CN113785552A

CN113785552A - Session management function selection

Info

Publication number: CN113785552A
Application number: CN201980095940.4A
Authority: CN
Inventors: 朱进国; 梁爽
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2019-04-30
Filing date: 2019-04-30
Publication date: 2021-12-10
Also published as: WO2020220319A1

Abstract

A method, apparatus, system, and computer-readable medium. A method of wireless communication comprising: receiving, at the serving unit, a session request message including selection parameters and user equipment location information from the mobility unit; sending 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 equipment location information; and forwarding the session request message from the service unit to the selected one of the one or more session management units.

Description

Session management function selection

Technical Field

The present invention generally relates to wireless communications.

Background

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

Long Term Evolution (LTE) is a standard developed by the third generation partnership project (3GPP) for wireless communication of mobile devices and data terminals. LTE-advanced (LTE-a) is a wireless communication standard that enhances the LTE standard. A fifth generation wireless system, referred to as 5G, enhances 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 business needs.

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 includes selection parameters and user equipment location information; sending said selection parameters from said 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 equipment location information; and forwarding the session request message from the service unit to the 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: sending a session request message from a mobility unit to a serving unit, wherein the session request message includes selection parameters 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 the 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, the description and the claims.

Drawings

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

fig. 2 illustrates an example call flow for a Protocol Data Unit (PDU) session setup with intermediate session management function (I-SMF) insertion, in accordance with some demonstrative 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, in accordance with some demonstrative embodiments;

fig. 5 illustrates an example of PDU session establishment with an inserted I-SMF, in accordance with some demonstrative 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 demonstrative 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 network. The wireless device should be able to operate anywhere, anytime and be able to find resources that the user desires to meet the user's desires. To enable such user experience, work is being done in the third generation partnership project (3GPP) for improved service discovery and allocation.

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

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 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 5G network of this example 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. AMF is NAS security termination and relays SMNAS between UE and SMF, etc.

SMF, including 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, and the like. An SMF service area is a collection of UPF service areas for all UPFs that may be controlled by one SMF. The SMF service area is stored as an NF profile in the NRF.

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

A User Plane Function (UPF) comprising: 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 triggers, etc. The UPF service area consists of one or more tracking areas within which PDU sessions associated with UPFs can be served by the RAN nodes via the N3 interface between the RAN and the UPF without requiring the addition of new UPFs or the removal/redistribution of UPFs therebetween. The a-UPF is an anchor UPF that remains unchanged during UE mobility. When the UE moves outside the a-UPF service area, the intermediate UPF (I-UPF) is inserted/relocated. The I-UPF uses N3 tunneling to connect with the RAN and N9 tunneling to connect with the a-UPF.

A Network Repository Function (NRF) storing NF profiles of available NF instances and their supported services and supporting 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 (discoverable). After startup, 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 an I-SMF for a PDU session is added or removed. For this purpose, the AMF obtains information about the service area of one or more SMFs from the NRF. During a mobility event, such as a handover or 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 a single network slicing selection assistance information (S-NSSAI) that can serve the UE location. If AMF detects that I-SMF is no longer needed, I-SMF is removed and directly interfaced with SMF of PDU session. If the AMF detects that the SMF cannot serve the UE location (e.g., due to movement), 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 an I-SMF relocation.

Fig. 2 illustrates an exemplary call flow for PDU session setup with I-SMF insertion, in accordance with some exemplary embodiments.

At 201, the UE initiates a UE requested PDU session setup procedure by sending a NAS message containing a PDU session setup request within an N1 SM container. The PDU session setup 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 an nrrf _ NFDiscovery _ Request message to the NRF that includes selection parameters. 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 if the UE location is outside all SMF service areas. If so, the AMF sends an 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 the second list of SMFs, and selects an SMF from the first list of SMFs, wherein the SMF service area in the second list of SMFs covers the UE position.

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

At 204, the I-SMF returns an Nsmf _ PDUSESSION _ CreateSMContext response message. The message includes a cause value indicating whether the request was accepted. The message also includes the I-SMF assigned SM context ID. 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 device 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 assigned by the I-SMF or by the I-UPF.

At 206, the I-SMF sends an Nsmf _ pdusesion _ 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. 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 assigned by SMF or UPF.

At 208, the SMF returns an Nsmf _ PDUSessionCreate 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, the N9 tunnel information for the UPF, and other information.

At 209, the I-SMF sends a 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, QFI (S), QoS profile (S), N3 tunnel information for I-UPF, S-NSSAI, etc.), N1 SM container (PDU session setup accept (QoS rule (S), S-NSSAI (S), DNN, etc.)). The AMF sends a response to the I-SMF.

At 210, the AMF sends an N2PDU session request message to the RAN. The message includes N2 SM information, NAS message (PDU session ID, N1 SM container (PDU session setup accept)).

At 211, the RAN may issue AN-specific signaling exchange with the UE that is related to 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 the QoS rules for the PDU session request received at 210. The RAN also assigns 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, reason, N2 SM information (PDU session ID, N3 tunnel information, list of accepted/rejected quality of service flow identifiers (QFI)), and other information.

At 213, AMF sends an Nsmf _ PDSUSessionUpdateSMContext request message (I-SMF SM context ID, N2 SM info) to I-SMF.

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

At 215, the I-SMF sends an Nsmf _ PDUSESION _ 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 multiple NFs or multiple NF services without using an SCP. Indirect communication refers to communication between multiple NFs or multiple NF services via an SCP. In some example embodiments, a Service Communication Proxy (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 an 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 messages transmitted between the two NF service instances are not known to the SCP because the SCP does not view 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. Not only for the non-roaming case, but also for the home routing case, it is unclear how delegation discovery can work for SMF selection. A system and method are disclosed in which an AMF is informed of information about the service area of the SMF. In some exemplary embodiments, the AMF includes logic or executable code for I-SMF selection.

A system and method for SMF to provide service areas for SMF in response messages to AMF is disclosed. Thus, the AMF has information about the SMF service area, and the AMF 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, in accordance with some demonstrative embodiments.

At 401, the UE initiates the UE-requested PDU session setup procedure by transmitting a NAS message containing a PDU session setup request within an N1 SM container. The PDU session setup 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 delegation discovery, so the AMF sends an Nsmf _ PDUSESSION _ CreateSMContext request to the SCP along with selection parameters. The message includes parameters such as SUPI, DNN, one or more S-NSSAIs, PDU session ID, AMF ID, request PDU session type, N1 SM container (PDU session setup request), and/or user location information. 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 recognize the Nsmf _ pdusesion _ CreateSMContext request, but rather performs NF discovery and selection using only the selection parameters.

At 403, the SCP sends an nrrf _ NFDiscovery _ Request message to the NRF including 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 the SMF service area of each SMF.

At 404, the SCP selects an SMF profile, where the SMF service area covers the UE location, and forwards an Nsmf pdusesion _ 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 the PCC rules from the PCF. The SMF may select a UPF based on parameters such as DNN, S-NSSAI, etc. The SMF establishes an N4 association with the selected I-UPF. The tunnel information may be assigned by SMF or by 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 an Nsmf _ PDSUSTesion _ 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 parameters include the AMF ID.

At 407, the SCP forwards an Nsmf pdusesion CreateSMContext response message to the AMF.

At 408, the SMF sends a Namf _ Communication _ N1N2 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, QFI (S), QoS profile (S), N3 tunnel information for UPF, S-NSSAI, etc.), N1 SM container (PDU session setup 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 I-SMF via the SCP.

At 409, the AMF sends an N2PDU session request to the RAN. This message contains the N2 SM information, NAS message (PDU session ID, N1 SM container (PDU session setup accept)).

At 410, the RAN may issue AN-specific signaling exchange with the UE that 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 the QoS rules for the PDU session request received at 410. The RAN assigns N3 tunnel information for the PDU session.

At 411, the RAN sends an N2PDU session response to the AMF. The message includes parameters such as PDU session ID, reason, N2 SM information (PDU session ID, N3 tunnel information, list of one or more accepted/rejected QFIs), etc.

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

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

At 414, the SMF sends an Nsmf _ pdusesion _ UpdateSMContext response message to the AMF via the SCP. The selection parameters include the AMF ID.

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

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

At 502, the AMF is configured to perform delegation discovery. The AMF sends an Nsmf pdusesion CreateSMContext request message to the SCP together with the selection parameters. The message may include parameters such as SUPI, DNN, one or more S-NSSAIs, PDU session ID, AMF ID, request PDU session type, N1 SM container (PDU session setup request), user location information. 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 recognize the Nsmf _ pdusesion _ CreateSMContext request message.

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

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

At 505, based on the cause value, the AMF may initiate another Nsmf pdusesion CreateSMContext request message to the SCP along with similar selection parameters, where the selection parameters do not include DNN. Excluding the DNN causes the SCP to select I-SMF to cover the current UE location. The message may include an indication that an SMF that is to be selected by the I-SMF to serve the PDU session is required.

At 506, the SCP sends an nrrf _ NFDiscovery _ Request message to the NRF that includes the selection parameters. The NRF returns a first list of SMF profiles. The SMF profile includes the 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 _ pdusesion _ CreateSMContext request to the selected I-SMF.

At 508, the I-SMF returns an Nsmf _ PDSUSTextion _ CreateSMContext response with the 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, etc. The message may include a cause value indicating that the request was 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 the user 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 assigned by the I-SMF or by the I-UPF.

At 510, the I-SMF has information indicating that it is desired to select an SMF that serves the PDU session. The I-SMF sends an Nsmf _ PDSSESSION _ 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 an nrrf _ 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 the SMF service area of each SMF.

At 512, the SCP selects an SMF from the second list and forwards the Nsmf _ pdusesion _ 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 the 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 assigned by SMF or by UPF.

At 514, the SMF sends an Nsmf pdusesion 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, the N9 tunnel information for the UPF, and the like. The selection parameters may include an I-SMF ID. The SCP forwards the message to the I-SMF.

At 515, the I-SMF sends a Namf _ Communication _ N1N2 MessageTransport 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 tunneling information for I-UPF, S-NSSAI, etc.), N1 SM container (PDU session setup accept (QoS rule (S), S-NSSAI (S), DNN, etc.)), 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 an N2PDU session request to the RAN. The message includes N2 SM information, NAS message (PDU session ID, N1 SM container (PDU session setup accept)).

At 517, the RAN may issue AN-specific signaling exchange with the UE that is related to the information received from the SMF. For example, the RRC connection reconfiguration may be accompanied by the UE establishing the necessary NG-RAN resources related to the QoS rules for the PDU session request received at step 510. The RAN may assign N3 tunnel information for the PDU session.

At 518, the RAN sends an N2PDU session response to the AMF. The message may include parameters such as PDU session ID, reason, N2 SM information (PDU session ID, N3 tunnel information, list of one or more accepted/rejected QFIs), etc.

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

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

At 521, the I-SMF sends an Nsmf _ PDUSES _ 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 the UE requested PDU session setup procedure by transmitting a NAS message containing a PDU session setup request within an N1 SM container. The PDU session setup request includes a PDU session ID, a requested PDU session type, a request S-NSSAI indicating a network slice, a requested DNN, and the like.

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

At 603, the SCP sends an nrrf _ NFDiscovery _ Request message to the NRF 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 a V-SMF from the SMF list, where the SMF service area covers the UE location.

At 604, the SCP forwards an Nsmf pdusesion CreateSMContext request message to the V-SMF.

At 605, the V-SMF returns an Nsmf _ pdusesion _ CreateSMContext response message with the 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, etc. The message may include a cause value indicating that the request was accepted. The selection parameters may include the 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 assigned by the V-SMF or by the V-UPF.

At 607, the V-SMF has information indicating that the PDU session is a home route. The V-SMF sends an Nsmf _ pdusesion _ 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, and the like.

At 608, the SCP sends an nrrf _ 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 an H-SMF from the H-SMF list at 609 and forwards the Nsmf _ pdusesion _ Create request message to the selected H-SMF.

At 610, the H-SMF can 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. The 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 assigned by the H-SMF or by the H-UPF. The H-SMF sends N9 tunnel information of the V-UPF to the H-UPF.

At 611, the H-SMF sends an Nsmf _ PDSSESSION _ Create response to the SCP along with the selection parameters. 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 the 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 _ N1N2MessageTransfer to the AMF along with the selection parameters. The message includes parameters such as PDU session ID, N2 SM information (PDU session ID, QFI (S), QoS profile (S), N3 tunnel information for I-UPF, S-NSSAI, etc.), N1 SM container (PDU session setup 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 an N2PDU session request to the RAN. The message includes N2 SM information, NAS message (PDU session ID, N1 SM container (PDU session setup accept)).

At 614, the RAN may issue AN-specific signaling exchange with the UE that is related to the information received from the SMF. For example, the RRC connection reconfiguration may be accompanied by the UE establishing the necessary NG-RAN resources related to the QoS rules for the PDU session request received at step 610. The RAN also assigns 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, reason, N2 SM information (PDU session ID, N3 tunnel information, list of one or more accepted/rejected QFIs), etc.

At 616, AMF sends an Nsmf _ PDSessionUpdateSMContext request (V-SMF SM context ID, N2 SM info) message to V-SMF via 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 N3 tunneling information received from the RAN.

At 618, the V-SMF sends an Nsmf _ PDUSES _ 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) including a Base Station (BS)720 and one or

more UEs

711, 712, and 713. In some demonstrative embodiments, the UE accesses BS720 using

configuration messages

731, 732, 733 communicated to BS720 from

UEs

711, 712, and 713, respectively, enabling subsequent communication with the UEs via

messages

741, 742, 743. The UE may be, for example, a smartphone, 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 UE711, 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 communication) 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, processor electronics 820 may 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 device 810.

Some embodiments of the present 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 includes selection parameters and user equipment location information; sending said selection parameters from said 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 equipment location information; and forwarding the session request message from the service unit to the 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: sending a session request message from a mobility unit to a serving unit, wherein the session request message includes selection parameters 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 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 the service area associated with the session management unit to the mobility unit.

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

Item 8. the wireless communication method of any of items 1 to 6, wherein the 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: receiving, at the user equipment, granted session parameters.

Item 10. the wireless communication method of any 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 of 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 elements in the above entries perform a proxy function, referred to as a 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 a mobility management function (AMF) in the previous description, and is shown in fig. 1-8. The vault unit performs a vault function, referred to in the foregoing description as a network vault function (NRF), which stores profiles and other information, 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 an Nsmf _ pdusesion _ CreateSMContext request message, and/or the selection parameters may include SUPI, DNN, one or more S-NSSAIs, PDU session ID, AMF ID, request type, N1 SM container (PDU session setup request). As used herein, the granted session parameters may include SMF ID, SMF SM context ID, and/or SMF service area, among 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. The 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 Disks (CDs), Digital Versatile Disks (DVDs), and the like. Thus, a 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 mean an "… example," and does not imply an ideal or preferred embodiment unless otherwise indicated.

Some of the disclosed embodiments may be implemented as devices or modules using hardware circuitry, software, or combinations thereof. For example, a hardware circuit implementation may include discrete analog and/or digital components integrated as part of a printed circuit board, for example. 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), which 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 media known in the art, including but not limited to communication over the internet, wired or wireless networks using appropriate protocols.

Although this document contains many specifics, 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 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 subcombination. 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 subcombination or variation of a subcombination. Similarly, while various operations are shown 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 embodiments and examples are described herein, however, other embodiments, enhancements and variations can be made based on what is described and illustrated herein.

Claims

1. A method of wireless communication, comprising:

receiving, at a serving element, a session request message from a mobility element, wherein the session request message includes selection parameters and user equipment location information;

sending said selection parameters from said 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 equipment location information; and

forwarding the session request message from the service unit to the selected one of the one or more session management units.

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:

sending a session request message from a mobility unit to a serving unit, wherein the session request message includes selection parameters and user equipment location information; and

at the mobility unit, a service area associated with the session management unit selected by the service unit is received from the session management unit in response to the session request message.

4. The wireless communication method of claim 3, further comprising:

a session establishment request is received at a mobility unit from a user equipment.

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

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

information about the service area associated with the session management unit is forwarded to the mobility unit.

7. The wireless communication method of any of claims 1-6, wherein the session request message is forwarded by a serving element.

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

9. The wireless communication method of any of claims 1-8, further comprising:

receiving, at the user equipment, granted session parameters.

10. The wireless communication method according to any of claims 1 to 9, wherein the service element is a Serving Communication Proxy (SCP).

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

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

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