WO2020220319A1

WO2020220319A1 - Session management function selection

Info

Publication number: WO2020220319A1
Application number: PCT/CN2019/085325
Authority: WO
Inventors: Jinguo Zhu; Shuang Liang
Original assignee: Zte Corporation
Priority date: 2019-04-30
Filing date: 2019-04-30
Publication date: 2020-11-05
Also published as: CN113785552A; CN113785552B

Abstract

Methods, apparatuses, systems, and computer readable media are described. A wireless communication method includes receiving, at a service element from a mobility element, a session request message including selection parameters and a user equipment location information, sending, from the service element to a repository element, the selection parameters, receiving, at the service element from the repository element, a list of one or more profiles for one or more session management elements, selecting, at the service element, one of the one or more session management elements based on the one or more profiles and the user equipment location information, and forwarding, from the service element to the selected one of the one or more session management elements, the session request message.

Description

SESSION MANAGEMENT FUNCTION SELECTION

TECHNICAL FIELD

This document is directed generally to wireless communications.

BACKGROUND

Mobile telecommunication technologies are moving the world toward an increasingly connected and networked society. In comparison with the existing wireless networks, next generation systems and wireless communication techniques will need to support a much wider range of use-case characteristics and provide a more complex and sophisticated range of access requirements and flexibilities.

Long-Term Evolution (LTE) is a standard for wireless communication for mobile devices and data terminals developed by 3rd Generation Partnership Project (3GPP) . LTE Advanced (LTE-A) is a wireless communication standard that enhances the LTE standard. The 5th generation of wireless system, known as 5G, advances the LTE and LTE-Awireless standards and is committed to supporting higher data-rates, large number of connections, ultra-low latency, high reliability and other emerging business needs.

SUMMARY

Apparatuses, methods, systems, and computer readable media are disclosed. In one aspect, a wireless communication method is disclosed. The method includes receiving, at a service element from a mobility element, a session request message including selection parameters and a user equipment location information; sending, from the service element to a repository element, the selection parameters; receiving, at the service element from the repository element, a list of one or more profiles for one or more session management elements; selecting, at the service element, one of the one or more session management elements based on the one or more profiles and the user equipment location information; and forwarding, from the service element to the selected one of the one or more session management elements, the session request message.

In another aspect, another wireless communication method is disclosed. The method includes sending, from a mobility element to a service element, a session request message including selection parameters and a user equipment location information; and receiving, at the mobility element from a session management element, in response to the session request message, a service area associated with a session management element selected by the service element.

In another aspect, another wireless communication method is disclosed. The method includes receiving, at a selected session management element from a mobility element, a session request message; determining, at the selected session management element, that a user equipment is in a service area supported by the selected session management element; and forwarding information about the service area associated with a session management element to the mobility element.

The above and other aspects and their implementations are described in greater detail in the drawings, the descriptions, and the claims.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 depicts an example architecture of a 5G network.

FIG. 2 depicts an example call flow for a protocol data unit session (PDU) establishment with an intermediate session management function (I-SMF) insertion, in accordance with some example embodiments.

FIG. 3 depicts an example architecture where the service communication proxy (SCP) may serve to proxy the control plane communication between network function services, in accordance with some example embodiments.

FIG. 4 shows an example of a PDU session establishment without the insertion of an I-SMF, in accordance with some example embodiments.

FIG. 5 shows an example of a PDU Session establishment with an I-SMF inserted, in accordance with some example embodiments.

FIG. 6 shows an example of a home routed PDU session establishment procedure, in accordance with some example embodiments.

FIG. 7 depicts an example of a system, in accordance with some example embodiments.

FIG. 8 depicts an example of an apparatus, in accordance with some example embodiments.

DETAILED DESCRIPTION

Next generation wireless networks are expected to provide new services to wireless devices operating in wireless networks. A wireless device should be able to operate anywhere, anytime and be able to find resources desired by a user to meet user expectations. To allow for such a user experience, work is underway in the third-generation partnership (3GPP) project for improved service discovery and allocation.

For example, a service communication proxy (SCP) may be included in a core network as a proxy for control plane communication between network function services. The SCP may delegate the network function service discovery, so the network function service does not need to perform service discovery. For example, in the 3GPP 5G standard release 15 (Rel-15 5GC) , the service discovery is performed by the network function service itself where special handling logic may be needed at the network function service. For example, the access and mobility management function (AMF) needs to know the session management function (SMF) service area which is obtained from the SMF profile from the network function repository function (NRF) and determines whether to insert/relocate/release an intermediate SMF (I-SMF) . In delegate discovery, the AMF sends a message to SCP, the SCP queries the NRF and the SCP discovers peer SMFs. The AMF is not aware of the SMF profile. The SCP needs specific logic to return the SMF profiles to the AMF. The SCP is not expected to handle specific logic. Therefore, there is a problem with how the delegated discovery can be used for SMF selection that is solved using some of the instant subject matter.

In some example embodiments, the SMF returns the SMF service area to the AMF so that the AMF can decide whether to insert/relocate/release the I-SMF.

FIG. 1 depicts an example architecture of a 5G network. In the architecture of FIG. 1, there are the following devices: user equipment (UE) , radio access network (RAN) . The example 5G network also includes:

AMF. The AMF includes the following functionalities: Registration management, Connection management, Reachability management and Mobility Management. This function also performs the access authentication and access authorization. The AMF is the NAS security termination and relay the SM NAS between UE and SMF, etc.

SMF. The SMF includes the following functionalities: session establishment, modification and release, UE IP address allocation and management (including optional authorization functions) , selection and control of UP function, downlink data notification, etc. The SMF service area is the collection of UPF service areas of all UPFs which can be controlled by one SMF. The SMF service area is stored in NRF as NF profile.

Intermediate SMF (I-SMF) is an SMF that is inserted, changed or removed to a protocol data unit (PDU) session as needed to control UPF (s) which cannot be controlled by the original SMF because the UPF (s) belong to a different SMF service area.

User plane function (UPF) . This function includes the following functionalities: serving as an anchor point for intra-/inter-radio access technology (RAT) mobility, packet routing and forwarding, traffic usage reporting, quality of service (QoS) handling for the user plane, downlink packet buffering and downlink data notification triggering, etc. The UPF service area is an area consisting of one or more tracking area (s) within which PDU Session associated with the UPF can be served by RAN nodes via a N3 interface between the RAN and the UPF without need to add a new UPF in between or to remove/re-allocate the UPF. The A-UPF is the anchor UPF which are keep unchanged during the UE mobility. The intermediate UPF (I-UPF) is inserted/relocated when the UE moves outside of the A-UPF service area. The I-UPF uses N3 tunnel to connect with RAN and use N9 tunnel to connect with A-UPF.

Network Repository Function (NRF) . The NRF stores the NF profile of available NF instances and their supported services and supports service discovery function. When it receives NF discovery request from NF instance or SCP, it provides the information of the discovered NF instances (be discovered) to the NF instance or SCP. After initiation the new network function instance registers its NF profiles in the NRF so other network function can discover the new network function instance by querying the NRF.

The AMF can detect when to add, or to remove, an I-SMF for a PDU session. For this purpose, the AMF gets information about the service area of the SMF (s) from the NRF. During mobility events such as a hand-over or an AMF change, if the service area of the SMF does not include the new UE location, then the AMF selects and inserts an I-SMF which can serve the UE location and the single-network slicing selection assistant information (S-NSSAI) . If the AMF detects that an I-SMF is no longer needed, it removes the I-SMF and interfaces directly with the SMF of the PDU Session. If the AMF detects that the SMF cannot serve the UE location (e.g. due to mobility) , then the AMF selects a new I-SMF that does serve the UE location. In the case when no existing I-SMF can serve the UE location, then the AMF initiates a I-SMF relocation.

FIG. 2 depicts an example call flow for the PDU Session establishment with I-SMF insertion, in accordance with some example embodiments.

At 201, the UE initiates the UE requested PDU session establishment procedure by the transmission of a NAS message containing a PDU session establishment request within the N1 SM container. The PDU session establishment request includes a PDU session ID, requested PDU session type, request S-NSSAI indicating the network slicing, requested date network name (DNN) , etc.

At 202, the AMF sends an Nnrf_NFDiscovery_Request message including the selection parameters to NRF. The NRF returns first list of SMF profiles that matching the requested S-NSSAI and requested DNN. The SMF profiles also include an SMF service area for each SMF. The AMF checks whether the UE location is outside of all the SMF service areas. If it is, the AMF sends Nnrf_NFDiscovery_Request including the similar selection parameters excluding the requested DNN to NRF. The selection parameters may also include the UE location. The NRF then returns a second list of SMF profiles. The AMF selects an I-SMF from the second SMF list in which the SMF service area covers the UE location and selects an SMF from the first SMF list.

At 203, the AMF sends an Nsmf_PDUSession_CreateSMContext request message to the I-SMF. The message includes a SUPI, DNN, S-NSSAI (s) , PDU session ID, AMF ID, request type, N1 SM container (PDU session establishment request) , user location information, SMF ID, and so on.

At 204, the I-SMF returns a Nsmf_PDUSession_CreateSMContext response message. This message includes a cause value indicating whether the request is accepted or not. This message also includes the SM context ID allocated by I-SMF. The AMF will use the SM context ID for subsequent messages to the I-SMF.

At 205, the I-SMF selects an I-UPF based on the user equipment location information. The I-SMF establishes the N4 association with the selected I-UPF. The N3 tunnel information and N9 tunnel information may be allocated by the I-SMF or by the I-UPF.

At 206, the I-SMF sends an Nsmf_PDUSession_Create request message to the SMF identified by the received SMF ID from the AMF. This message includes SUPI, DNN, S-NSSAI, I-SMF SM context ID, PDU session ID, I-SMF ID, N9 tunnel information of I-UPF, PDU session type, as well as other information.

At 207, the SMF may retrieve the UE SM context from the Unified Data Management (UDM) function The SMF may also establish a PCC association with the PCF and retrieve the PCC rules from the PCF. The SMF selects the UPF based on parameters such as DNN and S-NSSAI. The SMF establishes the N4 association with the selected I-UPF. The N9 tunnel information may be allocated by SMF or by UPF.

At 208, the SMF returns a Nsmf_PDUSession_Create response message to the I-SMF. This message includes an SMF SM context ID, QoS rule (s) sent to the UE, QoS profile (s) sent to the RAN, N9 tunnel information of UPF, as well as other information.

At 209, the I-SMF sends a Namf_Communication_N1N2Message transfer message to the AMF. This message includes parameters such as PDU Session ID, I-SMF SM Context ID, N2 SM information (PDU session ID, QFI (s) , QoS profile (s) , N3 tunnel info of I-UPF, S-NSSAI, etc) , N1 SM container (PDU session establishment accept (QoS Rule (s) , S-NSSAI (s) , DNN, etc. ) ) . The AMF sends the response to the I-SMF.

At 210, the AMF sends n N2 PDU session request message to the RAN. This message includes N2 SM information, NAS message (PDU session ID, N1 SM container (PDU session establishment accept) ) .

At 211, the RAN may issue an AN specific signalling exchange with the UE that is related to the information received from the SMF. For example, an radio resource control (RRC) connection reconfiguration may take place with the UE establishing the necessary NG-RAN resources related to the QoS Rules for the PDU session request received in 210. The RAN also allocates N3 tunnel info for the PDU Session.

At 212, the RAN sends N2 a PDU session response to the AMF. This message includes parameters such as PDU session ID, cause, N2 SM information (PDU session ID, N3 tunnel info, list of accepted/rejected quality of service flow identifier (QFI (s) ) , as well as other information.

At 213, the AMF sends a Nsmf_PDUSession_UpdateSMContext request message (I-SMF SM Context ID, N2 SM information) to the I-SMF.

At 214, the I-SMF initiates an N4 session modification procedure with the I-UPF to provide the N3 tunnel information received from the RAN.

At 215, the I-SMF sends an Nsmf_PDUSession_UpdateSMContext response to the AMF.

The SCP may serve to proxy the control plane communication between network function services. An example architecture is shown at FIG. 3. Direct Communication refers to communication between NFs or NF services without using an SCP. Indirect Communication refers to the communication between NFs or NF services via an SCP. In some example embodiments, the service communication proxy (SCP) may be used for indirect communication.

The SCP can be deployed in a distributed manner. For example, the SCP may be co-located with a network function, or can be shared by multiple network functions. The SCP can also support roaming between public land mobile networks (PLMNs) . The SCP may also support delegated discovery. Delegated discovery refers to delegating the discovery and associated selection of NF instances or NF service instances to an SCP.

In order to delegate discovery, the Network Function (NF) service may provide selection parameters to the SCP. The SCP uses the selection parameters to discover and select the NF instances or NF service instances. In some example embodiments, because the SCP does not look into the message, the SCP is agnostic to the message communicating between two NF service instances.

As shown in first call flow (e.g., FIG. 2) , the AMF uses the SMF service area to perform SMF discovery and selection. However, for delegate discovery, the AMF may not query the NRF. As such, the AMF does not have information regarding the SMF service area. The SCP has information regarding the SMF service area. It is unclear how the delegate discovery can work for SMF selection, not only for the non-roaming case, but also for the home routed case. The instant patent document discloses a system and method where the AMF is informed about the SMF service area. In some example embodiments, the AMF includes logic or executable code for I-SMF selection.

Disclosed in this patent document is a system and method for the SMF to provide the service area for the SMF in a response message to the AMF. Accordingly, the AMF has information regarding the SMF service area and the AMF includes the I-SMF selection logic without adding more complexity in SCP.

At 401, the UE initiates a UE requested PDU session establishment procedure by the transmission of a NAS message containing a PDU session establishment request within the N1 SM container. The PDU session establishment request includes a PDU session ID, requested PDU session type, request S-NSSAI indicating the network slicing, requested date network name (DNN) , etc.

At 402, the AMF is configured to perform delegated discovery therefore the AMF sends Nsmf_PDUSession_CreateSMContext request together with selection parameters to the SCP. This message includes parameters like SUPI, DNN, S-NSSAI (s) , PDU session ID, AMF ID, request PDU Session type, N1 SM container (PDU session establishment request) , and/or user location information. In order for the SCP to select the SMF, the selection parameters include like target NF type, UE location, DNN and S-NSSAI. The SCP does not need to recognize the Nsmf_PDUSession_CreateSMContext request, but only use the selection parameters to perform NF discovery and selection.

At 403, the SCP sends a Nnrf_NFDiscovery_Request message including the selection parameters to the NRF. The NRF returns a first list of SMF profiles that match the requested S-NSSAI and the requested DNN. The SMF profiles include an SMF service area for each SMF.

At 404, the SCP selects one SMF profile in which the SMF service area covers the UE location and forwards the Nsmf_PDUSession_CreateSMContext Request to the selected SMF..

At 405, the SMF may retrieve the UE SM context from the UDM. The SMF may establish a PCC association with the PCF and retrieve PCC rules from the PCF. The SMF may select the UPF based on parameters such as DNN, S-NSSAI, and so on. The SMF establishes the N4 association with the selected I-UPF. The tunnel information may be allocated by the SMF or by the UPF.

At 406, the SMF determines whether the UE location is within the SMF service area or not. If the UE location is within the SMF service area, the SMF returns with a Nsmf_PDUSession_CreateSMContext response message together with selection parameters to the SCP. The message includes the SMF ID, SMF SM context ID, and/or SMF service area. This message includes a cause value indicating the request is accepted. The selection parameters include the AMF ID.

At 407, the SCP forwards the Nsmf_PDUSession_CreateSMContext response message to the AMF.

At 408, the SMF sends a Namf_Communication_N1N2Messagetransfer message together with selection parameters to the AMF. The message includes parameters such as PDU session ID, N2 SM information (PDU session ID, QFI (s) , QoS profile (s) , N3 tunnel info of UPF, S-NSSAI, etc) , N1 SM container (PDU session establishment accept (QoS rule (s) , S-NSSAI (s) , DNN, and so on. ) ) . The selection parameters include the AMF ID. The SCP forwards the message to the AMF. The AMF sends a response to the I-SMF via the SCP.

At 409, the AMF sends N2 PDU session request to the RAN. This message includes N2 SM information, NAS message (PDU session ID, N1 SM container (PDU session establishment accept) ) .

At 410, the RAN may issue AN specific signalling exchange with the UE that is related to the information received from the SMF. For example, an RRC connection reconfiguration may take place with the UE establishing the necessary NG-RAN resources related to the QoS rules for the PDU session request received in 410. The RAN allocates N3 tunnel info for the PDU session.

At 411, the RAN sends N2 PDU session response to the AMF. This message includes parameters such as PDU Session ID, cause, N2 SM information (PDU session ID, N3 tunnel info, list of accepted/rejected QFI (s) ) , and so on.

At 412, the AMF sends a Nsmf_PDUSession_UpdateSMContext request (SMF SM context ID, N2 SM information, ) message to the SMF via SCP. The selection parameters include, for example, the SMF ID.

At 413, the SMF initiates an N4 session modification procedure with the I-UPF to provide the N3 tunnel information received from the RAN.

At 414, the SMF sends a Nsmf_PDUSession_UpdateSMContext response message to the AMF via the SCP. The selection parameters include the AMF ID.

FIG. 5 shows an example of a PDU Session establishment with an I-SMF inserted.

At 501, the UE initiates a UE requested PDU session establishment procedure by the transmission of a NAS message containing a PDU session establishment request within the N1 SM container. The PDU session establishment request includes a PDU session ID, requested PDU session type, request S-NSSAI indicating the network slicing, requested DNN, and so on.

At 502, the AMF is configured to perform delegated discovery. The AMF sends an Nsmf_PDUSession_CreateSMContext request message together with selection parameters to SCP. This message may include parameters such as SUPI, DNN, S-NSSAI (s) , PDU session ID, AMF ID, request PDU Session type, N1 SM container (PDU session establishment request) , user location information. In order for the SCP to select the SMF, the selection parameters include like target NF type, DNN, UE location, and/or S-NSSAI. The SCP uses the selection parameters to perform NF selection and does not need to recognize the Nsmf_PDUSession_CreateSMContext request message.

At 503, the SCP sends to NRF an Nnrf_NFDiscovery_Request message including the selection parameters. Based on the input parameters the NRF can’ t return a list of SMF which match all input parameters. Or the NRF responses with a list of SMF profiles, but all of them can’ t serve the current UE location.

At 504, the SCP send response to the AMF that the NF discovery fails, with a cause value indicating that the selection fails.

At 505, based on the cause value the AMF may initiates another Nsmf_PDUSession_CreateSMContext request message together with similar selection parameters excluding the DNN to SCP. The excluding of the DNN cause the SCP to selects an I-SMF covers the current UE location. The message may include an indication that a SMF serving the PDU Session is needed to be selected by the I-SMF.

At 506, the SCP sends to NRF an Nnrf_NFDiscovery_Request message including the selection parameters. The NRF returns a first list of SMF profiles. The SMF profiles include an SMF service area for each SMF.

At 507, the SCP selects one I-SMF from the first list in which the SMF service area covers the UE location and forwards the Nsmf_PDUSession_CreateSMContext Request to the selected I-SMF.

At 508, the I-SMF returns a Nsmf_PDUSession_CreateSMContext response with selection parameters to the AMF via the SCP. The message may include parameters such as the service area of the I-SMF, the I-SMF SM context ID, and so on. The message may include a cause value indicating the request is accepted. The selection parameters may include the AMF ID.The SCP forwards the message to the AMF

At 509, the I-SMF selects an I-UPF based on user location information. The I-SMF establishes the N4 association with the selected I-UPF. The N3 tunnel information and N9 tunnel information may be allocated by the I-SMF or by the I-UPF.

At 510, The I-SMF has information indicating that an SMF serving the PDU session needs to be selected. The I-SMF sends a Nsmf_PDUSession_Create request message with selection parameters to the SCP. The selection parameters may include the target NF type, S-NSSAI, and DNN. The message may include SUPI, DNN, S-NSSAI, I-SMF SM context ID, PDU session ID, I-SMF ID, N9 tunnel information of I-UPF, PDU session type, and so on.

At 511, the SCP sends to NRF an Nnrf_NFDiscovery_Request message including the selection parameters. The NRF returns a second list of SMF profiles that match the requested S-NSSAI and requested DNN. The SMF profiles include an SMF service area for each SMF.

At 512, the SCP selects one SMF from the second list and forwards the Nsmf_PDUSession_Create Request to the selected SMF.

At 513, the SMF may retrieve a UE SM context from the UDM. The SMF may establish a PCC association with the PCF and retrieve PCC rules from the PCF. The SMF selects a UPF based on parameters such as DNN and S-NSSAI. The SMF establishes the N4 association with the selected I-UPF. The tunnel information may be allocated by the SMF or by the UPF.

At 514, the SMF sends a Nsmf_PDUSession_Create response message with selection parameters to the SCP. This message may include a SMF SM context ID, QoS rule (s) sent to the UE, QoS profile (s) sent to the RAN, N9 tunnel information of UPF, and so on. The selection parameters may include the I-SMF ID. The SCP forwards the message to the I-SMF.

At 515, the I-SMF sends a Namf_Communication_N1N2MessageTransfer message with selection parameters to the AMF. The message may include parameters such as PDU session ID, I-SMF SM context ID, N2 SM information (PDU session ID, QFI (s) , QoS profile (s) , N3 Tunnel Info of I-UPF, S-NSSAI, etc) , N1 SM container (PDU session establishment accept (QoS Rule (s) , S-NSSAI (s) , DNN, etc. ) ) . The selection parameters may include the AMF ID. The SCP forwards the message to the AMF. The AMF sends a response to the I-SMF via the SCP.

At 516, the AMF sends N2 PDU session request to the RAN. The message includes N2 SM information, NAS message (PDU Session ID, N1 SM container (PDU session establishment accept) ) .

At 517, the RAN may issue AN specific signalling exchange with the UE that is related with the information received from SMF. For example, an RRC connection reconfiguration may take place with the UE establishing the necessary NG-RAN resources related to the QoS rules for the PDU session request received in step 510. The RAN may allocate N3 Tunnel Info for the PDU session.

At 518, the RAN sends N2 PDU session response to AMF. The message may include parameters such as PDU session ID, cause, N2 SM information (PDU session ID, N3 tunnel Info, list of accepted/rejected QFI (s) ) , and so on.

At 519, the AMF sends a Nsmf_PDUSession_UpdateSMContext request (I-SMF SM context ID, N2 SM information) message to the I-SMF via the SCP. The selection parameters may include the I-SMF ID.

At 520, the I-SMF initiates an N4 session modification procedure with the I-UPF to provide the N3 tunnel information received from the RAN.

At 521, the I-SMF sends a Nsmf_PDUSession_UpdateSMContext response message to the AMF via the SCP. The selection parameters may include the AMF ID

At 601, the UE initiates the UE requested PDU session establishment procedure by the transmission of a NAS message containing a PDU session establishment request within the N1 SM container. The PDU session establishment request includes a PDU session ID, requested PDU session type, request S-NSSAI indicating the network slicing, requested DNN, and so on.

At 602, based on a subscription the AMF determines that the requested PDU session is home routed. The AMF is configured to perform delegated discovery. As such, the AMF sends a Nsmf_PDUSession_CreateSMContext request message with selection parameters to the SCP. The message includes parameters like SUPI, DNN, S-NSSAI (s) , PDU session ID, AMF ID, request PDU Session type, N1 SM container (PDU session establishment request) , user location information, home routed indication, and so on. In order for the SCP to select the SMF, the selection parameters may include a target NF type, the S-NSSAI, and UE location information. The SCP use the selection parameters to perform NF selection and does not need to recognize the Nsmf_PDUSession_CreateSMContext request.

At 603, the SCP sends a Nnrf_NFDiscovery_Request message including the selection parameters to the NRF. The NRF returns a list of SMF profiles in which the SMF service area includes the UE location. The SCP selects V-SMF from the SMF list in which the SMF service area covers the UE location.

At 604, the SCP forwards the Nsmf_PDUSession_CreateSMContext request message to the V-SMF.

At 605, the V-SMF returns a Nsmf_PDUSession_CreateSMContext response message with selection parameters to the AMF via the SCP. The message may include parameters such as the service area of the V-SMF, the V-SMF SM context ID, and so on. The message may include a cause value indicating the request is accepted. The selection parameters may include the AMF ID.

At 606, the V-SMF selects V-UPF based on user location information. The V-SMF establishes the N4 association with the selected V-UPF. The N3 tunnel information and N9 tunnel information may be allocated by V-SMF or by V-UPF.

At 607, the V-SMF has information indicating the PDU session is home routed. The V-SMF sends a Nsmf_PDUSession_Create request message with selection parameters to the SCP. The selection parameters may include the target NF type, HPLMN ID, S-NSSAI, and DNN. The message may include SUPI, DNN, S-NSSAI, V-SMF SM context ID, PDU session ID, V-SMF ID, N9 tunnel information of V-UPF, PDU session type, and so on.

At 608, the SCP sends a Nnrf_NFDiscovery_Request message including the selection parameters to the NRF. The NRF may communicate with the NRF in HPLMN and returns a list of H-SMF profiles that match the requested S-NSSAI and requested DNN.

At 609, the SCP selects one H-SMF from the list of H-SMFs and forwards the Nsmf_PDUSession_Create request message to the selected H-SMF.

At 610, the H-SMF may retrieve UE SM context from the UDM. The H-SMF may also establish a PCC association with the PCF and retrieve PCC rules from the PCF. The H-SMF selects a H-UPF based on parameters such as DNN and S-NSSAI. The H-SMF establishes the N4 association with the selected H-UPF. The N9 tunnel information may be allocated by H-SMF or by H-UPF. The H-SMF sends the N9 tunnel information of the V-UPF to the H-UPF.

At 611, the H-SMF sends a Nsmf_PDUSession_Create response together with selection parameters to the SCP. This message includes SMF SM context ID, QoS rule (s) sent to the UE, QoS profile (s) sent to the RAN, N9 tunnel information of the UPF, and so on. The selection parameters may include the V-SMF ID. The SCP forwards the message to the V-SMF.

At 612, the V-SMF sends a Namf_Communication_N1N2Messagetransfer together with selection parameters to the AMF. This message includes parameters like PDU session ID, N2 SM information (PDU Session ID, QFI (s) , QoS Profile (s) , N3 tunnel info of I-UPF, S-NSSAI, etc) , N1 SM container (PDU session establishment accept (QoS Rule (s) , S-NSSAI (s) , DNN, etc. ) ) . The selection parameters include the AMF ID. The SCP forwards the message to the AMF. The AMF sends a response to the V-SMF via the SCP.

At 613, the AMF sends N2 PDU session request to RAN. The message includes N2 SM information, NAS message (PDU session ID, N1 SM container (PDU session establishment accept) ) .

At 614, the RAN may issue AN specific signalling exchange with the UE that is related to the information received from the SMF. For example, an RRC connection reconfiguration may take place with the UE establishing the necessary NG-RAN resources related to the QoS rules for the PDU session request received in step 610. The RAN also allocates N3 tunnel info for the PDU session.

At 615, the RAN sends N2 PDU session response message to the AMF. The message includes parameters such as PDU session ID, cause, N2 SM information (PDU session ID, N3 tunnel info, list of accepted/rejected QFI (s) ) , and so on.

At 616, the AMF sends a Nsmf_PDUSession_UpdateSMContext request (V-SMF SM Context ID, N2 SM information) message to the V-SMF via the SCP. The selection parameters include the V-SMF ID.

At 617, the V-SMF initiates an N4 session modification procedure with the V-UPF to provide the N3 tunnel information received from the RAN.

At 618, the V-SMF sends a Nsmf_PDUSession_UpdateSMContext response message to the AMF via the SCP. The selection parameters include the AMF ID.

FIG. 7 shows an example of a wireless communication system (e.g., a 5G cellular network) that includes a base station (BS) 720 and one or

more UEs

711, 712 and 713. In some example embodiments, the UEs access the BS 720 using

configuration messages

731, 732, 733 passed from

UEs

711, 712, and 713, respectively, to BS 720 enabling subsequent communication to the UEs via

messages

741, 742, 743. The UE may be, for example, a smartphone, cell phone, a tablet, a mobile computer, a machine to machine (M2M) device, an Internet of Things (IoT) device, or any other wirelessly connected computing device. BS 720 may include one or more of the AMF, NRF, SMF, I-SMF, UPF, A-UPF, I-UPF, or RAN.

FIG. 8 shows an example of an apparatus, in accordance with some example embodiments. An apparatus 810 such as a base station 720 or a wireless device such as as

UEs

711, 712, and/or 713 can include processor electronics 820 such as a microprocessor that implements one or more of the features disclosed in this document. BS 720 may include one or more of the AMF, NRF, SMF, I-SMF, UPF, A-UPF, I-UPF, or RAN. The apparatus 810 can include transceiver electronics 830 to send and/or receive wireless signals over one or more communication interfaces such as antenna 840. The apparatus 810 can include other communication interfaces for transmitting and receiving data (e.g., wired interfaces such as fiber communication) . The apparatus 810 can include one or more memories (not explicitly shown) configured to store information such as data and/or executable instructions. In some implementations, the processor electronics 820 can include at least a portion of transceiver electronics 830. In some embodiments, at least some of the disclosed techniques, modules or functions are implemented using the apparatus 810.

Some implementations may be described using the following clause-based description.

Clause 1. A wireless communication method, comprising: receiving, at a service element from a mobility element, a session request message including selection parameters and a user equipment location information; sending, from the service element to a repository element, the selection parameters; receiving, at the service element from the repository element, a list of one or more profiles for one or more session management elements; selecting, at the service element, one of the one or more session management elements based on the one or more profiles and the user equipment location information; and forwarding, from the service element to the selected one of the one or more session management elements, the session request message.

Clause 2. The wireless communication method of clause 1, wherein the repository element is a network repository function (NRF) .

Clause 3. A wireless communication method, comprising: sending, from a mobility element to a service element, a session request message including selection parameters and a user equipment location information; and receiving, at the mobility element from a session management element, in response to the session request message, a service area associated with a session management element selected by the service element.

Clause 4. The wireless communication method of clause 3, further comprising: receiving, at the mobility element from the user equipment, a session establishment request.

Clause 5. The wireless communication method of any of clauses 3 or 4, wherein the mobility element is an access and mobility management function (AMF) .

Clause 6. A wireless communication method, comprising: receiving, at a selected session management element from a mobility element, a session request message; determining, at the selected session management element, that a user equipment is in a service area supported by the selected session management element; and forwarding information about the service area associated with a session management element to the mobility element.

Clause 7. The wireless communication method of any of clauses 1 to 6, wherein the session request message is forwarded by a service element.

Clause 8. The wireless communication method of any of clauses 1 to 6, wherein information about the service area is forwarded by a service element.

Clause 9. The wireless communication method of any of clauses 1 to 8, further comprising: receiving, at the user equipment, granted session parameters.

Clause 10. The wireless communication method of any of clauses 1 to 9, wherein the service element is a service communication proxy (SCP) .

Clause 11. The wireless communication method any of clauses 1 to 10, wherein the session management element is a session management function (SMF) .

Clause 12. An apparatus comprising a processor configured to implement a method recited in one or more of clauses 1 to 11.

Clause 13. A computer program product having code stored thereon, the code, when executed by a processor, causing the processor to implement a method recited in one or more of clauses 1 to 11.

The service element in the foregoing clauses performs a proxy function and is referred to in the foregoing description as a service communication proxy (SCP) and is shown in FIGs. 3-8. The mobility element performs mobility functions and is referred to in the foregoing description as a mobility management function (AMF) and is shown in FIGs. 1-8. The repository element performs a repository function for storing profiles and other information and is referred to in the foregoing description as a network repository function (NRF) and is shown in FIGs. 1-8. The one or more session management elements perform session management functions and are referred to in the foregoing description as session management functions (SMF) .

In some example embodiments, a session request message may be a Nsmf_PDUSession_CreateSMContext request message, and/or the selection parameters may include SUPI, DNN, S-NSSAI (s) , PDU session ID, AMF ID, request type, N1 SM container (PDU session establishment request) . As used herein, granted session parameters may include the SMF ID, SMF SM context ID, and/or SMF service area, as well as other parameters described above.

Some of the embodiments described herein are described in the general context of methods or processes, which may be implemented in one embodiment by a computer program product, embodied in a computer-readable medium, including computer-executable instructions, such as program code, executed by computers in networked environments. A computer-readable medium may include removable and non-removable storage devices including, but not limited to, Read Only Memory (ROM) , Random Access Memory (RAM) , compact discs (CDs) , digital versatile discs (DVD) , etc. Therefore, the computer-readable media can include a non-transitory storage media. Generally, program modules may include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. Computer-or processor-executable instructions, associated data structures, and program modules represent examples of program code for executing steps of the methods disclosed herein. The particular sequence of such executable instructions or associated data structures represents examples of corresponding acts for implementing the functions described in such steps or processes.

In this document the term “exemplary” is used to mean “an example of” and, unless otherwise stated, does not imply an ideal or a preferred embodiment.

Some of the disclosed embodiments can be implemented as devices or modules using hardware circuits, software, or combinations thereof. For example, a hardware circuit implementation can include discrete analog and/or digital components that are, for example, integrated as part of a printed circuit board. Alternatively, or additionally, the disclosed components or modules can be implemented as an Application Specific Integrated Circuit (ASIC) and/or as a Field Programmable Gate Array (FPGA) device. Some implementations may additionally or alternatively include a digital signal processor (DSP) that is a specialized microprocessor with an architecture optimized for the operational needs of digital signal processing associated with the disclosed functionalities of this application. Similarly, the various components or sub-components within each module may be implemented in software, hardware or firmware. The connectivity between the modules and/or components within the modules may be provided using any one of the connectivity methods and media that is known in the art, including, but not limited to, communications over the Internet, wired, or wireless networks using the appropriate protocols.

While this document contains many specifics, these should not be construed as limitations on the scope of an invention that is claimed or of what may be claimed, but rather as descriptions of features specific to particular embodiments. Certain features that are described in this document in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable sub-combination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a sub-combination or a variation of a sub-combination. Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results.

Only a few implementations and examples are described and other implementations, enhancements and variations can be made based on what is described and illustrated in this disclosure.

Claims

A wireless communication method, comprising:

receiving, at a service element from a mobility element, a session request message including selection parameters and a user equipment location information;

sending, from the service element to a repository element, the selection parameters;

receiving, at the service element from the repository element, a list of one or more profiles for one or more session management elements;

selecting, at the service element, one of the one or more session management elements based on the one or more profiles and the user equipment location information; and

forwarding, from the service element to the selected one of the one or more session management elements, the session request message.
The wireless communication method of claim 1, wherein the repository element is a network repository function (NRF) .
A wireless communication method, comprising:

sending, from a mobility element to a service element, a session request message including selection parameters and a user equipment location information; and

receiving, at the mobility element from a session management element, in response to the session request message, a service area associated with a session management element selected by the service element.
The wireless communication method of claim 3, further comprising:

receiving, at the mobility element from the user equipment, a session establishment request.
The wireless communication method of any of claims 3 or 4, wherein the mobility element is an access and mobility management function (AMF) .
A wireless communication method, comprising:

receiving, at a selected session management element from a mobility element, a session request message;

determining, at the selected session management element, that a user equipment is in a service area supported by the selected session management element; and

forwarding information about the service area associated with a session management element to the mobility element.
The wireless communication method of any of claims 1 to 6, wherein the session request message is forwarded by a service element.
The wireless communication method of any of claims 1 to 6, wherein information about the service area is forwarded by a service element.
The wireless communication method of any of claims 1 to 8, further comprising:

receiving, at the user equipment, granted session parameters.
The wireless communication method of any of claims 1 to 9, wherein the service element is a service communication proxy (SCP) .
The wireless communication method any of claims 1 to 10, wherein the session management element is a session management function (SMF) .
An apparatus comprising a processor configured to implement a method recited in one or more of claims 1 to 11.
A computer program product having code stored thereon, the code, when executed by a processor, causing the processor to implement a method recited in one or more of claims 1 to 11.