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US-12628226-B2 - Methods for adaptive user equipment behavior for cell reconfiguration in NR-U

US12628226B2US 12628226 B2US12628226 B2US 12628226B2US-12628226-B2

Abstract

A method by a wireless device includes receiving, from a network node, a command associated with a procedure to setup or release a cell or a signal. While transmitting a Hybrid Automatic Repeat Request (HARQ), feedback associated with the procedure to setup or release the cell or signal, the wireless device detects one or more clear channel assessment (CCA) failures on an uplink signal. The wireless device extends a transmission period for transmitting the HARQ feedback associated with the procedure to setup or release the cell or signal based on the one or more CCA failures.

Inventors

  • Iana Siomina
  • Muhammad Ali Kazmi
  • Joakim Axmon

Assignees

  • TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

Dates

Publication Date
20260512
Application Date
20201002

Claims (20)

  1. 1 . A method performed by a wireless device, the method comprising: receiving, from a network node, a command associated with a procedure to activate or deactivate a secondary cell, SCell; while transmitting a Hybrid Automatic Repeat Request, HARQ, feedback associated with the procedure to activate or deactivate the SCell, detecting one or more clear channel assessment, CCA, failures on an uplink signal; and based on a number of times the wireless device is unable to send the HARQ feedback due to the one or more CCA failures on the uplink signal, extending a time period duration for transmitting the HARQ feedback associated with the procedure to activate or deactivate the SCell.
  2. 2 . The method of claim 1 , wherein extending the time period duration for transmitting the HARQ feedback comprises extending a variable time period duration based on the number of times the wireless device is unable to send the HARQ feedback due to the one or more CCA failures.
  3. 3 . The method of claim 1 , wherein extending the time period duration for transmitting the HARQ feedback comprises increasing a maximum number of times the wireless device is allowed to fail to send the HARQ feedback due to the one or more CCA failures.
  4. 4 . The method of claim 1 , wherein extending the time period duration for transmitting the HARQ feedback comprises adapting a starting time instance of an interruption period caused by the procedure.
  5. 5 . The method of claim 1 , wherein the HARQ feedback comprises a HARQ acknowledgement or a HARQ negative acknowledgement.
  6. 6 . The method of claim 1 , wherein the HARQ feedback comprises a measurement report.
  7. 7 . The method of claim 1 , wherein: detecting the one or more CCA failures on the uplink signal comprises determining that the HARQ feedback was not successfully sent to the network node during time period duration prior to a triggering of the procedure to activate or deactivate the SCell; and extending the transmission period for transmitting the HARQ feedback associated with the procedure comprises selecting an amount of time for performing the procedure based on the HARQ feedback not being successfully sent to the network node during the time period duration prior to a triggering of the procedure.
  8. 8 . The method of claim 7 , wherein the amount of time is selected from a plurality of time period durations based on a type of the one or more CCA failures, wherein each of the plurality of time period durations is associated with a respective type of CCA failure.
  9. 9 . The method of claim 7 , wherein the amount of time is an actual reporting delay associated with the one or more CCA failures or a maximum acceptable reporting delay for the one or more CCA failures.
  10. 10 . The method of claim 7 , wherein the amount of time is selected based on an actual number of transmission attempts of the HARQ feedback.
  11. 11 . The method of claim 1 , wherein the procedure to activate or deactivate the SCell comprises transmitting a PRACH preamble towards the cell.
  12. 12 . The method of claim 1 , wherein the procedure to activate or deactivate the SCell comprises transmitting a channel state information (CSI) report.
  13. 13 . The method of claim 1 , further comprising detecting an event triggering the procedure to activate or deactivate the SCell.
  14. 14 . The method of claim 13 , wherein the event comprises receiving a command from the network node.
  15. 15 . The method of claim 1 , further comprising: while performing the procedure to activate or deactivate the SCell, determining a CCA impact of performing the procedure; and comparing the CCA impact to at least one threshold, wherein the CCA failure is associated with one of a plurality of types of CCA failures, and wherein a respective one of a plurality of thresholds is associated with each type of CCA failure within the plurality of types of CCA failures.
  16. 16 . The method of claim 15 , further comprising: completing the procedure if the CCA impact of performing the procedure is equal to or less than the at least one threshold; or stopping the procedure if the CCA impact of performing the procedure is greater than the at least one threshold.
  17. 17 . The method of claim 15 , further comprising: restarting at least a portion of the procedure if the CCA impact of performing the procedure is equal to or greater than the at least one threshold.
  18. 18 . The method of claim 17 , further comprising counting a number of times at least the portion of the procedure has been restarted and abandoning the procedure if the number of times is greater than a threshold.
  19. 19 . The method of claim 1 , further comprising maintaining a timer and abandoning the procedure or a portion of the procedure if the timer expires.
  20. 20 . A wireless device comprising processing circuitry configured to perform any of the method of claim 1 .

Description

PRIORITY This nonprovisional application is a U.S. National Stage Filing under 35 U.S.C. § 371 of International Patent Application Serial No. PCT/IB2020/059259 filed Oct. 2, 2020 and entitled “METHODS FOR ADAPTIVE USER EQUIPMENT BEHAVIOR FOR CELL RECONFIGURATION IN NR-U” which claims priority to U.S. Provisional Patent Application No. 62/910,741 filed Oct. 4, 2019, both of which are hereby incorporated by reference in their entirety. TECHNICAL FIELD The present disclosure relates, in general, to wireless communications and, more particularly, systems and methods for adaptive user equipment behavior for cell reconfiguration in New Radio-Unlicensed (NRU). BACKGROUND New radio (NR) standard in 3rd Generation Partnership Project (3GPP) is being designed to provide service for multiple use cases such as enhanced mobile broadband (eMBB), ultra-reliable and low latency communication (URLLC), and machine type communication (MTC). Each of these services has different technical requirements. For example, the general requirement for eMBB is high data rate with moderate latency and moderate coverage, while URLLC service requires a low latency and high reliability transmission but perhaps for moderate data rates. New Radio Unlicensed (NR-U) or NR in Unlicensed Spectrum Some parts of the spectrum have become potentially available for license-assisted access to unlicensed operation. This spectrum can be used by operators to augment their service offerings in licensed bands by being operated under a license-exempt regime or Industrial, Scientific, and Medical (ISM) but must be shared with existing mobile services and other incumbent services. During the NR-U study Item in 3GPP, different unlicensed bands or shared bands have been further discussed, such as 2.4 GHz band, 3.5 GHz band, 5 GHz band, and 6 GHz band. For channel access mechanism, Long Term Evolution (LTE)-License Assisted Access (LAA) LBT (Listen-Before-Talk) mechanism is adopted as baseline for 5 GHz band and adopted as the starting point of the design for 6 GHz band. At least for band where absence of Wi-Fi cannot be guaranteed (e.g. by regulation), LBT can be performed in units of 20 MHz. During LBT, the transmitting node determines whether there are no other transmissions (by performing certain measurements and comparing to a threshold) and if so it starts Channel Occupancy Time (COT) which does not exceed maximum COT (MCOT) can vary by regions; otherwise, it seizes its transmissions for a certain time and may retry again later. However, unlike in LTE, there are more LBT categories in NR and for some categories (Cat2), there are also 16 μs Cat2 and 25 μs Cat2 LBT types, depending on the switching time between uplink (UL) and downlink (DL) (16 μs Cat2 means the switching longer than 16 but shorter than 25, and 25 μs Cat2 means 25 or longer). In addition, there is also a concept of UE transmitting based on LBT procedure during BS-initiated COT (shared COT). Similar to LTE, NR-U is expected to have discovery signals (DRS) or similar, e.g., to enable initial access and measurements. LTE DRS contains only Primary Synchronization Signal (PSS)/Secondary Synchronization Signal (SSS)/Cell-specific Reference Signals (CRS), but NR DRS may comprise more signals/channels. Channel Access Schemes FIG. 1 illustrates LTE LBT and COT, where “s” is the sensing time period. In this figure, if the channel is determined to be busy, after some deferral time the user equipment (UE) may try again to sense on the channel in order to determine whether the channel is available, and if so after some deterministic backoff time the UE may start transmitting uplink (UL) burst (during the UE's channel occupancy time) but for no longer than the maximum channel occupancy time (MCOT) which can be e.g. up to 10 ms, depending on the region. The channel access schemes for NR-based access for unlicensed spectrum can be classified into the following categories: Category 1 (Cat 1): Immediate transmission after a short switching gapCategory 2 (Cat 2): LBT without random back-off—like in LTECategory 3 (Cat 3): LBT with random back-off with a contention window of fixed sizeCategory 4 (Cat 4): LBT with random back-off with a contention window of variable size For different transmissions in a COT and different channels/signals to be transmitted, different categories of channel access schemes can be used. The applicability of the channel access schemes is described in 3GPP TR 38.889, for example. Channel access mechanisms for beamformed transmissions have been studied. It has been identified that omni-directional LBT should be supported. Using directional LBT for beamformed transmissions, i.e. LBT performed in the direction of the transmitted, has also been studied. Further consideration is required regarding directional LBT and its benefits for beamformed transmissions when the specifications are to be developed, taking into account regulations and fair co-existence with other technologies. Examples of S