Enabling time synchronization and time recovery services via subscription

Abstract

The present invention provides a method and apparatus for permitting time synchronization service requests or time-recoverable time synchronization service requests from application functions in a communication system. [Solution] In a wireless communication system, a time synchronization service network function that supports time synchronization services receives requests from application functions (AFs) to a UE or group of UEs requesting time synchronization services or, alternatively, time-recoverable time synchronization services. The time synchronization service network function obtains subscription data for the UE or group of UEs indicating whether the time synchronization request from the AF is permitted. If permitted, the request is allowed to start; otherwise, the request from the AF is rejected.

Description

Technical Field

[0001] Related Applications This application claims the benefit of Provisional Patent Application Serial No. 63 / 322301, filed Mar. 22, 2022, the disclosure of which is hereby incorporated by reference in its entirety.

[0002] This disclosure relates to time synchronization services in telecommunications systems.

Background Art

[0003] In general, all terms used herein shall be construed to have their ordinary meaning in the relevant technical field, unless a different meaning is explicitly given and / or implied from the context in which they are used. References to an element, apparatus, component, means, step, etc. shall all be construed openly as referring to at least one instance of that element, apparatus, component, means, step, etc., unless explicitly stated otherwise. Steps of the methods disclosed herein need not be performed in the exact order disclosed, unless the step is explicitly described as following or preceding another step and / or unless it is implicitly described that the step must follow or precede another step. Any feature of any of the embodiments disclosed herein can, where appropriate, be applied to other embodiments. Similarly, any advantage of any embodiment can be applied to any other embodiment, and vice versa. Other objectives, features, and advantages of the enclosed embodiments will become apparent from the following description.

[0004] Technical specifications (TS) 23.501 V17.3.0 and TS23.502 V17.3.0 of the Third Generation Partnership Project (3GPP®) define aspects related to fifth-generation system (5G system (5GS)) functionality that enables time-sensitive communications and time synchronization services. For example, to achieve time synchronization in a 5G system, 3GPP TS23.501 V17.3.0 explains that 5GS can operate with one or more Point Precision Time Protocol (PTP) instances, each PTP instance can operate as follows: 1) Time recognition systems as described in IEEE standard 802.1AS, 2) Boundary clocks specified in IEEE standard 1588, provisioned by profiles supported by the 3GPP specification (including SMPTE Profile for Use of IEEE Std 1588 Precision Time Protocol (PTP) in Professional Broadcast Applications ST 2059-2:2015), 3) Peer-to-peer transparent clocks described in IEEE standard 1588, provisioned by profiles supported by the 3GPP specification (including SMPTE Profile for Use of IEEE Std 1588 Precision Time Protocol in Professional Broadcast Applications ST 2059-2:2015), 4) An end-to-end transparent clock described in IEEE standard 1588, provisioned by a profile supported by the 3GPP specification (including SMPTE Profile for Use of IEEE Std 1588 Precision Time Protocol in Professional Broadcast Applications ST 2059-2:2015). According to 3GPP TS23.501 V17.3.0 clauses 5.27.1.8 and 5.27.1.9, application functions (AF) can influence timing allocation between RAN and UE, and UE / DS-TT can distribute timing information externally through implementation-specific means. Time synchronization services can also be enabled by using an access layer time allocation scheme.

[0005] Figure 1 shows the 3GPP Release 17 reference point for a 5G system that enables time-sensitive communications and time synchronization. This architecture includes a device-side time-sensitive network (TSN) translator (DS-TT) and a network-side TSN translator (NW-TT). The TSN translator function provides interoperability between TSN systems and 5G systems in both the user plane and the control plane. This architecture also includes a time-sensitive communications (TSC) and time synchronization function (TSCTSF) that controls the DS-TT and NW-TT for a common (g)PTP-based time synchronization service based on IEEE 802.1AS. As part of 3GPP Release 18, a technical report TR23.700-25 V.0.1.0 on enhancements to timing resilience, TSC, and URLLC has been produced. [Overview of the Initiative]

[0006] Currently, a challenge exists. Specifically, 3GPP Release 18TR23.700-25 outlines several important issues that need to be considered. Key Issue #3 concerns controlling time synchronization based on UE subscriptions, proposing the introduction of subscription parameters for time synchronization and their implementation in 5GS. The problem is that existing solutions do not address how to control time resilience using time synchronization.

[0007] Certain aspects and embodiments of this disclosure may provide solutions to the aforementioned problems or other problems. Embodiments of the solutions described herein propose using subscription data as an enabler for time synchronization services in 5GS.

[0008] The embodiments described herein describe the use of timing synchronization architectures and services provided in 5G systems (5GS), but it is clear that these solutions can be applied to any system that supports such services, including future 6G systems, though they are not limited thereto.

[0009] Embodiments of this disclosure provide solutions that enable timing synchronization control and more complex timing recovery services.

[0010] According to several embodiments, a method is provided for authorizing requests for time synchronization services or time-recoverable time synchronization services from application functions (AFs) that are implemented in a time synchronization service network function (e.g., TSCTSF in a 5G system).

[0011] This method includes the step of receiving a time synchronization request for a UE or group of UEs originating from an Application Function (AF). This request can be received via a Network Exposure Function (NEF) or directly from the AF. Alternatively, a time synchronization service request from the AF may further include a time synchronization request with a time recovery service. A time synchronization or time synchronization with time recovery request may include parameters related to the requested timing recovery service.

[0012] The method further includes the step of obtaining subscription data for a UE or group of UEs indicating whether a time synchronization request from the AF is permitted to be initiated. For example, the time synchronization service network function obtains the subscription data by sending a request to a User Data Management (UDM) node requesting subscription data related to time synchronization with a time synchronization service or time recovery service (if requested by the AF), and receiving subscription data indicating whether the time synchronization service is permitted, or instead, whether time synchronization with a time recovery service is permitted. In one example, the subscription data may include an indication that time synchronization with the time synchronization service or time recovery service is enabled or disabled. Alternatively, if the subscription data includes time synchronization or time synchronization with time recovery that matches the request from the AF, the time synchronization network function may decide to authorize the request from the AF if the request matches the subscription.

[0013] This method further includes the step of determining from the acquired subscription data for the UE or UE group that a request for time synchronization or alternatively time-recoverable time synchronization from the AF is not permitted, in which case the time synchronization service network function rejects the time synchronization service or time-recoverable time synchronization request received from the AF. A rejection message is sent back to the AF. In another example, if the time synchronization service network function determines that the subscription data permits a request for time synchronization service / time-recoverable time synchronization from the AF, it proceeds with activating / providing the time synchronization service or time-recoverable time synchronization service to the UE or UE group.

[0014] In one embodiment, the time synchronization service network function further subscribes to the user data management node to receive changes to the subscription to time synchronization, which has time synchronization or time recovery services. In another example, the time synchronization service network function then receives a notification from the UDM or AF to disable the time recovery service, and upon receiving the notification, can deactivate the time recovery service.

[0015] In another embodiment, the time synchronization service network function performs the step of receiving a notification from the UDM or AF to disable the time synchronization service, and upon receiving the notification, deactivates the time synchronization service and the timing resilience service if timing resilience was previously permitted and / or activated.

[0016] In one embodiment, a node that implements a time synchronization service network function is configured to implement any of the embodiments described herein.

[0017] In another embodiment, a node is provided comprising one or more processors and memory for storing instructions that, when executed by the one or more processors of a node performing a time synchronization service, perform any of the embodiments described herein.

[0018] In another embodiment, a computer-readable medium containing program instructions causing one or more processors of a node performing a time synchronization service to execute any of the embodiments described herein. [Brief explanation of the drawing]

[0019] The figures in the accompanying drawings incorporated herein and constituting part of herein illustrate several aspects of this disclosure and are useful in illustrating the principles of this disclosure together with the description herein.

[0020] [Figure 1]An exemplary embodiment is shown in which the cellular communication system of FIG. 1 is a fifth generation (5G) system (5GS).

[0021] [Figure 2] An example of a cellular communication system in which embodiments of the present disclosure can be implemented is shown.

[0022] [Figure 3] The service-based interface (SBI) architecture of the (5G) system (5GS) of FIG. 1 is shown.

[0023] [Figure 4] A procedure according to an embodiment of the present disclosure is shown.

[0024] [Figure 5A] Another procedure according to another embodiment of the present disclosure is shown.

[0025] [Figure 5B] A flowchart of a method in a time synchronization service network function according to some embodiments of the present disclosure is shown.

[0026] [Figure 6] It is a schematic block diagram of an exemplary embodiment of a network node. [Figure 7] It is a schematic block diagram of an exemplary embodiment of a network node. [Figure 8] It is a schematic block diagram of an exemplary embodiment of a network node.

MODE FOR CARRYING OUT THE INVENTION

[0027] Herein, some embodiments intended in this specification will be described more fully with reference to the accompanying drawings. However, other embodiments are included within the scope of the subject matter disclosed herein, and the disclosed subject matter should not be construed as being limited only to the embodiments described herein. Rather, these embodiments are provided as examples to convey the scope of the subject matter to those skilled in the art.

[0028] Wireless node: As used herein, “wireless node” refers to either a wireless access node or a wireless communication device.

[0029] Radio Access Node: As used herein, “radio access node,” “radio network node,” or “radio access network node” refers to any node within a radio access network (RAN) of a cellular communication network that operates to transmit and / or receive signals wirelessly. Examples of radio access nodes include, but are not limited to, base stations (e.g., New Radio (NR) base stations (gNBs) of the 3rd Generation Partnership Project (3GPP) 5th Generation (5G) NR network, or Extended or Evolutionary Node B (eNBs) of the 3GPP Long-Term Evolution (LTE) network), high-power or macro base stations, low-power base stations (e.g., micro base stations, pico base stations, home eNBs, etc.), relay nodes, network nodes that perform some of the functions of a base station (e.g., network nodes that perform a gNB central unit (gNB-CU), network nodes that perform a gNB distributed unit (gNB-DU), etc.), or network nodes that perform some of the functions of other radio access nodes.

[0030] Core Network Nodes: As used herein, “core network nodes” refers to any type of node within a core network, or a node / server / distributed server / dedicated platform that implements one or more core network functions, also known as network functions. Some examples of network functions include, for example, Mobility Management Entities (MMEs), Packet Data Network Gateways (P-GWs), Capability for Service Exposure Functions (SCEFs), and Home Subscriber Servers (HSSs). Some other examples of network functions include nodes that implement Access and Mobility Management Functions (AMFs), User Plane Functions (UPFs), Session Management Functions (SMFs), Authentication Server Functions (AUSFs), Network Slice Selection Functions (NSSFs), Network Exposure Functions (NEFs), Network Functions (NF) Repository Functions (NRFs), Policy Control Functions (PCFs), Unified Data Management (UDMs), and TSCTSFs. Generally, network functions can be implemented as network elements on dedicated hardware, as software instances running on dedicated hardware, or as virtualized functions instantiated on an appropriate platform (e.g., cloud infrastructure). Note that UPFs may include NW-TTs.

[0031] Communication Devices: As used herein, “communication devices” refers to any type of device that can access the access network. Examples of communication devices include, but are not limited to, mobile phones, smartphones, sensor devices, meters, vehicles, home appliances, medical appliances, media players, cameras, or any type of consumer electronic device, such as televisions, radios, lighting fixtures, tablet computers, laptops, and personal computers (PCs). Communication devices may be portable, handheld, computer-integrated, or vehicle-mounted mobile devices capable of communicating voice and / or data via wireless or wired connections. Communication devices may include or be connected to DS-TT.

[0032] Wireless Communication Devices: One type of communication device is a wireless communication device, which can be any type of wireless device that accesses (i.e., receives services from) a wireless network (e.g., a cellular network). Examples of wireless communication devices include, but are not limited to, user equipment devices (UEs) in a 3GPP network, machine-type communication (MTC) devices, and Internet of Things (IoT) devices. Such wireless communication devices may be (but are not limited to) mobile phones, smartphones, sensor devices, meters, vehicles, home appliances, medical appliances, media players, cameras, or any type of consumer electronics, such as televisions, radios, lighting fixtures, tablet computers, laptops, PCs, etc., or may be integrated into such devices. Wireless communication devices may be portable, handheld, computer-integrated, or vehicle-mounted mobile devices that enable the communication of voice and / or data over a wireless connection. Wireless communication devices may include or connect to DS-TT.

[0033] Network node: As used herein, "network node" refers to a node that is part of the RAN or core network of a cellular communication network / system.

[0034] This specification primarily describes 3GPP cellular communication systems, and therefore, it should be noted that 3GPP terminology or terms similar to 3GPP terminology will be used frequently. However, the concepts disclosed herein are not limited to 3GPP systems.

[0035] While the term "cell" may be used in this specification, it is important to note that, particularly with regard to the concept of 5G_NR, a beam may be used instead of a cell, and therefore the concepts described herein are equally applicable to both cells and beams.

[0036] Figure 2 shows an example of a cellular communication system 100 in which embodiments of the present disclosure may be implemented. In the embodiments described herein, the cellular communication system 100 is a 5G system (5GS) including a next-generation RAN (NG-RAN) and a 5G core (5GC), but is not limited thereto. In this example, the RAN in the 5GS includes NR base stations (gNBs) and optionally next-generation eNBs (ng-eNBs) (e.g., LTE RAN nodes connected to the 5GC), and includes base stations 102-1 and 102-2 that control the corresponding (macro) cells 104-1 and 104-2. Base stations 102-1 and 102-2 are generally referred to herein collectively as multiple base stations 102 and individually as base station 102. Similarly, (macro) cells 104-1 and 104-2 are generally referred herein collectively as multiple (macro) cells 104 and individually as (macro) cell 104. The RAN may also include a plurality of low-power nodes 106-1 to 106-4 that control the corresponding small cells 108-1 to 108-4. The low-power nodes 106-1 to 106-4 may be small base stations (such as pico base stations or femto base stations) or RRHs, etc. In particular, although not shown, one or more of the small cells 108-1 to 108-4 may be alternatively provided by base station 102. The low-power nodes 106-1 to 106-4 are generally collectively referred to as a plurality of low-power nodes 106 in this specification and individually referred to as low-power node 106. Similarly, the small cells 108-1 to 108-4 are generally collectively referred to as a plurality of small cells 108 in this specification and individually referred to as small cell 108. The cellular communication system 100 also includes a core network 110, called 5GC in a 5G system (5GS). The base station 102 (and optionally the low-power node 106) is connected to the core network 110.

[0037] Base station 102 and low-power node 106 provide services to radio communication devices 112-1 to 112-5 in corresponding cells 104 and 108. Radio communication devices 112-1 to 112-5 are generally referred to collectively as a plurality of radio communication devices 112 and individually as radio communication devices 112 in this specification. In the following description, radio communication devices 112 are often UEs, and such are sometimes referred to herein as UE112, but this disclosure is not limited thereto.

[0038] As shown, Figure 1 illustrates a wireless communication system represented as a 5G system architecture enabling time-sensitive communication and time synchronization, comprising a core network function in which the interaction between any two NFs is represented by a point-to-point reference point / interface. Figure 2 can be considered as one specific implementation of system 100 in Figure 2.

[0039] From the access side, the 5G system architecture shown in Figure 1, similar to the AMF200, consists of multiple UE112 connected to either the RAN102 or the access network (AN). Typically, the R(AN)102 consists of base stations such as eNBs or gNBs. From the core network side, the multiple NFs of the 5GC shown in Figure 1 include the UDM206, AMF200, SMF208, PCF210, TSCTSF(400), application function (AF)212, user data record (UDR, not shown), NSSF, and AUSF.

[0040] Reference point representations for 5G network architectures are used to define detailed call flows in prescriptive standardization. Reference point N1 is defined to transmit signaling between UE112 and AMF200. Reference points connecting AN102 and AMF200, and AN102 and UPF214 are defined as N2 and N3, respectively. Reference point N11 exists between AMF200 and SMF208, meaning that SMF208 is at least partially controlled by AMF200. N4 is used by SMF208 and UPF214 to configure UPF214 using control signals generated by SMF208, allowing UPF214 to report its status to SMF208. N9 is the reference point for connections between different UPF214s. N30 is the reference point between PCF210 and NEF. N33 is the reference point between NEF and AF212. N84 is the reference point between TSCTSF and PCF. N85 is a reference point between TSCTSF and NEF. N86 is a reference point between TSCTSF and AF (not shown).

[0041] The 5GC network aims to separate the UP and CP. The UP carries user traffic, while the CP carries signaling within the network. In Figure 1, UPF214 is located in the UP, which can host NW-TT, while all other NFs, namely AMF200, SMF208, PCF210, AF212, and UDM206, are located in the CP. Separating the UP and CP ensures that each plane resource scales independently. It is also possible to distribute the UPF separately from its CP function. In this architecture, the UPF can be placed very close to the UE to reduce the round-trip time (RTT) between the UE and the data network for some applications that require low latency.

[0042] The core 5G network architecture is composed of modularized functions. For example, AMF200 and SMF208 are independent functions within the CP. The separation of AMF200 and SMF208 allows for independent evolution and expansion. Other CP functions, such as PCF210 and AUSF204, can also be separated, as shown in Figure 2. This modular functional design allows the 5GC network to flexibly support a variety of services.

[0043] Each NF interacts directly with other NFs. Intermediate functions can be used to route messages from one NF to another. CP defines a set of interactions between two NFs as a service, making it reusable. This service enables modularity support. UP supports interactions such as forwarding operations between different UPFs.

[0044] Figure 3 shows a 5G network architecture that uses service-based interfaces between NFs within a CP, rather than the point-to-point reference point / interface used in the 5G network architecture of Figure 1. However, the NFs mentioned above with reference to Figure 1 correspond to the NFs shown in Figure 3. Services that an NF provides to other authorized NFs can be exposed to authorized NFs through service-based interfaces. In Figure 3, service-based interfaces are indicated by the letter "N" following the NF name, for example, Namf for the service-based interface of AMF200, Nsmf for the service-based interface of SMF208, etc. Although not explicitly shown in Figure 1, it should be made clear that all NFs depicted in Figure 1 can interact with NEFs and NRFs in Figure 3 as needed.

[0045] Some of the characteristics of the NF shown in Figures 1 and 3 can be described in the following way: The AMF200 provides UE-based authentication, authorization, mobility management, etc. Because the AMF200 is independent of the access technology, even if the UE112 uses multiple access technologies, it is essentially connected to a single AMF200. The SMF208 is responsible for session management and assigns Internet Protocol (IP) addresses to the UE. It also selects and controls the UPF214 for data transfer. If the UE112 has multiple sessions, a different SMF208 can be assigned to each session to manage them individually and, in some cases, provide different functionality for each session. The AF212 provides information about packet flow to the PCF210, which is responsible for policy control, in order to support QoS. The AF212 can also interact via the NEF using a public API to request exposed services, and can interact directly with the TSCTSF400 to provide individual traffic pattern parameters, or indirectly via the NEF if the AF is a third party. The TSCTSF400 creates a TSC assistance container based on the individual traffic pattern parameters it receives.

[0046] This specification describes the use of a 5G system to enable time-sensitive communication and time synchronization, but it should be noted that other supported systems, such as 6G or other systems, can be used. Furthermore, although the embodiments are described using TSCTSF and UDM, which are NFs of 5G, it will be apparent to those skilled in the art that the embodiments described herein are also applicable to equivalent functions in other systems.

[0047] Specific aspects and embodiments of this disclosure for controlling timing resilience through subscriptions may provide solutions to the aforementioned or other problems. Embodiments of the solutions described herein are based on the following principles: - A new subscription data type has been added for the time synchronization service. The new subscription data type includes the time synchronization service and the timing resilience service. both This includes authorization information. The new time-synchronous subscription data type is provisioned in the UDM / UDR for UEs or UE groups and their corresponding data network names (DNNs) / network slices (S-NSSAI). -When AF212 receives an AF request for time synchronization (which may include parameters related to timing resilience services, if AF is a third party, via NEF), TSCTSF400 uses the Nudm_SDM_Get service operation to retrieve subscription data regarding time synchronization for the UE or UE group (based on the AF request). -When using Nudm_SDM_Get, TSCTSF400 includes its NF identifier (NF ID), time synchronization subscription data type, DNN / S-NSSAI, and subscription data type keys: SUPI / internal group identifier (if AF212 is an operator domain), or GPSI / external group identifier (for third-party AFs). -When TSCTSF400 receives subscription data (from UDM) corresponding to the requested service, TSCTSF400 proceeds with activating the service as defined above. - If the subscription data does not correspond to the service requested by AF, TSCTSF will not activate the service.

[0048] Furthermore, the TSCTSF400 may subscribe to the UDM to obtain changes in time synchronization and timing resilience subscription data (using the Nudm_SDM_Subscribe service behavior): -If a time synchronization service subscription is added, the TSCTSF400 will proceed with activating the service; -If a timing resilience subscription is added in addition to a time synchronization subscription, the time synchronization service will be updated to support timing resilience, or timing resilience will be activated separately; -If a subscription to time synchronization is removed, the corresponding service will be deactivated, and timing resilience will also be deactivated if active (unless AF212 has requested deactivation first, or its time expiration date has already passed); -If only timing recovery is removed, this service will be stopped (unless AF requests the stop first or the time limit expires first). -The corresponding response is provided to AF212. -When using Nudm_SDM_subscribe, TSCTSF400 includes the time synchronization subscription data type, DNN / S-NSSAI, which indicates time synchronization and / or time resilience data, and the subscription data type key: SUPI / Internal Group Identifier (if AF212 is an operator domain), or GPSI / External Group Identifier (for third-party AFs). If the time synchronization service is deactivated (either via an AF request or if the subscription to time synchronization is removed in the UDM), the TSCTSF400 can unsubscribe from the UDM (using the Nudm_SDM_Unsubscribe service behavior) if it had previously subscribed to the UDM.

[0049] Interaction between UDM and TSCTSF Figure 4 shows one embodiment of the present disclosure in which the TSCTSF400 interacts with the UDM to obtain time synchronization and time resilience subscriptions and subscribe to changes thereof.

[0050] TSCTSF requests time synchronization data and / or time resilience synchronization data during service activation, as described in subsequent embodiments. TSCTSF requests a subscription to the service using an application programming interface (API) with the UDM (e.g., Nudm_SDM_Get). TSCTSF includes its NF ID, the (new) time synchronization subscription data type (time synchronization and / or time resilience), the DNN / S-NSSAI, and a key for the subscription data type: SUPI / internal group identifier (if the AF is an operator domain), or GPSI / external group identifier (if the AF is a third-party AF).

[0051] When TSCTSF receives subscription data (from UDM) corresponding to a service requested by an AF (i.e., an AF requesting time synchronization that may include additional time resilience), TSCTSF proceeds with activating the service as described below. If the subscription data does not correspond to the service requested by AF (either directly or via NEF), TSCTSF will not activate the service requested by AF. In addition to obtaining subscriptions, TSCTSF may also subscribe to UDMs (using the Nudm_SDM_Subscribe service behavior) to obtain changes to subscription data for time synchronization and timing resilience: -If a subscription to the time synchronization service is added, TSCTSF will proceed with activating the service; - If a timing resilience subscription is added in addition to a time synchronization subscription, the time synchronization service will be updated to support timing resilience, or timing resilience will be activated; -If a subscription to time synchronization is removed, the corresponding service will be deactivated, and timing resilience will also be deactivated if it is active (unless AF requests deactivation first or its time expiration date expires first); -If only timing recovery is removed, this service will be stopped (unless AF requests the stop first or the time limit expires first). -The corresponding response is provided to AF. Any changes to subscription data are notified to TSCTSF by the UDM via the notification API, Nudm_SDM_notify. Changes include authorizing a time synchronization or time resilience service that was not previously authorized. The API can also be used to revoke authorization, i.e., remove a service, as described above.

[0052] If TSCTSF subscribes to time synchronization and time resilience subscription changes using, for example, Nudm_SDM_subscribe, TSCTSF includes the time synchronization subscription data type, DNN / S-NSSAI, and subscription data type keys: SUPI / Internal Group Identifier (if the AF is an operator domain), or GPSI / External Group Identifier (if the AF is a third-party AF).

[0053] Any changes to the time synchronization and / or time resilience subscription will be communicated to TSCTSF via notification messages from UDM.

[0054] If the time synchronization service is deactivated (due to an AF request or if the subscription to time synchronization is removed by the UDM), the TSCTSF will unsubscribe from the UDM if it was subscribed to the UDM, in order to receive notifications from the UDM.

[0055] Time synchronization activation procedure Time synchronization and time recovery procedures can be activated using the same procedure described in Section 4.15.9 of 3GPP TS23.502 for activating time synchronization. 3GPP TS23.502 states that the AF uses a time synchronization activation procedure to activate, modify, or deactivate the (g) Precision Time Protocol (gPTP) instance of 5GS (see Section 4.15.9.3). A procedure is also provided to activate the access layer time distribution method, in which case time distribution from RAN to UE is affected by the AF, and UE / DS-TT can distribute timing information externally by implementation-specific means, but not necessarily PTP (see Section 4.15.9.4 of 3GPP TS23.502).

[0056] In this embodiment shown in Figure 5A, AF can activate a time synchronization service that has a time synchronization service or a time recovery service, using the Nnef_TimeSynchronization_ConfigCreate service operation, for example.

[0057] Step 1: AF creates a time synchronization service configuration for the PTP instance to request a time synchronization service by calling the Nnef_TimeSynchronization_ConfigCreate service operation on the UE or UE group. The request includes information indicating time synchronization and may include parameters related to time resilience services (if the request is for a time synchronization service with time resilience services). The request may include the subscription correlation ID and user plane node ID as references to the targets of the UE and AF session.

[0058] Step 2: The NEF (optional, only if the AF is a third party) authorizes the request. After successful authorization, the NEF invokes the corresponding TSCTSF and Ntsctsf_TimeSynchronization_ConfigCreate service actions with the parameters received from the AF. An AF, being part of the operator's trust domain, can invoke the service directly in TSCTSF.

[0059] Step 3a: TSCTSF interacts with UDM to obtain time synchronization and optionally time resilience subscription data.

[0060] Step 3b: TSCTSF receives subscription data for time synchronization. - If the subscription data indicates that the subscription to the time synchronization service is valid, TSCTSF will proceed with activating the service; - If the subscription data indicates a timing resilience subscription, and the timing resilience service is enabled or authorized in addition to time synchronization, the time synchronization service will be updated to support timing resilience, or timing resilience will be enabled separately. If the time synchronization service is disabled or not authorized, time resilience will not be authorized either, but the UDM may authorize the time synchronization service while not authorizing time resilience. The time resilience service will only be authorized if the time synchronization service is authorized.

[0061] Step 3: TSCTSF responds with the Ntsctsf_TimeSynchronization_ConfigCreate response. The Ntsctsf_TimeSynchronization_ConfigCreate response contains a PTP instance reference.

[0062] Step 4: The remaining activation steps are as described in TS23.502, V.17.3.0, section 4.15.9.3, except that if a time resilience subscription is provided by UDM indicating that time resilience is enabled, the time synchronization service will be updated to support time resilience or time resilience will be activated.

[0063] In step 3a or a subsequent step (not shown in the diagram), TSCTSF may subscribe to UDM for any changes to subscriptions related to time synchronization and time resilience.

[0064] Figure 5B shows several embodiments of how time synchronization service network functions (e.g., TSCTSF in a 5G system) are implemented.

[0065] In step 500B, the Time Synchronization Service Network function performs the step of receiving a time synchronization request for a UE or group of UEs originating from an Application Function (AF). This request may be received via a Network Exposure Function (NEF) or directly from an AF. Alternatively, a time synchronization service request from an AF may further include a time synchronization request with time recovery service. A time synchronization or time synchronization with time recovery request may include parameters related to the requested timing recovery service.

[0066] In step 510B, the Time Synchronization Service Network function performs the step of obtaining subscription data for a UE or UE group indicating whether the request for time synchronization from the AF is permitted to proceed. For example, the Time Synchronization Service Network function obtains subscription data by sending a request to a User Data Management (UDM) node requesting subscription data related to time synchronization with a Time Synchronization Service or Time Resilience Service (if requested by the AF), and receiving subscription data indicating whether the Time Synchronization Service is permitted or whether time synchronization with a Time Resilience Service is permitted. The subscription data may include an indication that time synchronization with the Time Synchronization Service or Time Resilience Service is enabled or disabled. Alternatively, if the subscription data includes time synchronization or time synchronization with time resilience that matches the request from the AF, the Time Synchronization Network function may decide to authorize the request from the AF if the request matches the subscription.

[0067] In step 520B, if the Time Synchronization Service Network function determines from the subscription data of the UE or UE group obtained in step 510B that it should not permit a request for time synchronization or time synchronization with time recovery from the AF, the Time Synchronization Service Network function rejects the time synchronization request received from the AF. A rejection message may be returned to the AF. On the other hand, if the Time Synchronization Service Network function determines that the subscription data approves the request for time synchronization service / time synchronization service with time recovery from the AF, it proceeds to activate / provide the time synchronization service or time synchronization service with time recovery to the UE or UE group (step 530B).

[0068] In one embodiment, the time synchronization service network function further subscribes to the user data management node to receive changes to the time synchronization or the subscription to the time synchronization and time resilience service. In another example, the time synchronization service network function then receives a notification from the UDM or AF to disable the time resilience service, and upon receiving the notification, can deactivate the time resilience service.

[0069] In another embodiment, the time synchronization service network function performs the step of receiving a notification from the UDM or AF to disable the time synchronization service, and upon receiving the notification, deactivates the time synchronization service and, if timing resilience was previously permitted and / or enabled (if time synchronization with timing resilience was previously enabled), also deactivates the timing resilience service.

[0070] Figure 6 is a schematic block diagram of a network node 800 according to some embodiments of the present disclosure. Optional functions are represented by dashed boxes. The network node 800 may be a core network node that implements, for example, NF (e.g., AMF200, SMF206, TSCTSF400, UDM, UDR, AF, UPF, etc.). As shown, the network node 800 includes one or more processors 804 (e.g., a central processing unit (CPU), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), and / or similar), memory 806, and a network interface 808. One or more processors 804 are also referred to herein as processing circuits. One or more processors 804 operate to provide one or more functions of the network node 800 described herein (e.g., one or more functions such as AMF200, SMF206, TSCTSF400, UDM, UDR, AF, UPF, etc., as described herein). In some embodiments, the function(s) are implemented by software stored, for example, in memory 806 and executed by one or more processors 804.

[0071] Figure 7 is a schematic block diagram showing virtualized embodiments of network node 800 according to several embodiments of the present disclosure. Here again, optional features are represented by dashed boxes. As used herein, a “virtualized” network node is an embodiment of network node 800 in which at least some of the functions of network node 800 are performed as virtual components (for example, via virtual machines running on physical processing nodes (for example) in the network). As illustrated, in this example, network node 800 includes one or more processing nodes 900 that are coupled to or included as part of network 902. Each processing node 900 includes one or more processors 904 (e.g., CPU, ASIC, FPGA, etc.), memory 906, and a network interface 908. In this example, the functions 910 of the network node 800 described herein (for example, one or more functions such as AMF200, SMF206, TSCTSF400, UDM, UDR, AF, UPF, etc., as described herein) are implemented by one or more processing nodes 900, or are distributed to two or more processing nodes 900 in any desired manner. In some specific embodiments, some or all of the functions 910 of the network node 800 described herein are implemented as virtual components executed by one or more virtual machines in a virtual environment hosted by the processing node 900.

[0072] In some embodiments, a computer program is provided that, when executed by at least one processor, causes at least one processor to perform the functions of a node (e.g., a processing node 900) that performs one or more of the functions 910 of a network node 800 in a virtual environment, according to any embodiment described herein. In some embodiments, a carrier is provided which includes the aforementioned computer program product. The carrier is one of the following: an electrical signal, an optical signal, a radio signal, or a computer-readable storage medium (e.g., a non-temporary computer-readable medium such as memory).

[0073] Figure 8 is a schematic block diagram of a network node 800 according to some other embodiments of the present disclosure. The network node 800 includes one or more modules 1000, each implemented in software. The modules 1000 provide the functionality of the network node 800 as described herein. This discussion is also applicable to the processing node 900 in Figure 7, where the modules 1000 may be implemented in one of the processing nodes 900 or distributed among multiple processing nodes 900.

[0074] The appropriate steps, methods, features, functions, or benefits disclosed herein can be performed through one or more functional units or modules of one or more virtual devices. Each virtual device may consist of a number of these functional units. These functional units can be implemented through processing circuits that may include one or more microprocessors or microcontrollers, as well as other digital hardware, such as digital signal processors (DSPs), special-purpose digital logic, etc. The processing circuits may be configured to execute program code stored in memory, which may include one or more types of memory, such as ROM (read-only memory), RAM (random-access memory), cache memory, flash memory devices, optical storage devices, etc. The program code stored in memory includes program instructions for executing one or more telecommunications and / or data communication protocols, as well as instructions for executing one or more techniques described herein. In some implementations, the processing circuits may be used to perform functions corresponding to each functional unit, according to one or more embodiments of the present disclosure.

[0075] The steps shown in the figures may represent a specific sequence of operations performed by a particular embodiment of this disclosure, but it should be understood that such a sequence is illustrative (for example, alternative embodiments may perform the operations in a different order, combine certain operations, or duplicate certain operations).

[0076] Some exemplary embodiments of this disclosure are as follows: A method in a first network node for implementing a first network function to support a time synchronization service in a communication system, comprising: Receiving a time synchronization request originating from an Application Function (AF) to a UE or group of UEs, the request may include parameters related to time resilience services; • Sending requests to the User Data Management (UDM) node to request subscription data related to time synchronization and / or time resilience services; • Receiving subscription data indicating whether time synchronization services are permitted or whether time synchronization with time recovery services is permitted. • Activate a time synchronization service that has a time synchronization service or time recovery service, according to the subscription data.

[0077] A method according to Embodiment 1, the method further comprising subscribing at a user data management node to receive any changes to the subscription to the time synchronization and / or time resilience service.

[0078] A method according to Embodiment 1 or 2, further comprising receiving a notification from the UDM or AF to disable the time recovery service, and, upon receiving the notification, deactivating the time recovery service.

[0079] A method according to Embodiment 1 or 2, further comprising receiving a notification from the UDM or AF to disable the time synchronization service, and, if such notification is received, deactivating the time synchronization service and the time recovery service if time recovery was previously permitted and / or activated.

[0080] A node that performs a first network function, configured to perform any of embodiments 1 to 4.

[0081] A node comprising one or more processors and memory for storing instructions that, when executed by one or more processors, execute any of embodiments 1 to 4.

[0082] A computer-readable medium containing program instructions for causing a computer to execute the methods of Embodiments 1 to 4.

[0083] A method in a second network node for implementing a second network function to support a subscription to a time synchronization service in a communication system, comprising: - Receiving requests to provide a first network node with subscription data related to time synchronization, which includes time synchronization services or time recovery services for a UE or group of UEs; • Send subscription data indicating whether time synchronization services are permitted or whether time synchronization with time recovery services is permitted.

[0084] A method according to Embodiment 8, the method further comprising receiving a subscription to report any changes to a time synchronization subscription having a time synchronization or time recovery service.

[0085] A method according to Embodiment 8 or 9, further comprising sending a notice to disable a time recovery service or a time synchronization service or both.

[0086] A node that performs a second network function configured to perform any of embodiments 8 to 10.

[0087] A node comprising one or more processors and memory for storing instructions that, when executed by one or more processors, execute any of embodiments 8 to 10.

[0088] A computer-readable medium containing program instructions for causing a computer to execute the methods of embodiments 8 to 10.

[0089] Those skilled in the art will recognize improvements and modifications to embodiments of the present disclosure. All such improvements and modifications are considered to be within the scope of the concepts disclosed herein.

Claims

1. A method for supporting a time synchronization service within a communication system, provided by a first network node that implements a time synchronization service network function, Receiving time synchronization requests to a UE or UE group originating from an application function (AF), Obtaining subscription data for the UE or UE group indicating whether the time synchronization request from the AF is permitted to be initiated, If it is determined that the subscription data for the UE or the UE group does not permit the time synchronization request from the AF, the time synchronization request from the AF will be rejected. If the subscription data determines that the AF has authorized the time synchronization service request, the time synchronization service will be started. Methods that include...

2. The request for the time synchronization service from the AF further includes a request for time synchronization with a time recovery service, and the subscription data indicates whether the request for time synchronization with a time recovery service is permitted. The method according to claim 1.

3. The aforementioned request for time synchronization or time resilience includes parameters related to the requested time resilience service. The method according to claim 1 or 2.

4. The step of obtaining the aforementioned subscription data is: Sending a request to a User Data Management (UDM) node to request the subscription data related to time synchronization having a time synchronization service or time recovery service, Receiving the subscription data indicating whether a time synchronization service is permitted or whether a time synchronization service with time resilience is permitted, Includes The method according to claim 1 or 2.

5. The subscription data includes an indication that the time synchronization service or time recovery service is enabled or disabled. The method according to any one of claims 1 to 4.

6. The method further includes subscribing at the user data management node to receive any changes to the subscription to time synchronization or time synchronization having a time recovery service. The method according to any one of claims 1 to 4.

7. Receiving a notification from the UDM or AF to disable the time recovery service, Upon receiving the aforementioned notification, the time recovery service will be deactivated, Includes The method according to any one of claims 2 to 6.

8. Receiving a notification from the UDM or AF to disable the time synchronization service, Upon receiving the aforementioned notification, the time synchronization service will be deactivated, and if time-recoverable time synchronization was previously permitted and / or activated, the time-recoverable service will be deactivated. Includes The method according to any one of claims 1 to 6.

9. A node that performs a time synchronization service network function configured to perform the method described in any one of claims 1 to 8.

10. A node comprising one or more processors and a memory for storing instructions that, when executed by the one or more processors of a node performing a time synchronization service, perform the method according to any one of claims 1 to 8.

11. A computer-readable medium containing program instructions for causing one or more processors of nodes performing a time synchronization service to perform the method according to any one of claims 1 to 8.

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