Search

EP-4118893-B1 - SUPPORTING QOS FLOW SPECIFIC UNCERTAINTY ATTRIBUTE

EP4118893B1EP 4118893 B1EP4118893 B1EP 4118893B1EP-4118893-B1

Inventors

  • DIACHINA, JOHN WALTER
  • Sandgren, Magnus
  • SINGH, BIKRAMJIT

Dates

Publication Date
20260506
Application Date
20210312

Claims (20)

  1. A network node (16) configured to communicate with a wireless device (22) via an access network (12), the wireless device (22) configured to communicate with an end station via a time sensitive network, TSN, (23) that is a logically separate network from the access network (12), the network node (16) comprising: processing circuitry (68) configured to: receive at least one parameter from a core network node (14), the at least one parameter indicating a level of synchronization accuracy that is required for a TSN clock in the TSN (23); determine, based on the level of synchronization accuracy for the TSN clock, one of a plurality of methods in the access network (12) for distributing access network clock information to the wireless device (22); and implement the method determined for distributing the access network clock information to the wireless device (22) and one of a plurality of methods in the access network (12) for determining downlink propagation delay information based on the level of synchronization accuracy for the TSN clock; each one of the plurality of methods for distributing the access network clock information and for determining the downlink propagation delay information being associated with a different level of synchronization accuracy for an access network clock, wherein the level of synchronization accuracy for the access network clock corresponds to an amount of end-to-end synchronization accuracy required for the TSN clock; wherein the plurality of methods for determining the downlink propagation delay information includes: a first method that includes determining downlink propagation delay in the access network (12) using a legacy TA process; and a second method that includes determining downlink propagation delay in the access network (12) using a round trip time, RTT, process, the RTT process having a higher synchronization accuracy than the legacy TA process.
  2. The network node (16) of Claim 1, wherein the downlink propagation delay information is configured to allow for updating of the access network clock associated with the access network clock information, the updated access network clock configured to allow for timestamping of TSN clock information for compensation of the TSN clock information.
  3. The network node (16) of any one of Claims 1 and 2, wherein the at least one parameter is time sensitive communication assistance information, TSCAI, the TSCAI having a grandmaster, GM, clock synchronization accuracy parameter.
  4. The network node (16) of any one of Claims 1-3, wherein the processing circuitry (68) is configured to relay TSN clock information through the access network (12) using at least one QoS flow for communication to the end station in the TSN (23) via the wireless device (22); wherein the at least one QoS flow optionally includes a first QoS flow and a second QoS flow, the processing circuitry (68) being configured to relay the TSN clock information through the access network (12) using the first QoS flow that is associated with a first protocol data unit, PDU, session from the wireless device (22) and the second QoS flow associated with a second PDU session from another wireless device (22) that is connected to the end station that requires the TSN clock; and wherein the at least one QoS flow is further optionally configured to indicate a plurality of levels of accuracy for the TSN clock.
  5. The network node (16) of any one of Claims 1-4, wherein the processing circuitry (68) is configured to distribute TSN clock information in a user plane of the access network (12).
  6. The network node (16) of any one of Claims 1-5, wherein the plurality of methods for distributing the access network clock information to the wireless device (22) includes at least one of: a first method configured to broadcast the access network clock information to the wireless device (22) using system information block, SIB, broadcast; and a second method configured to use radio resource control, RRC, unicast to distribute access network clock information to the wireless device (22).
  7. A wireless device (22) configured to communicate with a network node (16) via an access network (12) and with an end station in a time sensitive network, TSN, (23) that is a logically separate network from the access network (12), the wireless device (22) comprising: processing circuitry (84) configured to: receive access network clock information and downlink propagation delay information via one of a plurality of methods that meets a level of synchronization accuracy for the access network (12) that is required for a TSN clock in the TSN (23), each one of the plurality of methods being associated with a different level of synchronization accuracy for the access network clock, wherein the level of synchronization accuracy for the access network clock corresponds to an amount of end-to-end synchronization accuracy required for the TSN clock; and cause transmission of the TSN clock information to the end station in the TSN (23); wherein the plurality of methods for receiving the downlink propagation delay information includes: a first method that includes determining downlink propagation delay in the access network (12) using a legacy TA process, the determined downlink propagation delay configured to be used for access network clock compensation; and a second method that includes determining downlink propagation delay in the access network (12) using a round trip time, RTT, process, the RTT process having a higher synchronization accuracy than the legacy TA process, the determined downlink propagation delay configured to be used for access network clock compensation.
  8. The wireless device (22) of Claim 7, wherein the processing circuitry (84) is configured to: determine a propagation delay based at least on the downlink propagation delay; update the access network clock based on the determined propagation delay; perform egress timestamping on the TSN clock information that is received from the network node (16), the egress timestamping being performed using the updated access network clock; determine an adjustment is required for the TSN clock information based at least on the egress timestamping; and compensate the TSN clock information based on the determined adjustment; or wherein the processing circuitry (84) is configured to: determine a propagation delay based at least on the downlink propagation delay; update the access network clock based on the determined propagation delay; and perform ingress timestamping on the TSN clock information that is received from the end station in the TSN, the ingress timestamping being performed using the updated access network clock, the ingress timestamping being configured to be used for adjusting the TSN clock information.
  9. The wireless device (22) of any one of Claims 7-8, wherein the processing circuitry (84) is configured to relay the TSN clock information through the access network (12) using the at least one QoS flow; wherein the at least one QoS flow optionally includes a first QoS flow and a second QoS flow, the processing circuitry (84) being configured to relay the TSN clock information through the access network (12) using the first QoS flow that is associated with a first protocol data unit, PDU, session from the wireless device (22) and the second QoS flow associated with a second PDU session from another wireless device (22) that is connected to the end station that requires the TSN clock; and wherein the at least one QoS flow is further optionally configured to indicate a plurality of levels of accuracy for a TSN clock.
  10. The wireless device (22) of any one of Claims 7-9, wherein the processing circuitry (84) is configured to receive the TSN clock information in a user plane of the access network (12).
  11. The wireless device (22) of any one of Claims 7-10, wherein the plurality of methods for receiving the access network clock information includes at least one of: a first method configured to broadcast the access network clock information to the wireless device (22) using system information block, SIB, broadcast; and a second method configured to use radio resource control, RRC, unicast to distribute access network clock information to the wireless device (22).
  12. A method implemented by a network node (16) that is configured to communicate with a wireless device (22) via an access network (12), the wireless device (22) configured to communicate with an end station via a time sensitive network, TSN, (23) that is a logically separate network from the access network, the method comprising: receiving (S140) at least one parameter from a core network node (14), the at least one parameter indicating a level of synchronization accuracy that is required for a TSN clock in the TSN (23); and determining, based on the level of synchronization accuracy for the TSN clock, one of a plurality of methods in the access network (12) for distributing access network clock information to the wireless device (22); implementing (S142) the method determined for distributing the access network clock information to the wireless device (22) and one of a plurality of methods in the access network (12) for determining downlink propagation delay information based on the level of synchronization accuracy for the TSN clock; each one of the plurality of methods for distributing the access network clock information and for determining the downlink propagation delay information being associated with a different level of synchronization accuracy for an access network clock, wherein the level of synchronization accuracy for the access network clock corresponds to an amount of end-to-end synchronization accuracy required for the TSN clock; wherein the plurality of methods for determining the downlink propagation delay information includes: a first method that includes determining downlink propagation delay in the access network using a legacy TA process; and a second method that includes determining downlink propagation delay in the access network (12) using a round trip time, RTT, process, the RTT process having a higher synchronization accuracy than the legacy TA process.
  13. The method of Claim 12, wherein the downlink propagation delay information is configured to allow for updating of the access network clock associated with the access network clock information, the updated access network clock configured to allow for timestamping of TSN clock information for compensation of the TSN clock information.
  14. The method of any one of Claims 12 and 13, wherein the at least one parameter is time sensitive communication assistance information, TSCAI, the TSCAI having a grandmaster, GM, clock synchronization accuracy parameter.
  15. The method of any one of Claims 12-14, wherein the TSN clock information is relayed through the access network (12) using at least one QoS flow for communication to the end station in the TSN (23) via the wireless device (22); wherein the at least one QoS flow optionally includes a first QoS flow and a second QoS flow, the TSN clock information being relayed through the access network (12) using the first QoS flow that is associated with a first protocol data unit, PDU, session from the wireless device (22) and the second QoS flow associated with a second PDU session from another wireless device (22) that is connected to the end station that requires the TSN clock; and wherein the at least one QoS flow is further optionally configured to indicate a plurality of levels of accuracy for the TSN clock.
  16. The method of any one of Claims 12-15, wherein the TSN clock information is distributed in a user plane of the access network (12).
  17. The method of any one of Claims 12-16, wherein the plurality of methods for distributing the access network clock information to the wireless device (22) includes at least one of: a first method configured to broadcast the access network clock information to the wireless device (22) using system information block, SIB, broadcast; and a second method configured to use radio resource control, RRC, unicast to distribute the access network clock information to the wireless device (22).
  18. A method implemented by a wireless device (22) that is configured to communicate with a network node (16) via an access network (12) and with an end station in a time sensitive network, TSN, (23) that is a logically separate network from the access network (12), the method comprising: receiving (S154) access network clock information and downlink propagation delay information via one of a plurality of methods that meets a level of synchronization accuracy for the access network (12) that is required for a TSN clock in the TSN (23), each one of the plurality of methods being associated with a different level of synchronization accuracy for the access network clock, wherein the level of synchronization accuracy for the access network clock corresponds to an amount of end-to-end synchronization accuracy required for the TSN clock; and causing (S156) transmission of the TSN clock information to the end station in the TSN (23); wherein the plurality of methods for receiving the downlink propagation delay information includes: a first method that includes determining downlink propagation delay in the access network (12) using a legacy TA process, the determined downlink propagation delay configured to be used for access network clock compensation; and a second method that includes determining downlink propagation delay in the access network (12) using a round trip time, RTT, process, the RTT process having a higher synchronization accuracy than the legacy TA process, the determined downlink propagation delay configured to be used for access network clock compensation.
  19. The method of Claim 18, further comprising: determining a propagation delay based at least on the downlink propagation delay; updating the access network clock based on the determined propagation delay; performing egress timestamping on the TSN clock information that is received from the network node (16), the egress timestamping being performed using the updated access network clock; determining an adjustment is required for the TSN clock information based at least on the egress timestamping; and compensating the TSN clock information based on the determined adjustment; or the method further comprising: determining a propagation delay based at least on the downlink propagation delay; updating the access network clock based on the determined propagation delay; and performing ingress timestamping on the TSN clock information that is received from the end station in the TSN, the ingress timestamping being performed using the updated access network clock, the ingress timestamping being configured to be used for adjusting the TSN clock information.
  20. The method of any one of Claims 18-19, wherein the TSN clock information is relayed through the access network (12) using the at least one QoS flow; wherein the at least one QoS flow optionally includes a first QoS flow and a second QoS flow, the TSN clock information being relayed through the access network (12) using the first QoS flow that is associated with a first protocol data unit, PDU, session from the wireless device (22) and the second QoS flow associated with a second PDU session from another wireless device (22) that is connected to the end station that requires the TSN clock; and wherein the at least one QoS flow is further optionally configured to indicate a plurality of levels of accuracy for a TSN clock.

Description

FIELD The present disclosure relates to wireless communications, and in particular, to support of a quality of service (QoS) flow-specific uncertainty attribute. BACKGROUND The Third Generation Partnership Project (3GPP) is developing the Fifth Generation (5G) wireless network communications standard, also referred to as New Radio (NR), to support time sensitive networking (TSN). TSN is expected to be integrated into Ethernet-based industrial communication networks. Applications may include factory automation networking. This disclosure relates to the problem of inaccuracy and/or uncertainty inherent to methods for relaying the 5G system clock (i.e., an access network clock that serves as a reference time) from a source node in the 5G system to wireless devices (WDs) supporting IoT end devices. The inaccuracy of concern is the error introduced as a result of attempting to identify the radio frequency (RF) propagation delay that occurs when a 5G base station (gNodeB or gNB) transmits a 5G system clock over the radio interface within a message. The message may be, for example, within a system information block (SIB) or radio resource control (RRC) unicast message. The value of the 5G system clock should be compensated to ensure that the clock value received by the WD is as close as possible to the value of that clock in the corresponding gNB or other network node with knowledge of the 5G system clock. In other words, the better the accuracy of relaying the 5G system clock from its source node to the WD the better the accuracy that will be realized when external TSN Grandmaster (GM) clocks are relayed from a TSN grandmaster node through the 5G system to WDs (and subsequently to end-stations): Ingress timestamping is performed when an external TSN GM clock is received by a 5G system and egress timestamping is performed when that TSN GM clock (relayed through the 5G system) arrives at the WD. See FIG. 1. Note, that since the TSN GM clock can have an arbitrary placement, the ingress time stamping can be performed at various places within the 5GS system e.g., at the user plane function TSN translator (UPF- TT) or at the DS- TT.The difference between the two timestamps is a reflection of the 5G residence time experienced when relaying the TSN GM clock through the 5G system and it is therefore used to adjust the value of the external TSN GM clock upon its reception at the point of egress.The timestamping is based on the 5G system clock and the accuracy of delivering this clock to a WD is improved by allowing the propagation delay experienced when sending this clock from a network node to a WD to be more precisely determined. An additional source of inaccuracy occurs as a result of subsequent WD distribution of the clock to Internet of things (IoT) end devices. This distribution is used to enable TSN functionalities, e.g., Time-Aware Scheduling, of IoT device operations specific to the working domain (a specific factory area) associated with a given working clock. Identification of WDs Requiring 5G System Clock At present, a network node such as a gNB is expected to use implementation specific methods to determine which WDs need to receive 5G system clock information. Standardization of such methods does not yet exist. The network node must then decide (a) which method to use to provide 5G system clock information to WDs that require the system clock (i.e., SIB or RRC unicast) and (b) which method (if any) to use for allowing a WD to determine the downlink propagation delay (PD) compensation to apply to the 5G system clock received from the network node. Methods Available for determining downlink PD compensation 3GPP Timing Advance command 3GPP Timing Advance (TA) command is a legacy method utilized in cellular communication for uplink transmission synchronization for the following situations. a) In the beginning, at connection setup, an absolute timing parameter is communicated to a WD using medium access control (MAC) radio access response (RAR) element; andb) After connection setup, a relative timing correction can be sent to a WD using a MAC control element (CE) (e.g., WDs can move due to RF channel changes caused by the environment). The downlink Propagation Delay (PD) can be estimated for a given WD by (a) first summing the TA value indicated by the RAR (random access response) and all subsequent TA values sent using the MAC CE control element and (b) taking some portion of the total TA value resulting from summation of all the TA values (e.g., 50% could be used when assuming the downlink and uplink propagation delays are essentially the same). The estimated PD can then be utilized to understand time synchronization dynamics, e.g., for accurately tracking the value of a clock at the WD relative to the value of that clock in some other network node. Pre-compensation Besides the 3GPP TA method, methods based on pre-compensation can be devised to reduce the delay introduced by round trip time (RTT) where a compens