied to inter-PLMN handovers.

Fig. 14 is a block diagram of an example system 700 for wireless communication in accordance with an embodiment of the present disclosure. The embodiments described herein may be implemented in a system using any suitably configured hardware and/or software. Fig. 14 shows a system 700, the system 700 including Radio Frequency (RF) circuitry 710, baseband circuitry 720, application circuitry 730, memory/storage 740, display 750, camera 760, sensors 770, and input/output (I/O) interface 780, coupled to each other at least as shown.

The application circuitry 730 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The processor may include any combination of general purpose processors and special purpose processors, such as a graphics processor and an application processor. A processor may be coupled to the memory/storage and configured to execute instructions stored in the memory/storage to enable various applications and/or operating systems to run on the system.

Baseband circuitry 720 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The processor may include a baseband processor. The baseband circuitry may handle various radio control functions enabling communication with one or more radio networks through the radio frequency circuitry. The radio control functions may include, but are not limited to, signal modulation, encoding, decoding, radio frequency shifting, and the like. In some embodiments, the baseband circuitry may provide communications compatible with one or more radio technologies. For example, in some embodiments, the baseband circuitry may support communication with an Evolved Universal Terrestrial Radio Access Network (EUTRAN) and/or other Wireless Metropolitan Area Networks (WMANs), wireless Local Area Networks (WLANs), wireless Personal Area Networks (WPANs). Embodiments in which baseband circuitry is used for radio communications supporting more than one wireless protocol may be referred to as multi-mode baseband circuitry.

In various embodiments, baseband circuitry 720 may include circuitry to operate with signals that are not strictly considered to be at baseband frequencies. For example, in some embodiments, the baseband circuitry may include circuitry that operates with a signal having an intermediate frequency that is between the baseband frequency and the radio frequency.

RF circuitry 710 may enable communication with a wireless network through a non-solid medium using modulated electromagnetic radiation. In various embodiments, the RF circuitry may include switches, filters, amplifiers, and the like to facilitate communication with the wireless network.

In various embodiments, RF circuitry 710 may include circuitry to operate with signals that are not strictly considered radio frequencies. For example, in some embodiments, the RF circuitry may include circuitry that operates with signals having an intermediate frequency between a baseband frequency and a radio frequency.

In various embodiments, the transmitter circuitry, control circuitry, or receiver circuitry discussed above with respect to the user equipment, eNB, or gNB may be embodied in whole or in part in one or more of the RF circuitry, baseband circuitry, and/or application circuitry. As used herein, "circuitry" may refer to, be part of, or include an Application Specific Integrated Circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and/or memory (shared, dedicated, or group) that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable hardware components that provide the described functionality. In some embodiments, the electronic device circuitry may be implemented in, or functions associated with, one or more software or firmware modules.

In some embodiments, some or all of the constituent components of the baseband circuitry, application circuitry, and/or memory/storage may be implemented together on a system on a chip (SOC). Memory/storage 740 may be used to load and store data and/or instructions for a system, for example. Memory/storage for one embodiment may include any combination of suitable volatile memory, such as Dynamic Random Access Memory (DRAM), and/or non-volatile memory, such as flash memory. In various embodiments, the I/O interface 780 may include one or more user interfaces designed to enable a user to interact with the system and/or peripheral component interfaces designed to enable peripheral components to interact with the system. The user interface may include, but is not limited to, a physical keyboard or keypad, a touchpad, a speaker, a microphone, and the like. The peripheral component interfaces may include, but are not limited to, a non-volatile memory port, a Universal Serial Bus (USB) port, an audio jack, and a power interface. In various embodiments, the sensor 770 may include one or more sensing devices to determine environmental conditions and/or location information related to the system. In some embodiments, the sensors may include, but are not limited to, a gyroscope sensor, an accelerometer, a proximity sensor, an ambient light sensor, and a positioning unit. The positioning unit may also be part of, or interact with, baseband circuitry and/or radio frequency circuitry to communicate with components of a positioning network, such as Global Positioning System (GPS) satellites. In various embodiments, display 750 may include a display, such as a liquid crystal display and a touch screen display. In various embodiments, system 700 may be a mobile computing device, such as but not limited to a laptop computing device, a tablet computing device, a netbook, an ultrabook, a smartphone, and the like. In various embodiments, the system may have more or fewer components and/or different architectures. Where appropriate, the methods described herein may be implemented as a computer program. The computer program may be stored on a storage medium, such as a non-transitory storage medium.

In an embodiment of the present disclosure, an apparatus and method for system interworking are provided to process a UE capability ID during interworking with a different system capable of providing good communication performance and high reliability. Embodiments of the present disclosure are a combination of techniques/processes that may be employed in 3GPP specifications to create an end product.

One of ordinary skill in the art would understand that each of the units, algorithms, and steps described and disclosed in the embodiments of the present disclosure is implemented using electronic hardware or a combination of computer software and electronic hardware. Whether a function is run in hardware or software depends on the application conditions and the design requirements of the technical plan. Skilled artisans may implement the functionality in varying ways for each particular application, and such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure. A person skilled in the art will understand that he/she may refer to the working processes of the systems, devices and units in the above embodiments, since the working processes of the systems, devices and units are substantially the same. For ease of description and simplicity, these operations will not be described in detail. It should be understood that the systems, devices, and methods disclosed in embodiments of the present disclosure may be implemented in other ways. The above embodiments are merely exemplary. The partitioning of cells is based solely on logical functions, while other partitions exist when implemented. Multiple units or components may be combined or integrated in another system. It is also possible to omit or skip certain features. On the other hand, the mutual coupling, direct coupling or communicative coupling shown or discussed is operated indirectly through some ports, devices or units, or communicatively through electrical, mechanical or other forms.

The elements of the separation assembly as used for explanation may or may not be physically separate. The unit for displaying may or may not be a physical unit, i.e. located in one place or distributed over a plurality of network elements. Some or all of the units are used according to the purpose of the embodiment. Furthermore, each functional unit in each embodiment may be integrated in one processing unit, physically separated, or integrated in one processing unit having two or more units. If the software functional unit is implemented and used and sold as a product, it may be stored in a readable storage medium in a computer. Based on this understanding, the technical solutions proposed by the present disclosure can be implemented basically or partially in the form of software products. Alternatively, portions of the technical solution that facilitate conventional techniques may be implemented in the form of a software product. The software product in the computer is stored in a storage medium, comprising a plurality of commands for a computing device, such as a personal computer, server or network device, to execute all or some of the steps disclosed by the embodiments of the present disclosure. The storage medium includes a USB disk, a removable hard disk, a Read Only Memory (ROM), a Random Access Memory (RAM), a floppy disk, or other type of medium capable of storing program code.

While the disclosure has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the disclosure is not to be limited to the disclosed embodiment, but is intended to cover various arrangements made without departing from the scope of the broadest interpretation of the appended claims.

Claims

1. A user equipment, UE, for system interworking, comprising:

a memory;

a transceiver; and

a processor coupled to the memory and the transceiver,

wherein the processor is configured to:

controlling the transceiver to receive an indication from a network node, wherein the indication comprises an indication whether a UE capability Identification (ID) allocated or used in a current system is to be used in another system; and

executing the instruction;

wherein an access and mobility management function AMF of the network node instructs the UE and a next generation radio access network, NG-RAN, of the network node how to handle the UE capability ID;

the AMF or UCMF indicates information to the NG-RAN, and the NG-RAN indicates the information to the UE;

if the NG-RAN knows that a target evolved node b, eNB, and/or a target mobility management entity, MME, supports radio Access capability Signaling optimization, RACS, based on local configuration or the indication from the AMF or the UCMF, or if the NG-RAN knows that the target eNB and/or the target MME can handle the UE capability ID, or if the NG-RAN knows that the target eNB and/or the target MME supports the RACS and receives an indication from the AMF or the UCMF whether the UE capability ID allocated or used in the current system will be used in the other system, or if the NG-RAN has received an indication from the AMF or the UCMF that UE radio Access capability is not included in a source-to-target transparent container, the NG-RAN does not include UE radio Access capability in the source-to-target transparent container.

2. The UE of claim 1, wherein the current system is one of a fifth generation system (5 GS) and an Evolved Packet System (EPS) and the other system is the other of the 5GS and the EPS.

3. The UE of claim 2, wherein the processor is to perform a registration procedure in the 5GS and the processor is to perform an attach procedure in the EPS.

4. The UE of any of claims 1-3, wherein the UE capability ID is a Public Land Mobile Network (PLMN) assigned capability ID.

5. The UE according to any of claims 1-3, wherein the indication further comprises whether an interface exists or is co-located between a UE capability management function, UCMF, and a UE capability management unit, UCME, of the network node.

6. The UE of any of claims 1 to 3, wherein the indication is provided in a registration accept message, a UE configuration update message, or a downlink non-access stratum (NAS) message.

7. The UE of any of claims 1 to 3, the processor to determine whether to include the UE capability ID in a tracking area update procedure in accordance with the indication, or the processor to determine to include the UE capability ID in the tracking area update procedure.

8. The UE of any of claims 1 to 3, the processor to determine whether to include the UE capability ID in an attach request procedure in accordance with the indication, the processor to determine to include the UE capability ID in the attach request procedure, or the processor to determine not to include the UE capability ID in the attach request procedure.

9. A method of a user equipment, UE, for system interworking, the UE being operable with a current system and another system, the method comprising:

receiving an indication from a network node, wherein the indication comprises an indication whether a UE capability identity, ID, allocated or used in the current system is to be used in the other system; and

executing the instruction;

wherein an access and mobility management function, AMF, of the network node instructs the UE and a next generation radio access network, NG-RAN, of the network node how to handle the UE capability ID;

10. The method of claim 9, wherein the current system is one of a fifth generation system,5GS, and an evolved packet system, EPS, and the other system is the other of the 5GS and the EPS.

11. The method of claim 10, further comprising performing a registration procedure in the 5GS and performing an attach procedure in the EPS.

12. The method according to any of claims 9-11, wherein the UE capability ID is a public land mobile network, PLMN, UE capability ID.

13. The method according to any of claims 9 to 11, wherein the indication further comprises whether an interface exists or is co-located between a UE capability management function, UCMF, and a UE capability management unit, UCME, of the network node.

14. The method of any of claims 9 to 11, wherein the indication is provided in a registration accept message, a UE configuration update message, or a downlink non-access stratum, NAS, message.

15. The method of any of claims 9 to 11, further comprising determining whether to include the UE capability ID in a tracking area update procedure or determining to include the UE capability ID in the tracking area update procedure according to the indication.

16. The method of any of claims 9 to 11, further comprising determining, from the indication, whether to include the UE capability ID in an attach request procedure, to include the UE capability ID in the attach request procedure, or to not include the UE capability ID in the attach request procedure.

17. A network node for system interworking, comprising:

a memory;

a transceiver; and

a processor coupled to the memory and the transceiver,

wherein the processor is configured to:

controlling the transceiver to transmit an indication to a User Equipment (UE), wherein the indication comprises an indication whether a UE capability Identification (ID) allocated or used in a current system is to be used in another system;

18. The network node of claim 17, wherein the current system is one of a fifth generation system,5GS, and an evolved packet system, EPS, and the other system is the other of the 5GS and the EPS.

19. The network node according to claim 17 or 18, wherein the AMF or a UE capability management function UCMF of the network node indicates whether the UE capability ID allocated or used by the UE in the current system is to be used in the other system.

20. The network node of any of claims 17 or 18, wherein the UE capability ID is a public land mobile network, PLMN, allocated capability ID.

21. The network node of claim 19, wherein the indication further comprises the AMF or the UCMF indicating whether the UE is interfaced or co-located between the UCMF and a UE capability management unit, UCME, of the network node.

22. The network node according to any of claims 17 or 18, wherein the indication is provided in a registration accept message, a UE configuration update message or a downlink non-access stratum, NAS, message.

23. The network node of claim 17 or 18, wherein the AMF indicates information to the NG-RAN using a non-UE specific NG application protocol, NGAP, message.

24. The network node of claim 17 or 18, wherein the AMF or UCMF indicates information to the NG-RAN using a UE-specific NGAP message.

25. The network node of claim 17, wherein the NG-RAN is to send the UE capability ID to a target evolved universal terrestrial radio access network, E-UTRAN, in the source-to-target transparent container.

26. The network node of claim 17, wherein the NG-RAN is to indicate whether the AMF includes UE radio access capability in the source-to-target transparent container.

27. The network node of claim 17 or 18, wherein the AMF determines whether to include the UE capability ID in an MME UE context based on: whether the target MME and/or E-UTRAN support RACS and/or whether UCMF and UCME have interfaces or are collocated for communication; the AMF determining whether to include the UE capability ID in a UE context of the MME based on the indication from the NG-RAN and/or based on whether the target MME and/or the E-UTRAN support the RACS and/or whether the UCMF and the UCME have the interface or co-location to communicate with each other; alternatively, the AMF determines whether to include a UE capability ID in the MME UE context, rather than based on NG-RAN behavior and/or based on whether the target MME and/or the E-UTRAN support the RACS and/or whether the UCMF and the UCME have the interface or co-location to communicate with each other.

28. The network node of claim 27, wherein the AMF includes a UE capability ID in the MME UE context if the target MME and/or the E-UTRAN support the RACS and/or the UCMF and the UCME have an interface or co-location to communicate with each other.

29. The network node of claim 28, wherein the target MME includes the UE capability ID in a handover request step.

30. The network node of claim 29, wherein the target MME includes the UE capability ID in the handover request step based on E-UTRAN capabilities of the RACS, the target MME including the UE capability ID if the E-UTRAN supports the RACS.

31. The network node of claim 17, wherein, if a target MME of the network node receives the UE capability ID from the UE, but the target MME has no associated UE radio access capability, the target MME appears to the target MME to include the UE capability ID in a context request step to operate with the AMF of the network node, and the target MME retrieves UE radio access capability from the UCME of the network node to provide the UE capability ID.

32. The network node of claim 31, wherein the target MME notifies the AMF to provide associated UE radio access capabilities in the context requesting step, and the AMF provides the associated UE radio access capabilities to the target MME.

33. The network node of claim 17, wherein a target MME of the network node sends a context request message to an AMF of the network node, the AMF providing a UE context to the target MME to include the UE capability ID.

34. The network node of claim 33, wherein the target MME includes a request indication in the context request step, and if not, the AMF provides the UE capability ID based on whether the target MME and/or the E-UTRAN of the network node support RACS and/or whether UCMF and UCME of the network node have an interface or co-location to communicate with each other.

35. The network node of claim 17, wherein, if a target MME of the network node does not have an associated UE radio access capability for the UE capability ID, the target MME retrieves the UE radio access capability from a UCME of the network node and provides the UE capability ID to the UCME.

36. The network node of claim 35, wherein, if the UE capability ID is not received from the UE, the target MME retrieves the UE radio access capability from the UCME and provides the UE capability ID to the UCME.

37. A method of a network node for system interworking, comprising:

transmitting an indication to a User Equipment (UE), wherein the indication comprises an indication whether a UE capability ID allocated or used in a current system is to be used in another system;

the AMF or the UCMF indicates information to the NG-RAN, and the NG-RAN indicates the information to the UE;

38. The method of claim 37, wherein the current system is one of a fifth generation system,5GS, and an evolved packet system, EPS, and the other system is the other of the 5GS and the EPS.

39. The method according to claim 37 or 38, wherein the AMF or a UE capability management function UCMF of the network node indicates to the UE whether the UE capability ID allocated or used in the current system is to be used in the other system.

40. The method of any of claims 37 or 38, wherein the UE capability ID is a public land mobile network, PLMN, UE capability ID.

41. The method of claim 39, wherein the indicating further comprises the AMF or the UCMF indicating to the UE whether an interface or co-location exists between the UCMF and a UE Capability Management Element (UCME) of the network node.

42. The method of any one of claims 37 or 38, wherein the indication is provided in a registration accept message, a UE configuration update message, or a downlink non-access stratum, NAS, message.

43. The method of claim 37, wherein the AMF indicates information to the NG-RAN using a non-UE-specific NG application protocol, NGAP, message.

44. The method of claim 39, wherein the AMF or the UCMF indicates information to the NG-RAN using UE-specific NGAP messages.

45. The method of claim 37, wherein the NG-RAN is to send the UE capability ID to a target evolved universal terrestrial radio access network, E-UTRAN, in the source-to-target transparent container.

46. The method of claim 45, wherein the NG-RAN is to indicate whether the AMF includes UE radio access capability in the source-to-target transparent container.

47. The method of claim 39, wherein the AMF determines whether to include the UE capability ID in an MME UE context based on: whether the target MME and/or E-UTRAN support RACS and/or whether UCMF and UCME have interfaces or are collocated for communication with each other; the AMF determining whether to include the UE capability ID in the MME UE context based on the indication from the NG-RAN and/or based on whether the target MME and/or the E-UTRAN support the RACS and/or whether the UCMF and the UCME have the interface or co-location to communicate with each other; alternatively, AMF determines whether to include the UE capability ID in the MME UE context, rather than based on NG-RAN behavior and/or based on whether the target MME and/or the E-UTRAN support the RACS and/or whether the UCMF and the UCME have the interface or co-location to communicate with each other.

48. The method of claim 47, wherein the AMF includes a UE capability ID in the MME UE context if the target MME and/or the E-UTRAN support the RACS and/or the UCMF and the UCME have the interface or co-location to communicate with each other.

49. The method of claim 48, wherein the target MME comprises the UE capability ID in a handover request step.

50. The method of claim 49 wherein the target MME includes the UE capability ID in the handover request step based on E-UTRAN capabilities of the RACS, the target MME including the UE capability ID if the E-UTRAN supports the RACS.

51. The method of claim 37, wherein, if a target MME of the network node receives the UE capability ID from the UE, but the target MME has no associated UE radio access capability, the target MME appears to the target MME to include the UE capability ID in a context request step to operate with the AMF of the network node, and the target MME retrieves UE radio access capability from the UCME of the network node to provide the UE capability ID.

52. The method of claim 51, wherein the target MME notifies the AMF to provide associated UE radio access capabilities in the context requesting step, and the AMF provides the associated UE radio access capabilities to the target MME.

53. The method of claim 37, wherein a target MME of the network node sends a context request message to an AMF of the network node, the AMF providing a UE context to the target MME to include the UE capability ID.

54. The method of claim 53, wherein the target MME comprises a request indication in the context request step, and if not, the AMF provides the UE capability ID based on whether the target MME and/or the E-UTRAN of the network node support RACS and/or whether UCMF and UCME of the network node have an interface or co-location to communicate with each other.

55. The method of claim 37, wherein if a target MME of the network node does not have associated UE radio access capabilities for the UE capability ID, the target MME retrieves the UE radio access capabilities from a UCME of the network node and provides the UE capability ID to the UCME.

56. The method of claim 55, wherein, if the UE capability ID is not received from the UE, the target MME retrieves the UE radio access capability from the UCME and provides the UE capability ID to the UCME.

57. A system for system interworking, comprising:

a first network node, wherein how to handle a UE capability Identification (ID) is determined based on behavior of the first network node;

a second network node capable of communicating with the first network node, wherein the first network node is an access and mobility management function, AMF, the second network node is a next generation radio access network, NG-RAN, behavior of the AMF includes the AMF instructing the NG-RAN how to handle the UE capability ID, the AMF instructing a user equipment how to handle the UE capability ID, and/or the AMF does not instruct the NG-RAN how to handle the UE capability ID, and the NG-RAN determines how to handle the UE capability ID from local configuration information;

58. The system of claim 57, wherein determining how to process the UE capability ID comprises determining whether the UE capability ID allocated or used in a current system is used in another system, the current system being one of a fifth generation system (5 GS) and an Evolved Packet System (EPS) and the other system being the other of the 5GS and the EPS.

59. The system of claim 57 or 58, wherein the UE capability ID is a Public Land Mobile Network (PLMN) assigned capability ID.

60. The system of claim 57, wherein the AMF or a user equipment capability management function UCMF indicates information to the NG-RAN using a non-UE-specific NG application protocol (NGAP) message.

61. The system of claim 57, wherein the AMF or UCMF indicates information to the NG-RAN using UE-specific NGAP messages.

62. The system of claim 57, wherein the NG-RAN is to indicate whether the AMF includes UE radio access capability in the source-to-target transparent container.

63. The system of claim 57, wherein the first network node is a NG-RAN and the second network node is a target evolved universal terrestrial radio access network (E-UTRAN), the NG-RAN to send the UE capability ID to the E-UTRAN in a source-to-target transparent container.

64. The system of claim 57, wherein the AMF determines whether to include the UE capability ID in an MME UE context based on: whether the target MME and/or E-UTRAN support RACS and/or whether UCMF and UCME have interfaces or are collocated for communication with each other; the AMF determining whether to include the UE capability ID in the MME UE context based on the indication from the NG-RAN and/or based on whether the target MME and/or the E-UTRAN support the RACS and/or whether the UCMF and the UCME have the interface or co-location to communicate with each other; alternatively, AMF determines whether to include the UE capability ID in the MME UE context, rather than based on NG-RAN behavior and/or based on whether the target MME and/or the E-UTRAN support the RACS and/or whether the UCMF and the UCME have the interface or co-location to communicate with each other.

65. The system of claim 64, wherein the AMF includes the UE capability ID in the MME UE context if the target MME and/or the E-UTRAN support the RACS and/or the UCMF and the UCME have the interface or co-location to communicate with each other.

66. The system of claim 65, wherein the target MME includes the UE capability ID in a handover request step.

67. The system of claim 66 wherein the target MME includes the UE capability ID in the handover request step based on E-UTRAN capabilities of the RACS, the target MME including the UE capability ID if the E-UTRAN supports the RACS.

68. The system of claim 57 wherein, if a target MME of the network node receives the UE capability ID from a UE, but the target MME does not have associated UE radio access capability, the target MME appears to the target MME to include the UE capability ID in a context request step to operate with the AMF of the network node, and the target MME retrieves UE radio access capability from a UCME of the network node to provide the UE capability ID.

69. The system of claim 68, wherein the target MME notifies the AMF to provide associated UE radio access capabilities in the context requesting step, and the AMF provides the associated UE radio access capabilities to the target MME.

70. The system of claim 57, wherein a target MME of the network node sends a context request message to an AMF of the network node, the AMF providing UE context to the target MME to include the UE capability ID.

71. The system of claim 70, wherein the target MME includes a request indication in the context request step, and if not, the AMF provides the UE capability ID based on whether the target MME and/or the E-UTRAN of the network node support RACS and/or whether UCMF and UCME of the network node have an interface or co-location to communicate with each other.

72. The system of claim 57, wherein if a target MME of the network node does not have associated UE radio access capabilities for the UE capability ID, the target MME retrieves the UE radio access capabilities from a UCME of the network node and provides the UE capability ID to the UCME.

73. The system of claim 72, wherein, if the UE capability ID is not received from a UE, the target MME retrieves the UE radio access capability from the UCME and provides the UE capability ID to the UCME.

74. A method for system interworking, comprising:

determining how to handle the UE capability identity ID based on the behavior of the first network node;

wherein the first network node is an access and mobility management function, AMF, and the second network node is a next generation radio access network, NG-RAN, and the actions of the AMF include the AMF instructing the NG-RAN how to handle the UE capability ID, the AMF instructing a user equipment how to handle the UE capability ID, and/or the AMF not instructing the NG-RAN how to handle the UE capability ID, and the NG-RAN determining how to handle the UE capability ID based on local configuration information;

75. The method of claim 74, wherein determining how to process the UE capability ID comprises determining whether the UE capability ID allocated or used in a current system is used in another system, the current system being one of a fifth generation system (5 GS) and an Evolved Packet System (EPS) and the other system being the other of the 5GS and the EPS.

76. The method of claim 74 or 75, wherein the UE capability ID is a Public Land Mobile Network (PLMN) assigned capability ID.

77. The method of claim 74, wherein the AMF or a user equipment capability management function UCMF indicates information to the NG-RAN using a non-UE-specific NG application protocol (NGAP) message.

78. The method of claim 74, wherein the AMF or UCMF indicates information to the NG-RAN using UE-specific NGAP messages.

79. The method of claim 74, wherein the NG-RAN is to indicate whether the AMF includes UE radio access capability in the source-to-target transparent container.

80. The method of claim 74, wherein the first network node is a NG-RAN and the second network node is a target evolved universal terrestrial radio access network (E-UTRAN), the NG-RAN to send the UE capability ID to the E-UTRAN in a source-to-target transparent container.

81. The method of claim 74, wherein the AMF determines whether to include the UE capability ID in an MME UE context based on: whether the target MME and/or E-UTRAN support RACS and/or whether UCMF and UCME have interfaces or are collocated for communication with each other; the AMF determining whether to include the UE capability ID in the MME UE context based on the indication from the NG-RAN and/or based on whether the target MME and/or the E-UTRAN support the RACS and/or whether the UCMF and the UCME have the interface or co-location to communicate with each other; alternatively, AMF determines whether to include the UE capability ID in the MME UE context, rather than based on NG-RAN behavior and/or based on whether the target MME and/or the E-UTRAN support the RACS and/or whether the UCMF and the UCME have the interface or co-location to communicate with each other.

82. The method of claim 81, wherein the AMF includes a UE capability ID in the MME UE context if the target MME and/or the E-UTRAN support the RACS and/or the UCMF and the UCME have the interface or co-location to communicate with each other.

83. The method of claim 82, wherein the target MME comprises the UE capability ID in a handover request step.

84. The method of claim 83 wherein the target MME includes the UE capability ID in the handover request step based on E-UTRAN capabilities of the RACS, the target MME including the UE capability ID if the E-UTRAN supports the RACS.

85. The method of claim 82, wherein if a target MME of the network node receives the UE capability ID from a UE, but the target MME does not have associated UE radio access capability, the target MME appears to the target MME to include the UE capability ID in a context request step to operate with the AMF of the network node, and the target MME retrieves UE radio access capability from a UCME of the network node to provide the UE capability ID.

86. The method of claim 85, wherein the target MME notifies the AMF to provide associated UE radio access capabilities in the context requesting step, and the AMF provides the associated UE radio access capabilities to the target MME.

87. The method of claim 74, wherein a target MME of the network node sends a context request message to an AMF of the network node, the AMF providing UE context to the target MME to include the UE capability ID.

88. The method of claim 87, wherein the target MME includes a request indication in the context request step, and if not, the AMF provides the UE capability ID based on whether the target MME and/or the E-UTRAN of the network node support RACS and/or whether UCMF and UCME of the network node have an interface or co-location to communicate with each other.

89. The method of claim 74, wherein, if a target MME of the network node does not have associated UE radio access capabilities for the UE capability ID, the target MME retrieves the UE radio access capabilities from a UCME of the network node and provides the UE capability ID to the UCME.

90. The method of claim 89, wherein, if the UE capability ID is not received from a UE, the target MME retrieves the UE radio access capability from the UCME and provides the UE capability ID to the UCME.

91. A non-transitory machine-readable storage medium having stored thereon instructions which, when executed by a computer, cause the computer to perform the method of any of claims 9-16, 37-56, and 74-90.

92. A terminal device, comprising: a processor and a memory for storing a computer program, the processor for executing the computer program stored in the memory to perform the method of any of claims 9 to 16.

93. A network node, comprising: a processor and a memory for storing a computer program, the processor for executing the computer program stored in the memory to perform the method of any of claims 37 to 56 and 74 to 90.