WO2019197276A1 - N4 connection establishment for combined upf-nimf - Google Patents

Abstract

This disclosure is directed to a combined UPF-NIMF and a method performed by the UPF-NIMF, which method comprises: establishing (412, 414) a Packet Flow Control Protocol (PFCP) Small Data Communication (SDC) or Small Data Message Communication (SDMC) for a PFCP session with a SMF; and establishing a PDU, session for SDC or SDMC with a User Equipment (UE). Disclosed is also a corresponding Session Management Function, SMF and a corresponding method performed by the SMF, which method comprises: receiving, from a UE a request to establish a PDU session, and, in response to receiving the request to establish a PDU session: determining that the PDU session is for Small Data Communication (SDC); selecting a UPF that supports SDC; and establishing a Packet Flow Control Protocol (PFCP) Small Data Communication (SDC), or Small Data Message Communication (SDMC) for a PFCP session with the selected UPF.

Description

N4 CONNECTION ESTABLISHMENT FOR COMBINED UPF-NIMF

TECHNICAL FIELD

[0001] Embodiments presented herein relate to methods, nodes or functions, computer programs, and a computer program product for providing a User Plane Function (UPF) for supporting a Network loT Messaging Function (NIMF).

BACKGROUND

[0002] Generally, all terms used herein are to be interpreted according to their ordinary meaning in the relevant technical field, unless a different meaning is clearly given and/or is implied from the context in which it is used. All references to a/an/the element, apparatus, component, means, step, etc. are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, step, etc., unless explicitly stated otherwise. The steps of any methods disclosed herein do not have to be performed in the exact order disclosed, unless a step is explicitly described as following or preceding another step and/or where it is implicit that a step must follow or precede another step. Any feature of any of the embodiments disclosed herein may be applied to any other embodiment, wherever appropriate. Likewise, any advantage of any of the embodiments may apply to any other embodiments, and vice versa. Other objectives, features, and advantages of the enclosed embodiments will be apparent from the following description.

[0003] Small data communication is one of the subjects of a study that focused on Fifth Generation (5G) Cellular Internet of Things (CloT), that was performed by the Third Generation Partnership Project (3GPP) Working Group SA2, and that was documented in Technical Report (TR) 23.724 v0.2.0 [1] (hereinafter referred to as“TR 23.724”). Small data communication generally refers to small amounts of data sent relatively infrequently. Examples of small data

communication include: single UL or DL packet transmission; dual packet transmission, e.g., an UL packet followed by a DL packet, or a DL packet followed by an UL packet; and multiple packet transmission, e.g., one or a few UL and/or one or a few DL in any combination or order.

[0004] TR 23.724 identifies a number of key issues, including support for infrequent small data communication, which is described in detail in clause 5.1 of TR 23.724, and support for frequency small data communication, which is described in detail in clause 5.2 of TR 23.724. Both clause 5.1 and 5.2 set forth some architecture requirements to support delivery of structured (Internet Protocol (IP)) data and unstructured (non-IP) data as well as some architecture requirements to support charging, roaming, and policy control. Furthermore, there is an expectation that Application Programing Interfaces (APIs) for small data transmissions shall be available and that regulatory requirements (e.g., Lawful Intercept) shall be fulfilled at the same level as currently supported in the 3GPP Evolved Packet Core (EPC) architecture.

Network loT Messaging Function (NIMF)

[0005] A solution for CloT small data communication that fulfills the above requirements and assumptions is described in TR 23.724, clause 6.7, which describes an entity named Network loT Messaging Function (NIMF) at a general level. As defined by TR 23.724, a NIMF is an entity for store-and-forward of small data. The NIMF maps or proxies between“southbound” protocols (towards the CloT devices) and“northbound” protocols (towards the network and its loT customers). Clauses 6.7.2 and 6.7.4.1 of TR 23.724 describe different options related to the NIMF. For example, clause 6.7.2 of TR 23.724 states that the NIMF will support a northbound API, named“Nm API” for transmission of IP- based and non-IP-based protocols.

[0006] Where this new function will reside has not yet been decided. TR 23.724, clause 6.7.2 proposes that the NIMF might be an extension with an additional role for the 5G Network Exposure Function (NEF), or it might be a new 5G NF dedicated for small data communication (with or without a Service Based

Interface (SBI) connection), or it might be a new "standalone" entity. Each of these proposals has problems or disadvantages. Problems with Existing Solutions

[0007] One problem with having the NIMF be an extension of the NEF or other Control Plane (CP) Network Function (NF) is that the 5G User Plane (UP) is designed to handle IP communication between UE and DN, and, by use of the PDU Session type for unstructured (non-IP) data, the 5G UP also handles Non- IP communication with UEs. With the 5G UP being designed for this purpose, performing IP forwarding in the 5G CP seems hugely inappropriate. Thus, locating the NIMF in A NEF or other CP NF in the Service Based Architecture (SBA) seems inappropriate and does not take advantage of the efficiencies and advantages that the UP is designed to provide.

[0008] One problem with the NIMF as a standalone entity is the question of how a standalone NIMF would know when PDU sessions are created and deleted, and TR 23.724 does not define how a connection between the NIMF and a User Plane Function (UPF) or Session Management Function (SMF) is established when a Protocol Data Unit (PDU) session is created.

[0009] One problem with a NIMF generally is that both frequent and infrequent SDC have the same or very similar requirements for charging, policy control, lawful intercept, and roaming (just to name a few) as normal Mobile Broadband (MBB) data, and TR 23.724 does not provide any solutions to support efficient SMC transmissions, especially for low complexity, power constrained, and/or low data rate Cellular loT (CloT) UEs.

SUMMARY

[0010] Certain aspects of the present disclosure and their embodiments may provide solutions to the aforementioned or other challenges. According to one aspect of the present disclosure, a NIMF located in the 5G user plane is presented. In one embodiment, the NIMF may be integrated with a UPF and may use the N3 interface for SDC. Locating the NIMF in the UP, and especially in a combined UPF and NIMF, herein referred to as a UPF-NIMF, allows SDC to be transmitted over as few nodes or NFs a possible along its path through the mobile network, which reduces the transmission cost in terms of money, processing overhead, delay, etc. The UPF-NIMF provides an optimal solution to support efficient, infrequent, small data transmissions for low complexity, power constrained, and low data-rate CloT UEs.

[0011] In short, locating a NIMF as an entity on the user plane will efficiently support both IP and Non-IP communication, will maximize the reuse of existing functions for charging, policy control, lawful intercept and roaming, and will potentially also avoid mixing operational responsibilities. Using the N3 interface for small data transmissions will minimize the number of nodes or NFs that small data need to traverse, providing a good base for making massive loT small data communication as cost efficient as possible.

[0012] The present disclosure presents in detail the following: how a connection between a NIMF or a UPF-NIMF in the UP and a UPF or SMF is established when a PDU session is created; how N4 signaling is used to establish small data communication (SDC) connectivity between a NIMF (e.g., a UPF-NIMF) and a UE; and an example placement of an NIMF in the 5G architecture with a UPF “integrated” in the NIMF and hence with N4 interface and N3/N9 interfaces and northbound API for small data communication, such as Nm API, T8 NIDD API, and T8 API, etc. The NIMF of the present disclosure is part of the user plane, rather than the control plane, of the 5G system.

[0013] In one embodiment, the present disclosure provides a UPF that

possesses NIMF functionality, e.g., a UPF that is specialized for loT small data communication and can proxy between various protocols used towards loT devices and one or more API used towards the Application Servers (AS) or Service Capability Servers (SCS). In another embodiment, a new entity is provided, i.e., that is a NIMF combined with some or all of the functions of a UPF. In some embodiments, the protocol for the messages illustrated in step 3 and step 6 in the figure in clause 6.7.4.1 of TR 23.724 would then be new or extended messages of the Packet Forwarding Control Protocol (PFCP) specified in 3GPP TS 29.244 v15.1.0. [0014] There are, proposed herein, various embodiments which address one or more of the issues disclosed herein. Certain embodiments may provide one or more of the following technical advantages. The advantage of the proposed solution is that the NIMF would be an entity in the UP and can benefit from existing functions for charging, lawful intercept, and policy control. Furthermore support for roaming would then be solved by the existing 5G architecture for roaming. In addition there is no issue in exposing any internal mobile network information such as IMSI to the NIMF since it would be a function/entity within the mobile network.

[0015] One embodiment is directed to a method performed by a combined UPF and NIMF (UPF-NIMF). The method comprises: establishing (412, 414) a Packet Flow Control Protocol (PFCP) Small Data Communication (SDC) or Small Data Message Communication (SDMC) for a PFCP session with a SMF; and establishing a PDU, session for SDC or SDMC with a User Equipment (UE).

[0016]Another embodiment is directed to a method performed by Session Management Function, SMF. The method comprises: receiving, from a UE a request to establish a PDU session, and, in response to receiving the request to establish a PDU session: determining that the PDU session is for Small Data Communication (SDC); selecting a UPF that supports SDC; and establishing a Packet Flow Control Protocol (PFCP) Small Data Communication (SDC), or Small Data Message Communication (SDMC) for a PFCP session with the selected UPF.

[0017] Further embodiments will be discussed in the following.

[0018] Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to "a/an/the element, apparatus, component, means, step, etc." are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, step, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not have to be performed in the exact order disclosed, unless explicitly stated. BRIEF DESCRIPTION OF THE DRAWINGS

The proposed solutions are now described, by way of example, with reference to the accompanying drawings, in which:

Figure 1 illustrates a system having a UPF-NIMF that is accessible via an N4 connection according to an embodiment of the present disclosure;

Figure 2 illustrates a system 200 having a combined UPF-NIMF accessible via an N4 connection according to another embodiment of the present disclosure; Figure 3 illustrates a system having a combined UPF-NIMF accessible via an N4 connection according to yet another embodiment of the present disclosure;

Figure 4 illustrates the interaction between the SMF and the UPF-NIMF at PDU Session creation and deletion;

Figure 5 illustrates one example of a cellular communications network 500 according to some embodiments of the present disclosure;

Figure 6 is a schematic block diagram of a radio access node 600 according to some embodiments of the present disclosure;

Figure 7 is a schematic block diagram that illustrates a virtualized embodiment of the radio access node 600 according to some embodiments of the present disclosure;

Figure 8 is a schematic block diagram of the radio access node 600 according to some other embodiments of the present disclosure;

Figure 9 is a schematic block diagram of a UE 900 according to some

embodiments of the present disclosure;

Figure 10 is a schematic block diagram of the UE 900 according to some other embodiments of the present disclosure;

Figure 11 illustrates a communication system according to some embodiments of the present disclosure;

Figure 12 illustrates a communication system according to other embodiments of the present disclosure;

Figure 13 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment; Figure 14 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment;

Figure 15 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment;

Figure 16 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment.

DETAILED DESCRIPTION

[0019] Some of the embodiments contemplated herein will now be described more fully with reference to the accompanying drawings. Other embodiments, however, are contained within the scope of the subject matter disclosed herein, the disclosed subject matter should not be construed as limited to only the embodiments set forth herein; rather, these embodiments are provided by way of example to convey the scope of the subject matter to those skilled in the art. Additional information may also be found in the document(s) provided in the Appendix.

[0020] Radio Node: As used herein, a“radio node” is either a radio access node or a wireless device.

[0021] Radio Access Node: As used herein, a“radio access node” or“radio network node” is any node in a radio access network of a cellular

communications network that operates to wirelessly transmit and/or receive signals. Some examples of a radio access node include, but are not limited to, a base station (e.g., a New Radio (NR) base station (gNB) in a Third Generation Partnership Project (3GPP) Fifth Generation (5G) NR network or an enhanced or evolved Node B (eNB) in a 3GPP Long Term Evolution (LTE) network), a high- power or macro base station, a low-power base station (e.g., a micro base station, a pico base station, a home eNB, or the like), and a relay node.

[0022] Core Network Node: As used herein, a“core network node” is any type of node in a core network. Some examples of a core network node include, e.g., a Mobility Management Entity (MME), a Packet Data Network Gateway (P-GW), a Service Capability Exposure Function (SCEF), or the like.

[0023] Wireless Device: As used herein, a“wireless device” is any type of device that has access to (i.e., is served by) a cellular communications network by wirelessly transmitting and/or receiving signals to a radio access node(s). Some examples of a wireless device include, but are not limited to, a User Equipment device (UE) in a 3GPP network and a Machine Type Communication (MTC) device.

[0024] Network Node: As used herein, a“network node” is any node that is either part of the radio access network or the core network of a cellular communications network/system.

[0025] Note that the description given herein focuses on a 3GPP cellular communications system and, as such, 3GPP terminology or terminology similar to 3GPP terminology is oftentimes used. Flowever, the concepts disclosed herein are not limited to a 3GPP system.

[0026] Note that, in the description herein, reference may be made to the term “cell;” however, particularly with respect to 5G NR concepts, beams may be used instead of cells and, as such, it is important to note that the concepts described herein are equally applicable to both cells and beams. Conventional 5G Networks

[0027] A 5G network may contain zero or more of the following functions: a Access Network / Radio Access Network ((R)AN, also referred to herein as “RAN”); an Application Function (AF); an Application Server (AS); an

Authentication Server Function (AUSF); a Core Access and Mobility

Management Function (AMF); a Flome Security Edge Protection Proxy (hSEPP); a Network Exposure Function (NEF); a Network Internet of Things (loT)

Messaging Function (NIMF); a Network Repository Function (NRF); a Network Slice Selection Function (NSSF); a Policy Control Function (PCF); a Service Capacity Server (SCS); a Session Management Function (SMF); a Unified Data Management (UDM) entity; a User Plane Function (UPF); and a Visited Security Edge Protection Proxy (vSEPP).

[0028]As used herein, the terms“network node,”“network function,” and “network entity” are used interchangeably and refer to hardware, software, firmware, or a combination, that performs a defined function within a

telecommunications and/or data network. Examples of hardware include, but are not limited to, one or more processors, memory, or other circuitry.

[0029] The 5G network architecture defines some standard interfaces, such as:

• N1 : for communication between an AMF and a UE;

• N2 : for communication between an AMF and a RAN;

• N3 : for communication between a RAN and a UPF;

• N4 : for communication between a SMF and a UPF; and

• N6: for communication between a UPF and an AS.

[0030] In addition, network functions are accessible via Application Programming Interfaces (APIs), which following the naming convention of“N[entity acronym],” e.g.,“Nnssf” is the API for an NSSF,“Nnef” is the API for a NEF, and so on.

User Plane Function (UPF) + Network loT Messaging Function (NIMF)

[0031] According to one aspect of the present disclosure, a new, specialized UPF having NIMF capabilities, hereinafter referred to as a“UPF-NIMF,” is presented.

[0032] Figures 1 through 3 illustrate how a UPF-NIMF may fit into the 5G architecture described in 3GPP TS 23.501 v15 (hereinafter referred to as“TS 23.501”).

[0033] Figure 1 illustrates a system having a UPF-NIMF that is accessible via an N4 connection according to an embodiment of the present disclosure. Figure 1 illustrates a 5G system architecture, non-roaming scenario. In the embodiment illustrated in Figure 1 , system 100 includes an NSSF, an NEF, an NRF, a PCF, a UDM, an AF, an AMF, a SMF, an AUSF, a RAN that is serving a User Equipment (UE), a UPF, and an AS. In Figure 1 , some of the standard interfaces are labeled, e.g.,“N1 ,”“N2,” etc., and some of the APIs are also labeled, e.g.,“Npcf,” “Nsmf,” etc. [0034] In the embodiment illustrated in Figure 1 , system 100 also includes a combined UPF-NIMF that communicates with the RAN via the N3 interface, which communicates with the SMF via the N4 interface, and communicates with a combined SCS/AS via a northbound API for small data communication labeled “Nm API” in Figure 1. Communication using the Nm API is also referred to as the “Indirect Model of communication” (see 3GPP TS 23.682 Annex).

[0035] Thus, in the non-roaming scenario, the home RAN may communicate with the UPF-NIMF directly via the N3 interface, and the home SMF may

communicate with the UPF-NIMF via the N4 interface.

[0036] Figure 2 illustrates a system 200 having a combined UPF-NIMF accessible via an N4 connection according to another embodiment of the present disclosure. Figure 2 illustrates a 5G roaming system architecture, Cellular loT (CloT) home routed scenario. In the embodiment illustrated in Figure 2, a UE is roaming in a Visited Public Land Mobile Network (VPLMN) outside of the subscriber’s Home Public Land Mobile Network (HPLMN). In the embodiment illustrated in Figure 2, the VPLMN and HPLMN each have their own NEF, NRF, PCF, SMF, and UPF nodes. In the embodiment illustrated in Figure 2, the VPLMN has an NSSF, an AMF, and a RAN, while the HPLMN has a UDM, an AUSF, an AF, and an AS.

[0037] In the embodiment illustrated in Figure 2, the HPLMN in system 200 also includes a combined UPF-NIMF that communicates with the home SMF via the N4 interface, that communicates with the visited UPF via the N9 interface, and that communicates with a combined SCS/AS via the“Nm API.”

[0038] Thus, in the“home routed” scenario illustrated in Figure 2, the visited RAN in the VPLMN communicates with the UPF-NIMF in the HPLMN via the N3 interface to the visited UPF and from there through the N9 interface to the UPF- NIFM. The home SMF communicates with the UPF-NIMF via the N4 interface.

In this manner, a roaming UE has access to the UPF-NIMF in the subscriber’s home network.

[0039] Figure 3 illustrates a system having a combined UPF-NIMF accessible via an N4 connection according to yet another embodiment of the present disclosure. Figure 3 illustrates a 5G roaming system architecture, CloT local breakout scenario. In the embodiment illustrated in Figure 3, the VPLMN and FIPLMN each have their own NSSF, NEF, NRF, and PCF, nodes. In the embodiment illustrated in Figure 3, the VPLMN has an AMF, and SMF, a RAN, a UPF, and AF, an AS, and a SCS/AS, while the HPLMN has an AUSF and UDM.

[0040] In the embodiment illustrated in Figure 3, the VPMLN has a combined UPF-NIMF that communicates with the visited RAN via the N3 interface, that communicates with the visited SMF via the N4 interface, and that communicates with the SCS/AS in the visited network via the Nm API.

[0041]Thus, in the local breakout scenario illustrated in Figure 3, the visited RAN communicates with the UPF-NIMF in the VPLMN via the N3 interface and the visited SMF communicates with the UPF-NIFM in the VPLMN via the N4 interface.

[0042] The particular collection of nodes (NSSF, NEF, etc.) within the HPLMN and/or VPLMN as shown in Figures 1 through 3 are illustrative and not intended to be limiting. Figures 1 through 3 illustrate the concept that regardless of whether the subscriber’s UE is in the home network or roaming in a visited network, there is at least one user plane communications path to the UPF-NIMF according to embodiments of the present disclosure. Furthermore, the UPF- NIMF of the present disclosure is not limited to the N3, N4, and N9 interfaces; in alternative embodiments, the UPF-NIMF may support additional interfaces and/or may support different interfaces entirely. Likewise, the UPF-NIMF of the present disclosure is not limited to supporting the Nm API but may support additional APIs and/or may support different APIs entirely. Example SDC Connection Establishment Procedure

[0043] Figure 4 illustrates the interaction between the SMF and the UPF-NIMF at PDU Session creation and deletion. In the embodiment illustrated in Figure 4, the process starts with an interaction between the SMF and a UPF-NIMF to set up a Packet Flow Control Protocol (PFCP) association (step 400). [0044] In one embodiment, the SMF indicates it supports Small Data Communication (SDC) in the“CP Function Features” IE of the PFCP Association Setup Request message (step 402). In one embodiment, the UPF-NIMF indicates it supports Small Data Communication (SDC) in the“UP Function Features” IE of the PFCP Association Setup Response message (step 404). In an alternative embodiment, Small Data Message Communication (SDMC) capability is indicated or other similar name of the capability.

[0045] The SMF and UE then establish a Protocol Data Unit (PDU) session (step 406), e.g., in response to a request from the UE. During this process, a PFCP Session is established with the selected UPF (i.e., UPF-NIMF) using the PFCP Session Establishment Request / Response messages (see TS 29.244). In the embodiment illustrated in Figure 4, the SMF issues a PFCP Session

Establishment Request (step 408) and receives a PFCP Session Establishment Response (step 410).

[0046] In one embodiment, during this PFCP Session Establishment process, the SMF may determine that the PDU Session shall be used for SDC. This determination may be based on, for example, Domain Network Name (DNN), slice information, UE subscription information, local DNN configuration, or other local configuration. The SMF selects an UPF that has indicated Small Data Communication (SDC) capability. The UE subscription information, the DN configuration, the local SMF configuration, the UPF information received from NRF, or other information retrievable by the SMF, may contain information for selection of UPF-NIMF.

[0047] In one embodiment, the SMF provides the UPF-NIMF with additional information pertinent to SDC. The message may be referred to as a PFCP Small Data Messaging Request or PFCP Messaging Request or PFCP Small Data Communication Request or other name. In one embodiment, the additional information may identify a PDU session previously established. In the

embodiment illustrated in Figure 4, the SMF issues a PFCP Small Data

Messaging Request message (step 412) that includes a Fully Qualified Session Endpoint Identifier (F-SEID) that identifies the related PDU session previously established to be used for small data communication.

[0048] In some embodiments, additional information that may be needed by the NIMF function, such as an International Mobile Subscriber Identity (IMSI), an external ID, a Mobile Station International Subscriber Directory Number

(MSISDN), a UE Internet Protocol (IP) Address, a PDU Session Type, a PDU Session ID, a Serving PLMN Rate Control, Protocol Configuration Options (PCO) parameters, a Serving PLMN ID, an International Mobile Equipment Identity (IMEI) Software Version (IMEISV), and/or other subscription parameters or SMF parameters relevant for Small Data Communication may be provided.

[0049] In one embodiment, the SMF may include a Usage Reporting Rule to invoke message based reporting. The SMF may adapt the setting of the Usage Reporting Rule for message based reporting, e.g., to switch off volume based reporting.

[0050] In the embodiment illustrated in Figure 4, the UPF-NIMF responds to the PFCP Small Data Messaging Request by issuing a PFCP Small Data Messaging Response (step 414).

[0051] For structured (e.g., IP) data, in one embodiment, the UPF-NIMF stores the IP address of the PDU Session (if PDU Session type IPv6/IPv4), the IMSI and the external ID or MSISDN of the UE, and the IP version (IPv6, IPv4 or Unstructured) to use when communicating with the UE, and PCO parameters.

[0052] For unstructured (e.g., non-IP) data, in one embodiment, for Unstructured PDU Sessions, the UPF-NIMF stores the forwarding IP address of the

Unstructured PDU Session allocated by the SMF (see TS 23.501 [5],

clause 5.6.10.3), and PCO parameters.

[0053] In one embodiment, the NIMF part of the UPF-NIMF sets up the SDC based on the received information. In one embodiment, one or more APIs (e.g., the Nm API, the T8 Non-IP Data Delivery (NIDD) API, the T8 API, an operator specific API, a vendor specific API, etc.) may be associated with the established PDU Session for SDC. Depending on the protocol used by the UE, the NIMF may operate as a protocol proxy or application level gateway between the protocol used between the UE and the NIMF and the API used between the NIMF towards SCS/AS.

[0054] In the embodiment illustrated in Figure 4, the PFCP Small Data

Messaging Request in step 412 and the PFCP Small Data Messaging Response in step 414 are new messages, but in alternative embodiments, they may be extensions of existing messages. In one embodiment, for example, the PFCP Session Establishment Request and Response messages in steps 408 and 410, respectively, may be extended to support the passing of Small Data Messaging information to the UPF-NIMF.

[0055] Upon establishment of a PDU session, UL and DL small data

transmissions may take place (step 416) using IP data or Non-IP data depending on the PDU Session type used by the UE. In one embodiment, the higher layer protocols to be used are decided by application layer interactions between UE and NIMF or by DN configuration. Examples of higher layer protocols include, but are not limited to, Lightweight Machine-To-Machine (M2M), Constrained Application Protocol (CoAP), Message Queuing Telemetry Transport (MQTT), Datagram Transport Layer Security (DTLS), Hyper Text Transport Protocol (HTTP) and HTTP/2, Extensible Messaging and Presence Protocol (XMPP), Advanced Message Queuing Protocol (AMQP), Reliable Data Service (RDS), Long Range wireless data communication (LoRA), etc.

[0056] In the embodiment illustrated in Figure 4, the PDU session is deleted (step 418), during which the SMF and UPF-NIMF dismantle the PDU session and Small Data Messaging is released (step 420).

Example Embodiments

[0057] Figure 5 illustrates one example of a cellular communications network 500 according to some embodiments of the present disclosure. In the

embodiments described herein, the cellular communications network 500 is a 5G NR network. In this example, the cellular communications network 500 includes base stations 502-1 and 502-2, which in LTE are referred to as eNBs and in 5G NR are referred to as gNBs, controlling corresponding macro cells 504-1 and 504-2. The base stations 502-1 and 502-2 are generally referred to herein collectively as base stations 502 and individually as base station 502. Likewise, the macro cells 504-1 and 504-2 are generally referred to herein collectively as macro cells 504 and individually as macro cell 504. The cellular communications network 500 may also include a number of low power nodes 506-1 through 506-4 controlling corresponding small cells 508-1 through 508-4. The low power nodes 506-1 through 506-4 can be small base stations (such as pico or femto base stations) or Remote Radio Heads (RRHs), or the like. Notably, while not illustrated, one or more of the small cells 508-1 through 508-4 may alternatively be provided by the base stations 502. The low power nodes 506-1 through 506- 4 are generally referred to herein collectively as low power nodes 506 and individually as low power node 506. Likewise, the small cells 508-1 through 508- 4 are generally referred to herein collectively as small cells 508 and individually as small cell 508. The base stations 502 (and optionally the low power nodes 506) are connected to a core network 510.

The base stations 502 and the low power nodes 506 provide service to wireless devices 512-1 through 512-5 in the corresponding cells 504 and 508. The wireless devices 512-1 through 512-5 are generally referred to herein collectively as wireless devices 512 and individually as wireless device 512. The wireless devices 512 are also sometimes referred to herein as UEs.

[0058] Figure 6 is a schematic block diagram of a radio access node 600 according to some embodiments of the present disclosure. The radio access node 600 may be, for example, a base station 502 or 506. As illustrated, the radio access node 600 includes a control system 602 that includes one or more processors 604 (e.g., Central Processing Units (CPUs), Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), and/or the like), memory 606, and a network interface 608. The one or more processors 604 are also referred to herein as processing circuitry. In addition, the radio access node 600 includes one or more radio units 610 that each includes one or more transmitters 612 and one or more receivers 614 coupled to one or more antennas 616. The radio units 610 may be referred to or be part of radio interface circuitry. In some embodiments, the radio unit(s) 610 is external to the control system 602 and connected to the control system 602 via, e.g., a wired connection (e.g., an optical cable). However, in some other embodiments, the radio unit(s) 610 and potentially the antenna(s) 616 are integrated together with the control system 602. The one or more processors 604 operate to provide one or more functions of a radio access node 600 as described herein. In some embodiments, the function(s) are implemented in software that is stored, e.g., in the memory 606 and executed by the one or more processors 604.

[0059] Figure 7 is a schematic block diagram that illustrates a virtualized embodiment of the radio access node 600 according to some embodiments of the present disclosure. This discussion is equally applicable to other types of network nodes. Further, other types of network nodes may have similar virtualized architectures.

[0060]As used herein, a“virtualized” radio access node is an implementation of the radio access node 600 in which at least a portion of the functionality of the radio access node 600 is implemented as a virtual component(s) (e.g., via a virtual machine(s) executing on a physical processing node(s) in a network(s)).

As illustrated, in this example, the radio access node 600 includes the control system 602 that includes the one or more processors 604 (e.g., CPUs, ASICs, FPGAs, and/or the like), the memory 606, and the network interface 608 and the one or more radio units 610 that each includes the one or more transmitters 612 and the one or more receivers 614 coupled to the one or more antennas 616, as described above. The control system 602 is connected to the radio unit(s) 610 via, for example, an optical cable or the like. The control system 602 is connected to one or more processing nodes 700 coupled to or included as part of a network(s) 702 via the network interface 608. Each processing node 700 includes one or more processors 704 (e.g., CPUs, ASICs, FPGAs, and/or the like), memory 706, and a network interface 708.

[0061] In this example, functions 710 of the radio access node 600 described herein are implemented at the one or more processing nodes 700 or distributed across the control system 602 and the one or more processing nodes 700 in any desired manner. In some particular embodiments, some or all of the functions 710 of the radio access node 600 described herein are implemented as virtual components executed by one or more virtual machines implemented in a virtual environment(s) hosted by the processing node(s) 700. As will be appreciated by one of ordinary skill in the art, additional signaling or communication between the processing node(s) 700 and the control system 602 is used in order to carry out at least some of the desired functions 710. Notably, in some embodiments, the control system 602 may not be included, in which case the radio unit(s) 610 communicate directly with the processing node(s) 700 via an appropriate network interface(s).

[0062] In some embodiments, a computer program including instructions which, when executed by at least one processor, causes the at least one processor to carry out the functionality of radio access node 600 or a node (e.g., a processing node 700) implementing one or more of the functions 710 of the radio access node 600 in a virtual environment according to any of the embodiments described herein is provided. In some embodiments, a carrier comprising the aforementioned computer program product is provided. The carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium (e.g., a non-transitory computer readable medium such as memory).

[0063] Figure 8 is a schematic block diagram of the radio access node 600 according to some other embodiments of the present disclosure. The radio access node 600 includes one or more modules 800, each of which is

implemented in software. The module(s) 800 provide the functionality of the radio access node 600 described herein. This discussion is equally applicable to the processing node 700 of Figure 7 where the modules 800 may be

implemented at one of the processing nodes 700 or distributed across multiple processing nodes 700 and/or distributed across the processing node(s) 700 and the control system 602.

[0064] Figure 9 is a schematic block diagram of a UE 900 according to some embodiments of the present disclosure. As illustrated, the UE 900 includes one or more processors 902 (e.g., CPUs, ASICs, FPGAs, and/or the like), memory 904, and one or more transceivers 906 each including one or more transmitters 908 and one or more receivers 910 coupled to one or more antennas 912. The processors 902 are also referred to herein as processing circuitry. The transceivers 906 are also referred to herein as radio circuitry. In some

embodiments, the functionality of the UE 900 described above may be fully or partially implemented in software that is, e.g., stored in the memory 904 and executed by the processor(s) 902. Note that the UE 900 may include additional components not illustrated in Figure 9 such as, e.g., one or more user interface components (e.g., a display, buttons, a touch screen, a microphone, a

speaker(s), and/or the like), a power supply (e.g., a battery and associated power circuitry), etc.

[0065] In some embodiments, a computer program including instructions which, when executed by at least one processor, causes the at least one processor to carry out the functionality of the UE 900 according to any of the embodiments described herein is provided. In some embodiments, a carrier comprising the aforementioned computer program product is provided. The carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium (e.g., a non-transitory computer readable medium such as memory).

[0066] Figure 10 is a schematic block diagram of the UE 900 according to some other embodiments of the present disclosure. The UE 900 includes one or more modules 1000, each of which is implemented in software. The module(s) 1000 provide the functionality of the UE 900 described herein.

[0067] Figure 11 illustrates a communication system according to some embodiments of the present disclosure. In the embodiment illustrated in Figure 11 , the communication system includes a telecommunication network 1100, such as a 3GPP-type cellular network, which comprises an access network 1102, such as a RAN, and a core network 1104. The access network 1102 comprises a plurality of base stations 1106A, 1106B, 1106C, such as NBs, eNBs, gNBs, or other types of wireless Access Points (APs), each defining a corresponding coverage area 1108A, 1108B, 1108C. Each base station 1106A, 1106B, 1106C is connectable to the core network 1104 over a wired or wireless connection 1110. A first UE 1112 located in coverage area 1108C is configured to wirelessly connect to, or be paged by, the corresponding base station 1106C. A second UE 1114 in coverage area 1108A is wirelessly connectable to the corresponding base station 1106A. While a plurality of UEs 1112, 1114 are illustrated in this example, the disclosed embodiments are equally applicable to a situation where a sole UE is in the coverage area or where a sole UE is connecting to the corresponding base station 1106.

[0068] The telecommunication network 1100 is itself connected to a host computer 1116, which may be embodied in the hardware and/or software of a standalone server, a cloud-implemented server, a distributed server, or as processing resources in a server farm. The host computer 1116 may be under the ownership or control of a service provider, or may be operated by the service provider or on behalf of the service provider. Connections 1118 and 1120 between the telecommunication network 1100 and the host computer 1116 may extend directly from the core network 1104 to the host computer 1116 or may go via an optional intermediate network 1122. The intermediate network 1122 may be one of, or a combination of more than one of, a public, private, or hosted network; the intermediate network 1122, if any, may be a backbone network or the Internet; in particular, the intermediate network 1122 may comprise two or more sub-networks (not shown).

[0069] The communication system of Figure 11 as a whole enables connectivity between the connected UEs 1112, 1114 and the host computer 1116. The connectivity may be described as an Over-the-Top (OTT) connection 1124. The host computer 1116 and the connected UEs 1112, 1114 are configured to communicate data and/or signaling via the OTT connection 1124, using the access network 1102, the core network 1104, any intermediate network 1122, and possible further infrastructure (not shown) as intermediaries. The OTT connection 1124 may be transparent in the sense that the participating

communication devices through which the OTT connection 1124 passes are unaware of routing of uplink and downlink communications. For example, the base station 1106 may not or need not be informed about the past routing of an incoming downlink communication with data originating from the host computer 1116 to be forwarded (e.g., handed over) to a connected UE 1112. Similarly, the base station 1106 need not be aware of the future routing of an outgoing uplink communication originating from the UE 1112 towards the host computer 1116.

[0070] Figure 12 illustrates a communication system according to other embodiments of the present disclosure. The UE, base station, and host computer discussed in the preceding paragraphs will now be described with reference to Figure 12. In the embodiment illustrated in Figure 12, in a communication system 1200, a host computer 1202 comprises hardware 1204 including a communication interface 1206 configured to set up and maintain a wired or wireless connection with an interface of a different communication device of the communication system 1200. The host computer 1202 further comprises processing circuitry 1208, which may have storage and/or processing capabilities. In particular, the processing circuitry 1208 may comprise one or more programmable processors, ASICs, FPGAs, or combinations of these (not shown) adapted to execute instructions. The host computer 1202 further comprises software 1210, which is stored in or accessible by the host computer 1202 and executable by the processing circuitry 1208. The software 1210 includes a host application 1212. The host application 1212 may be operable to provide a service to a remote user, such as a UE 1214 connecting via an OTT connection 1216 terminating at the UE 1214 and the host computer 1202. In providing the service to the remote user, the host application 1212 may provide user data which is transmitted using the OTT connection 1216.

[0071]The communication system 1200 further includes a base station 1218 provided in a telecommunication system and comprising hardware 1220 enabling it to communicate with the host computer 1202 and with the UE 1214. The hardware 1220 may include a communication interface 1222 for setting up and maintaining a wired or wireless connection with an interface of a different communication device of the communication system 1200, as well as a radio interface 1224 for setting up and maintaining at least a wireless connection 1226 with the UE 1214 located in a coverage area (not shown in Figure 12) served by the base station 1218. The communication interface 1222 may be configured to facilitate a connection 1228 to the host computer 1202. The connection 1228 may be direct or it may pass through a core network (not shown in Figure 12) of the telecommunication system and/or through one or more intermediate networks outside the telecommunication system. In the embodiment shown, the hardware 1220 of the base station 1218 further includes processing circuitry 1230, which may comprise one or more programmable processors, ASICs, FPGAs, or combinations of these (not shown) adapted to execute instructions. The base station 1218 further has software 1232 stored internally or accessible via an external connection.

[0072] The communication system 1200 further includes the UE 1214 already referred to. The UE’s 1214 hardware 1234 may include a radio interface 1236 configured to set up and maintain a wireless connection 1226 with a base station serving a coverage area in which the UE 1214 is currently located. The hardware 1234 of the UE 1214 further includes processing circuitry 1238, which may comprise one or more programmable processors, ASICs, FPGAs, or combinations of these (not shown) adapted to execute instructions. The UE 1214 further comprises software 1240, which is stored in or accessible by the UE 1214 and executable by the processing circuitry 1238. The software 1240 includes a client application 1242. The client application 1242 may be operable to provide a service to a human or non-human user via the UE 1214, with the support of the host computer 1202. In the host computer 1202, the executing host application 1212 may communicate with the executing client application 1242 via the OTT connection 1216 terminating at the UE 1214 and the host computer 1202. In providing the service to the user, the client application 1242 may receive request data from the host application 1212 and provide user data in response to the request data. The OTT connection 1216 may transfer both the request data and the user data. The client application 1242 may interact with the user to generate the user data that it provides.

[0073] It is noted that the host computer 1202, the base station 1218, and the UE 1214 illustrated in Figure 12 may be similar or identical to the host computer 1116, one of the base stations 1106A, 1106B, 1106C, and one of the UEs 1112,

1114 of Figure 11 , respectively. This is to say, the inner workings of these entities may be as shown in Figure 12 and independently, the surrounding network topology may be that of Figure 11.

[0074] In Figure 12, the OTT connection 1216 has been drawn abstractly to illustrate the communication between the host computer 1202 and the UE 1214 via the base station 1218 without explicit reference to any intermediary devices and the precise routing of messages via these devices. The network

infrastructure may determine the routing, which may be configured to hide from the UE 1214 or from the service provider operating the host computer 1202, or both. While the OTT connection 1216 is active, the network infrastructure may further take decisions by which it dynamically changes the routing (e.g., on the basis of load balancing consideration or reconfiguration of the network).

[0075] The wireless connection 1226 between the UE 1214 and the base station 1218 is in accordance with the teachings of the embodiments described throughout this disclosure. One or more of the various embodiments improve the performance of OTT services provided to the UE 1214 using the OTT connection 1216, in which the wireless connection 1226 forms the last segment. More precisely, the teachings of these embodiments may reduce the number of network hops within the wireless network for SDC traffic and thereby provide benefits such as reduced latency, reduced transmission cost, and improved efficiency, especially to support efficient, infrequent, small data transmissions for low complexity, power constrained, and low data-rate CloT UEs.

[0076] A measurement procedure may be provided for the purpose of monitoring data rate, latency, and other factors on which the one or more embodiments improve. There may further be an optional network functionality for reconfiguring the OTT connection 1216 between the host computer 1202 and the UE 1214, in response to variations in the measurement results. The measurement procedure and/or the network functionality for reconfiguring the OTT connection 1216 may be implemented in the software 1210 and the hardware 1204 of the host computer 1202 or in the software 1240 and the hardware 1234 of the UE 1214, or both. In some embodiments, sensors (not shown) may be deployed in or in association with communication devices through which the OTT connection 1216 passes; the sensors may participate in the measurement procedure by supplying values of the monitored quantities exemplified above, or supplying values of other physical quantities from which the software 1210, 1240 may compute or estimate the monitored quantities. The reconfiguring of the OTT connection 1216 may include message format, retransmission settings, preferred routing, etc.; the reconfiguring need not affect the base station 1218, and it may be unknown or imperceptible to the base station 1218. Such procedures and functionalities may be known and practiced in the art. In certain embodiments, measurements may involve proprietary UE signaling facilitating the host computer 1202’s measurements of throughput, propagation times, latency, and the like. The measurements may be implemented in that the software 1210 and 1240 causes messages to be transmitted, in particular empty or‘dummy’ messages, using the OTT connection 1216 while it monitors propagation times, errors, etc.

[0077] Figure 13 is a flowchart illustrating a method implemented in a

communication system, in accordance with one embodiment. The

communication system includes a host computer, a base station, and a UE which may be those described with reference to Figures 11 and 12. For simplicity of the present disclosure, only drawing references to Figure 13 will be included in this section. In step 1300, the host computer provides user data. In sub-step 1302 (which may be optional) of step 1300, the host computer provides the user data by executing a host application. In step 1304, the host computer initiates a transmission carrying the user data to the UE. In step 1306 (which may be optional), the base station transmits to the UE the user data which was carried in the transmission that the host computer initiated, in accordance with the teachings of the embodiments described throughout this disclosure. In step 1308 (which may also be optional), the UE executes a client application associated with the host application executed by the host computer. [0078] Figure 14 is a flowchart illustrating a method implemented in a

communication system, in accordance with one embodiment. The

communication system includes a host computer, a base station, and a UE which may be those described with reference to Figures 11 and 12. For simplicity of the present disclosure, only drawing references to Figure 14 will be included in this section. In step 1400 of the method, the host computer provides user data.

In an optional sub-step (not shown) the host computer provides the user data by executing a host application. In step 1402, the host computer initiates a transmission carrying the user data to the UE. The transmission may pass via the base station, in accordance with the teachings of the embodiments described throughout this disclosure. In step 1404 (which may be optional), the UE receives the user data carried in the transmission.

[0079] Figure 15 is a flowchart illustrating a method implemented in a

communication system, in accordance with one embodiment. The

communication system includes a host computer, a base station, and a UE which may be those described with reference to Figures 11 and 12. For simplicity of the present disclosure, only drawing references to Figure 15 will be included in this section. In step 1500 (which may be optional), the UE receives input data provided by the host computer. Additionally or alternatively, in step 1502, the UE provides user data. In sub-step 1504 (which may be optional) of step 1500, the UE provides the user data by executing a client application. In sub-step 1506 (which may be optional) of step 1502, the UE executes a client application which provides the user data in reaction to the received input data provided by the host computer. In providing the user data, the executed client application may further consider user input received from the user. Regardless of the specific manner in which the user data was provided, the UE initiates, in sub-step 1508 (which may be optional), transmission of the user data to the host computer. In step 1510 of the method, the host computer receives the user data transmitted from the UE, in accordance with the teachings of the embodiments described throughout this disclosure. [0080] Figure 16 is a flowchart illustrating a method implemented in a

communication system, in accordance with one embodiment. The

communication system includes a host computer, a base station, and a UE which may be those described with reference to Figures 11 and 12. For simplicity of the present disclosure, only drawing references to Figure 16 will be included in this section. In step 1600 (which may be optional), in accordance with the teachings of the embodiments described throughout this disclosure, the base station receives user data from the UE. In step 1602 (which may be optional), the base station initiates transmission of the received user data to the host computer. In step 1604 (which may be optional), the host computer receives the user data carried in the transmission initiated by the base station.

[0081]Any appropriate steps, methods, features, functions, or benefits disclosed herein may be performed through one or more functional units or modules of one or more virtual apparatuses. Each virtual apparatus may comprise a number of these functional units. These functional units may be implemented via

processing circuitry, which may include one or more microprocessor or microcontrollers, as well as other digital hardware, which may include Digital Signal Processor (DSPs), special-purpose digital logic, and the like. The processing circuitry may be configured to execute program code stored in memory, which may include one or several types of memory such as Read Only Memory (ROM), Random Access Memory (RAM), cache memory, flash memory devices, optical storage devices, etc. Program code stored in memory includes program instructions for executing one or more telecommunications and/or data communications protocols as well as instructions for carrying out one or more of the techniques described herein. In some implementations, the processing circuitry may be used to cause the respective functional unit to perform

corresponding functions according one or more embodiments of the present disclosure.

[0082] While processes in the figures may show a particular order of operations performed by certain embodiments of the present disclosure, it should be understood that such order is exemplary (e.g., alternative embodiments may perform the operations in a different order, combine certain operations, overlap certain operations, etc.).

[0083] Some embodiments that have been described above may be summarized in the following manner:

Group A Embodiments : UPF-NIMF method embodiments

1. A method performed by a combined User Plane Function, UPF, and Network Internet of Things, loT, Messaging Function, NIMF, UPF-NIMF, the method comprising:

establishing (412, 414) a Packet Flow Control Protocol, PFCP, Small Data Communication, SDC, or Small Data Message Communication, SDMC, for a PFCP session with a Session Management Function, SMF; and

establishing a Protocol Data Unit, PDU, session (416) for Small Data Communication, SDC, or Small Data Messaging Communication, SDMC, with a User Equipment, UE.

2. The method of embodiment 1 wherein establishing the SDC or SDMC PFCP session with the SMF comprises:

receiving (412), from the SMF, a PFCP Small Data Communication Request message; and

sending (414), to the SMF, a PFCP Small Data Communication Response message.

3. The method of embodiment 1 or 2 wherein establishing the SDC or SDMC PFCP session with the SMF comprises receiving information associated with a SDC capability, and wherein establishing the PDU session for SDC or SDMC with the UE comprises establishing the PDU session based on the information associated with the SDC capability.

4. The method of any of embodiments 1 - 3 wherein the information associated with a SDC capability comprises at least one of: a PDU session identifier;

a PDU session type;

an International Mobile Subscriber Identity, IMSI;

an International Mobile Equipment Identifier, IMEI;

an IMEI Software Version, IMEISV;

an external identifier;

a Mobile Station International Subscriber Directory Number, MSISDN; an Internet Protocol, IP, address of the UE;

a serving Public Land Mobile Network, PLMN, rate control;

a serving PLMN identifier;

a Protocol Configuration Option, PCO, parameter; and

a usage reporting rule.

5. The method of any of embodiments 1 - 4 further comprising establishing the PFCP session with the SMF prior to establishing the PFCP SDC or SDMC with the SMF.

6. The method of embodiment 5 wherein establishing the PFCP session with the SMF comprises:

receiving (408), from the SMF, a PFCP Session Establishment Request message; and

sending (410), to the SMF, a PFCP Session Establishment Response message.

7. The method of any of embodiments 1 - 5 wherein at least one of the establishing (408, 410) a PFCP session with the SMF or establishing (412, 414) the SDC or SDMC PFCP session with the SMF steps is performed using signaling over a N4 interface or a N9 interface.

8. The method of any of embodiments 1 - 7 further comprising storing, by the UPF-NIMF, at least one of: an IP address of the PDU session; an IMSI, an external ID, or MSISDN of the UE; an IP version to use when communicating with the UE; a PDU session type; a Protocol Configuration Option, PCO, parameter; and a forwarding IP address of a PDU session allocated by the SMF.

9. The method of any of embodiments 1 - 8 further comprising associating, by the UPF-NIMF, an Application Programming Interface, API, with the

established PDU session.

10. The method of any of embodiments 1 - 9 wherein associating the API with the established PDU session comprises associating at least one of: a Nm API; a T8 Non-IP Data Delivery (NIDD) API; a T8 API; an operator-specific API; and a vendor-specific API with the established PDU session.

11. The method of any of embodiments 1 - 10 wherein the UPF-NIMF operates as a protocol proxy between a protocol used for communication between the UE and the UPF-NIMF and an API used for communication between the UPF-NIMF and a Service Capability Server, SCS, or Application Server, AS.

12. The method of any of embodiments 1 - 10 wherein the UPF-NIMF operates as a protocol proxy or an application level gateway between a protocol used for communication between the UE and the UPF-NIMF and an API used for communication between the UPF-NIMF and a Service Capability Server, SCS, or Application Server, AS.

13. The method of any of embodiments 1 - 12 wherein receiving the

information associated with a SDC capability while establishing the PFCP session with the UPF comprises receiving the information associated with a SDC capability as part of a PFCP Session Establishment Request message.

14. The method of any of embodiments 1 - 13, further comprising:

obtaining user data; and forwarding the user data to a host computer or the UE.

Group B Embodiments : SMF method embodiments

15. A method performed by Session Management Function, SMF, the method comprising:

receiving, from a User Equipment, UE, a request to establish a Protocol Data Unit, PDU, session (406), and, in response to receiving the request to establish a PDU session:

determining that the PDU session is for Small Data

Communication, SDC;

selecting a User Plane Function, UPF, that supports SDC; and establishing (412, 414) a Packet Flow Control Protocol, PFCP, Small Data Communication, SDC, or Small Data Message

Communication, SDMC, for a PFCP session with the selected UPF.

16. The method of embodiment 15 further comprising establishing a PFCP session with the selected UPF prior to establishing the PFCP SDC or SDMC for the PFCP session with the selected UPF.

17. The method of embodiment 16 wherein establishing the PFCP session with the selected UPF comprises:

sending (408) a PFCP Session Establishment Request message to the selected UPF; and

receiving (410) a PFCP Session Establishment Response message from the selected UPF.

18. The method of any of embodiments 15 - 17 wherein determining that the PDU session is for SDC comprises determining that the PDU sessions if for SDC based on at least one of:

a Domain Network Name, DNN;

a local DNN configuration; information about a network slice;

UE subscription information;

a local SMF configuration; and

UPF information received from a Network Repository Function, NRF.

19. The method of any of embodiments 15 - 18 wherein selecting a UPF that supports SDC comprises selecting a UPF that supports Network Internet of Things, loT, Messaging Function, NIMF, UPF-NIMF.

20. The method of any of embodiments 15 - 19 wherein selecting a UPF that supports SDC comprises selecting a UPF that supports SDC based on at least one of:

UE subscription information;

a data network configuration;

a local SMF configuration; and

UPF information received from a Network Repository Function, NRF.

21. The method of any of embodiments 15 - 20 wherein establishing a PFCP SDC or SDMC for a PFCP session with the selected UPF comprises:

sending (412), to the selected UPF, a PFCP Small Data Communication Request message; and

receiving (414), from the selected UPF, a PFCS Small Data

Communication Response message.

22. The method of any of embodiments 15 - 21 wherein the PFCP SDC Request message comprises information associated with a SDC capability.

23. The method of any of embodiments 15 - 22 wherein the information associated with a SDC capability comprises at least one of:

a PDU session identifier; a PDU session type;

an International Mobile Subscriber Identity, IMSI;

an International Mobile Equipment Identifier, IMEI;

an IMEI Software Version, IMEISV;

an external identifier;

a Mobile Station International Subscriber Directory Number, MSISDN; an Internet Protocol, IP, address of the UE;

a serving Public Land Mobile Network, PLMN, rate control;

a serving PLMN identifier;

a Protocol Configuration Option, PCO, parameter; and

a usage reporting rule.

24. The method of any of embodiments 15 - 23 wherein providing the UPF with information associated with a SDC capability further comprises receiving (414), from the UPF, a PFCP Small Data Messaging Response.

25. The method of any of embodiments 15 - 24 wherein at least one of the establishing (408, 410) and providing (412, 414) steps is performed using signaling over a N4 interface or a N9 interface.

Group C Embodiments : Apparatus and System embodiments

26. A combined User Plane Function, UPF, and Network Internet of Things, loT, Messaging Function, NIMF, UPF-NIMF, the UPS-NIMF comprising:

a network interface; and

processing circuitry configured to perform any of the steps of any of the Group A embodiments.

27. A Session Management Function, SMF, the SMF comprising:

a network interface; and

processing circuitry configured to perform any of the steps of any of the Group B embodiments. 28. A communication system including a host computer comprising:

processing circuitry configured to provide user data; and

a communication interface configured to forward the user data to a cellular network for transmission to a User Equipment, UE;

wherein the cellular network comprises a combined User Plane Function, UPF, and Network Internet of Things, loT, Messaging Function, NIMF, UPF- NIMF, the UPF-NIMF comprising processing circuitry configured to perform any of the steps of any of the Group A embodiments.

29. The communication system of the previous embodiment further including a Session Management Function, SMF, the SMF comprising processing circuitry configured to perform any of the steps of any of the Group B embodiments.

30. The communication system of the previous 2 embodiments, further including the UE, wherein the UE is configured to communicate with the UPF- NIMF using at least one of a Small Data Communication, SDC, protocol and a Small Data Message Communication, SDMC, protocol.

31. The communication system of the previous 3 embodiments, wherein: the processing circuitry of the UPF-NIMF is configured to execute a UPF-

NIMF application, thereby providing the user data; and

the UE comprises processing circuitry configured to execute a client application associated with the user data.

Group D Embodiments : OTT embodiments

32. A method implemented in a communication system including a host computer, a base station, and a User Equipment, UE, the method comprising: at the host computer, providing user data; and

at the host computer, initiating a transmission carrying the user data to the UE via a cellular network comprising the base station. 33. The method of the previous embodiment, further comprising, at the base station, transmitting the user data.

34. The method of the previous 2 embodiments, wherein the user data is provided at the host computer by executing a host application, the method further comprising, at the UE, executing a client application associated with the host application.

35. A User Equipment, UE, configured to communicate with a base station, the UE comprising a radio interface and processing circuitry configured to perform the method of the previous 3 embodiments.

36. A communication system including a host computer comprising:

processing circuitry configured to provide user data; and

a communication interface configured to forward user data to a cellular network for transmission to a User Equipment, UE;

wherein the UE comprises a radio interface and processing circuitry.

37. The communication system of the previous embodiment, wherein the cellular network further includes a base station configured to communicate with the UE.

38. The communication system of the previous 2 embodiments, wherein: the processing circuitry of the host computer is configured to execute a host application, thereby providing the user data; and

the UE’s processing circuitry is configured to execute a client application associated with the host application.

39. A method implemented in a communication system including a host computer, a base station, and a User Equipment, UE, the method comprising: at the host computer, providing user data; and

at the host computer, initiating a transmission carrying the user data to the UE via a cellular network comprising the base station.

40. The method of the previous embodiment, further comprising at the UE, receiving the user data from the base station.

41. A communication system including a host computer comprising:

communication interface configured to receive user data originating from a transmission from a User Equipment, UE, to a base station;

wherein the UE comprises a radio interface and processing circuitry.

42. The communication system of the previous embodiment, further including the UE.

43. The communication system of the previous 2 embodiments, further including the base station, wherein the base station comprises a radio interface configured to communicate with the UE and a communication interface configured to forward to the host computer the user data carried by a

transmission from the UE to the base station.

44. The communication system of the previous 3 embodiments, wherein: the processing circuitry of the host computer is configured to execute a host application; and

the UE’s processing circuitry is configured to execute a client application associated with the host application, thereby providing the user data.

45. The communication system of the previous 4 embodiments, wherein: the processing circuitry of the host computer is configured to execute a host application, thereby providing request data; and the UE’s processing circuitry is configured to execute a client application associated with the host application, thereby providing the user data in response to the request data.

46. A method implemented in a communication system including a host computer, a base station, and a User Equipment, UE, the method comprising: at the host computer, receiving user data transmitted to the base station from the UE.

47. The method of the previous embodiment, further comprising, at the UE, providing the user data to the base station.

48. The method of the previous 2 embodiments, further comprising:

at the UE, executing a client application, thereby providing the user data to be transmitted; and

at the host computer, executing a host application associated with the client application.

49. The method of the previous 3 embodiments, further comprising:

at the UE, executing a client application; and

at the UE, receiving input data to the client application, the input data being provided at the host computer by executing a host application associated with the client application;

wherein the user data to be transmitted is provided by the client application in response to the input data.

50. A communication system including a host computer comprising a communication interface configured to receive user data originating from a transmission from a User Equipment, UE, to a base station, wherein the base station comprises a radio interface and processing circuitry. 51. The communication system of the previous embodiment further including the base station.

52. The communication system of the previous 2 embodiments, further including the UE, wherein the UE is configured to communicate with the base station.

53. The communication system of the previous 3 embodiments, wherein: the processing circuitry of the host computer is configured to execute a host application; and

the UE is configured to execute a client application associated with the host application, thereby providing the user data to be received by the host computer. 54. A method implemented in a communication system including a host computer, a base station, and a User Equipment, UE, the method comprising: at the host computer, receiving, from the base station, user data originating from a transmission which the base station has received from the UE. 55. The method of the previous embodiment, further comprising at the base station, receiving the user data from the UE.

56. The method of the previous 2 embodiments, further comprising at the base station, initiating a transmission of the received user data to the host computer. Abbreviations

[0084] At least some of the following abbreviations may be used in this disclosure. If there is an inconsistency between abbreviations, preference should be given to how it is used above. If listed multiple times below, the first listing should be preferred over any subsequent listing(s).

1x RTT CDMA2000 1x Radio Transmission Technology

2G Second Generation

3G Third Generation

3GPP Third Generation Partnership Project

4G Fourth Generation

5G Fifth Generation

5GS Fifth Generation System

ABS Almost Blank Subframe

AF Application Function

AMF Core Access and Mobility Management Function

AMQP Advanced Message Queuing Protocol

AP Access Point

API Application Programming Interface

APN Access Point Name

ARQ Automatic Repeat Request

AS Application Server

ASIC Application Specific Integrated Circuit

ATM Asynchronous Transfer Mode

AUSF Authentication Server Function

AWGN Additive White Gaussian Noise

B2B Business-to-Business

BCCH Broadcast Control Channel

BCH Broadcast Channel • BS Base Station

• BSC Base Station Controller

• BTS Base Transceiver Station

• BW Bandwidth

• BWP Bandwidth Part

• BYOD Bring Your Own Device

• CA Carrier Aggregation

• CC Component Carrier

• CCCH Common Control Channel

• CD Compact Disk

• CDMA Code Division Multiple Access

• CGI Cell Global Identifier

• CloT Cellular Internet of Things

• CIR Channel Impulse Response

• CoAP Constrained Application Protocol

• COTS Commercial Off-the-Shelf

• CP Cyclic Prefix

• CPE Customer Premises Equipment

• CPICH Ec/No Common Pilot Channel received energy per chip divided by the power density in the band

• CPICH Common Pilot Channel

• CPU Central Processing Unit

• CQI Channel Quality Information

• C-RNTI Cell Radio Network Temporary Identifier

• CSI Channel State Information

• CSI-RS Channel State Information Reference Signal

• D2D Device-to-Device

• DAS Distributed Antenna System

• DC Direct Current DCCH Dedicated Control Channel

DIMM Dual In-Line Memory Module

DL Downlink

DM Demodulation

DMRS Demodulation Reference Signal

DN Data Network

DNN Data Network Name

DRX Discontinuous Reception

DSP Digital Signal Processor

DTCH Dedicated Traffic Channel

DTLS Datagram Transport Layer Security

DTX Discontinuous Transmission

DUT Device Under Test

DVD Digital Video Disk

ECGI Evolved Cell Global Identifier

E-CID Enhanced Cell Identifier (positioning method)

EEPROM Electrically Erasable Programmable Read Only Memory eMTC Enhanced Machine-Type Communication

eNB Enhanced or Evolved Node B

EPC Evolved Packet Core

ePDCCH Enhanced Physical Downlink Control Channel

EPROM Erasable Programmable Read Only Memory

E-SMLC Evolved Serving Mobile Location Center

E-UTRA Evolved Universal Terrestrial Radio Access

E-UTRAN Evolved Universal Terrestrial Radio Access Network

FDD Frequency Division Duplexing

FFS For Further Study

FPGA Field Programmable Gate Array

F-SEID Fully Qualified Session Endpoint Identifier • GERAN Global System for Mobile (GSM) Communications

Enhanced Data Rates for GSM Evolution Radio Access Network

• GHz Gigahertz

. gNB New Radio Base Station

• GNSS Global Navigation Satellite System

• GPS Global Positioning System

• GSM Global System for Mobile Communications

• HARQ Hybrid Automatic Repeat Request

• HDDS Holographic Digital Data Storage

• HD-DVD High-Density Digital Versatile Disc

• HO Handover

• HPLMN Home Public Land Mobile Network

• HRPD High Rate Packet Data

• HSPA High Speed Packet Access

• HSS Home Subscriber Server

• HTTP Hyper Text Transport Protocol

• I/O Input and Output

• ID Identifier / Identity

• IE Information Element

• IMEI International Mobile Equipment Identity

• IMEISV International Mobile Equipment Identity Software Version

• IMS Internet Protocol Multimedia Subsystem

• IMSI International Mobile Subscriber Identity

• loT Internet of Things

• IP Internet Protocol

• LAN Local Area Network

• LEE Laptop Embedded Equipment

• LME Laptop Mounted Equipment LoRa Long Range (wireless data communication)

LOS Line of Sight

LPP Long Term Evolution Positioning Protocol

LTE Long Term Evolution

M2M Machine-to-Machine

MAC Medium Access Control

MANO Management and Orchestration

MBMS Multimedia Broadcast Multicast Services

MBSFN Multimedia Broadcast Multicast Service Single

Frequency Network

MCE Multi-Cell/Multicast Coordination Entity

MDT Minimization of Drive Tests

MIB Master Information Block

MIMO Multiple Input Multiple Output

MME Mobility Management Entity

MNO Mobile Network Operator

MQTT Message Queuing Telemetry Transport

MSC Mobile Switching Center

MSISDN Mobile Station International Subscriber Directory Number

MSR Multi-Standard Radio

MTC Machine Type Communication

MVNO Mobile Virtual Network Operator

NB Node B

NB-loT Narrowband Internet of Things

NEF Network Exposure Function

NF Network Function

NFV Network Function Virtualization

NIC Network Interface Controller

NIDD Non - Internet Protocol Data Delivery NIMF Network Internet of Things Messaging Function

NPDCCH Narrowband Physical Downlink Control Channel

NR New Radio

NRF Network Repository Function

NSSF Network Slice Selection Function

NWDAF Network Data Analytics Function

O&M Operation and Maintenance

OCNG Orthogonal Frequency Division Multiple Access Channel

Noise Generator

OCS Online Charging System

OFDM Orthogonal Frequency Division Multiplexing

OFDMA Orthogonal Frequency Division Multiple Access

ONAP Open Network Automation Platform

OS Online Service

OSS Operations Support System

OTDOA Observed Time Difference of Arrival

OTT Over-the-Top

PBCH Physical Broadcast Channel

P-CCPCH Primary Common Control Physical Channel

PCell Primary Cell

PCF Policy Control Function

PCFICH Physical Control Format Indicator Channel

PCO Protocol Configuration Options

PDA Personal Digital Assistant

PDCCH Physical Downlink Control Channel

PDP Profile Delay Profile

PDSCH Physical Downlink Shared Channel

PDU Protocol Data Unit

PFCP Packet Forwarding Control Protocol • PGW or P-GW Packet Data Network Gateway

• PHICH Physical Hybrid Automatic Repeat Request Indicator

Channel

• PLMN Public Land Mobile Network

• PMI Precoder Matrix Indicator

• PRACH Physical Random Access Channel

• PRB Physical Resource Block

• PROM Programmable Read Only Memory

• PRS Positioning Reference Signal

• PSS Primary Synchronization Signal

• PSTN Public Switched Telephone Networks

• PUCCH Physical Uplink Control Channel

• PUSCH Physical Uplink Shared Channel

• QCI Quality of Service Class Identifier

• QoS Quality of Service

• RACH Random Access Channel

• RADIUS Remote Authentication Dial In User Service

• RAID Redundant Array of Independent Disks

• RAM Random Access Memory

• RAN Radio Access Network

• RAT Radio Access Technology

• RDS Reliable Data Service

• RE Resource Element

• RF Radio Frequency

• RLM Radio Link Management

• RNC Radio Network Controller

• RNTI Radio Network Temporary Identifier

• ROM Read Only Memory

• RRC Radio Resource Control • RRH Remote Radio Flead

• RRM Radio Resource Management

• RRU Remote Radio Unit

• RS Reference Signal

• RSCP Received Signal Code Power

• RSRP Reference Symbol Received Power / Reference Signal

Received Power

• RSRQ Reference Symbol Received Quality / Reference Signal

Received Quality

• RSSI Received Signal Strength Indicator

• RSTD Reference Signal Time Difference

• RUIM Removable User Identity

• SBA Service Based Architecture

• SBI Service Based Interface

• SCEF Service Capability Exposure Function

• SCell Secondary Cell

• SCH Synchronization Channel

• SCS Service Capability Server(s)

• SDC Small Data Communication(s)

• SDMC Small Data Message Communication(s)

• SDN Software Defined Network

• SDRAM Synchronous Dynamic Random Access Memory

• SDU Service Data Unit

• SEPP Security Edge Protection Proxy

• SFN System Frame Number

• SGW or S-GW Serving Gateway

• SI System Information

• SIB System Information Block

• SIM Subscriber Identity Module

• SMF Session Management Function • SNR Signal to Noise Ratio

• SOC System on a Chip

• SON Self-Organizing Network

• SONET Synchronous Optical Networking

• SRS Sounding Reference Signal

• SS Synchronization Signal

• SSS Secondary Synchronization Signal

• SUPI Subscriber Permanent Identifier

• TAI Tracking Area Identity

• TCP Transmission Control Protocol

• TDD Time Division Duplexing

• TDOA Time Difference of Arrival

• TOA Time of Arrival

• TPMI Transmit Precoding Matrix Indicator

• TR Technical Report

• TRP Transmission/Reception Point

• TS Technical Specification

• TSS Tertiary Synchronization Signal

• TTI Transmission Time Interval

• UDM Unified Data Management

• UDR User Data Repository

• UE User Equipment

• UL Uplink

• UMTS Universal Mobile Telecommunications System

• UP User Plane

• UPF User Plane Function

• UPF-NIMF User Plane Function - Network Internet of Things

Messaging Function

• URL Uniform Resource Locator

• USB Universal Serial Bus • USIM Universal Subscriber Identity Module

• UTDOA Uplink Time Difference of Arrival

• UTRA Universal Terrestrial Radio Access

• UTRAN Universal Terrestrial Radio Access Network · V2I Vehicle-to-lnfrastructure

• V2V Vehicle-to-Vehicle

• V2X Vehicle-to-Everything

• VPLMN Visited Public Land Mobile Network

• VMM Virtual Machine Monitor

· VNE Virtual Network Element

• VNF Virtual Network Function

• VoIP Voice over Internet Protocol

• VOLTE Voice over Long Term Evolution

• WAN Wide Area Network

· WCDMA Wideband Code Division Multiple Access

• WD Wireless Device

• WiMax Worldwide Interoperability for Microwave Access

• WLAN Wireless Local Area Network

• XMPP Extensible Messaging and Presence Protocol

Claims

1. A method performed by a combined User Plane Function, UPF, and Network Internet of Things, loT, Messaging Function, NIMF, UPF-NIMF, the method comprising:

establishing (412, 414) a Packet Flow Control Protocol, PFCP, Small Data Communication, SDC, or Small Data Message Communication, SDMC, for a PFCP session with a Session Management Function, SMF; and

establishing a Protocol Data Unit, PDU, session (416) for Small Data Communication, SDC, or Small Data Messaging Communication, SDMC, with a User Equipment, UE.

2. The method according to claim 1 wherein establishing the SDC or SDMC PFCP session with the SMF comprises:

receiving (412), from the SMF, a PFCP Small Data Communication Request message; and

sending (414), to the SMF, a PFCP Small Data Communication Response message.

3. The method according to claim 1 or 2 wherein establishing the SDC or SDMC PFCP session with the SMF comprises receiving information associated with a SDC capability, and wherein establishing the PDU session for SDC or SDMC with the UE comprises establishing the PDU session based on the information associated with the SDC capability.

4. The method according to any one of claim 1 - 3 wherein the information associated with a SDC capability comprises at least one of:

a PDU session identifier;

a PDU session type;

an International Mobile Subscriber Identity, IMSI;

an International Mobile Equipment Identifier, IMEI; an IMEI Software Version, IMEISV;

an external identifier;

a Mobile Station International Subscriber Directory Number, MSISDN; an Internet Protocol, IP, address of the UE;

a serving Public Land Mobile Network, PLMN, rate control;

a serving PLMN identifier;

a Protocol Configuration Option, PCO, parameter; and

a usage reporting rule.

5. The method according to any one of claim 1 - 4 further comprising establishing the PFCP session with the SMF prior to establishing the PFCP SDC or SDMC with the SMF.

6. The method according to claim 5 wherein establishing the PFCP session with the SMF comprises:

receiving (408), from the SMF, a PFCP Session Establishment Request message; and

sending (410), to the SMF, a PFCP Session Establishment Response message.

7. The method according to any one of claim 1 - 5 wherein at least one of the establishing (408, 410) a PFCP session with the SMF or establishing (412, 414) the SDC or SDMC PFCP session with the SMF steps is performed using signaling over a N4 interface or a N9 interface.

8. The method according to any one of claim 1 - 7 further comprising storing, by the UPF-NIMF, at least one of: an IP address of the PDU session; an IMSI, an external ID, or MSISDN of the UE; an IP version to use when communicating with the UE; a PDU session type; a Protocol Configuration Option, PCO, parameter; and a forwarding IP address of a PDU session allocated by the SMF.

9. The method according to any one of claim 1 - 8 further comprising associating, by the UPF-NIMF, an Application Programming Interface, API, with the established PDU session.

10. The method according to any one of claim 1 - 9 wherein associating the API with the established PDU session comprises associating at least one of: a Nm API; a T8 Non-IP Data Delivery (NIDD) API; a T8 API; an operator-specific API; and a vendor-specific API with the established PDU session.

11. The method according to any one of claim 1 - 10 wherein the UPF-NIMF operates as a protocol proxy between a protocol used for communication between the UE and the UPF-NIMF and an API used for communication between the UPF-NIMF and a Service Capability Server, SCS, or Application Server, AS.

12. The method according to any one of claim 1 - 10 wherein the UPF-NIMF operates as a protocol proxy or an application level gateway between a protocol used for communication between the UE and the UPF-NIMF and an API used for communication between the UPF-NIMF and a Service Capability Server, SCS, or Application Server, AS.

13. The method according to any one of claim 1 - 12 wherein receiving the information associated with a SDC capability while establishing the PFCP session with the UPF comprises receiving the information associated with a SDC capability as part of a PFCP Session Establishment Request message.

14. The method according to any one of claim 1 - 13, further comprising:

obtaining user data; and

forwarding the user data to a host computer or the UE.

15. A method performed by Session Management Function, SMF, the method comprising:

receiving, from a User Equipment, UE, a request to establish a Protocol Data Unit, PDU, session (406), and, in response to receiving the request to establish a PDU session:

determining that the PDU session is for Small Data

Communication, SDC;

selecting a User Plane Function, UPF, that supports SDC; and establishing (412, 414) a Packet Flow Control Protocol, PFCP, Small Data Communication, SDC, or Small Data Message

Communication, SDMC, for a PFCP session with the selected UPF.

16. The method according to claim 15 further comprising establishing a PFCP session with the selected UPF prior to establishing the PFCP SDC or SDMC for the PFCP session with the selected UPF.

17. The method according to claim 16 wherein establishing the PFCP session with the selected UPF comprises:

sending (408) a PFCP Session Establishment Request message to the selected UPF; and

receiving (410) a PFCP Session Establishment Response message from the selected UPF.

18. The method according to any one of claim 15 - 17 wherein determining that the PDU session is for SDC comprises determining that the PDU sessions if for SDC based on at least one of:

a Domain Network Name, DNN;

a local DNN configuration;

information about a network slice;

UE subscription information;

a local SMF configuration; and UPF information received from a Network Repository Function, NRF.

19. The method according to any one of claim 15 - 18 wherein selecting a UPF that supports SDC comprises selecting a UPF that supports Network Internet of Things, loT, Messaging Function, NIMF, UPF-NIMF.

20. The method according to any one of claim 15 - 19 wherein selecting a UPF that supports SDC comprises selecting a UPF that supports SDC based on at least one of:

UE subscription information;

a data network configuration;

a local SMF configuration; and

UPF information received from a Network Repository Function, NRF.

21. The method according to any one of claim 15 - 20 wherein establishing a PFCP SDC or SDMC for a PFCP session with the selected UPF comprises: sending (412), to the selected UPF, a PFCP Small Data Communication Request message; and

receiving (414), from the selected UPF, a PFCS Small Data

Communication Response message.

22. The method according to any one of claim 15 - 21 wherein the PFCP SDC Request message comprises information associated with a SDC capability.

23. The method according to any one of claim 15 - 22 wherein the information associated with a SDC capability comprises at least one of:

a PDU session identifier;

a PDU session type;

an International Mobile Subscriber Identity, IMSI;

an International Mobile Equipment Identifier, IMEI; an IMEI Software Version, IMEISV;

an external identifier;

a Mobile Station International Subscriber Directory Number, MSISDN; an Internet Protocol, IP, address of the UE;

a serving Public Land Mobile Network, PLMN, rate control;

a serving PLMN identifier;

a Protocol Configuration Option, PCO, parameter; and

a usage reporting rule.

24. The method according to any one of claim 15 - 23 wherein providing the UPF with information associated with a SDC capability further comprises receiving (414), from the UPF, a PFCP Small Data Messaging Response.

25. The method according to any one of claim 15 - 24 wherein at least one of the establishing (408, 410) and providing (412, 414) steps is performed using signaling over a N4 interface or a N9 interface.

26. A combined User Plane Function, UPF, and Network Internet of Things, loT, Messaging Function, NIMF, UPF-NIMF, the UPS-NIMF comprising:

a network interface; and

processing circuitry configured to perform the steps according to any of claim 1 -14.

27. A Session Management Function, SMF, the SMF comprising:

a network interface; and

processing circuitry configured to perform the steps according to any of claim 15-25.