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EP-3984330-B1 - PACKET DELAY BUDGET DETERMINATION FOR TSN TRAFFIC FORWARDING

EP3984330B1EP 3984330 B1EP3984330 B1EP 3984330B1EP-3984330-B1

Inventors

  • CHAO, HUA
  • WANG, HE

Dates

Publication Date
20260506
Application Date
20190617

Claims (12)

  1. A system comprising: a user plane function (235), comprising: at least one processor (910); and at least one memory (920) including computer program code (940); the at least one memory (920) and the computer program code (940) configured to, with the at least one processor (910), cause the user plane function (235) to: determine first residence time of a time-sensitive communication, TSC, Quality of Service, QoS, flow in a network-side time-sensitive networking, TSN, translator, NW-TT; determine second residence time of the TSC QoS flow in the user plane function (235); determine time delay at least in part based on the first residence time and at least in part based on the second residence time, the time delay being equal to a length of a sum of the first residence time and second residence time; and send an indication of the time delay to a session management function (265); and a session management function (265), comprising: at least one processor (910); and at least one memory (920) including computer program code (940); the at least one memory (920) and the computer program code (940) configured to, with the at least one processor (910), cause the session management function (265) to: receive, from the user plane function (235), the indication of time delay; and determine first packet delay budget of the TSC QoS flow in a core network, the first packet delay budget being equal to a sum of the first residence time, the second residence time of the TSC QoS flow in the user plane function (235) and propagation delay between a base station (225) and the user plane function (235).
  2. The system of claim 1, wherein the first residence time is determined based on at least one of: a hardware processing rate of the NW-TT, a buffer size of the NW-TT, QoS profile of the TSC QoS flow, and a number of TSC QoS flows in a TSN traffic class via a port of the NW-TT, the TSN traffic class and the port being associated with the TSC QoS flow.
  3. The system of claim 1, wherein the user plane function (235) is caused to determine the first residence time by: receiving a request for the first residence time from the session management function (265), the request indicating QoS profile of the TSC QoS flow and a port of the NW-TT associated with the TSC QoS flow; in response to receiving the request, determining a TSN traffic class associated with the TSC QoS flow from the QoS profile; and determining the first residence time based on the TSN traffic class, the port and the QoS profile.
  4. The system of claim 3, wherein the request is received from the session management function (265) during an establishment procedure or a release procedure for the TSC QoS flow.
  5. The system of claim 1, wherein the session management function (265) is further caused to: determine second packet delay budget of the TSC QoS flow in an access network by subtracting the first packet delay budget from reference packet delay budget for the TSC QoS flow; and send the second packet delay budget towards the base station (225).
  6. The system of claim 5, wherein the session management function (265) is further caused to: receive an indication of the reference packet delay budget from a policy control function.
  7. The system of claim 1, wherein the time delay is equal to a length of a sum of the first and second residence time.
  8. The session management function (265) of claim 1, wherein the session management function (265) is further caused to: send a request for the first residence time to the user plane function (235), the request indicating QoS profile of the TSC QoS flow and a port of the NW-TT associated with the TSC QoS flow, the QoS profile indicating a TSN traffic class associated with the TSC QoS flow.
  9. The system of claim 8, wherein the session management function (265) is further caused to: receive an indication of the port from a policy control function.
  10. The system of claim 8, wherein the request is sent to the user plane function (235) during an establishment procedure or a release procedure for the TSC QoS flow.
  11. The system of claim 1, wherein the session management function (265) is further caused to: create or update TSC context for the TSC QoS flow.
  12. A method comprising: determining, by a user plane function (235), first residence time of a time-sensitive communication, TSC, Quality of Service, QoS, flow in a network-side time-sensitive networking, TSN, translator, NW-TT; determining, by the user plane function, second residence time of the TSC QoS flow in the user plane function (235); determining, by the user plane function, time delay at least in part based on the first residence time and at least in part based on the second residence time, the time delay being equal to a length of a sum of the first residence time and second residence time; sending, by the user plan function, an indication of the time delay to a session management function (265) receiving, by a session management function (265), from the user plane function (235), the indication of time delay; and determining, by the session management function, first packet delay budget of the TSC QoS flow in a core network, the first packet delay budget being equal to a sum of the first residence time, the second residence time of the TSC QoS flow in the user plane function (235) and propagation delay between a base station (225) and the user plane function (235).

Description

FIELD The disclosure generally relates to the field of communications, and in particular, to determining packet delay budget (PDB) for time-sensitive networking (TSN) traffic forwarding. BACKGROUND Mechanisms for time-sensitive (or deterministic) transmission of data over Ethernet networks have been defined for Time-Sensitive Networking (TSN) in Institute of Electrical and Electronics Engineers (IEEE) standards such as IEEE P802.1Qcc. A TSN end station may act as "Talkers" which is a source of a time-sensitive stream, or act as "Listeners" which is a destination station for the stream. For the 3rd Generation Partnership Project (3GPP) Release 16 (Rel-16), the feasibility and industrial control use cases of TSN have been studied. It is agreed to extend the fifth generation (5G) System (5GS) by integrating the 5GS with TSN networks, for example, as defined in IEEE P802.1Qcc, to enable time sensitive communication (TSC). The 5GS may act as a TSN bridge and be integrated with an external TSN network. In order to meet the latency requirements of the TSN traffic, TSN resource reservation for the TSN traffic needs to consider the delay due to the 5GS acting as the TSN bridge. Conventionally, in a full centralized model of a TSN network, a Central Network Controller (CNC) calculates the AccumulatedLatency by accumulating bridge delay (per port pair per traffic class) and propagation delay (per port) from each bridge. Then, the CNC configures TSN features in each bridge for resource reservation. When the 5GS acts as a TSN bridge, there is a need to determine the delay induced by the 5GS accurately. ERICSSON: "TSCAI arrival time analysis", 3GPP DRAFT, S2-1904935 discusses TSC assistance information as known in the art. HUAWEI ET AL: "Updates on Solution #18", 3GPP DRAFT; S2-1812232 discusses QoS in relation to 3GPP and TSN networks as known in the art. NOKIA ET AL: "Introducing support for UE and UPF Residence Time for TSC Deterministic QoS", 3GPP DRAFT, S2-1906753 discusses QoS in TSN networks as known in the art. HUAWEI ET AL: "Mapping 5GS Bridge Delay to delays of TSN", 3GPP TS 23.501 discusses bridge delays in a TSN as known in the art. SUMMARY The invention is defined by the independent claims. Optional features are given in the dependent claims. BRIEF DESCRIPTION OF THE DRAWINGS Some example embodiments will now be described with reference to the accompanying drawings, where: FIG. 1 illustrates example system architecture of integrating the 5GS with a TSN network;FIG. 2 illustrates an example environment in which embodiments of the present disclosure can be implemented;FIG. 3 illustrates example bridge delay according to some example embodiments of the present disclosureFIG. 4 illustrates an example signaling flow between the UPF, the SMF and the gNB according to some example embodiments of the present disclosure;FIG. 5 illustrates an example signaling flow between various network functions (NFs) according to some example embodiments of the present disclosure;FIG. 6 illustrates a flowchart of an example method of determining residence time of a TSC QoS flow in the NW-TT according to some example embodiments of the present disclosure;FIG. 7 illustrates a flowchart of an example method of determining PDB of a TSC QoS flow in a core network according to some example embodiments of the present disclosure;FIG. 8 illustrates a flowchart of an example method of determining PDB of a TSC QoS flow in a core network according to some other example embodiments of the present In a fifth aspect, there is provided an apparatus comprising means for performing the method according to the third or fourth aspect. In a sixth aspect, there is provided a computer readable storage medium that stores a computer program thereon. The computer program, when executed by a processor of a device, causes the device to perform the method according to the third or fourth aspect. It is to be understood that the summary section is not intended to identify key or essential features of embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensible through the following description. BRIEF DESCRIPTION OF THE DRAWINGS Some example embodiments will now be described with reference to the accompanying drawings, where: FIG. 1 illustrates example system architecture of integrating the 5GS with a TSN network;FIG. 2 illustrates an example environment in which embodiments of the present disclosure can be implemented;FIG. 3 illustrates example bridge delay according to some example embodiments of the present disclosureFIG. 4 illustrates an example signaling flow between the UPF, the SMF and the gNB according to some example embodiments of the present disclosure;FIG. 5 illustrates an example signaling flow between various network functions (NFs) according to some example embodiments of the present disclosure;FIG. 6 illustrates a flowch