Network node, method for reporting session information performed by the node

Abstract

The present invention proposes a network node device and a session information reporting method performed by the node device to realize a differentiated technology that reduces the number of signaling between CP and UP in situations where a large amount of Session Reports may be generated.

Description

Technology Field

[0001] The present invention relates to signaling between a control plane and a user plane, and more specifically, to a technique for reducing the number of signaling between a control plane and a user plane. Background Technology

[0002] 5G communication systems support scenarios of eMBB (enhanced mobile broadband), mMTC (massive machine type communications), and URLLC (ultra-reliable and low latency communications) while accommodating as many terminals as possible based on limited wireless resources.

[0003] In particular, 5G defines a network structure to support terminals, base stations (access), cores, and servers from end to end, and separates the functions of control signaling and data transmission and reception that were performed in combination by a single node (e.g., S-GW, P-GW, etc.) in existing LTE (4G), thereby defining a network structure that distinguishes the control signaling function area (Control Plane) and the data transmission and reception function area (User Plane).

[0004] At this time, the control nodes of the Control Plane in 5G can be defined as the Access and Mobility Management Function (AMF) that controls the wireless access of terminals, the Policy Control Function (PCF) that manages / controls policies such as terminal information, subscription service information per terminal, and billing, the Session Management Function (SMF) that manages / controls sessions for using data services per terminal, the Network Exposure Function (NEF) that is responsible for the function of sharing information with the external network, the Unified Data Management / Authentication Function (UDM / AUSF) that manages / controls the user's subscriber DB and authentication, the NF Repository Function (NRF) that manages / controls the NF repository function, and the Changing Function (CHHF) that processes billing for subscribers.

[0005] In addition, in 5G, the data node of the User Plane can be defined as a User Plane Function (UPF) that transmits and receives data between a terminal and a server on an external service network (e.g., the Internet) through a session with the terminal based on the control (interconnection) of the SMF.

[0006] Among the control nodes of the Control Plane, the SMF provides the UPF with Usage Reporting Rules (URRs) for each session. The URR includes the information the SMF wishes to collect, the method of measuring that information, and the timing at which the information is to be reported.

[0007] Accordingly, the UPF of the User Plane collects relevant information based on the URR provided by the SMF, and if a specific period or event condition is met according to the measurement method, transmits / reports the relevant information to the SMF through a PFCP Session Report Request message to report information for each session.

[0008] Such UPFs generally manage a large number of sessions, and therefore, there may be cases where PFCP Session Report Request messages for reporting information about multiple sessions are generated simultaneously.

[0009] As such, when a large amount of signaling occurs in which the UPF simultaneously sends multiple PFCP Session Report Request messages to the SMF, the load on the network between the UPF and the SMF and on both network nodes, namely the UPF and the SMF, increases. Consequently, there is a problem in that events affecting multiple sessions, such as Control Plane-User Plane overload, Interface overload, SMF termination, or network anomalies, may occur.

[0010] Accordingly, the present invention proposes a technology that can transmit all Session Reports requiring reporting using a smaller number of messages, taking into account the situation where a UPF must simultaneously transmit multiple PFCP Session Report Request messages to an SMF. The problem to be solved

[0011] The present invention was created in consideration of the above-mentioned circumstances, and the objective of the present invention is to provide a network node device and a method for reporting session information performed by said node device, which enables the transmission of all Session Reports requiring reporting using a smaller number of messages, taking into account a situation where a UPF must simultaneously transmit multiple Session Report Request messages to an SMF. means of solving the problem

[0012] A network node device according to the first aspect of the present invention for achieving the above objective includes a message transmission unit that transmits a plurality of session-specific report information transmitted from a user plane to a control plane using a specific message transmitted from the user plane to the control plane; the specific message is a message transmitted in a larger transmission unit than a message that transmits session report information in a session unit.

[0013] Specifically, the aforementioned specific message may be a Node Report Request message that transmits network node report information on a network node basis.

[0014] Specifically, in the case where the specific message is used for transmitting multiple session-specific report information, the specific message may include a specific identifier defined in multiple session-specific report information as an information element (IE) that identifies the type of transmitted information within the message.

[0015] Specifically, in the case where the specific message is used to transmit report information for multiple sessions, the specific message may include a group IE of each session defined to include a session identifier and report information for each of the multiple sessions.

[0016] Specifically, the report information included in the above group IE may have the same IE as the report information IE defined in the Session Report Request message that transmits the session's report information on a session-by-session basis.

[0017] Specifically, the system may further include a buffering unit that performs buffering to store report information generated on a session basis according to at least one of a preset buffering time (Time), the number of report information items in a session (Count), and the size of the report information in a session (Size), and transmits the buffered multiple session-specific report information to the message transmission unit.

[0018] Specifically, the buffering unit can perform the buffering for at least one of a pre-configured specific subscriber, specific base station, specific location, and specific interface with another network node.

[0019] Specifically, the buffering unit can increase or decrease the buffering period by changing at least one of the set buffering time (Time), the number of report information items in the session (Count), and the size of the report information items in the session (Size).

[0020] A method for reporting session information performed in a network node device according to a second aspect of the present invention for achieving the above objective includes a message transmission step of transmitting a plurality of session-specific reporting information transmitted from a user plane to a control plane using a specific message transmitted from the user plane to the control plane; wherein the specific message may be a message transmitted in a larger transmission unit than a message transmitting session reporting information in a session unit.

[0021] Specifically, the aforementioned specific message may be a Node Report Request message that transmits network node report information on a network node basis.

[0022] Specifically, in the case where the specific message is used for transmitting multiple session-specific report information, the specific message may include a specific identifier defined in multiple session-specific report information as an information element (IE) that identifies the type of transmitted information within the message.

[0023] Specifically, the specific message may include a group IE of each session defined to include a session identifier and report information for each of the multiple sessions, when the specific message is used to transmit report information for multiple sessions.

[0024] Specifically, according to at least one of a preset buffering time (Time), the number of report information items in a session (Count), and the size of the report information items in a session (Size), the buffering step for storing report information generated on a session basis and delivering the buffered multiple session-specific report information may be further included. Effects of the invention

[0025] According to the network node device and the session information reporting method performed by the node device of the present invention, a new technology is realized that reduces the number of signaling between the control plane and the user plane by enabling the transmission of all session reports using a smaller number of messages in situations where a large number of Session Report Request messages may occur.

[0026] Thus, according to the present invention, the number of signalings between the control plane and the user plane is reduced, thereby achieving the effect of reducing network load and reducing the processing load of related NFs / network nodes such as UPF / SMF. Brief explanation of the drawing

[0027] Figure 1 is an example diagram showing the structure of a 5G system. Figure 2 is an example diagram showing a situation where a large amount of Session Reports are generated in existing technology. Figure 3 is an example diagram showing the concept of reducing the number of signaling when a large amount of Session Reports are generated in the present invention. FIG. 4 is a block diagram showing the configuration of a network node device according to one embodiment of the present invention. FIGS. 5 and 6 show an example of defining an IE identifier and a Session Report structure within a message in the present invention. FIG. 7 is an operation flowchart showing a session information reporting method performed in a network node device according to an embodiment of the present invention. Specific details for implementing the invention

[0028] Hereinafter, preferred embodiments of the present invention will be described with reference to the attached drawings.

[0029] The present invention relates to signaling between a control plane and a user plane, and more specifically, to a technique for reducing the number of signaling between a control plane and a user plane.

[0030] Figure 1 is an example diagram showing the structure of a 5G system.

[0031] As can be seen in Figure 1, the 5G communication system supports scenarios of eMBB (enhanced mobile broadband), mMTC (massive machine type communications), and URLLC (ultra-reliable and low latency communications) while accommodating as many terminals as possible based on limited wireless resources.

[0032] In particular, 5G defines a network structure to support terminals, base stations (access), cores, and servers from end to end, and separates the functions of control signaling and data transmission and reception that were performed in combination by a single node (e.g., S-GW, P-GW, etc.) in existing LTE (4G), thereby defining a network structure that distinguishes the control signaling function area (Control Plane) and the data transmission and reception function area (User Plane).

[0033] At this time, the control nodes of the Control Plane in 5G can be defined as the Access and Mobility Management Function (AMF) that controls the wireless access of terminals, the Policy Control Function (PCF) that manages / controls policies such as terminal information, subscription service information per terminal, and billing, the Session Management Function (SMF) that manages / controls sessions for using data services per terminal, the Network Exposure Function (NEF) that is responsible for the function of sharing information with the external network, the Unified Data Management / Authentication Function (UDM / AUSF) that manages / controls the user's subscriber DB and authentication, the NF Repository Function (NRF) that manages / controls the NF repository function, and the Changing Function (CHHF) that processes billing for subscribers.

[0034] In addition, in 5G, the data node of the User Plane can be defined as a User Plane Function (UPF) that transmits and receives data between a terminal and a server on an external service network (e.g., the Internet) through a session with the terminal based on the control (interconnection) of the SMF.

[0035] Among the control nodes of the Control Plane, the SMF provides the UPF with Usage Reporting Rules (URRs) for each session. The URR includes the information the SMF wishes to collect, the method of measuring that information, and the timing at which the information is to be reported.

[0036] Accordingly, the UPF of the User Plane collects relevant information based on the URR provided by the SMF, and if a specific period or event condition is met according to the measurement method, transmits / reports the relevant information to the SMF through a PFCP Session Report Request message to report information for each session.

[0037] Such UPFs generally manage a large number of sessions, and therefore, there may be cases where PFCP Session Report Request messages for reporting information about multiple sessions are generated simultaneously.

[0038] As such, when a large amount of signaling occurs as UPF simultaneously sends multiple PFCP Session Report Request messages to SMF, the load on the network between UPF and SMF and on both network nodes, namely UPF and SMF, is bound to increase.

[0039] Figure 2 shows a situation where a large amount of Session Reports are generated in the existing technology.

[0040] As can be seen in Figure 2, a UPF managing a large number of sessions may simultaneously generate reporting events for multiple sessions based on specific periods or event conditions corresponding to each URR, and in this case, it simultaneously sends (N4) PFCP Session Report Request messages for information reporting for each session.

[0041] Of course, SMF replies to each session-specific (N4) PFCP Session Report Response message received from UPF with each (N4) PFCP Session Report Request message.

[0042] As can be seen from the above, when a large amount of signaling occurs in which UPF simultaneously sends multiple PFCP Session Report Request messages to SMF, the load on the network between UPF and SMF and on both network nodes, i.e., UPF and SMF, increases, and this can lead to problems such as Control Plane-User Plane overload, Interface overload, or SMF termination or network anomalies affecting multiple sessions.

[0043] Accordingly, the present invention proposes a new technique to reduce the number of signaling between the control plane and the user plane, taking into account the situation where the UPF must simultaneously transmit multiple PFCP Session Report Request messages to the SMF, thereby enabling all Session Reports requiring reporting to be transmitted using a smaller number of messages.

[0044] Figure 3 illustrates the core of the technology proposed in the present invention, namely, the concept of reducing the number of signaling when a large amount of Session Reports are generated.

[0045] The technology proposed in this invention, that is, a new technology for reducing the number of signalings between the control plane (CP) and the user plane (UP), is centered on utilizing a message that is transmitted in a larger transmission unit than a message that transmits session report information in session units, such as (N4) PFCP Session Report Request message.

[0046] As can be seen in FIG. 3, as an example, the technology proposed in the present invention utilizes a PFCP Node Report Request message that can transmit a Node Report at the network node level as defined in the standard (Rel.16 3GPP 29.244), such as a message that is transmitted in a larger transmission unit than (N4) a PFCP Session Report Request message.

[0047] Accordingly, according to the present invention, when a report event occurs simultaneously for multiple sessions in accordance with a specific period or event condition corresponding to each URR, the UPF transmits the report information for each session using the PFCP Node Report Request message, unlike the existing method of simultaneously transmitting the (N4) PFCP Session Report Request message for each session.

[0048] In this way, SMF will send one PFCP Node Report Response message in response to the PFCP Node Report Request message received from UPF, and since the report information for each session can be checked within the PFCP Node Report Request message, the necessary processing / communication for each session can be performed as before based on the report information.

[0049] Thus, in light of the situation where a UPF must simultaneously transmit multiple PFCP Session Report Request messages to an SMF, the present invention proposes a technique to reduce the number of signaling between CP and UP by using a transmission unit larger than a session-unit N4 message, such as a node-unit Node Report message, thereby enabling the transmission of all Session Reports requiring reporting using a smaller number of messages.

[0050] Hereinafter, with reference to FIG. 4, I will specifically describe the configuration of a network node device (hereinafter collectively referred to as the network device) that realizes the proposed technology of the present invention, namely, the technology of reducing the number of signaling between CP and UP.

[0051] First, the network node implementing the proposed technology of the present invention may be a data node of the user plane (UP), i.e., a UPF, as the entity generating a large amount of N4 messages between CP and UP.

[0052] Referring specifically to FIG. 4, a network node (100) according to one embodiment of the present invention may include a message transmission unit (120) and a buffering unit (130).

[0053] In addition, since the network node (100) of the present invention is assumed to be an embodiment of a UPF, the network node (100) may further include a session control unit (110).

[0054] To briefly explain the 5G UPF, it controls the terminal's PDU session based on the control (interconnection) of the SMF and is responsible for transmitting and receiving data between the terminal and nodes (e.g., UPF, Edge / Cloud DN (Internet)) through the terminal's PDU session.

[0055] To explain more specifically, the 5G SMF assigns an IP to the terminal (UE) so that it can use User Plane services and establishes a session. The SMF controls and manages the session for the terminal (UE) by working in conjunction with the UPF, which processes the terminal (UE)'s User Plane packets.

[0056] Before issuing a command to the UPF to control the session, this SMF first performs a PFCP Association Setup procedure to establish a PFCP association with the UPF, and in this procedure, can check the features supported by each other.

[0057] UPF is installed as a distributed network, Edge Area, or B2B / Enterprise site, and receives rules (Rule, PDR / QER / FAR / URR) containing PDU session information and service requirements from SMF, processes terminal PDU session traffic, i.e., actual User Plane packets according to these rules, and transmits the necessary Session Report to SMF according to the URR for each PDU session as described above.

[0058] The network node (100, UPF) of the present invention may include a message transmission unit (120) and a buffering unit (130) as a configuration for realizing the proposed technology of the present invention, namely, the technology of reducing the number of signaling between CP and UP.

[0059] And, assuming an embodiment in which the network node (100) of the present invention is a UPF, the session control unit (110) of the network node (100) performs the functions of the UPF described above, namely receiving rules (Rule, PDR / QER / FAR / URR) from the SMF, processing session traffic, generating a Session Report, etc.

[0060] Accordingly, the report information of the session mentioned below refers to the report information generated (generated) for the session where the report event occurred, based on the basis for determining whether the session control unit (110) meets specific period or event conditions according to each URR for multiple sessions.

[0061] The message transmission unit (120) can be responsible for transmitting multiple session-specific report information transmitted from the User Plane to the Control Plane using a specific message transmitted from the User Plane (UP) to the Control Plane (CP).

[0062] Here, a specific message refers to a message transmitted in a larger transmission unit than a message transmitting session report information on a session-by-session basis.

[0063] More specifically, a specific message is a message that is transmitted in a larger transmission unit than (N4) PFCP Session Report Request message, and may be a Node Report Request message (PFCP Node Report Request message) that can transmit / transmit network node report information, i.e., Node Report, at the network node level.

[0064] Accordingly, the message transmission unit (120) can transmit multiple session-specific report information transmitted from the user plane (UP) to the control plane (CP) by using a specific message, such as a PFCP Node Report Request message, transmitted from the user plane (UP) to the control plane (CP).

[0065] Below, I will specifically explain the method of transmitting session-specific report information using / utilizing the PFCP Node Report Request message in the present invention.

[0066] The standard (Rel.16 3GPP 29.244) defines a PFCP Node Report Request message that can transmit Node Reports at the network node level. However, it does not define or support a method to transmit information of different sessions through the PFCP Node Report Request message.

[0067] In the present invention, a new IE identifier is defined in a specific message, namely a PFCP Node Report Request message, and a structure is defined to configure and include report information of different sessions within the message, thereby realizing the transmission of session-specific report information using the PFCP Node Report Request message.

[0068] Specifically, in the present invention, when a specific message, i.e., a PFCP Node Report Request message, is used to transmit multiple session-specific report information, a specific identifier defined in multiple session-specific report information is defined as an information element (IE) that identifies the type of transmitted information within the message.

[0069] In the PFCP Node Report Request message, an IE (hereinafter referred to as Node Report Type) is defined to identify the type of transmission information within the message.

[0070] In the present invention, a specific identifier (hereinafter referred to as BSRI (Bulk Session Report Information)) capable of identifying the fact that the PFCP Node Report Request message is used for transmitting report information per session is additionally defined as an IE identifier to be used as the Node Report Type IE of the PFCP Node Report Request message.

[0071] Accordingly, when the message transmission unit (120) transmits multiple session-specific report information using a PFCP Node Report Request message as described above, it includes a specific identifier "BSRI" additionally defined in the present invention as the Node Report Type IE of the PFCP Node Report Request message, thereby enabling the intended use of the PFCP Node Report Request message to be identified.

[0072] FIG. 5 illustrates an embodiment in which Node Report Type IE is additionally defined in the present invention, and for example, as shown in FIG. 5, a "BSRI" bit can be added to the 8th bit of the Spare Octet of Node Report Type IE.

[0073] Furthermore, in the present invention, when a specific message, i.e., a PFCP Node Report Request message, is used to transmit report information for multiple sessions, a group IE of each session is defined to include the session identifier and report information of each session for each of the multiple sessions.

[0074] In the present invention, in order to realize a structure for configuring / including reporting information of different sessions within a PFCP Node Report Request message, a group IE (Bulk Session Report Grouped IE) is additionally defined.

[0075] The group IE defined in the present invention may be defined to include the session identifier of a session (hereinafter F-SEID) and the reporting information of a session.

[0076] At this time, the report information included in the group IE may have the same IE as the report information IE (hereinafter referred to as Session Report IE) used to transmit report information in the existing PFCP Session Report Request message, that is, the Session Report IE defined in the PFCP Session Report Request message.

[0077] FIG. 6 illustrates an embodiment showing the form (structure) of Group IE additionally defined in the present invention.

[0078] As illustrated in FIG. 6, the group IE defined in the present invention can be defined in a form (structure) in which the session identifier F-SEID of the session is added to the Session Report IE (Report Type, Downlink Data Report, ..., Additional Usage Report Information) used in the existing PFCP Session Report Request message of the session.

[0079] Accordingly, assuming that N session-specific report information (Session Report) is transmitted using one PFCP Node Report Request message, the PFCP Node Report Request message may include N group IEs (F-SEID + Session Report IE) configured for each session.

[0080] Accordingly, when the message transmission unit (120) transmits multiple (N) session-specific report information using a PFCP Node Report Request message as described above, it includes N group IEs (F-SEID + Session Report IE) of the form (structure) defined in the present invention within the PFCP Node Report Request message, thereby enabling all N Session Reports to be transmitted and distinguished by session using one PFCP Node Report Request message.

[0081] Meanwhile, in the present invention, in order to transmit multiple session-specific report information in bulk into a single Node Report Request message as described above, it is possible to buffer Session Reports that have occurred over a certain period of time.

[0082] The buffering unit (130), configured for this purpose, performs buffering to store report information generated on a session basis according to at least one of a preset buffering time (Time), the number of report information items in a session (Count), and the size of the report information items in a session (Size), and is responsible for transmitting the buffered multiple session-specific report information to the message transmission unit (120).

[0083] For example, the buffering unit (130) may, according to a preset buffering time (Time, e.g., 5 seconds), not immediately send the session report information (Session Report) generated from the session control unit (110) when the session report information (Session Report) is generated, but buffer the report information (Session Report) generated from the first report information (Session Report) that needs to be reported until 5 seconds have elapsed, and then transmit the buffered multiple session-specific report information (Session Report) to the message transmission unit (120).

[0084] Alternatively, for another example, the buffering unit (130) may not send the session report information (Session Report) immediately when it occurs in the session control unit (110) according to a preset buffering count (e.g., 10), but may buffer up to 10 session reports generated starting from the first session report information (Session Report) that requires reporting, and then transmit the buffered multiple session reports (Session Reports) to the message transmission unit (120).

[0085] Alternatively, for another example, the buffering unit (130) may, depending on the pre-set session report size (e.g., 30kB), not send the session report information (Session Report) immediately when it occurs in the session control unit (110), but buffer the reports from the first report information (Session Report) that needs to be reported until the total size of the reports (Session Reports) generated exceeds 30kB, and then transmit the buffered multiple session-specific reports (Session Reports) to the message transmission unit (120).

[0086] Of course, the buffering unit (130) may buffer the session report information (Session Report) and then transmit it by combining (AND / OR) the buffering time (Time), the number of session report information (Count), and the size of the session report information (Size) in various ways.

[0087] Settings such as buffering time (Time), number of session report information (Count), and size of session report information (Size) can be transmitted from the SMF to the network node (100, UPF), or can be set by the network node (100, UPF) itself.

[0088] In addition, in the present invention, the settings of the buffering time (Time), the number of report information items (Count) and the size of the report information items (Size) of the session, as described above, can be dynamically changed (increased / decreased).

[0089] Specifically, the buffering unit (130) can increase or decrease the buffering period by changing at least one of the buffering time (Time), the number of report information items (Count) of the session, and the size of the report information items (Size) of the session.

[0090] For example, the buffering unit (130) can increase or decrease the buffering period by increasing or decreasing the buffering time, the number of reports (Count), and the size of reports (Size) by taking into account the state of the SMF (e.g., the level at which the SMF receives a large amount, the overload state of the SMF, the delay when the SMF receives the Bulk, etc.) when receiving multiple reports (Session Reports) in bulk through one Node Report Request message as described above.

[0091] Furthermore, in the present invention, it is possible to selectively control / change the application target for transmitting multiple session-specific report information in bulk form into one Node Report Request message as described above.

[0092] To this end, the buffering unit (130) can perform the aforementioned buffering on at least one of a specific subscriber, a specific base station, a specific location, and a specific interface with another network node.

[0093] Here, a specific subscriber can be identified based on UE ID / SUPI, S-NSSAI, PEI, IMSI information, IP, etc., a specific base station can be identified based on gNB ID, IP, etc., and a specific interface can be identified at the level of detailed physical / logical ports assigned to N3, N4, N6, and N9 I / F names.

[0094] For example, if there are four virtual ports A, B, C, and D in the interface going from the network node (100, UPF) of the present invention to N6 (Internet), and if the present invention is to be applied only to traffic going out to a specific port A to transmit multiple session-specific report information in bulk form, then by pre-configuring a specific port A, the buffering unit (130) can perform the aforementioned buffering on the specific port A and transmit multiple report information (Session Report) buffered only for the specific port A to the message transmission unit (120), and accordingly, the message transmission unit (120) can transmit multiple report information (Session Report) for the specific port A in bulk form in one Node Report Request message as described above.

[0095] In addition, as another example, if the present invention is to be applied only to traffic transmitted / received to a specific base station to transmit multiple session-specific report information in bulk form, by pre-setting a specific base station, the buffering unit (130) can perform the aforementioned buffering on the specific base station and transmit multiple report information (Session Report) buffered only for the specific base station to the message transmission unit (120), and the message transmission unit (120) can transmit multiple report information (Session Report) for the specific base station in bulk form in one Node Report Request message as described above.

[0096] In the present invention, an SMF that receives one PFCP Node Report Request message from a UPF will reply with one PFCP Node Report Response message in response to the PFCP Node Report Request message received from the UPF.

[0097] At this time, since the SMF can identify the report information (Session Report) separated by session by checking each group IE (F-SEID + Session Report IE) within a single Node Report Request message, it can communicate and process with the necessary NFs for each session, such as PCF, CHF, AMF, etc., as before based on the Session Report of each session.

[0098] Thus, according to the network node (100) of the present invention, considering the situation where a large number of Session Reports transmitted by the UPF to the SMF may occur simultaneously, by utilizing Node messages with a transmission unit larger than the Session Report Request message, all Session Reports of multiple sessions requiring reporting can be transmitted, thereby reducing the number of signalings between the Control Plane and the User Plane.

[0099] Meanwhile, SMF can request the Session Report of some individual sessions again from UPF if, during the process of performing necessary communication / processing based on the Session Report of each session by checking each group IE (F-SEID + Session Report IE) within a single PFCP Node Report Request message, it is determined that some individual sessions (e.g., one or more) have problems or that re-receiving the Session Report is necessary.

[0100] In this way, the network node (100, particularly the message transmission unit (120)) of the present invention may transmit a plurality of report information (Session Report) in bulk form in one PFCP Node Report Request message as described above, and if a re-request from the SMF for some individual sessions is confirmed, the Session Report may be re-transmitted for each of the said individual sessions (e.g., one or more) through the (N4) PFCP Session Report Request message, or the Session Report for said individual sessions (e.g., one or more) may be re-transmitted in bulk form in one Node Report Request message as described above.

[0101] In addition, in the present invention, when a re-request from SMF is confirmed for some individual sessions transmitted in bulk form in one PFCP Node Report Request message as described above, the buffering settings can be changed (increased / decreased).

[0102] For example, in the network node (100, particularly the buffering unit (130)) of the present invention, the buffering time (Time), the number of reported information (Count), and the size of the reported information (Size) can be increased or decreased by considering the state of the SMF (e.g., the level at which the SMF is received in large quantities, the overload state of the SMF, the delay when Bulk is received from the SMF, etc.).

[0103] As explained above, according to the present invention, in a situation where a large number of Session Report Request messages may occur, a new technology is realized that reduces the number of signaling between the Control Plane and the User Plane by utilizing Node messages with a transmission unit larger than the Session Report Request messages to enable the transmission of all Session Reports for multiple sessions requiring reporting.

[0104] Thus, according to the present invention, the number of signalings between the control plane and the user plane is reduced, thereby achieving the effect of reducing network load and reducing the processing load of related NFs / network nodes such as UPF / SMF.

[0105] Hereinafter, with reference to FIG. 7, a method for realizing the proposed technology of the present invention, namely the technology for reducing the number of signaling between CP and UP (hereinafter, session information reporting method) will be explained in detail.

[0106] Before proceeding with the explanation, Figure 7 describes an example in which a UPF of a User Plane is referred to as a network node (NF) according to the present invention.

[0107] UPF and SMF must know whether they support the proposed technology of the present invention, namely the function of transmitting multiple session-specific report information in bulk form in a single Node Report Request message (hereinafter, BSR function).

[0108] To this end, SMF and UPF can identify mutually supported features during the process of performing the PFCP Association Setup procedure, and indicate that BSR functions are available through the CP Function Features delivered to the PFCP Association Setup Request and the UP Function Features delivered to the Association Setup Response.

[0109] Accordingly, SMF and UPF can activate the BSR function by confirming mutual support for the BSR function through the PFCP Association Setup procedure (S10).

[0110] According to the session information reporting method of the present invention, a network device (100, UPF) buffers session reports that have occurred over a certain period of time (S20) in order to transmit a plurality of session-specific report information in bulk form in one Node Report Request message.

[0111] Specifically, according to the session information reporting method of the present invention, a network device (100, UPF) can perform buffering to store report information generated on a session basis according to at least one of a preset buffering time (Time), the number of report information items of a session (Count), and the size of the report information of a session (Size).

[0112] For example, a network device (100, UPF) may buffer session reports that occur from the time of the first session report that needs to be reported until 5 seconds have elapsed, without sending the session report immediately when the session report occurs, according to a preset buffering time (Time, e.g., 5 seconds).

[0113] Alternatively, for another example, a network device (100, UPF) may buffer up to 10 session reports generated from the first session report that needs to be reported, without sending the session report immediately when the session report is generated, according to a pre-configured buffering count (e.g., 10).

[0114] Alternatively, for another example, a network device (100, UPF) may not send the session report immediately when it occurs, depending on the pre-configured session report size (Size, e.g., 30kB), but may buffer the session reports from the first session report that needs to be reported until the total size of the session reports that occur exceeds 30kB.

[0115] Of course, the network device (100, UPF) may buffer the session report by combining the buffering time (Time), the number of session reports (Count), and the size of the session reports (Size) in various ways (AND / OR).

[0116] And, according to the session information reporting method of the present invention, the network device (100, UPF) includes a plurality of session-specific reporting information buffered in step S20 in a specific message transmitted from the user plane (UP) to the control plane (CP) (S30).

[0117] Here, the specific message is a message that is transmitted in a larger transmission unit than (N4) PFCP Session Report Request message, and may be a Node message (PFCP Node Report Request message) that can transmit / transmit network node report information, i.e., Node Report, at the network node level.

[0118] Specifically, in the present invention, when a PFCP Node Report Request message is used to transmit multiple session-specific report information, it is defined so that a specific identifier defined in multiple session-specific report information is included as an information element (IE) that identifies the type of transmitted information within the message.

[0119] In the PFCP Node Report Request message, an IE (hereinafter referred to as Node Report Type) is defined to identify the type of transmission information within the message.

[0120] In the present invention, a specific identifier BSRI is additionally defined as an IE identifier to be used as the Node Report Type IE of a PFCP Node Report Request message, which can identify the fact that the PFCP Node Report Request message is used for transmitting report information per multiple sessions.

[0121] Accordingly, when the network device (100, UPF) transmits multiple session-specific report information using a PFCP Node Report Request message as described above, it includes a specific identifier "BSRI" additionally defined in the present invention as the Node Report Type IE of the PFCP Node Report Request message (see FIG. 5), thereby enabling the intended use of the PFCP Node Report Request message to be identified.

[0122] Furthermore, in the present invention, when a specific message, i.e., a PFCP Node Report Request message, is used to transmit report information for multiple sessions, a group IE of each session is defined to include the session identifier and report information of each session for each of the multiple sessions.

[0123] In the present invention, in order to realize a structure for configuring / including reporting information of different sessions within a PFCP Node Report Request message, a group IE (Bulk Session Report Grouped IE) is additionally defined.

[0124] The group IE defined in the present invention may be defined to include the session identifier of a session (hereinafter F-SEID) and the reporting information of a session.

[0125] At this time, the report information included in the group IE may have the same IE as the report information IE (Session Report IE) used to transmit report information in the existing PFCP Session Report Request message, that is, the Session Report IE defined in the PFCP Session Report Request message (see Fig. 6).

[0126] Accordingly, in the present invention, assuming that N session-specific report information (Session Report) is transmitted using one PFCP Node Report Request message, the PFCP Node Report Request message may include N group IEs (F-SEID + Session Report IE) configured for each session.

[0127] Accordingly, when the network device (100, UPF) transmits multiple (N) session-specific report information using a PFCP Node Report Request message as described above, it includes N group IEs (F-SEID + Session Report IE) of the form (structure) defined in the present invention within the PFCP Node Report Request message, thereby enabling all N Session Reports to be transmitted and distinguished by session using one PFCP Node Report Request message.

[0128] And, according to the session information reporting method of the present invention, the network device (100, UPF) transmits a PFCP Node Report Request message, which is composed of a plurality (N) of session-specific report information into one Node message at S30, to the SMF (S40).

[0129] In the present invention, an SMF that receives one PFCP Node Report Request message from a UPF will reply with one PFCP Node Report Response message in response to the PFCP Node Report Request message received from the UPF (S40).

[0130] At this time, the SMF can identify the group IE (F-SEID + Session Report IE) within a single PFCP Node Report Request message to check the report information (Session Report) separated by session, and thus can communicate with and process the necessary NFs for each session, such as PCF, CHF, AMF, etc., based on the Session Report of each session as before.

[0131] Thus, according to the network node (100) of the present invention, considering the situation where a large number of Session Reports transmitted by the UPF to the SMF may occur simultaneously, by utilizing Node messages with a transmission unit larger than the Session Report Request message, all Session Reports of multiple sessions requiring reporting can be transmitted, thereby reducing the number of signalings between the Control Plane and the User Plane.

[0132] Meanwhile, SMF can request the Session Report of some individual sessions again from UPF if, during the process of performing necessary communication / processing based on the Session Report of each session by checking each group IE (F-SEID + Session Report IE) within a single PFCP Node Report Request message, it is determined that some individual sessions (e.g., one or more) have problems or that re-receiving the Session Report is necessary.

[0133] Accordingly, according to the session information reporting method of the present invention, a network device (100, UPF) transmits a plurality of report information (Session Report) in bulk form in one PFCP Node Report Request message as described above, and when a re-request from SMF for some individual sessions is confirmed, it may re-transmit the Session Report for each of the said individual sessions (e.g., one or more) through a (N4) PFCP Session Report Request message, or it may re-transmit the Session Report for said individual sessions (e.g., one or more) in bulk form in one Node Report Request message again as described above (S50).

[0134] In addition, according to the session information reporting method of the present invention, the network device (100, UPF) can increase or decrease the buffering period by increasing or decreasing the buffering time (Time), the number of reported information (Count), and the size of the reported information (Size) when necessary, taking into account the state of the SMF (e.g., the level at which the SMF receives a large amount, the overload state of the SMF, the delay when receiving Bulk from the SMF, etc.) (S60).

[0135] According to the session information reporting method of the present invention, the network device (100, UPF) will repeatedly perform the aforementioned steps S20 and subsequent steps unless the BSR function is turned off (S70 No).

[0136] As explained above, according to the present invention, in a situation where a large number of Session Report Request messages may occur, a new technology is realized that reduces the number of signaling between the Control Plane and the User Plane by utilizing Node messages with a transmission unit larger than the Session Report Request messages to enable the transmission of all Session Reports for multiple sessions requiring reporting.

[0137] Thus, according to the present invention, the number of signalings between the control plane and the user plane is reduced, thereby achieving the effect of reducing network load and reducing the processing load of related NFs / network nodes such as UPF / SMF.

[0138] A session information reporting method according to one embodiment of the present invention may be implemented in the form of program instructions that can be executed through various computer means and recorded on a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, etc., either alone or in combination. The program instructions recorded on the medium may be those specifically designed and configured for the present invention, or may be those known and available to those skilled in the art of computer software. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tapes; optical recording media such as CD-ROMs and DVDs; magneto-optical media such as floptical disks; and hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, and flash memory. Examples of program instructions include machine code, such as that generated by a compiler, as well as high-level language code that can be executed by a computer using an interpreter, etc. The hardware devices described above may be configured to operate as one or more software modules to perform the operation of the present invention, and vice versa.

[0139] Although the present invention has been described in detail with reference to preferred embodiments, the present invention is not limited to the above-described embodiments, and the technical concept of the present invention extends to the scope in which various modifications or alterations are possible by anyone with ordinary knowledge in the technical field to which the present invention belongs, without departing from the gist of the present invention as claimed in the following claims. Industrial applicability

[0140] According to the network node device and the session information reporting method performed on the node device according to the present invention, the invention is industrially applicable as it overcomes the limitations of existing technology by realizing a differentiated technology that reduces the number of signalings between CP and UP in situations where a large amount of Session Reports are generated, and as there is sufficient possibility for the commercialization or business of the applied device, not just the use of the related technology, but also to the extent that it can be clearly and realistically implemented. Explanation of the symbols

[0141] 100 : Network Node 110: Session Control Unit 120: Message Transmission Unit 130 : Buffering section

Claims

Claim 1 A network node device comprising a message transmission unit that transmits a plurality of session-specific report information transmitted from a user plane to a control plane using a specific message transmitted from the user plane to the control plane; wherein the specific message includes group information elements (IEs) of each session when the specific message is used to transmit a plurality of session-specific report information, and the report information included in the group information elements has an IE identical to the report information IE defined in the message transmitting the session report information on a session-by-session basis. Claim 2 A network node device according to claim 1, wherein the specific message is a message transmitted in a larger transmission unit than a message transmitting session report information in a session unit, and includes a Node Report Request message transmitting network node report information in a network node unit. Claim 3 A network node device according to claim 1, characterized in that, in the case where the specific message is used for transmitting multiple session-specific report information, the specific message includes a specific identifier defined in multiple session-specific report information as an information element (IE) that identifies the type of transmission information within the message. Claim 4 A network node device according to claim 1, characterized in that the specific message includes a group IE of each session defined to include a session identifier and report information for each of the multiple sessions, when the specific message is used to transmit report information for multiple sessions. Claim 5 A network node device according to claim 4, characterized in that the report information included in the group IE has the same IE as the report information IE defined in the Session Report Request message that transmits the session report information on a session-by-session basis. Claim 6 A network node device according to claim 1, further comprising a buffering unit that performs buffering to store report information generated on a session basis according to at least one of a preset buffering time (Time), the number of report information items (Count) of a session, and the size (Size) of a session, and transmits the buffered multiple session-specific report information to the message transmission unit. Claim 7 A network node device according to claim 6, wherein the buffering unit performs the buffering for at least one of a pre-configured specific subscriber, specific base station, specific location, and specific interface with another network node. Claim 8 A network node device according to claim 6, wherein the buffering unit changes at least one of the set buffering time (Time), the number of session report information (Count), and the size of session report information (Size) to increase or decrease the buffering period. Claim 9 A method for reporting session information performed in a network node device, comprising a message transmission step of transmitting a plurality of session-specific reporting information transmitted from a user plane to a control plane using a specific message transmitted from the user plane to the control plane; wherein the specific message includes group information elements (IEs) of each session when the specific message is used to transmit a plurality of session-specific reporting information, and the reporting information included in the group information elements has an IE identical to the reporting information IE defined in the message transmitting the session reporting information on a session-by-session basis.

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