Method and apparatus for controlling a packet data connection

Abstract

Methods and apparatus for controlling a packet data connection are disclosed. According to one embodiment, a user plane entity receives a request from a control plane entity to modify parameters related to a packet data connection for which at least a portion is to be deleted. Upon receiving the request, the user plane entity stops only the forwarding and counting of packets in one of a downlink direction and an uplink direction for the at least a portion of the packet data connection that is to be deleted.

Description

Technical Field

[0001] Embodiments of this disclosure generally relate to communications, and more specifically to methods and apparatus for controlling packet data connections. Background Technology

[0002] This section introduces aspects that may facilitate a better understanding of this disclosure. Therefore, the statements in this section should be read in that sense and should not be construed as an admission of what is prior art or what is not prior art.

[0003] In the architecture of 3GPP Release 16 (R16), the core network has been divided into the control plane and the user plane. Figure 1 This diagram illustrates an architectural reference model with Control and User Plane Separation (CUPS) for non-roaming and roaming scenarios in an Evolved Packet System (EPC). As shown, the EPC control plane may include the Serving Gateway Control Plane (SGW-C) and the Packet Data Network (PDN) Gateway Control Plane (PGW-C). The EPC user plane may include the SGW User Plane (SGW-U) and the PGW User Plane (PGW-U). Figure 2 An exemplary architecture of the fifth-generation core network (5GC) is shown. As illustrated, the control plane of the 5GC may include Session Management Function (SMF), and the user plane of the 5GC may include User Plane Function (UPF).

[0004] The user plane interacts with the control plane via the Sx / N4 interface and reports the corresponding service usage to the control plane. The control plane then collects all necessary information and generates a billing data record (CDR), or sends the billing information to surrounding nodes such as the billing function (CHF), billing gateway (CG), and online billing system (OCS). Summary of the Invention

[0005] This summary is provided to present in a simplified form a selection of concepts further described in the detailed description below. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to limit the scope of the claimed subject matter.

[0006] One of the objectives of this disclosure is to provide an improved solution for controlling fractional data connections. In particular, one of the problems this disclosure aims to address is the potential for subscriber billing inconsistencies among multiple cascaded user plane entities in existing solutions when at least a portion of a packet data connection is removed.

[0007] According to a first aspect of this disclosure, a method performed by a user plane entity is provided. The method may include receiving from a control plane entity a request to modify parameters associated with a packet data connection for which at least a portion is to be deleted. The method may further include, upon receiving the request, stopping packet forwarding and counting only in one of the downlink and uplink directions for the at least portion of the packet data connection to be deleted.

[0008] This method ensures consistent billing for subscribers, thereby preventing overcharging.

[0009] In one embodiment of this disclosure, the user plane entity may be the Serving Gateway User Plane (SGW-U), and the control plane entity may be the SGW Control Plane (SGW-C).

[0010] In one embodiment of this disclosure, for the packet data connection to be deleted, only the forwarding and counting of packets in the uplink direction can be stopped.

[0011] In one embodiment of this disclosure, the request may be received in response to one of the following: a detach procedure initiated by a user equipment (UE); a detach procedure initiated by a mobility management entity (MME); a detach procedure initiated by a home subscriber server (HSS); a packet data network (PDN) connection disconnection procedure requested by a UE; and a PDN connection disconnection procedure requested by an MME.

[0012] In one embodiment of this disclosure, the user plane entity may be the PDN gateway user plane (PGW-U), and the control plane entity may be the PGW control plane (PGW-C).

[0013] In one embodiment of this disclosure, for one or more bearers that are to be deleted in the packet data connection, forwarding and counting of packets in the downlink direction may be stopped only.

[0014] In one embodiment of this disclosure, the request may be received in response to one of the following: a dedicated bearer deactivation process initiated by the MME; and a bearer deactivation process initiated by the PGW.

[0015] In one embodiment of this disclosure, the packet data connection may be a PDN connection.

[0016] In one embodiment of this disclosure, the request may be an Sx session modification request.

[0017] In one embodiment of this disclosure, the user plane entity may be a user plane function (UPF) that acts as the N3 endpoint, and the control plane entity may be a session management function (SMF).

[0018] In one embodiment of this disclosure, for the packet data connection to be deleted, only forwarding and counting of packets in the uplink direction can be stopped.

[0019] In one embodiment of this disclosure, the UPF acting as an N3 endpoint may delete the packet data connection after one or more other UPFs acting as Protocol Data Unit (PDU) Session Anchors (PSAs) delete the packet data connection.

[0020] In one embodiment of this disclosure, the request may be received in response to one of the following: a UE request for a PDU session release procedure for non-roaming; a UE request for a PDU session release procedure for roaming with local routing; a UE request for a PDU session release procedure for roaming with home routing; a serving network or access network request for a PDU session release procedure for non-roaming; a serving network or access network request for a PDU session release procedure for roaming with local routing; and a serving network or access network request for a PDU session release procedure for roaming with home routing.

[0021] In one embodiment of this disclosure, the user plane entity may be a UPF acting as a PSA, and the control plane entity may be an SMF.

[0022] In one embodiment of this disclosure, for the packet data connection to be deleted, only the forwarding and counting of packets in the downlink direction can be stopped.

[0023] In one embodiment of this disclosure, after one or more UPFs acting as N3 endpoints delete the packet data connection, the UPF acting as PSA may delete the packet data connection.

[0024] In one embodiment of this disclosure, the request may be received in response to one of the following: a policy control function (PCF) or SMF request for a PDU session release procedure for non-roaming; a PCF or SMF request for a PDU session release procedure for roaming with local routing; and a PCF or SMF request for a PDU session release procedure for roaming with home routing.

[0025] In one embodiment of this disclosure, the packet data connection may be a PDU session.

[0026] In one embodiment of this disclosure, the request may be an N4 session modification request.

[0027] According to a second aspect of this disclosure, a method performed by an SMF is provided. The method may include sending one or more first requests to one or more first UPFs acting as N3 endpoints to modify parameters associated with the PDU session to be deleted, in response to a PDU session release procedure requested by a UE or a serving network or access network. The method may further include sending one or more second requests to one or more second UPFs acting as PSAs to delete the PDU session. The method may further include sending one or more third requests to the one or more first UPFs to delete the PDU session after the one or more second UPFs have deleted the PDU session.

[0028] According to a third aspect of this disclosure, a method performed by an SMF is provided. The method may include, in response to a PDU session release procedure requested by a PCF or the SMF, sending one or more first requests to one or more first UPFs acting as a PSA to modify parameters associated with the PDU session to be deleted. The method may further include sending one or more second requests to one or more second UPFs acting as N3 endpoints to delete the PDU session. The method may further include, after the one or more second UPFs have deleted the PDU session, sending one or more third requests to the one or more first UPFs to delete the PDU session.

[0029] According to a fourth aspect of this disclosure, an apparatus for implementing a user plane entity is provided. The apparatus may include at least one processor and at least one memory. The at least one memory may contain instructions executable by the at least one processor, thereby enabling the apparatus to operate to receive from a control plane entity a request to modify parameters associated with a packet data connection for which at least a portion is to be deleted. The apparatus may also be operable to, upon receiving the request, stop packet forwarding and counting only in one of the downlink and uplink directions for the at least portion of the packet data connection to be deleted.

[0030] In one embodiment of this disclosure, the apparatus may be operable to perform the method according to the first aspect described above.

[0031] According to a fifth aspect of this disclosure, an apparatus for implementing an SMF is provided. The apparatus may include at least one processor and at least one memory. The at least one memory may contain instructions executable by the at least one processor, thereby enabling the apparatus to be operable to send one or more first requests to one or more first UPFs acting as N3 endpoints to modify parameters associated with the PDU session to be deleted, in response to a PDU session release procedure requested by a UE or a serving network or access network. The apparatus is also operable to send one or more second requests to one or more second UPFs acting as PSAs to delete the PDU session. The apparatus is further operable to send one or more third requests to the one or more first UPFs to delete the PDU session after the one or more second UPFs have deleted the PDU session.

[0032] According to a sixth aspect of this disclosure, an apparatus for implementing an SMF is provided. The apparatus may include at least one processor and at least one memory. The at least one memory may contain instructions executable by the at least one processor, thereby enabling the apparatus to be operable to send one or more first requests to one or more first UPFs acting as PSAs for modifying parameters associated with the PDU session to be deleted, in response to a PDU session release process requested by a PCF or the SMF. The apparatus is also operable to send one or more second requests to one or more second UPFs acting as N3 endpoints for deleting the PDU session. The apparatus is further operable to send one or more third requests to the one or more first UPFs for deleting the PDU session after the one or more second UPFs have deleted the PDU session.

[0033] According to a seventh aspect of this disclosure, a computer program product is provided. The computer program product may include instructions. When executed by at least one processor, the instructions cause the at least one processor to perform the method according to any one of the first to third aspects described above.

[0034] According to an eighth aspect of this disclosure, a computer-readable storage medium is provided. The computer-readable storage medium may contain instructions. When executed by at least one processor, the instructions cause the at least one processor to perform the method according to any one of the first to third aspects described above.

[0035] According to a ninth aspect of this disclosure, an apparatus for implementing a user plane entity is provided. The apparatus may include a receiving module for receiving from a control plane entity a request to modify parameters associated with a packet data connection for which at least a portion is to be deleted. The apparatus may further include a control module for, upon receiving the request, stopping packet forwarding and counting only in one of the downlink and uplink directions for the at least portion of the packet data connection to be deleted.

[0036] According to a tenth aspect of this disclosure, an apparatus for implementing an SMF (Self-Managing Function) is provided. The apparatus may include a modification module for sending one or more first requests to one or more first UPFs acting as N3 endpoints to modify parameters associated with the PDU session to be deleted, in response to a PDU session release procedure requested by a UE or a serving network or access network. The apparatus may further include a first deletion module for sending one or more second requests to one or more second UPFs acting as PSAs to delete the PDU session. The apparatus may further include a second deletion module for sending one or more third requests to the one or more first UPFs to delete the PDU session after the one or more second UPFs have deleted the PDU session.

[0037] According to the eleventh aspect of this disclosure, an apparatus for implementing an SMF is provided. The apparatus may include a modification module for sending one or more first requests to one or more first UPFs acting as PSAs to modify parameters associated with the PDU session to be deleted, in response to a PDU session release process requested by a PCF or the SMF. The apparatus may further include a first deletion module for sending one or more second requests to one or more second UPFs acting as N3 endpoints to delete the PDU session. The apparatus may further include a second deletion module for sending one or more third requests to the one or more first UPFs to delete the PDU session after the one or more second UPFs have deleted the PDU session.

[0038] According to a twelfth aspect of this disclosure, a method is provided implemented in a communication system including a control plane entity and a user plane entity. The method may include, at the control plane entity, sending a request to the user plane entity for modifying parameters associated with a packet data connection for which at least a portion is to be deleted. The method may also include, at the user plane entity, receiving from the control plane entity the request for modifying parameters associated with the packet data connection. The method may further include, at the user plane entity, upon receiving the request, stopping packet forwarding and counting only in one of the downlink and uplink directions for the at least portion of the packet data connection to be deleted.

[0039] According to a thirteenth aspect of this disclosure, a communication system including a control plane entity and a user plane entity is provided. The control plane entity may be configured to send a request to the user plane entity for modifying parameters associated with a packet data connection for which at least a portion is to be deleted. The user plane entity may be configured to: receive the request for modifying parameters associated with the packet data connection from the control plane entity; and upon receiving the request, for the at least portion of the packet data connection to be deleted, stop forwarding and counting packets only in one of the downlink and uplink directions. Attached Figure Description

[0040] These and other objects, features, and advantages of this disclosure will become apparent from the following detailed description of illustrative embodiments of the disclosure, which will be read in conjunction with the accompanying drawings.

[0041] Figure 1 This is a diagram showing the CUPS in the EPC;

[0042] Figure 2 This is a diagram illustrating an exemplary architecture for 5GC;

[0043] Figures 3A-3B It is a diagram illustrating the problems with existing solutions;

[0044] Figure 4 This is a flowchart illustrating a method performed by a user-plane entity according to an embodiment of the present disclosure;

[0045] Figures 5A-5B Each of these is a flowchart illustrating a method performed by an SMF according to an embodiment of this disclosure;

[0046] Figure 6 This is a flowchart illustrating an exemplary process in an EPC according to an embodiment of the present disclosure;

[0047] Figure 7 This is a flowchart illustrating an exemplary process in an EPC according to an embodiment of the present disclosure;

[0048] Figure 8 This is a flowchart illustrating an exemplary process in 5GC according to an embodiment of the present disclosure;

[0049] Figure 9 This is a flowchart illustrating an exemplary process in 5GC according to an embodiment of the present disclosure;

[0050] Figure 10 This is a flowchart illustrating an exemplary process in 5GC according to an embodiment of the present disclosure;

[0051] Figure 11 This is a flowchart illustrating an exemplary process in 5GC according to an embodiment of the present disclosure;

[0052] Figure 12 This is a flowchart illustrating an exemplary process in 5GC according to an embodiment of the present disclosure;

[0053] Figure 13 This is a flowchart illustrating an exemplary process in 5GC according to an embodiment of the present disclosure;

[0054] Figure 14 This is a block diagram illustrating an apparatus suitable for use in practicing some embodiments of the present disclosure;

[0055] Figure 15 This is a block diagram illustrating an apparatus for implementing a user face entity according to an embodiment of the present disclosure;

[0056] Figure 16 This is a block diagram illustrating an apparatus for implementing SMF according to embodiments of the present disclosure; and

[0057] Figure 17 This is a block diagram illustrating an apparatus for implementing SMF according to an embodiment of the present disclosure. Detailed Implementation

[0058] For purposes of explanation, certain details are set forth in the following description to provide a thorough understanding of the disclosed embodiments. However, it will be apparent to those skilled in the art that the embodiments may be implemented without these specific details or using equivalent configurations.

[0059] According to current 3GPP protocols, for the detach / deactivation process in CUPS, an Sx modification process exists before the Sx termination process for the purpose of stopping counting and stopping packet forwarding. When there is a UE / MME / SGSN / HSS-initiated detach process or a UE / MME-requested PDN connection disconnection, an Sx modification message exists before the Sx termination message. The term SGSN refers to Serving GPRS Support Node, and the term GPRS refers to General Packet Radio Service. The SGW-C will send an Sx session modification request to the SGW-U to instruct the SGW-U to stop counting the affected bearers. The SGW-C should also instruct the SGW-U to discard downlink packets received from the PGW-U for the affected bearers and uplink packets received from the evolved Node B (eNodeB) for the affected bearers.

[0060] When there is a bearer deactivation initiated by the PDN gateway (GW) or a dedicated bearer deactivation initiated by the MME, the PGW-C will send an Sx session modification request to the PGW-U to instruct the PGW-U to stop counting for the affected bearer and stop forwarding both uplink and downlink packets.

[0061] For UE / MME / SGSN / HSS-initiated detach procedure or UE / MME-requested PDN connection disconnect procedure, if SGW-C instructs SGW-U to stop counting and stop forwarding packets for both uplink and downlink, PGW-U can still forward downlink packets to SGW-U and record these packets in CDR for billing. This means that for downlink packets, there will be subscriber billing inconsistencies between PGW-U and SGW-U.

[0062] For bearer deactivation initiated by the PDN GW or dedicated bearer deactivation initiated by the MME, if the PGW-C instructs the PGW-U to stop counting and forwarding both uplink and downlink packets for the affected bearer, the SGW-U can still forward uplink packets to the PGW-U and record these packets in the CDR. This will cause subscriber billing inconsistencies between the PGW-U and SGW-U for uplink packets.

[0063] The situation is similar in the 5GC architecture. In 5GC, if there are multiple UPFs associated with a PDU session, all UPF resources used by the PDU session will be released immediately during the PDU session release process, so each UPF discards both uplink and downlink packets simultaneously.

[0064] like Figure 3AAs shown, if the UPF (N3 endpoint) is released before the UPF (PSA) is released, the UPF (PSA) can still forward downlink packets and count these packets in the billing. However, these packets will be discarded by the UPF (N3 endpoint). This will cause inconsistencies in downlink billing for subscribers across multiple UPFs, resulting in overcharging in the UPF (PSA).

[0065] like Figure 3B As shown, if the UPF(PSA) is released before the UPF(N3 endpoint) is released, the UPF(N3 endpoint) can still forward uplink packets and count these packets in the billing. However, these packets will be discarded by the UPF(PSA). This will cause inconsistencies in uplink billing for subscribers across multiple UPFs, resulting in overcharging in the UPF(PSA).

[0066] This disclosure proposes an improved solution for controlling packet data connections. The basic idea is that during the Sx modification process of the EPC, the SGW-C instructs the SGW-U to stop counting and forwarding only uplink packets. The PGW-C instructs the PGW-U to stop counting and forwarding only downlink packets. In 5GC, the UPF (N3 endpoint) will discard any remaining uplink packets of the PDU session before the UPF (PSA) is released. The UPF (PSA) will discard any remaining downlink packets of the PDU session before the UPF (N3 endpoint) is released.

[0067] As an example, this solution can be applied to Figure 1 and Figure 2 The architecture shown. Figure 1 Details of the architecture can be found in 3GPP Technical Specification (TS) 23.214 V16.1.0, and Figure 2 Details of the architecture are available in 3GPP TS23.501V16.5.0. Both documents are combined in full hereby.

[0068] It should be noted that, within the context of this disclosure, the term UE or terminal device as used herein may also be referred to as, for example, access terminal, mobile station, mobile unit, user station, etc. It can refer to any (stationary or mobile) terminal device capable of accessing a wireless communication network and receiving services from it. By way of example and not limitation, UE may include portable computers, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback devices, mobile phones, cellular phones, smartphones, tablet computers, wearable devices, personal digital assistants (PDAs), integrated or embedded wireless network cards, external plug-in wireless network cards, and so on.

[0069] In Internet of Things (IoT) scenarios, a UE or terminal device can represent a machine or other device that performs monitoring and / or measurement and transmits the results of such monitoring and / or measurement to another UE or terminal device and / or network device. In this case, the UE or terminal device can be a machine-to-machine (M2M) device, which, in the 3GPP context, can be referred to as a machine-type communication (MTC) device. Specific examples of such machines or devices can include sensors, metering devices such as power meters, industrial machinery, bicycles, vehicles, or household or personal appliances (e.g., refrigerators, televisions), personal wearable devices (such as watches), and so on.

[0070] As used herein, the term "communication system" refers to a system that follows any suitable communication standard (such as first-generation (1G), 2G, 2.5G, 2.75G, 3G, 4G, 4.5G, 5G communication protocols) and / or any other protocols currently known or to be developed in the future. Furthermore, communication between terminal devices and network nodes in a communication system can be performed according to any suitable generation of communication protocols (including, but not limited to, 1G, 2G, 2.5G, 2.75G, 3G, 4G, 4.5G, 5G communication protocols) and / or any other protocols currently known or to be developed in the future. Additionally, the specific terminology used herein is not intended to limit this disclosure to communication systems associated with that specific term, but rather these specific terms can be applied more generally to other communication systems.

[0071] In the following text, reference will be made to Figure 4-17 Describe the solution in detail. Figure 4 This is a flowchart illustrating a method performed by a user plane entity according to an embodiment of this disclosure. It should be noted that the network entities or functions mentioned in this document can be implemented as network units on dedicated hardware, as software instances running on dedicated hardware, or as virtualization functions instantiated on a suitable platform (e.g., on cloud infrastructure). At block 402, the user plane entity receives a request from the control plane entity to modify parameters associated with a packet data connection for which at least a portion will be deleted. Upon receiving this request, at block 404, the user plane entity, for the at least portion of the packet data connection to be deleted, stops packet forwarding and counting only in one of the downlink and uplink directions. In this way, subscriber billing consistency can be ensured, thereby avoiding overcharging.

[0072] For example, the user plane entity and another user plane entity can be associated with the same packet data connection. Only one of the downlink and uplink directions can depend on the relative positions between the two user plane entities. If the user plane entity (e.g., SGW-U or N3 endpoint UPF) is downstream of another user plane entity (e.g., PGW-U or PSAUPF) and closest to the RAN side, then only one of the downlink and uplink directions is the uplink direction. On the other hand, if the user plane entity (e.g., PGW-U or PSAUPF) is upstream of another user plane entity (e.g., SGW-U or N3 endpoint UPF) and closest to the data network side, then only one of the downlink and uplink directions is the downlink direction.

[0073] As a first option, the user plane entity can be SGW-U, and the control plane entity can be SGW-C. For this option, for the packet data connection (PDN connection) to be deleted, only uplink packet forwarding and counting are stopped. For example, a request can be received in response to one of the following: a UE-initiated detach procedure; a detach procedure initiated by the MME or SGSN; a detach procedure initiated by the HSS; a UE-requested PDN connection termination procedure; and an MME-requested PDN connection termination procedure.

[0074] As a second option, the user plane entity can be PGW-U, and the control plane entity can be PGW-C. For this option, only downlink packet forwarding and counting are stopped for one or more bearers to be deleted in the packet data connection (PDN connection). For example, a request can be received in response to one of the following: a dedicated bearer deactivation procedure initiated by the MME; and a bearer deactivation procedure initiated by the PGW. In both the first and second options above, the request can be an Sx session modification request.

[0075] As a third option, the user plane entity can be a UPF acting as an N3 endpoint (such as an uplink classifier, fork point, intermediate UPF, etc.), and the control plane entity can be an SMF. For this option, only uplink packet forwarding and counting are stopped for the packet data connection (PDU session) to be deleted. For example, a request can be received in response to one of the following: a UE-requested PDU session release procedure for non-roaming; a UE-requested PDU session release procedure for roaming with local breakout; a UE-requested PDU session release procedure for roaming with home routing; a PDU session release procedure for non-roaming requested by the serving network or access network; a PDU session release procedure for roaming with local breakout requested by the serving network or access network; and a PDU session release procedure for roaming with home routing requested by the serving network or access network. Additionally, the UPF acting as an N3 endpoint can delete the packet data connection after one or more other UPFs acting as PSAs have deleted the packet data connection.

[0076] As a fourth option, the user plane entity can be a UPF acting as a PSA, and the control plane entity is an SMF. For this option, only downlink packet forwarding and counting are stopped for the packet data connection (PDU session) to be deleted. For example, a request can be received in response to one of the following: a PDU session release procedure requested by a PCF or SMF for non-roaming; a PDU session release procedure requested by a PCF or SMF for roaming with local routing; and a PDU session release procedure requested by a PCF or SMF for roaming with home routing. Additionally, the UPF acting as a PSA can delete the packet data connection after one or more UPFs acting as N3 endpoints have deleted the packet data connection. In the third and fourth options above, the request can be an N4 session modification request.

[0077] It should be noted that in the above examples used to implement blocks 402 and 404, the modification request received at block 402 can be the same as an existing modification request, and the user plane entity can be configured to execute block 404 in response to receiving the modification request. Alternatively, it may be possible to modify the existing modification request to explicitly indicate that the at least portion of the packet data connection to be deleted only stops packet forwarding and counting in one of the downlink and uplink directions.

[0078] Figure 5AThis is a flowchart illustrating a method performed by an SMF according to an embodiment of the present disclosure. At block 502, in response to a PDU session release procedure requested by the UE or serving network or access network, the SMF sends one or more first requests to one or more first UPFs acting as N3 endpoints to modify parameters associated with the PDU session to be deleted. For example, the first request could be an N4 session modification request. At block 504, the SMF sends one or more second requests to one or more second UPFs acting as PSAs to delete the PDU session. At block 506, when one or more second UPFs have already deleted the PDU session, the SMF sends one or more third requests to one or more first UPFs to delete the PDU session. For example, the second or third request could be an N4 session release request. Figure 5A This method can ensure consistent billing for subscribers, thereby avoiding overcharging.

[0079] Figure 5B This is a flowchart illustrating a method performed by an SMF according to an embodiment of the present disclosure. At block 508, in response to a PDU session release procedure requested by a PCF or SMF, the SMF sends one or more first requests to one or more first UPFs acting as PSAs to modify parameters associated with the PDU session to be deleted. For example, the first request could be an N4 session modification request. At block 510, the SMF sends one or more second requests to one or more second UPFs acting as N3 endpoints to delete the PDU session. At block 512, when one or more second UPFs have deleted the PDU session, the SMF sends one or more third requests to one or more first UPFs to delete the PDU session. For example, the second or third request could be an N4 session release request. Figure 5B This method can ensure consistent billing for subscribers, thereby avoiding overcharging.

[0080] Based on the above description, one aspect of this disclosure provides a method implemented in a communication system including a control plane entity and a user plane entity. The method may include: sending a request at the control plane entity to the user plane entity for modifying parameters associated with a packet data connection for which at least a portion is to be deleted. The method may further include: at the user plane entity, receiving from the control plane entity the request for modifying parameters associated with the packet data connection. The method may further include: at the user plane entity, upon receiving the request, stopping packet forwarding and counting only in one of the downlink and uplink directions for the at least portion of the packet data connection to be deleted.

[0081] Furthermore, another aspect of this disclosure provides a communication system including a control plane entity and a user plane entity. The control plane entity can be configured to send a request to the user plane entity for modifying parameters associated with a packet data connection for which at least a portion is to be deleted. The user plane entity can be configured to: receive from the control plane entity the request for modifying parameters associated with the packet data connection; and upon receiving the request, for the at least portion of the packet data connection to be deleted, stop forwarding and counting packets only in one of the downlink and uplink directions.

[0082] Figure 6 This is a flowchart illustrating an exemplary process in an EPC according to an embodiment of this disclosure. At step 1, the UE / MME / SGSN / HSS initiates a detach procedure or the UE / MME requests the PDN connection to be disconnected, wherein the SGW-C marks the connection to be deleted. At steps 2a and 2b, the SGW-C instructs the SGW-U to stop counting for the affected bearer and stop forwarding uplink packets. At step 3, the SGW-C sends a delete session request message to the PGW-C. At steps 4a and 4b, the PGW-C sends an Sx session termination request to the PGW-U to release the Sx session. At step 5, the PGW-C sends a delete session response message to the SGW-C. At steps 6a and 6b, the SGW-C sends an Sx session termination request to the SGW-U to release the Sx session.

[0083] Figure 7 This is a flowchart illustrating an exemplary process in an EPC according to an embodiment of the present disclosure. At step 1, the MME or PDN GW initiates bearer deactivation, where the PGW-C marks the bearer to be deleted. At steps 2a and 2b, the PGW-C instructs the PGW-U to stop counting and stop forwarding downlink packets for the affected bearer. At step 3, the PGW-C sends a bearer deletion request message to the SGW-C. At steps 4a and 4b, the SGW-C instructs the SGW-U to stop counting and stop forwarding uplink packets for the affected bearer. At steps 5a and 5b, the SGW-C sends a bearer deletion request message to the MME. At steps 6a and 6b, the SGW-C instructs the SGW-U to remove the Packet Detection Rule (PDR) for the affected bearer. At step 7, the SGW-C sends a bearer deletion response to the PGW-C. At steps 8a and 8b, the PGW-C instructs the PGW-U to remove the PDR for the affected bearer.

[0084] Figure 8This is a flowchart illustrating an exemplary process in a 5GC according to an embodiment of this disclosure. At step 1, the UE or serving network or (R)AN or AMF requests the release of the PDU session for both non-roaming and roaming with local routing. At steps 2a and 2b, the SMF sends an N4 Modification Request to instruct the UPF (N3 endpoint) to discard any remaining uplink packets of the PDU session. The symbol “×” in the figure indicates stopping any further forwarding of packets. At steps 3a-3d, the SMF sends an N4 Release Request to instruct the UPF (PSA) to discard any remaining packets of the PDU session and release all tunnel resources and context associated with the N4 session. At steps 4a and 4b, the SMF sends an N4 Release Request to the remaining UPF to discard any remaining packets of the PDU session and release all tunnel resources and context associated with the N4 session. At step 5, the remaining PDU release process is performed.

[0085] Figure 9 This is a flowchart illustrating an exemplary process in a 5GC according to an embodiment of this disclosure. At step 1, the PCF / H-SMF requests a PDU session release procedure for roaming with home-based routing. At steps 2a and 2b, the H-SMF sends an N4 modification request to instruct the H-UPF (PSA1) to discard any remaining downlink packets of the PDU session. At step 3, the H-SMF prepares an SM release PDU session command message and initiates PDU session release to the UE by invoking the Nsmf_PDUSession_Update request service operation to the V-SMF. At steps 4a and 4b, the V-SMF sends an N4 modification request to instruct the V-UPF (PSA2) to discard any remaining downlink packets of the PDU session. At steps 5a and 5b, the V-SMF sends an N4 release request to instruct the UPF (N3 endpoint) to discard any remaining packets of the PDU session and release all tunnel resources and context associated with the N4 session. At steps 6a and 6b, the V-SMF sends an N4 release request to the remaining UPFs to discard any remaining packets of the PDU session and release all tunnel resources and context associated with the N4 session. At step 7, N1 / N2 resource release is performed. At step 8, the V-SMF responds to the Nsmf_PDUSession_Update request invoked at step 3 and confirms the PDU session release. At steps 9a and 9b, the H-SMF sends an N4 release request to the remaining UPFs to discard any remaining packets of the PDU session and release all tunnel resources and context associated with the N4 session. At step 10, the remaining PDU release process is performed.

[0086] Based on the above description, the following changes are recommended for 3GPP TS 23.214 16.0.0, which are highlighted with underscores.

[0087] 6.3.1.6 Includes a PDN connection release process.

[0088] …

[0089] 1. Initiate the procedures listed in this step as specified in the relevant clauses of this specification. Execute the relevant steps of the procedures specified in the diagram above.

[0090] 2. The SGW-C sends an Sx session modification request to the SGW-U. The SGW-C should instruct the SGW-U to stop counting uplink packets for the affected bearers. The SGW-C should also... The SGW-U is instructed to drop incoming data received from the eNodeB for the affected bearers. Line link grouping .

[0091] …

[0092] 6.3.1.7 It has the capability to carry out modifications.

[0093] …

[0094] 1. Initiate the procedures listed in this step as specified in the relevant clauses of this specification. Execute the relevant steps of the procedures specified in the diagram above.

[0095] 2. PGW-C sends an Sx session modification request to PGW-U. For "Dedicated Bearer Activation," PGW-C may instruct PGW-U to assign an F-TEID for the dedicated bearer. For "PGW / MME-Initiated Bearer Deactivation Procedure," PGW-C should instruct PGW-U to stop counting and forwarding for the affected bearers. downlink Grouping.

[0096] 3. PGW-U sends an Sx session modification response to PGW-C confirming the successful modification of the Sx session.

[0097] 4. Perform the relevant steps of the process specified in the diagram above.

[0098] 5. SGW-C sends an Sx session modification request to SGW-U. For "Dedicated Bearer Activation," SGW-C may instruct SGW-U to allocate F-TEIDs for the dedicated bearer. For "PGW / MME-Initiated Bearer Deactivation Procedure," SGW-C should instruct SGW-U to stop counting and forwarding for the affected bearer. uplink Grouping.

[0099] …

[0100] 6.3.4.1.1 Procedure for SGSN with terminating S4 interface

[0101] …

[0102] 1. Initiate the procedures listed in this step as specified in the relevant clauses of this specification. Execute the relevant steps of the procedures specified in the diagram above.

[0103] 2a. SGW-C sends an Sx session modification request to SGW-U to modify the Sx session. SGW-C should request SGW-U to stop counting uplink packets for the affected bearers. SGW-C should also request SGW-U to... For the affected bearer drop from uplink packets received by eNodeB .

[0104] 2b. SGW-U sends an Sx session modification response to SGW-C confirming the successful modification of the Sx session.

[0105] 2c. Perform the relevant steps of the process specified in the diagram above.

[0106] 3a. PGW-C can send an Sx session termination request to PGW-U to release the Sx session.

[0107] 3b. PGW-U sends an Sx session termination response to PGW-C confirming the release of the Sx session.

[0108] 3c. Perform the relevant steps of the process specified in the diagram above.

[0109] 3d.SGW-C can send an Sx session termination request to SGW-U to release the Sx session.

[0110] 3e. SGW-U sends an Sx session termination response to SGW-C confirming the release of the Sx session.

[0111] 4. Perform the relevant steps of the process specified in the diagram above.

[0112] 5a. The SGW-C may send an Sx session modification request to the SGW-U during the detach and bearer deactivation process. The SGW-C shall instruct the SGW-U to stop deactivating the affected bearer. Uplink packets Perform the counting. SGW-C should also indicate... SGW-U is targeted at The affected bearer dropped uplink packets received from the eNodeB. .

[0113] …

[0114] 6.3.4.1.2 Procedure for SGSN with terminating Gn / Gp interface

[0115] …

[0116] 1. Initiate the procedures listed in this step as specified in the relevant clauses of this specification. Execute the relevant steps of the procedures specified in the diagram above.

[0117] 2a. When the PGW-C initiates a bearer deactivation process, the PGW-C sends an Sx session modification request to the PGW-U. The PGW-C should instruct the PGW-U to stop deactivating the affected bearer. Downlink packets Perform a count. The PGW-C should also instruct the PGW-U to discard data received from the affected bearer. downlink Grouping.

[0118] …

[0119] Additionally, it is recommended that the following first changes be made to 3GPP TS 23.502V16.0.0, among which... Figure 10 It is the first change Figure 4 3.4.2.1-1, and the following text is the first revised text.

[0120] 4.3.4.2 UE or network request for PDU session release for non-roaming and roaming with local routing

[0121] This process is used in non-roaming and roaming scenarios with local detouring.

[0122] Figure 4 3.4.2.1-1 illustrates the PDU session release procedure requested by the UE, serving network, or (R)AN. This procedure allows the UE, serving network, or (R)AN to initiate the release of a PDU session. Figure 4 Section 3.4.2.2-1 illustrates the PDU session release procedure requested by the PCF or SMF. This procedure allows the PCF or SMF to initiate the release of the PDU session. In the case of LBO, the procedure is essentially the same as in the non-roaming case, the difference being that the AMF, SMF, UPF, and PCF are located in the visited network.

[0123] 4.3.4.2.1 Release of PDU sessions requested by the UE, serving network, or (R)AN for non-roaming and roaming with local routing

[0124] This clause defines the release of PDU sessions during the following processes: non-roaming and roaming with local routing.

[0125] - Release initiated by UE.

[0126] - Release initiated by the service network.

[0127] Release initiated by -(R)AN.

[0128] Figure 4 3.4.2.1-1: PDU session release requested by the UE, serving network, or (R)AN for non-roaming and roaming with local routing.

[0129] 1. This process is triggered by one of the following events:

[0130] 1a. The UE initiates a PDU session release procedure by transmitting a NAS message (N1 SM container (PDU session release request (PDU session ID)), PDU session ID). The NAS message, using the indication of the user location information, is forwarded by the (R)AN to the AMF. This message is relayed via N2 and the AMF to the SMF corresponding to the PDU session ID. The AMF invokes the Nsmf_PDUSession_UpdateSMContext service operation and provides the N1 SM container along with the user location information (ULI) received from the (R)AN to the SMF.

[0131] Note 1: Depending on the access type, when the UE is in CM-IDLE state, the UE can trigger the service request process before it can release the PDU session.

[0132] 1b. In cases where the PDU session states between the UE and AMF do not match, or in other cases where neither N1 nor N2 SM signaling is required before releasing the SM context, the AMF may invoke the Nsmf_PDUSession_ReleaseSMContext service operation to request the release of the PDU session.

[0133] 1c.(R)AN may decide to instruct the SMF that PDU session-related resources be released, for example, when all QoS flows of the PDU session are released.

[0134] Note 2: In this case, the SMF decides whether to keep the PDU session active while deactivating the user plane connection, or to release the PDU session.

[0135] If the SMF receives one of the triggers in step 1a or 1b, the SMF initiates the PDU session release procedure.

[0136] 1d.AMF may invoke the Nsmf_PDUSession_UpdateSMContext service operation to request the release of the PDU session using the release indication, where N1 or N2 SM signaling may be required before the release of the SM context (e.g., due to a change in the network slice set used for the UE, where, as described in Clause 5.15.5.2.2 of TS 23.501[2], the network slice instance is no longer available, or as specified in Clause 4.2.9.2, the network slice-specific re-authentication and re-authorization process triggered by the AAA server fails, or as specified in Clause 4.2.9.4, a slice-specific authorization revocation triggered by the AAA server occurs, or as described in Clause 5.31.4.1 of TS 23.501[2], the AMF determines that the pure control plane indication associated with the PDU session is no longer applicable).

[0137] 2. If multiple UPFs associated with a PDU session exist (e.g., due to the insertion of a UL CL, a fork point, or a redundant I-UPF (if the redundant I-UPF is used for URLLC), the following procedure is triggered.

[0138] 2a. The SMF sends an N4 session modification request message to the UL CL, fork point, or redundant I-UPF (including the N3 endpoint) of the PDU session. The UPF should discard any remaining uplink packets of the PDU session.

[0139] 2b. The UPF acknowledges the N4 session modification request by sending an N4 session modification response message to the SMF.

[0140] 3. The SMF releases the IP address / prefix allocated to the PDU session and releases the corresponding user plane resources (including PSA):

[0141] 3a. The SMF sends an N4 session release request (N4 session ID) message to the UPF (including PSA) of the PDU session. The UPF should discard any remaining packets of the PDU session and release all tunnel resources and context associated with the N4 session.

[0142] 3b. The UPF acknowledges the N4 session release request by sending an N4 session release response (N4 session ID, [small data rate control status], [APN rate control status]) message to the SMF.

[0143] If the PDU session uses small data rate control, then the UPF includes the small data rate control state.

[0144] 3c. This includes the same process as in step 3a.

[0145] 3d. This includes the same process as in step 3b.

[0146] If NEF has been selected as the anchor point for a PDU session with control plane CIoT 5GS optimization enabled (which is the unstructured PDU session type described in Clause 4.3.2.2), and the SMF-NEF connection has been released for that PDU session.

[0147] Note 3: If only one UPF is associated with a PDU session, or if multiple UPFs are associated with a PDU session but the UPF (N3 endpoint) and PSA2 are both located in a single UPF, skip steps 3c-3d.

[0148] 4. If multiple UPFs associated with a PDU session exist (e.g., due to the insertion of a UL CL, a fork point, or a redundant I-UPF (if the redundant I-UPF is used for URLLC), the following procedure is triggered.

[0149] 4a. The SMF sends an N4 session release request message to the UL CL, fork point, or redundant I-UPF (including the N3 endpoint) of the PDU session. The UPF should discard any remaining packets of the PDU session and release all tunnel resources and context associated with the N4 session.

[0150] 4b. The UPF acknowledges the N4 session release request by sending an N4 session release response message to the SMF.

[0151] Note 4: If the UPF (N3 endpoint) and PSA2 are both located in a single UPF, the SMF also releases the IP address / prefix assigned to the PDU session.

[0152] 5. If the PDU session release process is triggered by step 1a or 1c above, the SMF creates an N1 SM including a PDU session release command message (PDU session ID, reason). The reason may indicate the triggering of establishing a new PDU session with the same characteristics (e.g., when a process associated with SSC mode 2 is invoked).

[0153] If the user plane connection of the PDU session is active, the message sent by the SMF to the AMF should include an N2 SM resource release request. If the user plane connection of the PDU session is not active, the message sent by the SMF to the AMF should not include an N2 SM resource release request.

[0154] Note 5: The SSC mode is defined in Clause 5.6.9 of TS 23.501[2].

[0155] 5a. (If the PDU session release was initiated by the UE in step 1a, or has already been triggered by the (R)AN in step 1c) The SMF responds to the AMF with an Nsmf_PDUSession_UpdateSMContext response (N2 SM resource release request, N1 SM container (PDU session release command)). If the PDU session release was initiated by the UE and if the UP connection of the PDU session is active, the N2 SM resource release request is included.

[0156] 5b. If the PDU session release is initiated by the AMF in step 1b, i.e. the SMF receives the Nsmf_PDUSession_ReleaseSMContext request from the AMF, the SMF responds to the AMF with the Nsmf_PDUSession_ReleaseSMContext response (optionally including small data rate control status and APN rate control status).

[0157] If the UPF includes the APN rate control state and / or the small data rate control state in step 3, then the SMF includes the APN rate control state and / or the small data rate control state, and the AMF stores the small data rate control state and / or the APN rate control state in the UE context within the AMF.

[0158] The AMF and SMF should remove all contexts (including PDU session IDs) associated with a PDU session that has been indicated as released at the UE. The SMF should remove any event subscriptions made by the SMF to the AMF that are no longer needed due to the release of the PDU session. Skip steps 6 to 13.

[0159] 5c. If the PDU session release is initiated by the AMF in step 1d, i.e., the SMF receives an Nsmf_PDUSession_UpdateSMContext request with a release indication requesting the release of the PDU session from the AMF, then the SMF responds to the AMF with an Nsmf_PDUSession_UpdateSMContext response, which may contain an N1 SM container (PDU session release command) to release the PDU session at the UE.

[0160] If the UP connection of the PDU session is active, the Nsmf_PDUSession_UpdateSMContext response should also include an N2 resource release request (PDU session ID) to release the (R)AN resources associated with the PDU session.

[0161] 6. If the UE is in CM-IDLE state and does not indicate that "N1 SM delivery can be skipped", the AMF initiates a network-triggered service request procedure to send a NAS message (PDU session ID, N1 SM container) to the UE, and skips steps 8 and 9.

[0162] If the message received from the SMF in step 5 does not include the N2 SM resource release request, the AMF sends a NAS message (PDU session ID, N1 SM container) to the UE and skips steps 8 and 9.

[0163] If the PDU session has control plane CIoT 5GS optimization enabled, the SMF should not include the N2 SM resource release request in the message sent to the AMF. The AMF sends a NAS message (PDU session ID, N1 SM container) to the UE and skips steps 8 and 9.

[0164] If the UE is in the CM-CONNECTED state and the message received from the SMF in step 5 includes an N2 SM resource release request, then the AMF will transmit the SM information (N2 SM resource release request, N1 SM container) received from the SMF in step 5 to (R)AN.

[0165] If a message from the SMF includes a small data rate control state, the AMF stores it in the UE context within the AMF.

[0166] 7. When the (R)AN has received an N2 SM request for releasing the AN resources associated with the PDU session, it sends an AN-specific signaling exchange to the UE to release the corresponding AN resources.

[0167] In the NG-RAN case, a NAS message is sent to the UE in an RRC message, which can occur when the UE releases NG-RAN resources associated with the PDU session. If it is not necessary to release NG-RAN resources (i.e., the user plane of the PDU session is deactivated), a NAS message is sent to the UE in an RRC message, which does not release NG-RAN resources associated with the PDU session.

[0168] During this process, (R)AN sends any NAS messages received from AMF in step 6 (N1 SM container (PDU session release command)).

[0169] 8. [Conditionally] If (R)AN has already received an N2 SM request for releasing AN resources, then (R)AN confirms the N2 SM resource release request by sending an N2 SM resource release confirmation (user location information, auxiliary RAT usage data) message to AMF.

[0170] If the PLMN has been configured with auxiliary RAT usage reports, the NG-RAN node can provide RAN usage data reports.

[0171] 9a. The AMF calls the SMF to call Nsmf_PDUSession_UpdateSMContext(N2 SM resource release confirmation (auxiliary RAT usage data), user location information).

[0172] 9b.SMF responds to AMF using the Nsmf_PDUSession_UpdateSMContext response.

[0173] 10. The UE confirms the PDU session release command by sending a NAS message (PDU session ID, N1 SM container (PDU session release confirmation)) via (R)AN.

[0174] 11. [Conditional] (R)AN forwards NAS messages from the UE by sending N2 NAS uplink transmission (NAS message (PDU session ID, N1 SM container (PDU session release confirmation)), user location information) to the AMF.

[0175] 12a. The AMF calls the SMF to call Nsmf_PDUSession_UpdateSMContext(N1 SM container(PDU session release confirmation, user location information).

[0176] 12b.SMF responds to AMF using the Nsmf_PDUSession_UpdateSMContext response.

[0177] Steps 10-12 can occur before steps 8-9.

[0178] 13. If step 5a or 5c has been performed, the SMF waits, as needed, until it has received a response to the N1 and N2 information provided in step 5.

[0179] The SMF invokes `Nsmf_PDUSession_SMContextStatusNotify` to notify the AMF that the SM context used for this PDU session has been released. If the UPF included the small data rate control state and / or APN rate control state in step 3, the SMF includes the small data rate control state and / or APN rate control state in its request to the AMF in this step. The AMF releases the association between the SMF ID and the PDU session ID, DNN, and S-NSSAI, and stores the small data rate control state and / or APN rate control state in the UE context within the AMF. The SMF should remove any event subscriptions to the AMF that are no longer needed due to the PDU session release.

[0180] Note 5: The UE and 5GC will obtain synchronization of the state of the (released) PDU session during the next service request or registration process.

[0181] 14. If a dynamic PCC is applied to this session, the SMF invokes the SM policy defined in Clause 4.16.6 to associate the termination procedure to delete the PDU session.

[0182] 15. SMF notifications are sent to any entity that has subscribed to user location information related to PDU session changes.

[0183] 16. If the SMF is processing the last PDU session for the UE against the associated (DNN, S-NSSAI), the SMF unsubscribes from the UDM for Session Management Subscription Data Change Notifications via the Nudm_SDM_Unsubscribe(SUPI, DNN, S-NSSAI) service operation. The UDM can unsubscribe from the UDR for subscription notifications via Nudr_DM_Unsubscribe(SUPI, Subscription Data, Session Management Subscription Data, DNN, S-NSSAI).

[0184] 17. The SMF invokes the Nudm_UECM_Deregistration service operation, which includes the DNN and PDU session IDs. The UDM removes the associations it has stored between the SMF identity and the associated DNN and PDU session IDs. The UDM can update this information via Nudr_DM_Update(SUPI, subscription data, UE context in SMF data).

[0185] The following second change is recommended for 3GPP TS 23.502V16.0.0, among which... Figure 11 It is the second change Figure 4 3.4.2.2-1, and the following text is the second revised text.

[0186] 4.3.4.2.2 PDU session release requested by PCF or SMF for non-roaming and roaming with local routing

[0187] This clause defines the release of PDU sessions during the following processes: non-roaming and roaming with local routing.

[0188] - Release initiated by PCF.

[0189] - Release initiated by SMF.

[0190] Figure 4 3.4.2.1-1: PDU session release requested by PCF or SMF for non-roaming and roaming with local routing

[0191] 1. This process is triggered by one of the following events:

[0192] 1a. (PDU Session Release Initiated by PCF) PCF may invoke the SM policy associated with the termination procedure as defined in Clause 4.16.6 to request the release of a PDU session.

[0193] 1b. (PDU Session Release Initiated by SMF) SMF may decide to release a PDU session in the following scenarios:

[0194] - Based on a request from the DN (cancel UE authorization for accessing the DN);

[0195] - Based on requests from UDM (subscription change) or CHF;

[0196] -If the SMF receives an event notification from the AMF that the UE is outside the LADN service area.

[0197] - A locally configured strategy (e.g., the release process can be associated with UPF reallocation for SSC mode 2 / mode 3); or

[0198] - If the SMF is notified by the (R)AN that the PDU session resource establishment has failed during the mobility process.

[0199] SMF initiates the PDU session release process.

[0200] 2. If multiple UPFs associated with a PDU session exist (e.g., due to the insertion of a UL CL, a fork point, or a redundant I-UPF (if the redundant I-UPF is used for URLLC), the following procedure is triggered.

[0201] 2a. The SMF sends an N4 Session Modification Request message to the UPF (including PSA) of the PDU session. The UPF should discard any remaining downlink packets of the PDU session.

[0202] 2b. The UPF acknowledges the N4 session modification request by sending an N4 session modification response message to the SMF.

[0203] 2c. This includes the same process as in step 2a.

[0204] 2d. This includes the same process as in step 2b.

[0205] Note 1: If the UPF (N3 endpoint) and PSA2 are both located in a single UPF, skip steps 2c-2d.

[0206] 3a-3b. These steps are the same as steps 4a-4b in clause 4.3.4.2.1.

[0207] Note 2: If the UPF (N3 endpoint) and PSA2 are both located in a single UPF, the SMF also releases the IP address / prefix assigned to the PDU session.

[0208] 4a-4d. These steps are the same as steps 3a-3d in clause 4.3.4.2.1.

[0209] 5. If the SMF has been notified by the AMF that the UE is unreachable, for example, due to the UE being in MICO mode or a periodic registration failure, then the AMF is notified by the SMF that the PDU session has been released, allowing the process to continue in step 13. Skip steps 6-12.

[0210] SMF creates an N1 SM that includes a PDU session release command message (PDU session ID, reason). The reason can indicate a trigger for establishing a new PDU session with the same characteristics (e.g., when a procedure associated with SSC mode 2 is invoked).

[0211] If the user plane connection of the PDU session is active, the message sent by the SMF to the AMF should include an N2 SM resource release request (PDU session ID) in Namf_Communication_N1N2MessageTransfer to release the (R)AN resources associated with the PDU session. If the user plane connection of the PDU session is not active, the message sent by the SMF to the AMF should not include an N2 SM resource release request.

[0212] Note 3: The SSC mode is defined in Clause 5.6.9 of TS 23.501[2].

[0213] SMF calls the Namf_Communication_N1N2MessageTransfer service operation (N1 SM container (PDU session release command, skip indicator).

[0214] The “Skip Indicator” tells the AMF whether it can skip sending the N1 SM container to the UE (e.g., when the UE is in CM-IDLE state). The SMF includes the “Skip Indicator” in Namf_Communication_N1N2MessageTransfer unless the procedure is triggered to change the PDU session anchor point of a PDU session with SSC mode 2.

[0215] If the UE is in CM-IDLE state and the "skip indicator" is included in the Namf_Communication_N1N2MessageTransfer service operation, the AMF confirms this step by sending a Namf_Communication_N2N2MessageTransfer response message ("N1 SM message not transmitted") to the SMF and skips steps 6 to 12.

[0216] 6-12. These steps are the same as steps 6-12 in Clause 4.3.4.2.1.

[0217] 13. As needed, the SMF waits until it has received a response to the N1 and N2 information provided in step 5.

[0218] The SMF invokes Nsmf_PDUSession_SMContextStatusNotify to notify the AMF that the SM context of this PDU session has been released. If the UPF includes a small data rate control state and / or an APN rate control state in step 4, the SMF includes the small data rate control state and / or the APN rate control state in its request to the AMF in this step. The AMF releases the association between the SMF ID and the PDU session ID, DNN, and S-NSSAI, and stores the small data rate control state and / or the APN rate control state in the UE context within the AMF.

[0219] SMF should remove any event subscriptions to AMF that are no longer needed due to the release of PDU sessions.

[0220] Note 4: The UE and 5GC will obtain synchronization of the state of the (released) PDU session during the next service request or registration process.

[0221] 14. (PDU Session Release Initiated by SMF) If a dynamic PCC is applied to this session, the SMF invokes the SM policy associated termination procedure defined in Clause 4.16.6 to delete the PDU session.

[0222] 15-17. These steps are the same as steps 15-17 in Clause 4.3.4.2.1.

[0223] The following third change is recommended for 3GPP TS 23.502 V16.0.0, among which... Figure 12 It is the third change Figure 4 3.4.3.1-1, and the following text is the third revised text.

[0224] 4.3.4.3 Release of roaming PDU session for home routing requested by the UE or network

[0225] This process is used in roaming scenarios where home routing is used.

[0226] 4.3.4.3.1 Release of roaming PDU session for home-area routing requested by the UE, serving network, or (R)AN

[0227] This clause defines the release of a roaming PDU session used for home-area routing during the following process:

[0228] - Release initiated by UE.

[0229] - Release initiated by the service network.

[0230] Release initiated by -(R)AN.

[0231] Figure 4 3.4.3.1-1: Release of roaming PDU session for home routing requested by the UE, serving network, or (R)AN.

[0232] 1. This process is triggered by one of the following events:

[0233] 1a. (UE-Initiated Release) As in step 1a of clause 4.3.4.2.1, with the following addition: The V-SMF invokes the Nsmf_PDUSession_Update request (SM context ID, information from the UE's SM message, such as PCO, "Trigger PDU Session Release" indication, time zone, user location information) service operation to request the H-SMF to release the PDU session. The H-SMF responds to the request immediately in step 3a.

[0234] 1b. (Release Initiated by Serving Network) As specified in Clause 4.2.2.3, the serving network initiates a PDU session release during a deregistration process initiated by the UE or the serving network. In this case, there is no NASSM message between the UE and the V-SMF. The V-SMF initiates the release of the PDU session at the H-SMF by invoking the Nsmf_PDUSession_Release request in step 3b.

[0235] As in step 1b of Clause 4.3.4.2.1, if, for example, due to a change in the network slice set used for the UE (where the network slice instance is no longer available (e.g., as described in Clause 5.15.5.2.2 of TS 23.501[2], or as specified in Clause 4.2.9.2, the network slice-specific re-authentication and re-authorization process triggered by the AAA server fails, or as specified in Clause 4.2.9.4, a slice-specific authorization revocation triggered by the AAA server occurs)), the serving network also initiates a PDU session release if neither N1 SM signaling nor N2 SM signaling is required before releasing the SM context.

[0236] 1c. This step is the same as step 1c in clause 4.3.4.2.1.

[0237] 1d. This step is the same as step 1d in clause 4.3.4.2.1. PDU session release is specified in step 5a-19.

[0238] 2a-2b. These steps are the same as steps 2a-2b in Clause 4.3.4.2.1. SMF is the SMF in VPLMN.

[0239] 3. This process is triggered by one of the following events:

[0240] 3a. This step is a follow-up to 1a.

[0241] 3b. This step is a follow-up to 1b.

[0242] 3c. This step is a follow-up to 1c.

[0243] 3d. This step is a follow-up step to 1d.

[0244] If the SMF receives a trigger in step 3a, the H-SMF initiates the PDU session release process.

[0245] 4a-4b. These steps are the same as steps 3a-3b in clause 4.3.4.2.1. SMF is the SMF in HPLMN.

[0246] 5a. (UE-Initiated Release) The H-SMF prepares the SM release PDU session command message and initiates the PDU session release to the UE by calling the Nsmf_PDUSession_Update request service operation to the V-SMF. The Nsmf_PDUSession_Update request contains the necessary information (e.g., release reason or PCO) required by the V-SMF to construct the SM release PDU session command for the UE.

[0247] 5b. (Release initiated by the service network) H-SMF responds to a PDU release request from V-SMF with an Nsmf_PDUSession_Release response.

[0248] If the UPF includes a small data rate control state in step 4, then the SMF includes a small data rate control state in its request to the AMF.

[0249] If control plane CIoT 5GS optimization is enabled for this PDU session, skip steps 6 and 7.

[0250] 6a-6b. V-SMF releases the corresponding user plane resources (including PSA). These steps are the same as steps 3c-3d in Clause 4.3.4.2.1, but are controlled by the SMF in VPLMN.

[0251] Note 1: If the UPF (N3 endpoint) and PSA2 are both located in a single UPF, skip steps 6a-6b.

[0252] 7a-7b. V-SMF releases the corresponding user plane resources (including the N3 endpoint). These steps are the same as steps 4a-3b in Clause 4.3.4.2.1, but are controlled by the SMF in VPLMN.

[0253] Note 2: If the UPF (N3 endpoint) and PSA2 are both located in a single UPF, the SMF also releases the IP address / prefix assigned to the PDU session.

[0254] 8-16. These steps are the same as steps 5-12 in clause 4.3.4.2.1.

[0255] 17. (UE-Initiated Release) The V-SMF responds to the Nsmf_PDUSession_Update request invoked in step 5a and confirms the PDU session release. The Nsmf_PDUSession_Update response may carry information such as the PCO received from the UE in the SM PDU session release acceptance, as well as user location information, time zone, and secondary RAT usage data.

[0256] 18. (Release Initiated by UE or Serving Network) The H-SMF releases the SM policy control association with the PCF by invoking the SM policy association termination procedure defined in Clause 4.16.6. For PDU session releases initiated by the serving network, this step occurs between steps 3b and 5b.

[0257] 19. (UE-initiated release) The H-SMF should remove all contexts associated with the PDU session:

[0258] 19a.H-SMF requests V-SMF to release all contexts associated with the PDU session by invoking the Nsmf_PDUSession_StatusNotify (release) operation.

[0259] 19b.V-SMF requests AMF to release all contexts associated with the PDU session by calling Nsmf_PDUSession_SMContexStatusNotify(release). AMF releases the association between the SMF ID and the PDU session ID.

[0260] The following fourth change is recommended for 3GPP TS 23.502V16.0.0, among which... Figure 13 It is the fourth change Figure 4 3.4.3.2-1, and the following text is the fourth revised text.

[0261] 4.3.4.3.2 Release of PDU session for roaming used for home routing requested by HPLMN

[0262] This clause defines the release of roaming PDU sessions used for home-area routing during the following process:

[0263] - Release initiated by PCF.

[0264] Release initiated by -H-SMF.

[0265] Figure 4 3.4.3.2-1: Release of PDU session for roaming used for home routing requested by HPLMN

[0266] 1. This process is triggered by one of the following events:

[0267] 1a. This step is the same as step 1a in clause 4.3.4.2.2.

[0268] 1b. This step is the same as step 1b in clause 4.3.4.2.2.

[0269] H-SMF initiates the PDU session release process.

[0270] 2a-2b. These steps are the same as steps 2a-2b in Clause 4.3.4.2.2. SMF is the SMF in HPLMN.

[0271] 3. The H-SMF prepares the SM release PDU session command message and initiates PDU session release to the UE by calling the Nsmf_PDUSession_Update request service operation to the V-SMF. The Nsmf_PDUSession_Update request contains the necessary information (e.g., release reason or PCO) required by the V-SMF to construct the SM release PDU session command to the UE.

[0272] 4a-4b. These steps are the same as steps 2c-2d in clause 4.3.4.2.2. SMF is the SMF in VPLMN.

[0273] Note 1: If the UPF (N3 endpoint) and PSA2 are both located in a single UPF, skip steps 4a-4b.

[0274] 5a-5b. V-SMF releases the corresponding user plane resources (including the N3 endpoint). These steps are the same as steps 3a-3b in Clause 4.3.4.2.2. The SMF is the SMF in the VPLMN.

[0275] Note 2: If the UPF (N3 endpoint) and PSA2 are both located in a single UPF, the SMF also releases the IP address / prefix assigned to the PDU session.

[0276] 6a-6b. V-SMF releases the corresponding user plane resources (including PSA). These steps are the same as steps 4c-4d in Clause 4.3.4.2.2.

[0277] Note 3: If the UPF (N3 endpoint) and PSA2 are both located in a single UPF, skip steps 6a-4b.

[0278] 7-15. These steps are the same as steps 5-12 in clause 4.3.4.2.2.

[0279] 16. The V-SMF responds to the Nsmf_PDUSession_Update request invoked in step 3 and acknowledges the PDU session release. The Nsmf_PDUSession_Update response may carry information such as the PCO received from the UE in the SM PDU session release acceptance, as well as user location information, time zone, and secondary RAT usage data.

[0280] 17a-17b. H-SMF releases the corresponding user plane resources (including PSA). These steps are the same as steps 4a-4b in Clause 4.3.4.2.2, but are controlled by the SMF in HPLMN.

[0281] 18. (H-SMF-initiated release) H-SMF releases the SM policy control association with PCF by invoking the SM policy association termination procedure defined in Clause 4.16.6.

[0282] 19. H-SMF should remove all contexts associated with the PDU session:

[0283] 19a.H-SMF requests V-SMF to release all contexts associated with the PDU session by invoking the Nsmf_PDUSession_StatusNotify (release) operation.

[0284] 19b.V-SMF requests AMF to release all contexts associated with the PDU session by calling Nsmf_PDUSession_SMContexStatusNotify(release). AMF releases the association between the SMF ID and the PDU session ID.

[0285] Figure 14 This is a block diagram illustrating an apparatus suitable for use in practicing some embodiments of this disclosure. For example, any of the aforementioned User Face Entity and SMF can be implemented using apparatus 1400. As shown, apparatus 1400 may include a processor 1410, a memory 1420 storing programs, and an optional communication interface 1430 for data communication with other external devices via wired and / or wireless communication.

[0286] The program includes program instructions that, when executed by processor 1410, enable device 1400 to operate according to embodiments of the present disclosure, as discussed above. That is, embodiments of the present disclosure can be implemented at least in part by computer software executable by processor 1410, or by hardware, or by a combination of software and hardware.

[0287] Memory 1420 may be of any type suitable for the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor-based memory devices, flash memory, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and removable memory. Processor 1410 may be of any type suitable for the local technical environment and, as a non-limiting example, may include one or more of a general-purpose computer, a special-purpose computer, a microprocessor, a digital signal processor (DSP), and a processor based on a multi-core processor architecture.

[0288] Figure 15 This is a block diagram illustrating an apparatus for implementing a user plane entity according to an embodiment of the present disclosure. As shown, the apparatus 1500 includes a receiving module 1502 and a control module 1504. The receiving module 1502 may be configured to receive from the control plane entity a request for modifying parameters associated with a packet data connection for which at least a portion will be deleted, as described above with respect to box 402. The control module may be configured, upon receiving the request, to stop forwarding and counting packets only in one of the downlink and uplink directions for the at least portion of the packet data connection to be deleted, as described above with respect to box 404.

[0289] Figure 16 This is a block diagram illustrating an apparatus for implementing an SMF according to an embodiment of the present disclosure. As shown, apparatus 1600 includes a modification module 1602, a first deletion module 1604, and a second deletion module 1606. Modification module 1602 may be configured to, in response to a PDU session release procedure requested by a UE or serving network or access network, send one or more first UPFs acting as N3 endpoints to one or more first UPFs for modifying parameters associated with the PDU session to be deleted, as described above with respect to box 502. First deletion module 1604 may be configured to send one or more second UPFs acting as PSAs to one or more second UPFs for deleting the PDU session, as described above with respect to box 504. Second deletion module 1606 may be configured to, when one or more second UPFs have already deleted the PDU session, send one or more third UPFs to one or more first UPFs for deleting the PDU session, as described above with respect to box 506.

[0290] Figure 17 This is a block diagram illustrating an apparatus for implementing an SMF according to an embodiment of the present disclosure. As shown, apparatus 1700 includes a modification module 1702, a first deletion module 1704, and a second deletion module 1706. Modification module 1702 can be configured to send one or more first requests to one or more first UPFs acting as PSAs to modify parameters associated with the PDU session to be deleted, as described above with respect to box 508, in response to a PDU session release process requested by a PCF or SMF. First deletion module 1704 can be configured to send one or more second requests to one or more second UPFs acting as N3 endpoints to delete the PDU session, as described above with respect to box 510. Second deletion module can be configured to send one or more third requests to one or more first UPFs to delete the PDU session when one or more second UPFs have already deleted the PDU session, as described above with respect to box 512. The above modules can be implemented by hardware, software, or a combination of both.

[0291] Generally, various exemplary embodiments can be implemented in hardware or dedicated circuitry, software, logic, or any combination thereof. For example, some aspects may be implemented in hardware, while others may be implemented in firmware or software executable by a controller, microprocessor, or other computing device, although this disclosure is not limited thereto. While various aspects of exemplary embodiments of this disclosure may be shown and described as block diagrams, flowcharts, or other graphical representations, it should be well understood that, as non-limiting examples, the blocks, apparatuses, systems, techniques, or methods described herein may be implemented in hardware, software, firmware, dedicated circuitry or logic, general-purpose hardware or controllers, other computing devices, or combinations thereof.

[0292] Therefore, it should be understood that at least some aspects of the exemplary embodiments of this disclosure can be practiced in various components such as integrated circuit chips and modules. Accordingly, it should be understood that the exemplary embodiments of this disclosure can be implemented in devices embodied as integrated circuits, wherein the integrated circuits may include circuitry (and possibly firmware) embodying at least one or more of a data processor, digital signal processor, baseband circuitry, and radio frequency circuitry configurable to operate according to the exemplary embodiments of this disclosure.

[0293] It should be understood that at least some aspects of the exemplary embodiments of this disclosure may be embodied in computer-executable instructions, which are executed by one or more computers or other devices, such as in one or more program modules. Generally, program modules include routines, programs, objects, components, data structures, etc., which perform a specific task or implement a specific abstract data type when executed by a processor in a computer or other device. The computer-executable instructions may be stored on a computer-readable medium, such as a hard disk, optical disk, removable storage medium, solid-state memory, RAM, etc. Those skilled in the art will understand that the functionality of the program modules in various embodiments may be combined or distributed as needed. Furthermore, the functionality may be embodied, wholly or partially, in firmware or hardware equivalents (such as integrated circuits, field-programmable gate arrays (FPGAs), etc.).

[0294] References to "an embodiment," "one embodiment," etc., in this disclosure indicate that the described embodiment may include a particular feature, structure, or characteristic, but not every embodiment must include that particular feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Additionally, when a particular feature, structure, or characteristic is described in connection with an embodiment, implementing such a feature, structure, or characteristic in connection with other embodiments is within the knowledge of those skilled in the art, whether or not it is explicitly described. It should be noted that two consecutively shown blocks in the drawings may actually be executed substantially in parallel, or these blocks may sometimes be executed in reverse order, depending on the functionality involved.

[0295] It should be understood that although the terms “first,” “second,” etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element, without departing from the scope of this disclosure. As used herein, the term “and / or” includes any one and all combinations of one or more of the associated listed terms.

[0296] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. As used herein, the singular forms “a” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that the terms “comprising,” “having,” and / or “including” as used herein refer to the presence of the stated features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. The term “connection” as used herein covers direct and / or indirect connections between two elements.

[0297] This disclosure includes any novel features or combinations of features explicitly disclosed herein or in any generalized form. Various modifications and adaptations to the exemplary embodiments of this disclosure will become apparent to those skilled in the art when read in conjunction with the accompanying drawings, in light of the foregoing description. However, any and all modifications will still fall within the scope of the non-limiting and exemplary embodiments of this disclosure.

Claims

1. A method executed by a user-face entity, said user-face entity being a user-face function (UPF), said method comprising: The system receives a request to modify parameters associated with a PDU session that will be deleted, which is part of the release process of the Protocol Data Unit (PDU) session, which is a control plane entity of the Session Management Function (SMF) and a roaming protocol data unit used for home routing. The request is an N4 session modification request. Wherein, when the SMF is the home SMF and the UPF is the home UPF, the N4 session modification request instructs the home UPF to stop forwarding services in the downlink direction and also to stop considering the service for usage monitoring, or When the SMF is a visiting SMF and the UPF is a visiting UPF, the N4 session modification request instructs the visiting UPF to stop forwarding services in the uplink direction and also to stop considering the services for usage monitoring. Send an N4 session modification response to the control plane entity; Upon receiving the request, for the at least portion of the PDU session to be deleted, service forwarding is stopped only in one of the downlink and uplink directions, and service usage monitoring is also stopped. Receive an N4 session release request message from the control plane entity to discard any remaining packets of the PDU session and release all tunnel resources and context associated with the N4 session; and Send an N4 session release response message to the control plane entity in response to the N4 session release request message.

2. The method according to claim 1, wherein, The user plane entity is the UPF that serves as the N3 endpoint.

3. The method according to claim 1, wherein, The request is received in response to the following: The policy control function PCF or SMF requests the release process of the roaming PDU session for home routing.

4. A method performed by a session management function (SMF), comprising: In response to the release procedure of the Protocol Data Unit (PDU) session for roaming used for home routing, a request is sent to the User Plane Function (UPF) to modify parameters associated with the PDU session to be deleted, wherein the request is an N4 session modification request. Wherein, when the SMF is the home SMF and the UPF is the home UPF, the N4 session modification request instructs the home UPF to stop forwarding services in the downlink direction and also to stop considering the service for usage monitoring, or Specifically, when the SMF is a visiting SMF and the UPF is a visiting UPF, the N4 session modification request instructs the visiting UPF to stop forwarding services in the uplink direction and also to stop considering the service for usage monitoring; after the UPF has deleted the PDU session, an N4 session release request message is sent to the UPF to discard any remaining packets of the PDU session and release all tunnel resources and context associated with the N4 session; and Receive an N4 session release response message from the UPF in response to the N4 session release request message.

5. An apparatus (1400) for implementing a user face entity, wherein the user face entity is a user face function (UPF), comprising: At least one processor (1410); as well as At least one memory (1420) containing instructions executable by the at least one processor (1410), thereby enabling the device (1400) to: The system receives a request to modify parameters associated with a PDU session that will be deleted, which is part of the release process of the Protocol Data Unit (PDU) session, which is a control plane entity of the Session Management Function (SMF) and a roaming protocol data unit used for home routing. The request is an N4 session modification request. Wherein, when the SMF is the home SMF and the UPF is the home UPF, the N4 session modification request instructs the home UPF to stop forwarding services in the downlink direction and also to stop considering the service for usage monitoring, or When the SMF is a visiting SMF and the UPF is a visiting UPF, the N4 session modification request instructs the visiting UPF to stop forwarding services in the uplink direction and also to stop considering the services for usage monitoring. Send an N4 session modification response to the control plane entity; upon receiving the request, for the at least part of the PDU session to be deleted, stop forwarding services in only one of the downlink and uplink directions and also stop considering the use monitoring of the services; Receive an N4 session release request message from the control plane entity to discard any remaining packets of the PDU session and release all tunnel resources and context associated with the N4 session; and Send an N4 session release response message to the control plane entity in response to the N4 session release request message.

6. The apparatus (1400) according to claim 5, wherein, The device (1400) is operable to perform the method according to any one of claims 2 to 3.

7. An apparatus (1400) for implementing Session Management Function (SMF), comprising: At least one processor (1410); as well as At least one memory (1420) containing instructions executable by the at least one processor (1410), thereby enabling the device (1400) to: In response to the release procedure of the Protocol Data Unit (PDU) session for roaming used for home routing, a request is sent to the User Plane Function (UPF) to modify parameters associated with the PDU session to be deleted, wherein the request is an N4 session modification request. Wherein, when the SMF is the home SMF and the UPF is the home UPF, the N4 session modification request instructs the home UPF to stop forwarding services in the downlink direction and also to stop considering the service for usage monitoring, or Specifically, when the SMF is a visiting SMF and the UPF is a visiting UPF, the N4 session modification request instructs the visiting UPF to stop forwarding services in the uplink direction and also to stop considering the service for usage monitoring; after the UPF has deleted the PDU session, an N4 session release request message is sent to the UPF to discard any remaining packets of the PDU session and release all tunnel resources and context associated with the N4 session; and Receive an N4 session release response message from the UPF in response to the N4 session release request message.

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