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EP-4738952-A2 - HARQ PROCESS SELECTION

EP4738952A2EP 4738952 A2EP4738952 A2EP 4738952A2EP-4738952-A2

Abstract

Example embodiments of the present disclosure relate to de-prioritization of retransmission. A device determines whether user data is absent in a transport block that is to be retransmitted through a hybrid automatic repeat request process. The device deprioritizes selection of the hybrid automatic repeat request process for one or more transmissions on a configured grant based at least in part on the determination. Through this solution, it is possible to avoid or deprioritize unnecessary retransmissions of the transport blocks without user data.

Inventors

  • WU, CHUNLI
  • LI, ZEXIAN
  • MALDONADO, ROBERTO
  • KUO, PING-HENG

Assignees

  • Nokia Technologies Oy

Dates

Publication Date
20260506
Application Date
20210330

Claims (15)

  1. A device (300, 110) comprising: at least one processor (310); and at least one memory (320) including computer program code; wherein the at least one memory (320) and the computer program code are configured to, with the at least one processor (310), cause the device to: determine (210) whether user data is absent in a transport block which is a transport block for a retransmission through a hybrid automatic repeat request process; and deprioritize (220) selection of the hybrid automatic repeat request process for the retransmission on a configured grant in accordance with a determination that user data is absent in the transport block.
  2. The device of claim 1, wherein the at least one memory (320) and the computer program code are configured to, with the at least one processor (310), further cause the device to: in accordance with a determination that the selection of the hybrid automatic repeat request process is deprioritized, flush the transport block from a buffer associated with the hybrid automatic repeat request process; and/or stop at least one timer for the hybrid automatic repeat request process, wherein the at least one timer comprises at least one of a configured grant timer and a configured grant retransmission timer started in a previous transmission of the transport block in the hybrid automatic repeat request process.
  3. The device of claim 1 or 2, wherein the at least one memory (320) and the computer program code are configured to, with the at least one processor (310), further cause the device to: in accordance with a determination that the selection of the hybrid automatic repeat request process is deprioritized, determine whether a configured grant retransmission timer for the hybrid automatic repeat request process expires, wherein the configured grant retransmission timer is started in a previous transmission of the transport block in the hybrid automatic repeat request process; and/or in accordance with a determination that the configured grant retransmission timer expires, flush the transport block from a buffer associated with the hybrid automatic repeat request process.
  4. The device of any of claims 1 to 3, wherein the at least one memory (320) and the computer program code are configured to, with the at least one processor (310), further cause the device to: determine whether the transport block is allowed to be transmitted on the configured grant, and determine whether the user data is absent in the transport block in accordance with a determination that the transport block is allowed to be transmitted on the configured grant.
  5. The device of any of claims 1 to 4, wherein the at least one memory (320) and the computer program code are configured to, with the at least one processor (310), further cause the device to select the hybrid automatic repeat request process to perform the retransmission of the transport block on the configured grant in accordance with a determination that user data is included in the transport block.
  6. The device of any of claims 1 to 5, wherein the selection of the hybrid automatic repeat request process for the retransmission is deprioritized by: assigning the hybrid automatic repeat request process with a lower priority than one or more other hybrid automatic repeat request processes for retransmissions and/or one or more hybrid automatic repeat request processes for initial transmissions of transport blocks including user data, or assigning the hybrid automatic repeat request process with a lowest priority.
  7. The device of any of claims 1 to 6, wherein the at least one memory (320) and the computer program code are configured to, with the at least one processor (310), further cause the device to select, among hybrid automatic repeat request processes for retransmissions and/or initial transmissions, a hybrid automatic repeat request process based on priorities of the hybrid automatic repeat request processes.
  8. A method comprising: determining (210) whether user data is absent in a transport block which is a transport block for a retransmission through a hybrid automatic repeat request process; and deprioritizing (220) selection of the hybrid automatic repeat request process for the retransmission on a configured grant in accordance with a determination that user data is absent in the transport block.
  9. The method of claim 8, further comprising: in accordance with a determination that the selection of the hybrid automatic repeat request process is deprioritized, flushing the transport block from a buffer associated with the hybrid automatic repeat request process; and/or stopping at least one timer for the hybrid automatic repeat request process, wherein the at least one timer comprises at least one of a configured grant timer and a configured grant retransmission timer started in a previous transmission of the transport block in the hybrid automatic repeat request process.
  10. The method of claim 8 or 9, further comprising: in accordance with a determination that the selection of the hybrid automatic repeat request process is deprioritized, determining whether a configured grant retransmission timer for the hybrid automatic repeat request process expires, wherein the configured grant retransmission timer is started in a previous transmission of the transport block in the hybrid automatic repeat request process; and/or in accordance with a determination that the configured grant retransmission timer expires, flushing the transport block from a buffer associated with the hybrid automatic repeat request process.
  11. The method of any of claims 8 to 10, further comprising: determining whether the transport block is allowed to be transmitted on the configured grant, and wherein determining whether the user data is absent in the transport block comprises: in accordance with a determination that the transport block is allowed to be transmitted on the configured grant determining whether the user data is absent in the transport block.
  12. The method of any of claims 8 to 11, further comprising: selecting the hybrid automatic repeat request process to perform the retransmission of the transport block on the configured grant in accordance with a determination that user data is included in the transport block.
  13. The method of any of claims 8 to 12, wherein the selection of the hybrid automatic repeat request process for the retransmission is deprioritized by: assigning the hybrid automatic repeat request process with a lower priority than one or more other hybrid automatic repeat request processes for retransmissions and/or one or more hybrid automatic repeat request processes for initial transmissions of transport blocks including user data, or assigning the hybrid automatic repeat request process with a lowest priority.
  14. The method of any of claims 8 to 13, further comprising: selecting, among hybrid automatic repeat request processes for retransmissions and/or initial transmissions, a hybrid automatic repeat request process based on priorities of the hybrid automatic repeat request processes.
  15. A computer readable medium comprising program instructions which, when executed, cause an apparatus to perform at least the method of any of claims 8 to 14.

Description

FIELD Embodiments of the present disclosure generally relate to the field of telecommunication and in particular, to a device, a method, and a computer readable medium for hybrid automatic repeat request (HARQ) process selection. BACKGROUND In wireless communications, an uplink (UL) transmission without a dynamic UL grant may be referred to as a grant-free (GF) UL transmission or a configured grant (CG) transmission. In the CG transmissions, a communication device may be configured to use the CG resources to transmit transport blocks (TBs) without a dynamic UL grant. For 5G New Radio in unlicensed spectrum (NR-U), the communication device may be required to retransmit a TB in a HARQ process when it does not receive any feedback from the other communication device, so as to ensure that the TB is successfully received. During operation, the terminal device may use multiple HARQ processes for initial transmissions or retransmissions of different TBs. When a CG is available, the terminal device may decide which HARQ process to be selected for transmission on the CG. Background art is known from 3GPP draft document R2-2003226 relating to remaining issues of intra-UE prioritization in a HARQ process. SUMMARY There are provided a device, a method, and a computer readable medium, as defined by the claims. In general, example embodiments of the present disclosure provide a solution for selection of a HARQ process for a CG. Embodiments that do not fall under the scope of the claims, if any, are to be interpreted as examples useful for understanding various embodiments of the disclosure. In a first aspect of the present disclosure, there is provided a device. The device comprises at least one processor; and at least one memory including computer program code; where the at least one memory and the computer program code are configured to, with the at least one processor, cause the device to determine whether user data is absent in a transport block that is to be retransmitted through a hybrid automatic repeat request process; and deprioritize selection of the hybrid automatic repeat request process for one or more transmissions on a configured grant based at least in part on the determination. In a second aspect of the present disclosure, there is provided a method. The method comprises determining whether user data is absent in a transport block that is to be retransmitted through a hybrid automatic repeat request process; and deprioritizing selection of the hybrid automatic repeat request process for one or more transmissions on a configured grant based at least in part on the determination. In a third aspect of the present disclosure, there is provided an apparatus. The apparatus comprises means for determining whether user data is absent in a transport block that is to be retransmitted through a hybrid automatic repeat request process; and means for deprioritizing selection of the hybrid automatic repeat request process for one or more transmissions on a configured grant based at least in part on the determination. In a fourth aspect of the present disclosure, there is provided a computer readable medium. The computer readable medium comprises program instructions for causing an apparatus to perform at least the method according to the first aspect of the present disclosure. 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 an example communication environment in which example embodiments of the present disclosure can be implemented;Fig. 2 illustrates a flowchart of a method implemented at a device according to some example embodiments of the present disclosure;Fig. 3 illustrates a simplified block diagram of a device that is suitable for implementing example embodiments of the present disclosure; andFig. 4 illustrates a block diagram of an example computer readable medium in accordance with some example embodiments of the present disclosure. Throughout the drawings, the same or similar reference numerals represent the same or similar element. DETAILED DESCRIPTION Principle of the present disclosure will now be described with reference to some example embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitation as to the scope of the disclosure. Embodiments described herein can be implemented in various manners other than the ones described below. In the following description and claims, unless defined otherwise, all technical