CN113785552B - Session management function selection - Google Patents

Abstract

A method, apparatus, system, and computer readable medium. A method of wireless communication comprising: receiving, at the service unit, a session request message including selection parameters and user equipment location information from the mobility unit; transmitting the selection parameters from the service unit to a repository unit; receiving, at the service unit, a list of one or more profiles for one or more session management units from the repository unit; selecting, at the service unit, one of the one or more session management units based on the one or more profiles and the user device location information; and forwarding the session request message from the service unit to a selected one of the one or more session management units.

Description

Session management function selection

Technical Field

The present invention relates generally to wireless communications.

Background

Mobile telecommunications technology is pushing the world towards increasingly connected and networked society. Next generation systems and wireless communication technologies will need to support a wider range of use case characteristics and provide a more complex and accurate range of access requirements and flexibility than existing wireless networks.

Long Term Evolution (LTE) is a standard developed by the third generation partnership project (3 GPP) for wireless communication of mobile devices and data terminals. LTE-advanced (LTE-a) is a wireless communication standard that enhances the LTE standard. The fifth generation wireless system, referred to as 5G, has improved the LTE and LTE-a wireless standards and is used to support higher data rates, large numbers of connections, ultra low latency, high reliability, and other emerging commercial requirements.

Disclosure of Invention

The invention discloses an apparatus, a method, a system and a computer readable medium. In one aspect, a method of wireless communication is disclosed. The method comprises the following steps: receiving, at a serving element, a session request message from a mobility element, wherein the session request message comprises a selection parameter and user equipment location information; transmitting the selection parameters from the service unit to a repository unit; receiving, at the service unit, a list of one or more profiles from the repository unit, wherein the list of one or more profiles is for one or more session management units; selecting, at the service unit, one of the one or more session management units based on the one or more profiles and the user device location information; and forwarding the session request message from the service unit to a selected one of the one or more session management units.

In another aspect, another method of wireless communication is disclosed. The method comprises the following steps: transmitting a session request message from a mobility unit to a service unit, wherein the session request message comprises a selection parameter and user equipment location information; and receiving, at the mobility unit, a service area associated with the session management unit selected by the service unit from the session management unit in response to the session request message.

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

The above and other aspects and embodiments thereof are described in more detail in the accompanying drawings, description and claims.

Drawings

FIG. 1 illustrates an example architecture of a 5G network;

FIG. 2 illustrates an example call flow for Protocol Data Unit (PDU) session establishment with intermediate session management function (I-SMF) insertion, according to some example embodiments;

FIG. 3 illustrates an example architecture in which a Service Communication Proxy (SCP) may be used to proxy control plane communications between network function services, according to some example embodiments;

Fig. 4 illustrates an example of PDU session establishment without an inserted I-SMF, according to some example embodiments;

Fig. 5 illustrates an example of PDU session establishment with an I-SMF inserted, according to some example embodiments;

Fig. 6 illustrates an example of a home routing PDU session establishment procedure in accordance with some demonstrative embodiments;

FIG. 7 illustrates an example of a system according to some example embodiments;

Fig. 8 illustrates an example of an apparatus according to some example embodiments.

Detailed Description

Next generation wireless networks are expected to provide new services to wireless devices operating in the wireless networks. The wireless device should be able to operate anywhere, at any time and find the resources desired by the user to meet the user's desires. To allow such user experience, work is done in the third generation partnership project (3 GPP) for improved service discovery and distribution.

For example, a Service Communication Proxy (SCP) may be included in the core network as a proxy for control plane communication between network function services. The SCP may delegate network function service discovery so that the network function service need not perform service discovery. For example, in 3GPP 5G standard release 15 (Rel-155 GC), service discovery is performed by the network function service itself, where special processing logic may be required. For example, an access and mobility management function (AMF) needs to know a Session Management Function (SMF) service area obtained from an SMF profile of a network function repository function (NRF) and determine whether to insert/relocate/release an intermediate SMF (I-SMF). In delegated discovery, the AMF sends a message to the SCP, the SCP queries the NRF, and the SCP discovers the peer SMF. The AMF does not know the SMF profile. The SCP needs specific logic to return the SMF profile to the AMF. The SCP is not expected to handle the specific logic. Thus, there is a problem of how the delegated discovery can be used for SMF selection, which is solved by the solution of the present invention.

In some exemplary 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 shows an example architecture of a 5G network. In the architecture of fig. 1, the following devices are present: user Equipment (UE), radio Access Network (RAN). The example 5G network further includes:

AMF comprising the following functions: registration management, connection management, reachability management, and mobility management. The function also performs access authentication and access authorization. The AMF is NAS security termination and relays SMNAS, etc. between the UE and the SMF.

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

Intermediate SMFs (I-SMFs) are inserted into, changed to, or removed from Protocol Data Unit (PDU) sessions as needed to control one or more UPFs that cannot be controlled by the original SMF because they belong to different SMF service areas.

User Plane Functions (UPFs), including: anchor points 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 consists of one or more tracking areas in which PDU sessions associated with the UPF may be serviced by the RAN node via an N3 interface between the RAN and the UPF without requiring the addition of a new UPF or the removal/reassignment of the UPF therebetween. The a-UPF is an anchor UPF that remains unchanged during UE movement. When the UE moves outside the a-UPF service area, an intermediate UPF (I-UPF) is inserted/relocated. The I-UPF uses an N3 tunnel to connect with the RAN and an N9 tunnel to connect with the a-UPF.

A Network Repository Function (NRF) stores NF profiles of available NF instances and services supported thereby, and supports a service discovery function. When a NF discovery request is received from a NF instance or SCP, the NF instance or SCP is provided with information of the discovered NF instance (which can be discovered). After start-up, the new network function instance registers its NF profile in the NRF so that other network functions can discover the new network function instance by querying the NRF.

The AMF may detect when to add or remove an I-SMF for a PDU session. For this purpose, the AMF obtains information about the service areas of one or more SMFs from the NRF. During a mobility event, such as a handover or an AMF change, if the service area of the SMF does not include a new UE location, the AMF selects and inserts an I-SMF and single network split selection assistance information that can serve the UE location (S-NSSAI). If the AMF detects that I-SMF is no longer needed, the I-SMF is removed and interfaced directly with the SMF of the PDU session. If the AMF detects that the SMF is unable to service the UE location (e.g., due to movement), the AMF selects a new I-SMF that does service the UE location. In the case when no existing I-SMF can serve the UE location, then the AMF initiates an I-SMF relocation.

Fig. 2 illustrates an exemplary call flow for PDU session establishment with I-SMF insertion, according to some example embodiments.

In 201, the UE initiates a PDU session establishment procedure requested by the UE by sending a NAS message containing a PDU session establishment request within the N1 SM container. The PDU session establishment request includes a PDU session ID, a requested PDU session type, a request S-NSSAI indicating a network slice, a requested Date Network Name (DNN), and the like.

At 202, the amf sends a Nnrf _ NFDiscovery _request message to the NRF that includes a selection parameter. The NRF returns a first list of SMF profiles that match the requested S-NSSAI and the requested DNN. The SMF profile also includes an SMF service area for each SMF. The AMF checks whether the UE location is outside all SMF service areas. If so, the AMF sends Nnrf _ NFDiscovery _Request to the NRF that includes similar selection parameters, where the selection parameters do not include the requested DNN. The selection parameters may also include UE location. The NRF then returns a second list of SMF profiles. The AMF selects an I-SMF from a second SMF list, and selects an SMF from a first SMF list, wherein the SMF service area in the second SMF list covers the UE location.

At 203, the AMF sends Nsmf _ PDUSession _ CreateSMContext request message to the I-SMF. The message includes SUPI, DNN, one or more S-nsais, PDU session ID, AMF ID, request type, N1 SM container (PDU session establishment request), user location information, SMF ID, etc.

At 204, the i-SMF returns Nsmf _ PDUSession _ CreateSMContext response message. The message includes a cause value indicating whether the request is accepted. The message also includes the SM context ID assigned by the 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 an N4 association with the selected I-UPF. The N3 tunnel information and the N9 tunnel information may be allocated by the I-SMF or by the I-UPF.

At 206, the i-SMF sends Nsmf _ PDUSession _create request message to the SMF identified by the SMF ID received from the AMF. The message includes SUPI, DNN, S-NSSAI, I-SMF SM context ID, PDU session ID, I-SMF ID, N9 tunnel information for I-UPF, PDU session type, and other information.

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

At 208, the SMF returns a Nsmf _ PDUSession _Create response message to the I-SMF. The message includes the SMF SM context ID, one or more QoS rules sent to the UE, one or more QoS profiles sent to the RAN, N9 tunnel information for UPF, and other information.

At 209, the I-SMF sends Namf _communication_N1N2message transfer Message to the AMF. The message includes parameters such as PDU session ID, I-SMF SM context ID, N2 SM information (PDU session ID, one or more QFIs, one or more QoS profiles, N3 tunnel information for I-UPF, S-NSSAI, etc.), N1 SM container (PDU session setup accept (one or more QoS rules, one or more S-NSSAI, DNN, etc.)), etc. The AMF sends a response to the I-SMF.

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

At 211, the ran may issue AN-specific signaling exchange with the UE, which is related to the information received from the SMF. For example, radio Resource Control (RRC) connection reconfiguration may be accompanied by the UE establishing the necessary NG-RAN resources related to QoS rules for the PDU session request received at 210. The RAN also allocates N3 tunnel information for the PDU session.

At 212, the ran sends an N2a PDU session response to the AMF. The message includes parameters such as PDU session ID, cause, N2 SM information (PDU session ID, N3 tunnel information, list of accepted/rejected quality of service flow identifiers (QFI)), and other information.

At 213, the AMF sends 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 N3 tunnel information received from the RAN.

At 215, the i-SMF sends a Nsmf _ PDUSession _ UpdateSMContext response to the AMF.

The SCP may be used to proxy control plane communications between network function services. An example architecture is shown at fig. 3. Direct communication refers to communication between NF's or NF services without using an SCP. Indirect communication refers to communication between multiple NFs or between multiple NF services via an SCP. In some exemplary embodiments, a service communication agent (SCP) may be used for indirect communication.

The SCP may be deployed in a distributed manner. For example, the SCP may operate co-located with the network function or may be shared by multiple network functions. The SCP may also support roaming between multiple Public Land Mobile Networks (PLMNs). The SCP may also support delegated discovery. Delegated discovery refers to delegating discovery and association selection of multiple NF instances or multiple NF service instances to a SCP.

To delegate discovery, a Network Function (NF) service may provide selection parameters to the SCP. The SCP uses the selection parameters to discover and select NF instances or NF service instances. In some exemplary embodiments, the SCP is agnostic of messages communicated between two NF service instances because the SCP is not looking at the messages.

As shown in the first call flow (e.g., fig. 2), the AMF uses the SMF service area to perform SMF discovery and selection. However, for delegated discovery, the AMF may not query the NRF. Therefore, the AMF does not have information about the SMF service area. The SCP has information about the SMF service area. It is not clear how the delegated discovery can work for SMF selection, not only for non-roaming cases, but also for home routing cases. A system and method are disclosed in which an AMF is notified of information about an SMF service region. In some exemplary embodiments, the AMF includes logic or executable code for I-SMF selection.

A system and method for SMF is disclosed to provide a service area for SMF in a response message to AMF. Thus, the AMF has information about the SMF service area and includes I-SMF selection logic without adding more complexity in the SCP.

Fig. 4 illustrates an example of PDU session establishment without an inserted I-SMF, according to some example embodiments.

In 401, the UE initiates a PDU session establishment procedure requested by the UE by transmitting a NAS message containing the PDU session establishment request within the N1 SM container. The PDU session establishment request includes a PDU session ID, a requested PDU session type, a request S-NSSAI indicating a network slice, a requested Date Network Name (DNN), and the like.

At 402, the AMF is configured to perform delegated discovery, so the AMF sends Nsmf _ PDUSession _ CreateSMContext request to the SCP along with the selection parameters. The message includes parameters such as SUPI, DNN, one or more S-nsais, 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 SMF, the selection parameters include, for example, target NF type, UE location, DNN, and S-NSSAI. The SCP need not identify Nsmf _ PDUSession _ CreateSMContext requests, but only uses the selection parameters to perform NF discovery and selection.

At 403, the scp sends to the NRF a Nnrf _ NFDiscovery _request message that includes the selection parameters. The NRF returns a first list of SMF profiles that match the requested S-NSSAI and the requested DNN. The SMF profile includes an SMF service area of each SMF.

At 404, the SCP selects an SMF profile, wherein the SMF service area covers the UE location, and the SCP forwards 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 the like. The SMF establishes an N4 association with the selected I-UPF. The tunnel information may be distributed by the SMF or by the UPF.

At 406, the SMF determines whether the UE location is within the SMF service area. If the UE location is within the SMF service area, the SMF returns to the SCP with a Nsmf _ PDUSTession _ CreateSMContext response message along with the selection parameters. The message includes an SMF ID, an SMF SM context ID, and/or an SMF service area. The message includes a cause value indicating that the request was accepted. The selection parameter includes an AMF ID.

At 407, the scp forwards the Nsmf _ PDUSession _ CreateSMContext response message to the AMF.

At 408, the smf sends Namf _communication_n1n MESSAGEGTRANSFER message to the AMF along with the selection parameters. The message includes parameters such as PDU session ID, N2 SM information (PDU session ID, one or more QFIs, one or more QoS profiles, N3 tunnel information for UPF, S-NSSAI, etc.), N1 SM container (PDU session establishment acceptance (one or more QoS rules), one or more S-NSSAI, DNN, etc.). The selection parameter includes an 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 an N2 PDU session request to the RAN. This message contains N2 SM information, NAS message (PDU session ID, N1 SM container (PDU session establishment accept)).

At 410, the ran may issue AN-specific signaling exchange with the UE, which relates to the information received from the SMF. For example, radio Resource Control (RRC) connection reconfiguration may be accompanied by the UE establishing the necessary NG-RAN resources related to QoS rules for the PDU session request received at 410. The RAN allocates N3 tunnel information for the PDU session.

At 411, the ran sends an N2 PDU session response to the AMF. The message includes parameters such as PDU session ID, cause, N2 SM information (PDU session ID, N3 tunnel information, list of one or more accepted/rejected QFI), etc.

At 412, the amf sends Nsmf _ PDUSession _ UpdateSMContext request (SMF SM context ID, N2 SM information) message to the SMF via the SCP. The selection parameters include, for example, an SMF ID.

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

At 414, the smf sends Nsmf _ PDUSession _ UpdateSMContext response message to the AMF via the SCP. The selection parameter includes an AMF ID.

Fig. 5 shows an example of PDU session establishment with I-SMF inserted.

In 501, the UE initiates a PDU session establishment procedure requested by the UE by transmitting a NAS message containing the PDU session establishment request within an N1 SM container. The PDU session establishment request includes a PDU session ID, a requested PDU session type, a request S-NSSAI indicating a network slice, a requested DNN, etc.

At 502, the amf is configured to perform delegated discovery. The AMF sends Nsmf _ PDUSession _ CreateSMContext request message to the SCP along with the selection parameters. The message may include parameters such as SUPI, DNN, one or more S-nsais, 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 SMF, the selection parameters include similar 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 identify Nsmf _ PDUSession _ CreateSMContext request messages.

At 503, the scp sends Nnrf _ NFDiscovery _request message to the NRF, which includes the selection parameters. Based on the input parameters, the NRF cannot return a list of SMFs that match all the input parameters. Or NRF responds to a list of SMF profiles, but none of them can serve the current UE location.

At 504, for NF discovery failure, the SCP sends a response to the AMF, where the cause value indicates the selection failure.

Based on the cause value, the AMF may initiate another Nsmf _ PDUSession _ CreateSMContext request message to the SCP at 505, along with a similar selection parameter, where the selection parameter does not include DNN. Excluding DNN allows the SCP to select I-SMF to cover the current UE location. The message may include an indication that the SMF serving the PDU session needs to be selected by the I-SMF.

At 506, the scp sends a Nnrf _ NFDiscovery _request message to the NRF that includes the selection parameters. The NRF returns a first list of SMF profiles. The SMF profile includes an SMF service area of each SMF.

At 507, the scp selects an 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 Nsmf _ PDUSTession _ CreateSMContext response with the selected parameters to the AMF through the SCP. The message may include parameters such as the service area of the I-SMF, the I-SMF SM context ID, etc. The message may include a cause value indicating that the request was accepted. The selection parameter may include an AMF ID. The SCP forwards the message to the AMF.

The I-SMF selects an I-UPF based on the user location information 509. The I-SMF establishes an N4 association with the selected I-UPF. The N3 tunnel information and the 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 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 for I-UPF, PDU session type, etc.

At 511, the scp sends a Nnrf _ NFDiscovery _request message to the NRF that includes the selection parameters. The NRF returns a second list of SMF profiles that match the requested S-NSSAI and the requested DNN. The SMF profile includes an SMF service area of 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 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 selects the UPF based on parameters such as DNN and S-NSSAI. The SMF establishes an N4 association with the selected I-UPF. The tunnel information may be distributed by the SMF or by the UPF.

At 514, the smf sends Nsmf _ PDUSession _create response message with the selection parameters to the SCP. The message may include the SMF SM context ID, one or more QoS rules sent to the UE, one or more QoS profiles sent to the RAN, N9 tunnel information for UPF, etc. The selection parameter may include an I-SMF ID. The SCP forwards the message to the I-SMF.

At 515, the i-SMF sends Namf _communication_n1n MessageTransport message with the 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, one or more QFIs, one or more QoS profiles, N3 tunnel information for I-UPF, S-NSSAI, etc.), N1 SM container (PDU session establishment acceptance (one or more QoS rules, one or more S-NSSAI, DNN, etc.)), etc. The selection parameter may include an 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 an 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 signaling exchange with the UE, which relates to the information received from the SMF. For example, RRC connection reconfiguration may be accompanied by the UE establishing the necessary NG-RAN resources related to QoS rules for the PDU session request received at step 510. The RAN may allocate N3 tunnel information for the PDU session.

At 518, the ran sends an N2 PDU session response to the AMF. The message may include parameters such as PDU session ID, cause, N2 SM information (PDU session ID, N3 tunnel information, list of one or more accepted/rejected QFI), etc.

At 519, the AMF sends Nsmf _ PDUSession _ UpdateSMContext request (I-SMF SM context ID, N2 SM information) message to the I-SMF via the SCP. The selection parameter may include an I-SMF ID.

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

At 521, the i-SMF sends Nsmf _ PDUSess ion _ UpdateSMContext response message to the AMF via the SCP. The selection parameters may include AMF ID

Fig. 6 illustrates an example of a home routing PDU session establishment procedure in accordance with some demonstrative embodiments.

At 601, the UE initiates a UE-requested PDU session establishment procedure by transmitting a NAS message containing the PDU session establishment request within an N1 SM container. The PDU session establishment request includes a PDU session ID, a requested PDU session type, a request S-NSSAI indicating a network slice, a requested DNN, etc.

At 602, the AMF determines that the requested PDU session is home routed based on the subscription. The AMF is configured to perform delegated discovery. Thus, the AMF sends Nsmf _ PDUSession _ CreateSMContext request message with the selection parameters to the SCP. The message includes parameters such as SUPI, DNN, one or more S-nsais, PDU session ID, AMF ID, request PDU session type, N1 SM container (PDU session establishment request), user location information, home routing indication, etc. In order for the SCP to select SMF, the selection parameters may include the target NF type, S-NSSAI, and UE location information. The SCP uses the selection parameters to perform NF selection and does not need to identify Nsmf _ PDUSession _ CreateSMContext requests.

At 603, the scp sends to the NRF a Nnrf _ NFDiscovery _request message that includes the selection parameters. The NRF returns a list of SMF profiles, where the SMF service area includes the UE location. The SCP selects V-SMF from the SMF list, where the SMF service area covers the UE location.

At 604, the SCP forwards Nsmf _ PDUSession _ CreateSMContext request message to the V-SMF.

At 605, the v-SMF returns Nsmf _ PDUSession _ CreateSMContext response message with the selection parameters to the AMF via the SCP. The message may include parameters such as a service area of V-SMF, V-SMF SM context ID, etc. The message may include a cause value indicating that the request was accepted. The selection parameter may include an AMF ID.

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

At 607, the v-SMF has information indicating that the PDU session is a home route. The V-SMF sends 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 for V-UPF, PDU session type, etc.

At 608, the scp sends a Nnrf _ NFDiscovery _request message to the NRF that includes the selection parameters. The NRF may communicate with the NRF in the HPLMN and return a list of H-SMF profiles that match the requested S-NSSAI and the requested DNN.

The scp selects one H-SMF from the H-SMF list and forwards Nsmf _ PDUSession _create request message to the selected H-SMF at 609.

At 610, the H-SMF may retrieve the 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. H-SMF selects H-UPF based on parameters such as DNN and S-NSSAI. The H-SMF establishes an 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 N9 tunnel information of the V-UPF to the H-UPF.

The h-SMF sends the Nsmf _ PDUSession _create response to the SCP along with the selection parameters at 611. The message includes the SMF SM context ID, one or more QoS rules sent to the UE, one or more QoS profiles sent to the RAN, N9 tunnel information for UPF, etc. The selection parameter may include a V-SMF ID. The SCP forwards the message to the V-SMF.

At 612, the v-SMF sends Namf _communication_n1n MESSAGETRANSFER to the AMF along with the selection parameters. The message includes parameters such as PDU session ID, N2 SM information (PDU session ID, one or more QFIs, one or more QoS profiles, N3 tunnel information for I-UPF, S-NSSAI, etc.), N1 SM container (PDU session establishment acceptance (one or more QoS rules, one or more S-NSSAI, DNN, etc.)). The selection parameter includes an AMF ID. The SCP forwards the message to the AMF. The AMF sends a response to the V-SMF via the SCP.

The amf sends an N2 PDU session request to the RAN at 613. 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 signaling exchange with the UE, which relates to the information received from the SMF. For example, RRC connection reconfiguration may be accompanied by the UE establishing the necessary NG-RAN resources related to QoS rules for the PDU session request received at step 610. The RAN also allocates N3 tunnel information for the PDU session.

At 615, the ran sends an N2PDU session response message to the AMF. The message includes parameters such as PDU session ID, cause, N2 SM information (PDU session ID, N3 tunnel information, list of one or more accepted/rejected QFI), etc.

At 616, the amf sends Nsmf _ PDUSession _ UpdateSMContext request (V-SMF SM context ID, N2 SM information) message to the V-SMF via the SCP. The selection parameter includes a 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 Nsmf _ PDUSess ion _ UpdateSMContext response message to the AMF via the SCP. The selection parameter includes an AMF ID.

Fig. 7 shows an example of a wireless communication system (e.g., a 5G cellular network) including a Base Station (BS) 720 and one or more UEs 711, 712, and 713. In some example embodiments, the UE accesses BS720 using configuration messages 731, 732, 733 communicated from UEs 711, 712, and 713, respectively, to BS720, enabling subsequent communications with the UE via messages 741, 742, 743. The UE may be, for example, a smart phone, a cellular 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. BS720 may include one or more of AMF, NRF, SMF, I-SMF, UPF, A-UPF, I-UPF, or RAN.

Fig. 8 illustrates an example of an apparatus according to some example embodiments. Device 810, such as base station 720 or a wireless device, such as UEs 711, 712, and/or 713, may include processor electronics 820, such as a microprocessor, that implement one or more features disclosed herein. BS720 may include one or more of AMF, NRF, SMF, I-SMF, UPF, A-UPF, I-UPF, or RAN. Device 810 may include transceiver electronics 830 to transmit and/or receive wireless signals over one or more communication interfaces, such as antenna 840. Device 810 may include other communication interfaces (e.g., wired interfaces, such as fiber-optic communications) for sending and receiving data. Device 810 may 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 may include at least a portion of the transceiver electronics 830. In some embodiments, at least some of the disclosed techniques, modules, or functions are implemented using device 810.

Some embodiments of the invention may be described based on the following items.

Item 1. A wireless communication method, comprising: receiving, at a serving element, a session request message from a mobility element, wherein the session request message comprises a selection parameter and user equipment location information; transmitting the selection parameters from the service unit to a repository unit; receiving, at the service unit, a list of one or more profiles from the repository unit, wherein the list of one or more profiles is for one or more session management units; selecting, at the service unit, one of the one or more session management units based on the one or more profiles and the user device location information; and forwarding the session request message from the service unit to a selected one of the one or more session management units.

Item 2. The wireless communication method of item 1, wherein the repository unit is a Network Repository Function (NRF).

Item 3. A wireless communication method, comprising: transmitting a session request message from a mobility unit to a service unit, wherein the session request message comprises a selection parameter and user equipment location information; and receiving, at the mobility unit, a service area associated with the session management unit selected by the service unit from the session management unit in response to the session request message.

Item 4. The wireless communication method of item 3, further comprising: a session establishment request is received at a mobility unit from a user equipment.

Item 5. The wireless communication method of any one of items 3 or 4, wherein the mobility unit is an access and mobility management function (AMF).

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

Item 7. The wireless communication method of any one of items 1 to 6, wherein the session request message is forwarded by a service unit.

Item 8. The wireless communication method of any one of items 1 to 6, wherein information about the service area is forwarded by a service unit.

Item 9. The wireless communication method according to any one of items 1 to 8, further comprising: a granted session parameter is received at the user equipment.

Item 10. The wireless communication method of any one of items 1 to 9, wherein the service element is a Service Communication Proxy (SCP).

Item 11. The wireless communication method according to any one of items 1 to 10, wherein the session management unit is a Session Management Function (SMF).

Item 12. An apparatus comprising a processor, wherein the processor is configured to implement the method according to one or more of items 1 to 11.

Item 13. A computer program product having code stored thereon, wherein the code, when executed by a processor, causes the processor to implement the method according to one or more of items 1 to 11.

The service units in the above entries perform proxy functions, referred to as Service Communication Proxy (SCP) in the previous description, and are shown in fig. 3-8. The mobility unit performs a mobility function, referred to as mobility management function (AMF) in the previous description, and is shown in fig. 1-8. The repository unit performs a repository function of storing profiles and other information, referred to as Network Repository Function (NRF) in the previous description, and is shown in fig. 1-8. One or more session management units perform session management functions and are referred to as Session Management Functions (SMFs) in the foregoing description.

In some example embodiments, the session request message may be Nsmf _ PDUSession _ CreateSMContext request message, and/or the selection parameters may include SUPI, DNN, one or more S-nsais, PDU session ID, AMF ID, request type, N1 SM container (PDU session establishment request). As used herein, the granted session parameters may include an SMF ID, an SMF SM context ID, and/or an SMF service area, as well as other parameters described above.

Some 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. Computer readable media may include removable and non-removable storage devices including, but not limited to, read Only Memory (ROM), random Access Memory (RAM), compact Discs (CD), digital Versatile Discs (DVD), and the like. Thus, the computer readable medium may include a non-transitory storage medium. 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.

The term "exemplary" is used herein to represent an example of …, and does not imply a desired or preferred embodiment unless otherwise indicated.

Some of the embodiments disclosed may be implemented as a device or module using hardware circuitry, software, or a combination thereof. For example, a hardware circuit implementation may include discrete analog and/or digital components, for example, integrated as part of a printed circuit board. Alternatively or additionally, the disclosed components or modules may be implemented as Application Specific Integrated Circuits (ASICs) and/or Field Programmable Gate Array (FPGA) devices. Some embodiments may additionally or alternatively include a Digital Signal Processor (DSP) that is a special purpose microprocessor having an architecture optimized for the operational needs of the digital signal processing associated with the disclosed functionality of the present invention. Similarly, the various components or sub-components within each module may be implemented in software, hardware, or firmware. Connectivity between modules and/or components within modules may be provided using any of the connection methods and mediums known in the art, including, but not limited to, communication over the internet, wired or wireless networks using appropriate protocols.

Although numerous details are included herein, these should not be construed as limitations on the scope of the claimed invention or of what may be claimed, but rather as descriptions of features of particular embodiments. Certain features that are described 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 subcombination. Furthermore, 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 subcombination or variation of a subcombination. Similarly, although individual operations are illustrated in the figures in a particular order, this should not be understood as requiring that such operations be performed in the particular order or sequence illustrated, or that all illustrated operations be performed, to achieve desirable results.

Only a few embodiments and examples are described herein, however, other embodiments, enhancements, and variations may be made based on what is described and illustrated herein.

Claims (8)

1. A method of wireless communication, comprising:

In a session establishment inserted in an intermediate session management unit I-SMF, receiving, at a service communication proxy SCP, a first session request message from an access and mobility management function AMF, said first session request message comprising first selection parameters comprising user equipment location information and DNN; when the first NF based on the first selection parameter finds failure, sending a cause value indicating the failure to the AMF;

The SCP receiving a second session request message from the AMF, the second session request message comprising a second selection parameter comprising the user equipment location information but not DNN, such that the SCP selects an I-SMF covering the user equipment location information, the second session request message further comprising indication information for indicating the I-SMF to select a session management unit SMF serving a session;

The SCP sends the second selection parameters to a repository unit so that the repository unit performs second NF discovery;

The SCP receiving a first list comprising one or more profiles from the repository unit, wherein the first list of one or more profiles is for one or more I-SMFs;

The SCP selects I-SMF covering the user equipment position information according to one or more of the profiles and the user equipment position information in the first list, and forwards the second session request message to the I-SMF;

The SCP receives the service area of the I-SMF from the I-SMF and forwards the service area to the AMF;

The SCP receives a third session request message sent by the I-SMF, wherein the third session request message comprises a third selection parameter;

The SCP sends the third selection parameters to the repository unit so that the repository unit performs NF discovery for the third time, wherein the third selection parameters comprise S-NSSAI and DNN;

The SCP receiving a second list comprising one or more profiles from the repository unit, wherein the second list of one or more profiles is for one or more SMFs, the SMFs being selected in dependence on one or more of the profiles in the second list;

in home routing session establishment, receiving, at the SCP, a first session request message from the AMF, the first session request message including a first selection parameter including user equipment location information, the AMF carrying a home routing indication in the first session request message when determining that the session requested by the user equipment is a home route;

The SCP sends the first selection parameter to the repository unit so that the repository unit performs first NF discovery;

The SCP receiving a first list comprising one or more profiles from the repository unit, wherein the first list of one or more profiles is for one or more visitor session management units V-SMF;

the SCP selects a V-SMF covering the user equipment position information according to one or more profiles in the first list and the user equipment position information, and forwards the first session request message to the V-SMF;

The SCP receives the service area of the V-SMF from the V-SMF and forwards the service area to the AMF;

The SCP receives a second session request message from the V-SMF, wherein the second session request message comprises a second selection parameter, and the SCP sends the second selection parameter to the repository unit so as to enable the repository unit to perform second NF discovery, and the second selection parameter comprises S-NSSAI and DNN;

the SCP receives a second list comprising one or more profiles from the repository unit, wherein the second list of one or more profiles is for one or more H-SMFs, the H-SMFs being selected according to one or more of the profiles in the second list.

2. The wireless communication method of claim 1, wherein the repository unit is a network repository function NRF.

3. A method of wireless communication, comprising:

In the session establishment of an interposed intermediate session management unit I-SMF, an access and mobility management function AMF sends a first session request message to a service communication proxy SCP, the session request message comprising a first selection parameter, the first selection parameter comprising user equipment location information and DNN; responding to the first session request message, and receiving a cause value sent by the SCP and used for indicating failure of first NF discovery;

The AMF sends a second session request message to the SCP based on the cause value, wherein the second session request message comprises a second selection parameter, and the second selection parameter comprises the user equipment position information but does not comprise DNN; the second session request message causes the SCP to send the second selection parameter to a repository unit to cause the repository unit to perform a second NF discovery, and to receive a first list including one or more profiles from the repository unit, to select an I-SMF that covers the user equipment location information according to one or more of the profiles in the first list, the user equipment location information, to forward the second session request message to the I-SMF, and to receive a service area of the I-SMF from the I-SMF; wherein the first list of one or more profiles is for one or more I-SMFs; the second session request message further includes indication information, where the indication information is used to instruct the I-SMF to select a session management unit SMF serving a session;

the AMF receives the service area of the I-SMF forwarded by the SCP;

in the home routing session establishment, an AMF sends a first session request message to the SCP, wherein the first session request message comprises a first selection parameter, and the first selection parameter comprises user equipment position information; the AMF determines that the session requested by the user equipment is the home location route, and carries a home location route indication in a first session request message; the first session request message causes the SCP to send the first selection parameter to the repository unit to cause the repository unit to perform a first NF discovery, and to receive a first list including one or more profiles from the repository unit, select a visitor session management unit V-SMF that covers the user equipment location information according to the one or more profiles in the first list and the user equipment location information, forward the first session request message to the V-SMF, and receive a service area of the V-SMF from the V-SMF; wherein the first list of one or more profiles is for one or more V-SMFs;

And the AMF receives the service area of the V-SMF forwarded by the SCP.

4. The wireless communication method of claim 3, further comprising: a session establishment request is received from a user equipment at the AMF.

5. A method of wireless communication, comprising:

in the session establishment inserted in the intermediate session management unit I-SMF, receiving a second session request message forwarded by the service communication proxy SCP at the selected I-SMF;

The selection process of the I-SMF comprises the following steps: receiving, at the SCP, a first session request message from an access and mobility management function AMF, the session request message comprising first selection parameters comprising user equipment location information and DNN; when the first NF based on the first selection parameter finds failure, sending a cause value indicating the failure to the AMF; the SCP receiving a second session request message from the AMF, the second session request message comprising a second selection parameter comprising the user equipment location information but not DNN, such that the SCP selects an intermediate session management unit I-SMF covering the user equipment location information; the second session request message further includes indication information, where the indication information is used to instruct the I-SMF to select a session management unit SMF serving a session; the SCP sends the second selection parameters to a repository unit so that the repository unit performs second NF discovery; the SCP receiving a first list comprising one or more profiles from a repository unit, wherein the first list of one or more profiles is for one or more I-SMFs; the SCP selects I-SMF covering the user equipment position information according to one or more of the profiles and the user equipment position information in the first list;

The I-SMF sends the service area to the AMF through the SCP;

The I-SMF sending a third session request message to the SCP, the third session request message comprising third selection parameters to cause the SCP to send the third selection parameters to the repository unit, the repository unit performing a third NF discovery, the third selection parameters comprising S-NSSAI and the DNN, the SCP receiving a second list comprising one or more profiles from the repository unit, wherein the second list of one or more profiles is for one or more SMFs, the SMF being selected according to one or more of the profiles in the second list;

In the establishment of a home routing session, receiving a first session request message forwarded by the SCP at a selected visiting place session management unit V-SMF; the selection process of the V-SMF comprises the following steps: receiving, at the SCP, a first session request message from the AMF; the first session request message comprises a first selection parameter, and the first selection parameter comprises user equipment position information; the AMF determines that the session requested by the user equipment is the home location route, and carries a home location route indication in a first session request message; the SCP sends the first selection parameter to the repository unit so that the repository unit performs first NF discovery; the SCP receiving a first list comprising one or more profiles from the repository unit, wherein the first list of one or more profiles is for one or more visitor session management units V-SMF; the SCP selecting a V-SMF covering the user equipment location information according to one or more profiles in the first list and the user equipment location information;

The V-SMF sends the service area to the AMF through the SCP;

The V-SMF sends a second session request message to the SCP, wherein the second session request message comprises a second selection parameter, so that the SCP sends the second selection parameter to the repository unit to enable the repository unit to perform second NF discovery, and the second selection parameter comprises S-NSSAI and DNN; the SCP receives a second list comprising one or more profiles from the repository unit, wherein the second list of one or more profiles is for one or more H-SMFs, the H-SMFs being selected according to one or more of the profiles in the second list.

6. The wireless communication method according to any one of claims 1 to 5, further comprising: a granted session parameter is received at the user equipment.

7. An apparatus comprising a processor, wherein the processor is configured to implement the method of any one of claims 1 to 5.

8. A computer program product having code stored thereon, wherein the code, when executed by a processor, causes the processor to implement the method of any of claims 1 to 5.