Patent Description:
As a type of a communication service and expected data rate, etc. are diversified in the LTE communication system, expansion of the LTE frequency and evolution to the <NUM> communication system are actively progressing.

The rapidly evolving <NUM> communication system not only accommodates as many user equipments as possible based on limited radio resources but also supports scenarios of enhanced mobile broadband (eMBB), massive machine type communications (mMTC), and ultra-reliable and low latency communications (URLLC).

In the <NUM> communication system, the network structure to support, from end to end, the user equipments, base stations (radio access networks), cores, and servers is defined. Further, the control signaling functions and data transmission/reception functions that is performed in combination by a single node (e.g., S-GW, P-GW, etc.) in the existing LTE (<NUM>) communication system are separated in the <NUM> communication system. Accordingly, a network structure that separates the Control Plane for the control signaling functions and the User Plane for the data transmission/reception functions is defined.

In this case, various nodes are included in the Control Plane. For example, the Access and Mobility Management Function (AMF) that controls wireless access of the user equipment, the Policy Control Function (PCF) that manages/controls policies such as user equipment information and subscription service information for each user equipment, billing, and the like, the Session Management Function (SMF) that manages/controls a session for using data services for each user equipment, and the Network Exposure Function (NEF) that performs an information sharing function with an external network may be included in the Control Plane.

In addition, functions such as the User Plane Function (UPF) may be included in the User Plane.

Non-patent Literature "<NPL>, provides N4 session establishment/modification/release procedures.

Non-patent Literature <NPL>, provides N4 parameter description with updated session context.

Non-patent Literature 3GPP TS <NUM> v15. <NUM> provides a technical specification for core network and terminals.

Various messages are transmitted between a SMF and a UPF through an N4 interface by using a packet forwarding control protocol (PFCP). The transmitted message may include, for example, a session message, QoS, usage (billing), and the like.

The problem to be solved by the present disclosure is to provide a technology that enables the above-described message to be transmitted through the N4 interface between the SMF and the UPF to be transmitted in real time without loss and delay.

In accordance with the present invention, there is provided a network function (NF), as defined by independent claim <NUM>. The NF comprises, a communication unit configured to receive, from another NF, a first message regarding association between the NF and the another NF, the first message including delivery information on a second message to be transmitted to the another NF; and a message processing unit configured to: obtain, from the first message, delivery information designated for each message type using the first message, and transmit the second message to the another NF using the selected resource. The list of resources indicates resources of the another NF that the NF can select, when the NF transmits the second message to the another NF. An IP and a port, used for transmission of the second message, are designated as among a plurality of IPs and a plurality of ports supported by the another NF, based on the delivery information.

In accordance with the present invention, there is provided a packet processing method performed by a network function (NF), as defined by independent claim <NUM>. The method comprises, receiving, from another NF, a first message regarding association between the NF and the another NF; obtaining, from the first message, delivery information designated for each message type using the first message; selecting, from a list of resources included in the delivery information, a resource based on a message type of the second message to be transmitted to the another NF; and transmitting, to the another NF, the second message using the selected resource. The list of resources indicates resources of the another NF that the NF can select, when the NF transmits the second message to the another NF. An IP and a port, used for transmission of the second message, are designated as among a plurality of IPs and a plurality of ports supported by the another NF, based on the delivery information.

According to an embodiment, the message transmitted between the SMF and the UPF may be transmitted based on delivery information. In this case, an associated address used for message delivery is not bound to a specific value and may be selected from a number of values, and a specific number (seq. No) may also be selectively assigned to the message. Therefore, overload and delay in the message delivery may be prevented, and stability of the message delivery may also be improved. Through this, connection without delay, QoS guarantee, and real-time billing are possible. In addition, since the associated addresses are assigned for each message, bypass for various switches or routers is possible.

The advantages and features of the present disclosure and the methods of accomplishing these will be clearly understood from the following description taken in conjunction with the accompanying drawings. However, embodiments are not limited to those embodiments described, as embodiments may be implemented in various forms. It should be noted that the present embodiments are provided to make a full disclosure and also to allow those skilled in the art to know the full range of the embodiments. Therefore, the embodiments are to be defined only by the scope of the appended claims.

In describing the embodiments of the present disclosure, if it is determined that detailed description of related known components or functions unnecessarily obscures the gist of the present disclosure, the detailed description thereof will be omitted. Further, the terminologies to be described below are defined in consideration of functions of the embodiments of the present disclosure and may vary depending on a user's or an operator's intention or practice. Accordingly, the definition thereof may be made on a basis of the content throughout the specification.

<FIG> shows a diagram illustrating an architecture <NUM> of the <NUM> system according to an embodiment.

The <NUM> system represented by the architecture <NUM> of <FIG> will be described. The <NUM> system is a technology evolved from a 4th generation LTE mobile communication technology. The <NUM> system is a new Radio Access Technology (RAT) and an expanded technology of the Long Term Evolution (LTE) through an evolution of an existing mobile communication network structure or a clean-state structure, and supports extended LTE (eLTE), non-3GPP access, and the like.

However, because the architecture <NUM> illustrated in <FIG> is just an example, the idea of the present disclosure is not interpreted as being limited to the architecture <NUM> illustrated in <FIG> nor the <NUM> communication system.

The architecture <NUM> includes various components (for example, a network function (NF)). Hereinafter, these components will be described.

Referring to <FIG>, an Authentication Server Function (AUSF), an (Core) Access and Mobility Management Function (AMF), a Session Management Function (SMF) <NUM>, a Policy Control Function (PCF), an Application Function (AF), Unified Data Management (UDM), a Data Network (DN) <NUM>, a User Plane Function (UPF) <NUM>, an (Radio) Access Network ((R)AN) <NUM> or a base station <NUM>, and a User Equipment (UE) <NUM>, etc. are shown.

Among these components, the UPF <NUM> is a component included in a user plane in the <NUM> system. Further, the SMF <NUM> is a component included in a control plane separated from the user plane.

In addition, referring to <FIG>, the AUSF, the AMF, the SMF <NUM>, the PCF, the AF, or the UDM, etc. are connected through a service-based interface (SBI) <NUM>. Further, the SMF <NUM> and UPF <NUM> are connected through an N4 interface by using a Packet Forwarding Control Protocol (PFCP).

However, according to an embodiment, the SMF <NUM> and the UPF <NUM> may be connected through the SBI <NUM> other than the N4 interface, in this case, an interface connecting the SMF <NUM> and the UPF <NUM> may be referred to as an Nupf interface.

<FIG> shows a diagram illustrating a message type transmitted between the UPF <NUM> and the SMF <NUM> according to an embodiment.

First, between the UPF <NUM> and the SMF <NUM>, various messages regarding control over packet delivery are transmitted through the N4 interface by using a PFCP or the SBI <NUM> as described above. The transmitted message may include, for example, a request message for setup, update, and release of association, a response message to the request message for the association, a request message for establishment, modification, and release of a session, and a response message to the request message for the session. Further, the transmitted message may include, for example, a request message for a session report, and a response message to the request message for the session report. In addition, although not shown in <FIG>, a message regarding control over QoS or a message regarding packet usage that is a basis for billing may be included in the transmitted message.

Herein, according to an embodiment, the message regarding the association transmitted between the UPF <NUM> and the SMF <NUM> includes delivery information that defines a manner in which a message other than the messages for the association, for example, the messages for the session, the messages for the session report, the message regarding the control over the QoS, or the message regarding the packet usage is transmitted between the UPF <NUM> and the SMF <NUM> (Hereinafter, a 'message' is defined as referring to any one of the messages for the session, the messages for the session report, the message regarding the control over the QoS, or the message regarding the packet usage, which is a message other than the messages for the association.

The UPF <NUM> transmits a message to the SMF <NUM> based on the delivery information, and the SMF <NUM> also transmits a message to the UPF <NUM> based on the delivery information. If a message is transmitted based on the delivery information, overload of the message may be resolved so that the message may be transmitted without loss or delay. Therefore, distributed arrangement or long-range arrangement may be possible for the UPFs <NUM>. Hereinafter, each of the UPF <NUM> and the SMF <NUM> enabling the above-described effect will be described.

<FIG> shows a diagram illustrating a configuration of the UPF <NUM> according to an embodiment. Referring to <FIG>, the UPF <NUM> includes a communication unit <NUM>, an information storage unit <NUM>, and a message processing unit <NUM>, but the configuration of the UPF <NUM> is not limited to that shown in <FIG>.

First, the communication unit <NUM> is a port for transmitting and receiving a message, and may be implemented in hardware or software.

The information storage unit <NUM> may be implemented by a memory or the like. The information storage unit <NUM> may store delivery information received from the SMF <NUM> through the communication unit <NUM>, and the delivery information will be described later. On the other hand, not only the delivery information but also other various information may be stored in the information storage unit <NUM>.

The message processing unit <NUM> generates a message regarding association. The message processing unit <NUM> may be implemented by a memory storing an instruction programmed to perform a function to be described below and a microprocessor that executes the instruction.

As described above, the message regarding the association includes a request message for setup, update, and release of the association, and a response message to the request message for the association. Through the message regarding the association, a control function over a load of the SMF <NUM> may be set or released, a buffering function of the UPF <NUM> may be set or released, and a method in which an IP is allocated to the UPF <NUM> may be designated, but they are not limited thereto. The message regarding the association generated by the message processing unit <NUM> is transmitted to the SMF <NUM> through the communication unit <NUM>.

On the other hand, when the message regarding the association is received from the SMF <NUM> through the communication unit <NUM>, the message processing unit <NUM> may perform the setup, the update, or the release of the association according to the received message regarding the association.

The message processing unit <NUM> generates the delivery information. The generated delivery information is included in the above-described message regarding the association, thereby being transmitted to the SMF <NUM> through the communication unit <NUM>.

Herein, the delivery information includes at least one of information on a message type, an associated address used for message delivery, associated reliability including items to be controlled for the message delivery, and a resource priority. An example of the delivery information is shown in <FIG>.

Among them, the message type indicates a type of a message. For example, the message types may include a request message for establishment, modification, and release of a session, a response message to the request message for the session, a request message for a session report, and a response message to the request message for the session report, as well as a message regarding control over QoS or a message regarding packet usage, which is a basis for billing, etc. Herein, the message type may be classified based on a rule included in the message, such as a packet detection rule (PDR), a forward action rule (FAR), a QoS enforcement rule (QER), or a usage report rule (URR). Alternatively, the message type may be classified based on detailed information element included in each of the rules.

Further, the associated address used for the message delivery includes a source IP, a destination IP, a source port, and a destination port for the message. Specifically, it may be assumed that N number of IPs and M number of ports (N and M are natural numbers) are available in the UPF <NUM>, and P number of IPs and Q number of ports (P and Q are natural numbers) are available in the SMF <NUM>. In this case, for each message transmitted from the SMF <NUM> to the UPF <NUM>, the source IP may be selected from the P number of IPs, the source port may be selected from the Q number of ports, the destination IP may be selected from the N number of IPs, and the destination port may be selected from the M number of ports. In other words, the source IP or the destination IP, or the source port or the destination port of a message transmitted from the SMF <NUM> to the UPF <NUM> may be selected from a number of Ips or ports rather than be limited or bound to a specific one. Details on the associated address used for the message delivery is illustrated in <FIG>.

The associated reliability for the message delivery includes at least one of a manner in which a specific number (seq. No) is assigned to a message, standby time (expiry timeout) before receiving a response to a request, and the maximum number of times of re-transmission (max.

Among them, the seq. No is a number that is assigned to each message but does not overlap each other, and is related to an order of processing of a message. No may be assigned to each message in an incremental manner, or in a randomly selective manner.

The expiry timeout indicates maximum time that the SMF <NUM> may stand by until receiving a response after transmitting a request for a message to the UPF <NUM>.

retry indicates the maximum number of times that the SMF <NUM> may re-transmit, after transmitting a request for a message to the UPF <NUM>, the request for the message until a response is received.

The resource priority of the message is information indicating an order in which a resource of the SMF <NUM> may be allocated to each message. The resource priority may be determined based on at least one of the above-described message type information, the associated address used for the message delivery, and the associated reliability for the message delivery.

Herein, the associated address used for the message delivery and the associated reliability for the message delivery may have different values depending on the message type. For example, the associated address of a message in a case of the message type of the session establishment may be different from the associated address of a message in a case of the message type of the session modification or the session release. In addition, the associated reliability of the message in the case of the message type of the session establishment may be different from the associated reliability of the message in the case of the message type of the session modification or the session release.

The above-described delivery information is included in the message regarding the association and transmitted from the UPF <NUM> to the SMF <NUM> through the communication unit <NUM>. A message processing unit <NUM> of the SMF <NUM> obtains the delivery information from the received message regarding the association. The obtained delivery information is used in a process in which the SMF <NUM> transmits a message to the UPF <NUM>. For example, the associated address, the associated reliability, and the resource priority of a message to be transmitted are determined according to the message type of the message, and the message is transmitted from the SMF <NUM> to the UPF <NUM> based on the determination.

As described above, according to an embodiment, the delivery information generated by the UPF <NUM> may be included in the message regarding the association and transmitted to the SMF <NUM>. The SMF <NUM> may consider the delivery information when transmitting a message to the UPF <NUM>. In this case, the associated address used for the message delivery may not be bound to a specific value and may be selected from a plurality of values, and the seq. No may also be selectively assigned to a message. Therefore, overload and delay in the message delivery may be prevented, and stability of the message delivery may also be improved, thereby enabling connection without delay, QoS guarantee, and real-time billing. In addition, since the associated address is assigned to each message, bypass for various switches or routers is possible.

Heretofore, it was described that the UPF <NUM> generates the delivery information, and the generated delivery information is transmitted from the UPF <NUM> to the SMF <NUM>, and the SMF <NUM> transmits a message based on the delivery information. Hereinafter, it will be described that the SMF <NUM> generates delivery information, and the generated delivery information is transmitted from the SMF <NUM> to the UPF <NUM>, and the UPF <NUM> transmits a message to the SMF <NUM> based on the delivery information.

<FIG> shows a diagram illustrating a configuration of the SMF <NUM> according to an embodiment. Referring to <FIG>, the SMF <NUM> includes a communication unit <NUM>, an information storage unit <NUM>, and the message processing unit <NUM>, but the configuration of the SMF <NUM> is not limited to that shown in <FIG>.

The information storage unit <NUM> may be implemented by a memory or the like. The information storage unit <NUM> may store delivery information received from the UPF <NUM> through the communication unit <NUM>, and the delivery information will be described later. On the other hand, not only the delivery information but also other various information may be stored in the information storage unit <NUM>.

The message processing unit <NUM> generates a message regarding association. Herein, since the message processing unit <NUM> generates the same message regarding the association that the message processing unit <NUM> of the UPF <NUM> generates, a description thereof will be skipped.

The message processing unit <NUM> generates the delivery information. The generated delivery information is included in the above-described message regarding the association, thereby being transmitted to the UPF <NUM> through the communication unit <NUM>.

Herein, the delivery information is identical to that of the above description for the UPF <NUM>, and thus a description thereof will be skipped.

The above-described delivery information is included in the message regarding the association and transmitted from the SMF <NUM> to the UPF <NUM> through the communication unit <NUM>. The message processing unit <NUM> of the UPF <NUM> obtains the delivery information from the received message regarding the association. The obtained delivery information is used in a process in which the UPF <NUM> transmits a message to the SMF <NUM>. For example, an associated address, associated reliability, and a resource priority of a message to be transmitted are determined according to a message type of the message, and the message is transmitted from the UPF <NUM> to the SMF <NUM> based on the determination.

As described above, according to an embodiment, the delivery information generated by the SMF <NUM> may be included in the message regarding the association and transmitted to the UPF <NUM>. The UPF <NUM> may consider the delivery information when transmitting a message to the SMF <NUM>. In this case, the associated address used for the message delivery is not bound to a specific value and may be selected from a plurality of values, and the seq. No may also be selectively assigned to a message. Therefore, overload and delay in the message delivery may be prevented, and stability of the message delivery may also be improved, thereby enabling connection without delay, QoS guarantee, and real-time billing. In addition, since the associated address is assigned to each message, bypass for various switches or routers is possible.

<FIG> shows a flowchart illustrating a packet processing method according to an embodiment. However, since <FIG> illustrates just an example, a procedure of the packet processing method is not limited to that illustrated in <FIG>.

Referring to <FIG>, in a step S100, the SMF <NUM> transmits a request message for association setup to the UPF <NUM>. The request message for the association setup may be generated by the message processing unit <NUM> of the SMF <NUM>. The above-described delivery information is included in the request message for the association setup.

In a step S110, the UPF <NUM> sets up the association according to the request message for the association setup received in the step S100, and then in a step S120, the UPF <NUM> transmits a response message indicating that the setup of the association has been performed to the SMF <NUM>.

Thereafter, in a step S130, various messages such as a session message are transmitted and received between the UPF <NUM> and the SMF <NUM>. In this case, the session message to be transmitted by the UPF <NUM> to the SMF <NUM> may be transmitted to the SMF <NUM> based on the delivery information included in the request message for the association setup received in the step S100. For example, in the step S130, an associated address and associated reliability of the session message to be transmitted by the UPF <NUM> to the SMF <NUM> may be determined and then transmitted based on the delivery information included in the request message for the association setup received in the step S100.

On the other hand, in a step S200, the SMF <NUM> may determine whether to update the association setup or not. If it is determined not to update the association setup, the step S130 may be repeatedly performed. However, if it is determined to update the association setup, in a step S300, the SMF <NUM> transmits a request message for the association update to the UPF <NUM>. The request message for the association update may be generated by the message processing unit <NUM> of the SMF <NUM>, and the request message for the association update includes the above-described delivery information.

Herein, the SMF <NUM> may determine whether to update the association setup or not based on at least one of the following matters.

Alternatively, the SMF <NUM> may determine whether to update the association setup in case of receiving an update request from a NF such as an AMF or based on the following matters.

In a step S310, the UPF <NUM> updates the association according to the request message for the association update received in the step S300, and then, in a step S320, transmits a response message indicating that the update has been completed to the SMF <NUM>.

Thereafter, in a step S330, various messages such as the session message are transmitted and received between the UPF <NUM> and the SMF <NUM>. At this time, the session message to be transmitted by the UPF <NUM> to the SMF <NUM> may be transmitted to the SMF <NUM> based on the delivery information included in the request message for the association update received in the step S300. For example, in the step S330, the associated address and the associated reliability of the session message to be transmitted by the UPF <NUM> to the SMF <NUM> may be determined and then transmitted based on the delivery information included in the request message for the association update received in the step S300.

On the other hand, <FIG> illustrates a situation in which the request messages for the association setup or for the association update is transmitted from the SMF <NUM> to the UPF <NUM>, but the idea of the present disclosure is not limited to that illustrated in <FIG>. For example, the identical idea of the present disclosure may be applied to a situation in which the request messages for the association setup or for the association update is transmitted from the UPF <NUM> to the SMF <NUM>.

On the other hand, the idea of the present disclosure described heretofore is applied to the case where the session message is transmitted between the SMF <NUM> and the UPF <NUM>, but it is not understood that the idea of the present disclosure is limited to the case. In other words, even when a message is transmitted between the NFs shown in <FIG> according to an embodiment, the idea of the present disclosure may be applied. For example, the idea of the present disclosure may be applied to a case where a message is transmitted between the UPFs <NUM>, a case where a message is transmitted between the SMFs <NUM>, a case where a message is transmitted between the AMF and the SMF <NUM>, a case where a message is transmitted between the PCF and the SMF <NUM>, etc. In this case, one of subjects that transmits and receives a message may be referred to as a NF and the other subject may be referred to as another NF.

As described above, according to an embodiment, a message transmitted between the SMF <NUM> and the UPF <NUM> may be transmitted based on the delivery information. At this time, the associated address used for the message delivery is not bound to a specific value and may be selected from a number of values, and the seq. No may also be selectively assigned to the message. Therefore, overload and delay in the message delivery may be prevented, and stability of the message delivery may also be improved, thereby enabling connection without delay, QoS guarantee, and real-time billing. In addition, since the associated address is assigned to each message, bypass for various switches or routers is possible.

According to an embodiment, when the message is transmitted, the overload and the delay may be prevented, and the stability of the message delivery may also be improved, thereby enabling connection without delay, QoS guarantee, and real-time billing.

Claim 1:
A network function, NF, comprising:
a communication unit (<NUM>, <NUM>) configured to receive, from another NF, a first message regarding association between the NF and the another NF, the first message including delivery information on a second message to be transmitted to the another NF; and
a message processing unit (<NUM>, <NUM>) configured to:
obtain, from the first message, delivery information designated for each message type using the first message,
select, from a list of resources included in the delivery information, a resource based on a message type of the second message to be transmitted to the another NF, and
transmit the second message to the another NF using the selected resource,
wherein the list of resources indicates resources of the another NF that the NF can select, when the NF transmits the second message to the another NF, and
wherein an IP and a port, used for transmission of the second message, are designated as among a plurality of IPs and a plurality of ports supported by the another NF, based on the delivery information.