Patent Description:
The subject matter described herein relates to improving data communications conducted in fifth generation (<NUM>) telecommunication networks. More particularly, the subject matter described herein relates to methods, systems, and computer readable media for providing a unified interface that is configured to support small and infrequent data communication between a user equipment and application function via a network exposure function.

Presently, <NUM> telecommunications networks often need to conduct infrequent communication of small data between low powered user equipment (UE) and application functions (AFs). In particular, these small and infrequent communications are used for cellular based communication between Internet of things (IoT) devices and AFs. This manner of communication enables low powered wide area (LWPA)-based IoT use cases where power constrained UE devices may utilize both the <NUM> control plane and the <NUM> data plane for data transmission. In generally, 3GPP provides different methods and/or interfaces that facilitate infrequent communications of small data such as using Internet protocol (IP) data delivery using an N6 interface over the user plane or using non-IP data delivery (NIDD) over a control plane. Although there are several different paths that can be used to communicate small and infrequent data in <NUM> communication networks, several technical difficulties can arise when an AF is required to support different methods of AF communication. For example, problems may arise when a roaming network is configured to only support Internet protocol (IP) data delivery and is not able to support non-Internet protocol data delivery (NIDD). Difficulties can also arise in local breakout roaming scenarios where a visited network supports NIDD via a user plane function (UPF) whereas the UE's home network supports NIDD via a network exposure function (NEF). Further, problems for an AF can also appear when a UE is used across multiple network slices and each slice may support a different deployment model (e.g., a slice provisioned with a NEF, a slice provisioned without a NEF, or a slice that only supports IP data deliver via a UPF without a NEF).

As such, there exists a need for improved methods and systems for providing a unified interface configured to support infrequent communications via a network exposure function or service.

<CIT> forms part of the relevant background art and discloses a method in a core network of a cellular communications system to enable Data over Non-Access Stratum, DoNAS, data delivery in a roaming scenario.

<CIT> also forms part of the relevant background art and discloses a method of performing communication, by a network exposure function (NEF), in a wireless communication system.

Methods, systems, and computer readable media for providing a unified interface that is configured to support communication between a user equipment (UE) and application function (AF) via a network exposure function (NEF) are disclosed. One method includes receiving, by a NEF and from a session management function (SMF), a protocol data unit (PDU) session event change notification message associated with a UE, establishing, by the NEF, a data delivery path between the UE and an application function (AF) via one of a plurality of data delivery planes that traverse the NEF in response to the PDU session event change notification message, wherein the plurality of data delivery planes includes a non-IP data delivery, NIDD, based data communication path established in a control plane between the UE and the AF via the NEF, a NIDD based data communication path established between the UE and the AF via the NEF and a UPF that are communicatively connected using a N6 point to point tunnel, and an Internet protocol (IP) data delivery based data communication path between the UE and AF that are communicatively connected via the NEF and the UPF using a N6 interface and processing, by the NEF, messages communicated between the UE and the AF via NEF over any of the plurality of data delivery planes using a single unified interface supported by the NEF, wherein the single unified interface provides mobile originated, MO, messages to the AF and mobile terminated, MT, messages from the AF and towards the UE regardless of the data delivery path and the data delivery plane.

According to an aspect of the subject matter described herein, a method wherein the UE includes a low-powered Internet of things (IoT) device.

According to an aspect of the subject matter described herein, a method wherein the single unified interface includes a T8 and/or N33 interface.

According to an aspect of the subject matter described herein, a method wherein the NEF is configured to switch between the plurality of data delivery planes while maintaining the attachment of the UE.

According to an aspect of the subject matter described herein, a method wherein the NEF is configured to establish listening servers to monitor for packet traffic from a UPF in response to receiving the PDU session event change notification message.

According to an aspect of the subject matter described herein, a method wherein the NEF functions as a PDU session anchor during the use of each of the plurality of data delivery planes. One example system for providing a unified interface that is configured to support communication between a user equipment (UE) and application function (AF) via a network exposure function (NEF) includes a network node comprising at least one processor and memory, wherein the memory and the at least one processor belong to unified interface device configured to host a NEF. The network node further includes a unified interface manager that is stored in the memory of the NEF and when executed by the at least one processor is configured for receiving from a session management function (SMF) a protocol data unit (PDU) session event change notification message associated with a UE, establishing a data delivery path between the UE and an application function (AF) via one of a plurality of data delivery planes that traverse the NEF in response to the PDU session event change notification message, wherein the plurality of data delivery planes includes a non-IP data delivery, NIDD, based data communication path established in a control plane between the UE and the AF via the NEF, a NIDD based data communication path established between the UE and the AF via the NEF and a UPF that are communicatively connected using a N6 point to point tunnel, and an Internet protocol (IP) data delivery based data communication path between the UE and AF that are communicatively connected via the NEF and the UPF using a N6 interface, and processing messages communicated between the UE and the AF via the NEF over any of the plurality of data delivery planes using a single unified interface supported by the NEF, wherein the single unified interface provides mobile originated, MO, messages to the AF and mobile terminated, MT, messages from the AF and towards the UE regardless of the data delivery path and the data delivery plane.

According to an aspect of the subject matter described herein, a system wherein the UE includes a low-powered Internet of things (IoT) device.

According to an aspect of the subject matter described herein, a system wherein the single unified interface includes a T8 and/or N33 interface.

According to an aspect of the subject matter described herein, a system wherein the NEF is configured to switch between the plurality of data delivery planes while maintaining the attachment of the UE.

According to an aspect of the subject matter described herein, a system wherein the NEF is configured to establish listening servers to monitor for packet traffic from a UPF in response to receiving the PDU session event change notification message.

According to an aspect of the subject matter described herein, a system wherein the NEF functions as a PDU session anchor during the use of each of the plurality of data delivery planes.

One example non-transitory computer readable medium comprising computer executable instructions embodied in the non-transitory computer readable medium that when executed by at least one processor of at least one computer cause the at least one computer to perform steps comprising: receiving, by a NEF and from a session management function (SMF), a protocol data unit (PDU) session event change notification message associated with a UE, establishing, by the NEF, a data delivery path between the UE and an application function (AF) via one of a plurality of data delivery planes that traverse the NEF in response to the PDU session event change notification message, wherein the plurality of data delivery planes includes a non-IP data delivery, NIDD, based data communication path established in a control plane between the UE and the AF via the NEF, a NIDD based data communication path established between the UE and the AF via the NEF and a UPF that are communicatively connected using a N6 point to point tunnel, and an Internet protocol (IP) data delivery based data communication path between the UE and AF that are communicatively connected via the NEF and the UPF using a N6 interface and processing, by the NEF, messages communicated between the UE and the AF via the NEF over any of the plurality of data delivery planes using a single unified interface supported by the NEF, wherein the single unified interface provides mobile originated, MO, messages to the AF and mobile terminated, MT, messages from the AF and towards the UE regardless of the data delivery path and the data delivery plane.

The subject matter described herein may be implemented in hardware, software, firmware, or any combination thereof. As such, the terms "function" "node" or "module" as used herein refer to hardware, which may also include software and/or firmware components, for implementing the feature being described. In one example implementation, the subject matter described herein may be implemented using a computer readable medium having stored thereon computer executable instructions that when executed by the processor of a computer control the computer to perform steps. Example computer readable media suitable for implementing the subject matter described herein include non-transitory computer-readable media, such as disk memory devices, chip memory devices, programmable logic devices, and application specific integrated circuits. In addition, a computer readable medium that implements the subject matter described herein may be located on a single device or computing platform or may be distributed across multiple devices or computing platforms.

Reference will now be made in detail to various embodiments of the subject matter described herein, examples of which are illustrated in the accompanying drawings.

The communication of small infrequent data between a user equipment and an application function in a <NUM> network is primarily used for low-powered loT devices or other which have power constraints or restrictions. Notably, there are three modes or interfaces that can be used to facilitate the small infrequent data communication between the user equipment and the application function for low powered or power constrained IoT devices operating in the <NUM> network. For example, the first mode of data communication can be conducted as a non-IP data delivery (NIDD) based data transmission between the user equipment and the application function via a NEF that using an N33 interface and/or a T8 interface over the <NUM> system control plane. The second mode of data communication can be conducted as NIDD based data communication between the user equipment and the application function via a UPF using an N6 point to point tunnel interface over the <NUM> system control plane. Further, a third mode of data communication can be conducted as IP data delivery between the user equipment and the application function via the UPF using an N6 interface over a <NUM> system user plane. These three different data delivery options are respectively illustrated in <FIG> and described in detail below.

<FIG> depicts a NIDD data path that exists between a user equipment and application function over a <NUM> control plane via a NEF. In particular, <FIG> shows a <NUM> system <NUM> that includes a user equipment <NUM>, a control plane <NUM>, and an application function <NUM>. Further, <FIG> illustrates control plane <NUM> as including a radio access network (RAN) <NUM>, an access and mobility management function (AMF) <NUM>, a session management function (SMF) <NUM>, a network exposure function (NEF) <NUM>, a unified data management function (UDM) <NUM> that are collectively responsible for establishing the data communication path between user equipment <NUM> and application function <NUM> over a control plane. Notably, a protocol data unit (PDU) session establishment procedure is conducted between user equipment <NUM> and SMF <NUM>. During the session establishment procedure, a NEF identity (e.g., corresponding to NEF <NUM>) is acquired by SMF <NUM> as part of the subscription data that is received from UDM <NUM>. Once the NEF identity information is received by SMF <NUM>, an SMF-NEF connection establishment procedure is conducted. In particular, a NIDD mobile originated (MO) message communication path between user equipment <NUM> and application function <NUM> is established. Similarly, a NIDD mobile terminated (MT) message communication path is established between application function <NUM> and user equipment <NUM>. To facilitate the communication path(s), an N33/T8 interface between application function <NUM> and NEF <NUM> is established by the NEF. Once the communication path through control plane <NUM> is established, user equipment <NUM> and application function <NUM> can communicate small and infrequent data over <NUM> system <NUM>. Specifically, NEF based NIDD data communication provides an API based interface (i.e., a T8/N33 interface) towards application function <NUM> for both MO and MT message communication between user equipment <NUM> and application function <NUM> over control plane <NUM>. As such, NEF <NUM> serves and functions as a PDU session anchor for the data delivery path in this scenario.

<FIG> depicts a NIDD data path that exists between a user equipment and application function over a <NUM> control plane via a UPF. In particular, <FIG> shows a <NUM> system <NUM> that includes a user equipment <NUM>, a control plane <NUM>, and an application function <NUM>. Further, <FIG> illustrates control plane <NUM> as including a RAN <NUM>, AMF <NUM>, SMF <NUM>, and UPF <NUM> that are collectively responsible for establishing the data communication path. Notably, data communication using NIDD via UPF over control plane <NUM> is initiated by a PDU session event procedure (e.g., a PDU session establishment procedure) that is conducted between user equipment <NUM> and SMF <NUM>. During this procedure, SMF <NUM> selects a UPF (e.g., UPF <NUM>) and performs an N4 session establishment procedure (i.e., between SMF <NUM> and UPF <NUM>). Afterwards, an N6 point to point tunnel <NUM> is established by the UPF between UPF <NUM> and application function <NUM> to support the unstructured NIDD data communication in <NUM> system <NUM>. In particular, UPF based NIDD provides an N6 point to point tunnel interface (between UPF <NUM> and application function <NUM>) for MO and MT message communication between user equipment <NUM> and application function <NUM> over control plane <NUM>. As such, UPF <NUM> serves and functions as a PDU session anchor for the data delivery path in this scenario.

<FIG> depicts an IP data delivery path that exists between a user equipment and application function over a <NUM> user plane via a UPF. In particular, <FIG> shows a <NUM> system <NUM> that includes a user equipment <NUM>, a user plane <NUM>, and application function <NUM>. Further, <FIG> illustrates user plane <NUM> as including a RAN <NUM>, SMF <NUM>, and UPF <NUM> that are collectively responsible for establishing the data communication path on the user plane. Notably, data communication using IP data delivery via UPF over user plane <NUM> is initiated by a PDU session event procedure (e.g., PDU session establishment procedure) that is conducted between user equipment <NUM> and SMF <NUM>. During this procedure, SMF <NUM> selects UPF <NUM> and performs an N4 session establishment procedure (i.e., between SMF <NUM> and UPF <NUM>). Afterwards, data communication over the user plane <NUM> is conducted. Notably, UPF based IP data delivery provides an N6 interface (i.e., between UPF <NUM> and application function <NUM>) for MO and MT message communication between user equipment <NUM> and application function <NUM> over the <NUM> data plane (i.e., user plane <NUM>). As such, UPF <NUM> acts as a PDU session anchor for the data delivery path in this scenario.

In general, there are several situations where the application function will be required to support all three of the aforementioned methods of application function communication. Example scenarios include a user equipment entering a roaming network that only supports conventional IP data delivery and is not configured to support NIDD data delivery or a local breakout roaming scenario where a user equipment leaves a home network that supports NIDD via NEF and enters a visited network that only supports NIDD via UPF. Another example is if the user equipment is used across multiple network slices, wherein each slice supports a different deployment model (e.g., a first slice is equipped with a NEF, an adjacent slice is equipped without a NEF or only supports IP data delivery via UPF without a NEF). Accordingly, it would be advantageous for the application function to be configured to support a plurality of interfaces for a number of different data delivery paths. As such, the disclosed subject matter pertains to a NEF element that is provisioned with a unified interface that is configured to internally support i) an N33/T8 interface (i.e., NIDD via NEF) using a control plane data transfer, ii) a N6 point to point tunnel interface (i.e., NIDD via UPF) using a control plane data transfer, and iii) a N6 interface (i.e., IP data delivery) based interface that is specific to IoT use cases utilizing a user plane data transfer.

It should be noted that an AF that is configured to only support an N6 interface (i.e., does not include NEF interface capability) is significantly limited and prevents the application function to leverage many exposure services offered by a NEF. In particular, an AF restricted in this manner would be unable to utilize valuable services provided by a NEF including, but not limited to, i) monitoring an IoT device state through MONTE service, ii) an AF traffic influencing service for edge routing use cases, iii) charging third-party service providers (i.e., sponsor data connectivity), iv) setting network parameters (e.g., sleep timers and the like), and v) setting an application function session with required quality of service (QoS) and the like.

In contrast, the disclosed subject matter is configured to utilize a single unified interface at the application function via NEF for all three of the aforementioned deployment models. In particular, the NEF is configured to track the current data delivery path (e.g., PDU session paths) utilized by the user equipment and accommodate any path switching using a single T8/N33 interface that is directed towards an application function destination in order to enable the small and infrequent data communication between the user equipment and the application function.

<FIG> depicts a logical block diagram of a <NUM> communication network <NUM>. Notably, network <NUM> comprises an aggregated unified interface system <NUM> that facilitates the communication paths between a user equipment <NUM> and an application function <NUM>. In particular, system <NUM> includes three communication planes <NUM>-<NUM>, and a unified interface <NUM> that can be used to provide a small data delivery communication path between user equipment <NUM> (e.g., a low powered loT device) and application function <NUM>. Although <FIG> shows a number of instances of the same network element (e.g., UPFs <NUM> and UPF <NUM>, RAN <NUM>, <NUM>, <NUM>, etc.) existing on the different communication planes, <FIG> is a logical diagram and as such, these represented network elements may be embodied as a single network element that is configured to function on each of the illustrated communication planes.

In some embodiments, communication plane <NUM> comprises a control plane that establishes a NIDD data path between user equipment <NUM> and application function <NUM> via NEF <NUM> (as per 3GPP standards). Notably, NEF <NUM> can be used to establish a communicative connection with unified interface <NUM> to communicate MO and MT message data communications between user equipment <NUM> and application function <NUM>.

In some embodiments, unified interface <NUM> can be embodied as a separate element or incorporated within NEF <NUM>. For example, NEF <NUM> can be configured to operate or act as an interworking function (IWF) and can offload any multiple interface requirement (e.g., N6 point-to-point interface and N6 interface) from the AF.

In particular, NEF <NUM> functions as a PDU session anchor for the small data delivery path over communication plane <NUM>, as well as communication planes <NUM>-<NUM> as described below.

In some embodiments, system <NUM> further includes a second communication plane <NUM> that comprises a control plane that provides a NIDD data path between user equipment <NUM> and application function <NUM>. In particular, communication plane <NUM> provides a NIDD data path via UPF <NUM> (as per 3GPP standards) that includes an N6 point to point tunnel interface <NUM>. Specifically, N6 point to point tunnel interface <NUM> is established between UPF <NUM> and the NEF <NUM> that is located in communication plane <NUM>. Accordingly, the MO and MT messaging communication conducted between user equipment <NUM> and application function <NUM> traverses through communication plane <NUM> using point-to-point tunnel interface <NUM>, NEF <NUM>, and unified interface <NUM>.

Likewise, system <NUM> includes a third communication plane <NUM> comprising a user plane (or data plane) that provides an IP data delivery path between user equipment <NUM> and application function <NUM>. In particular, communication plane <NUM> enables a UPF based IP data path (as per 3GPP standards) over an N6 interface that terminates at the NEF <NUM> that is located in communication plane <NUM>. Notably, MO and MT messaging communication between user equipment <NUM> and application function <NUM> is facilitated via NEF <NUM> and unified interface <NUM> as shown in <FIG>.

As indicated above, the disclosed subject matter supports a unified interface <NUM> that enables communication between NEF <NUM> in the first communication plane <NUM> and application function <NUM>. Notably, NEF <NUM> is provisioned with an AF configuration table <NUM> (as shown in <FIG>), which maps AFs and their corresponding IP addresses, data network name (DNN) information, and/or single Network Slice Selection Assistance Information (NSSAI) identification data to the N6 listening ports of the NEF. In particular, <FIG> depicts configuration table <NUM>, which includes an application function identifier column <NUM>, a DNN column <NUM>, a S-NSSAI column <NUM>, a NEF listening server IP address and port column <NUM>, and a server type column <NUM>. The information stored in configuration table <NUM> can be used at NEF <NUM> to start listening servers that monitor for incoming packets received on an N6 interface or N6 point-to-point tunnel interface as described below. Specifically, these listening servers are configured to enable data delivery between user equipment <NUM> and application function <NUM> through a UPF <NUM> via an N6 interface (e.g., IP data delivery) or an N6 point-to-point tunnel interface (e.g., NIDD via UPF <NUM> and tunnel interface <NUM>).

After being preconfigured, NEF <NUM> initiates listening servers to listen for incoming N6 (TCP/IP) from UPF <NUM> and N6 point-to-point tunneled (e.g., unified data protocol (UDP)/IP) data traffic from UPF <NUM> using configuration details (not shown) contained in table <NUM>. NEF <NUM> can perform the NIDD configuration procedure for a given user equipment as per 3GPP specification(s). For example, NEF <NUM> can create the NIDD configuration context for a given user equipment using the application function identifier, T8 Long Term Transaction Reference Identifier (TLTRI) information (e.g., NIDD context identifier), subscription permanent identifier (SUPI), and generic public subscription identifier (GPSI). Notably, NEF <NUM> can be preconfigured by storing DNN and S-NSSAI information as per 3GPP specifications that map to an application function identifier and optionally, user equipment identifiers in configuration table <NUM>.

In some embodiments, NEF <NUM> subscribes with SMF <NUM> in order to monitor for one or more of a plurality of PDU session events (e.g., as indicated in TS <NUM>) for user equipment <NUM> sending a Nsmf_EventExposure_Subscribe service operation request to SMF <NUM>. Notably, the request can include user equipment GPSI and/or SUPI data that was received in the NIDD configuration call flow. Examples of the aforementioned plurality of PDU session events includes, but is not limited to, i) user plane (UP) path change, ii) a PDU session release procedure, iii) a public land mobile network (PLMN) change, iv) a UE IP address change, v) a communication failure, and vi) a PDU session establishment procedure.

After NEF <NUM> subscribes with the SMF, user equipment <NUM> establishes the PDU session with NEF <NUM>, UPF <NUM> (or UPF <NUM>) using any one of the three modes. If the user equipment attempts to establish a session over NIDD via NEF <NUM> through a control plane, then communication plane <NUM> is utilized. In embodiments where the session is established over NIDD via a NEF, NEF <NUM> is notified during the PDU session establishment procedure through a Nnef_SMContext_Create Request message from the SMF (e.g., SMF <NUM> or <NUM>). Alternatively, in embodiments where the session is established via a UPF (e.g., NIDD via UPF or IP data delivery via UPF), the NEF subscribes to the SMF to be notified about PDU session events.

Afterwards, NEF <NUM> updates the user equipment context information with a PDU session identifier and a SMF identifier for UE <NUM>. In some embodiments, NEF <NUM> may update a UE context data structure table as shown in <FIG>. Notably, <FIG> illustrates an example UE context data table <NUM> that may include a number of entries, each of which corresponds to a user equipment identifier (see column <NUM>). UE context data table <NUM> further includes an application function identifier column <NUM>, a PDU session type column <NUM>, context identifier column <NUM>, DNN and S-NSSAI column <NUM>, PDU session status column <NUM>, NIDD authorization duration column <NUM>, N6 tunnel point to point information column <NUM>, and UE information derived from SMF events column <NUM>. Although <FIG> depicts nine columns in UE context data table <NUM>, additional columns (or fewer columns) can be utilized without departing from the scope of the disclosed subject matter.

In some embodiments, NEF <NUM> marks (e.g., in column <NUM> of UE context data table <NUM>) the data delivery path as NIDD via NEF for handling the communication of MO and MT messages between user equipment <NUM> and application function <NUM>. As such, NEF <NUM> processes the MO and MT messages as defined by 3GPP NIDD services (e.g., as specified in TS <NUM> section <NUM>). More specifically, NEF <NUM> communicates data with application function <NUM> over an N33/T8 interface that is facilitated by unified interface <NUM>.

In some embodiments, NEF <NUM> receives a PDU session event change notification (e.g., a PDU session establishment event/UP path change notification) from an SMF (e.g., SMF <NUM> in communication plane <NUM>) indicating a PDU session establishment for NIDD via UPF (e.g., UPF <NUM>). In this scenario, NEF <NUM> enables a N6 tunnel listener server (not shown) to accept MO messages from UPF <NUM>. In addition, the N6 tunnel listener server at NEF <NUM> is enabled to send the MT messages received from AF <NUM> via unified interface <NUM> and UPF <NUM> to user equipment <NUM>. Afterwards, NEF <NUM> updates the user equipment context information with a local context information database (e.g., update entry for UE <NUM> in UE context data table <NUM>). For example, NEF <NUM> can store PDU session information and user equipment information corresponding to UE <NUM> (e.g., IPv6 prefix of user equipment to be used later for MT messages from application function <NUM>) in UE context data table <NUM>.

At this point, NEF <NUM> may be configured to process the MO and MT messages received via the data delivery path from UE <NUM> and AF <NUM>, respectively. Specifically, NEF <NUM> may receive the UE generated MO messages from UPF <NUM> via N6 point-to-point tunnel interface <NUM> (which is established by UPF <NUM>). Afterwards, NEF <NUM> can be configured to extract the application payload information (e.g., transmission control protocol (TCP)/IP payload data) from the encapsulated UDP MO payload messages that are received from UPF <NUM> via tunnel interface <NUM>. Specifically, NEF <NUM> can extract and/or retrieve the user equipment context information, including source IP address and port identifier, from the encapsulated TCP packet. Afterwards, NEF <NUM> may extract the encapsulated TCP/IP payload which can be sent as NIDD MO submit messages to the application function <NUM> over unified interface <NUM>, e.g., a T8/N33 interface, (e.g., using a context identifier retrieved from context data information for user equipment <NUM>) created during the NIDD configuration procedure.

In some embodiments, NEF <NUM> is configured to receive the NIDD MT messages from application function <NUM> over unified interface <NUM>. NEF <NUM> then constructs a N6 compliant message (e.g., a UDP packet) that contains the TCP/IP payload of the MT message received from application function <NUM>. Notably, the new message is directed by NEF <NUM> towards user equipment <NUM> using the user equipment IP address previously retrieved and subsequently encapsulated into UDP packets. In particular, NEF <NUM> sends the UDP packets over to UPF <NUM> via the N6 point-to-point tunnel interface <NUM>. Upon receipt of the UDP packets, UPF <NUM> eventually sends the encapsulated MT messages towards user equipment <NUM> using a PDU session established over the control plane (e.g., communication plane <NUM>) to user equipment <NUM>.

Once the communication session is completed, NEF <NUM> receives a PDU session release event from SMF <NUM> and ceases to process the MT messages received from application function <NUM> via the unified interface <NUM>. In some embodiments, NEF <NUM> may be configured to buffer MT messages until the PDU session is re-established.

As indicated above, a third communication plane <NUM> can be utilized to establish a data delivery path over the user plane. For example, NEF <NUM> can be configured to receive a PDU session event message (e.g., a PDU session establishment message) when user equipment <NUM> establishes an IP type PDU session. In response, NEF <NUM> stores the user equipment's IP address in the user equipment context information (e.g., UE context data table <NUM>) and processes the MO and MT messages communicated between UE <NUM> and application function <NUM>. In particular, NEF <NUM> receives the MO IP data messages from UPF <NUM> over an N6 interface. NEF <NUM> subsequently retrieves and/or extracts the application payload from the received TCP/IP packets and encapsulates the MO message in a T8/N33 message that is sent to application function <NUM> using TLTRI (e.g., NIDD configuration context identifier). Further, NEF <NUM> can receive a MT message from application function <NUM> over unified interface <NUM> (e.g., T8/N33 interface) and can be configured to subsequently extract (e.g., decrypt) and/or retrieve the data payload from the encapsulated message. Notably, NEF <NUM> constructs the TCP/IP payload message using an application payload and subsequently sends the message to UE <NUM> via UPF <NUM> using the user equipment IP address. Specifically, UPF <NUM> routes the message towards a user equipment <NUM> over a user plane (e.g., communication plane <NUM>) via a RAN based user equipment IP address. Further, NEF <NUM> can be configured to remove the user equipment context information from the context information database (e.g., UE context data table <NUM>) upon receiving a PDU session release event message from SMF <NUM> and subsequently stop processing the communicated MO and MT messages.

<FIG> is a block diagram illustrating an example network node <NUM> configured for providing a unified interface that is configured to support a data delivery communication path between a user equipment and application function via a NEF. Network node <NUM> may represent any suitable entity or entities for performing aspects of supporting the unified interface. In some embodiments, node <NUM> may represent or include one or more 5GC network functions, e.g., a network exposure service, network exposure function, or the like. In some embodiments, network node <NUM> may represent or include a network gateway, a network proxy, an edge security device, or any related computing device that is configured to host a NEF or similar functionality.

In some embodiments, network node <NUM> or a related module may be configured (e.g., via programming logic) to support a unified interface, which may be embodied as a T8 and/or N33 interface supported by the hosted NEF. In particular, the unified interface that is implemented at a network node <NUM> can communicate and support small and infrequent data communications directed to an application function from a UE and/or loT device. Notably, in this scenario, the terminating application function is agnostic and unaware of the underlying data communication path in the <NUM> network that is being utilized by the user equipment and the network node <NUM>. The disclosed solution further enables both non-IP and IP based communication (e.g., NIDD and non-IP data delivery). Consequently, the disclosed subject matter thereby allows seamless data service for a user equipment or IoT device moving among different data communication paths without any service impact. It is further noted that there are no customized interfaces being implemented at other network functions, i.e., the disclosed subject matter is based on existing 3GPP defined interfaces.

Referring to <FIG>, network node <NUM> may include one or more communications interface(s) <NUM> for communicating messages via a communications environment, e.g., a home 5GC network. In some embodiments, communications interface(s) <NUM> may include a unified interface (e.g., a T8/N33 interface) for communicating with one or more application functions in the manner described above. Further, communication interfaces <NUM> can further include the necessary interfaces utilized by listener servers established by the NEF to establish a data delivery path with a UPF (e.g., an N6 interface, a N6 point to point tunnel interface, etc.).

Network node <NUM> may include a unified interface manager <NUM>. Unified interface manager <NUM> may be any suitable entity (e.g., software executing on at least one processor of the network node) for performing one or more aspects of disclosed data delivery techniques via the unified interface. In some embodiments, unified interface manager <NUM> may include functionality for preconfiguring a configuration database (e.g., configuration table <NUM> in <FIG>) stored in local data storage <NUM>, maintaining and updating a UE context database (e.g., UE context data table <NUM> in <FIG>), and performing the necessary algorithms for executing and supporting the disclosed modes of small and infrequent data communication between a low powered UE and AF in a <NUM> network. For example, in some embodiments, unified interface manager <NUM> can be configured to i) receive, from a session management function, a protocol data unit session event change notification message associated with a UE, ii) establish a data delivery path between the UE and an application function via one of a plurality of data delivery planes that traverse the NEF in response to the PDU session event change notification message, and iii) process messages communicated between the UE and the AF over any of the plurality of data delivery planes using a single unified interface supported by the NEF. In particular, the three delivery planes that unified interface manager <NUM> can establish include a non-IP data delivery (NIDD) based data communication path established in a control plane between the UE and the AF via the NEF, a NIDD based data communication path established between the UE and the AF via the NEF and a UPF that are communicatively connected using a N6 point to point tunnel, and an Internet protocol (IP) data delivery based data communication path between the UE and AF that are communicatively connected via the NEF and the UPF using a N6 interface.

In some embodiments, network node <NUM> may access (e.g., read from and/or write information to) data storage <NUM>. Data storage <NUM> may be any suitable entity (e.g., a computer readable medium or memory) for storing various data. As indicated above, data storage <NUM> can be configured to store a plurality of different databases, such as a configuration database (represented by configuration table <NUM> shown in <FIG>) or the UE context data structure that enables data communication between the UE and AF (represented by UE context data table <NUM> shown in <FIG>).

<FIG> is a diagram illustrating an example process <NUM> for providing a unified interface that is configured to support small and infrequent data communication between a user equipment and application function via a network exposure function. In some embodiments, example process <NUM> described herein, or portions thereof, may be performed at or performed by network node <NUM>, unified interface manager <NUM>, and/or another module or node.

In step <NUM>, a PDU session event change notification message associated with a UE is received by a NEF and from a session management function (SMF). Notably, the NEF has previously subscribed to the SMF for PDU session events for a given UE (e.g., using a Nsmf_EventExposure_Subscribe service operation). In the event the UE triggers a PDU session event (e.g., UP path change, a PDU session release, a PLMN change, a UE IP address change, a communication failure, and a PDU session establishment, etc.), the SMF will notify the NEF of the session event.

In step <NUM>, the NEF establishes a data delivery path between the UE and an AF via one of a plurality of data delivery planes that traverse the NEF in response to the PDU session event change notification message. In some embodiments, the NEF determines the data delivery plane in which to service the communication session between the UE and the AF. In some embodiments, the NEF is configured to establish the appropriate data delivery path based on a notification contained in the PDU session event change notification message. For example, if the NEF is notified that the UE is attempting a establish a session over a control plane via a UPF, the NEF will enable an N6 tunnel listener server to accept MO messages from the UPF over the control plane (e.g., NIDD data path over control plane via UPF). In the event the NEF is notified that the UE is attempting a establish a session over a user plane via a UPF, the NEF will enable an N6 listener server to receive MO messages from the UPF over the user plane (e.g., non-IP data delivery data path over user plane via UPF). In addition, the NEF may also be configured to directly receive MO messages itself from the UE over the control plane (e.g., NIDD data path over control plane via NEF).

In block <NUM>, messages communicated between the UE and the AF over any of the plurality of data delivery planes are processed by the NEF using a single unified interface supported by the NEF. In some embodiments, the NEF is configured to process the MO and MT messages communicated between the UE and AF. Notably, regardless of the data delivery path utilized (e.g., NIDD data path over control plane via NEF, NIDD data path over control plane via UPF, or non-IP data delivery data path over user plane via UPF), the NEF is configured to utilize a single unified interface to provide MO messages to the AF and receive MT messages from the AF. In some embodiments, the unified interface may be a T8/N33 interface.

It will be appreciated that process <NUM> is for illustrative purposes and that different and/or additional actions may be used. It will also be appreciated that various actions described herein may occur in a different order or sequence.

Claim 1:
A method (<NUM>) for providing a unified interface that is configured to support communication between a user equipment, UE, (<NUM>) and application function, AF, (<NUM>) via a network exposure function, NEF, (<NUM>) the method comprising:
receiving (<NUM>), by a NEF and from a session management function, SMF, (<NUM>) a protocol data unit, PDU, session event change notification message associated with a UE;
establishing (<NUM>), by the NEF, a data delivery path between the UE and an application function, AF, (<NUM>) via one of a plurality of data delivery planes (<NUM>-<NUM>) that traverse the NEF in response to the PDU session event change notification message, wherein the plurality of data delivery planes (<NUM>-<NUM>) includes a non-IP data delivery, NIDD, based data communication path established in a control plane between the UE (<NUM>) and the AF (<NUM>) via the NEF (<NUM>), a NIDD based data communication path established between the UE and the AF via the NEF and a UPF that are communicatively connected using a N6 point to point tunnel (<NUM>), and an Internet protocol (IP) data delivery based data communication path between the UE and AF that are communicatively connected via the NEF and the UPF using a N6 interface; and
processing (<NUM>), by the NEF, messages communicated between the UE and the AF via the NEF over any of the plurality of data delivery planes using a single unified interface (<NUM>) supported by the NEF, wherein the single unified interface provides mobile originated, MO, messages to the AF and mobile terminated, MT, messages from the AF and towards the UE regardless of the data delivery path and the data delivery plane.