Apparatus and method for wireless communication

Abstract

The present disclosure provides an apparatus and method for wireless communication, the apparatus comprising: a processing system configured to receive a downlink control information (DCI) message comprising a data-to-feedback timing indicator, where the DCI message schedules a downlink data message, and the data-to-feedback timing indicator is a value that does not indicate feedback timing; deferring a feedback transmission of the downlink data message based on the value; activating a timer based on the value; entering an active mode when the timer is activated to monitor information of a downlink control channel; and entering an inactive mode to stop monitoring of the downlink control channel when the timer expires.

Description

[0001] This application is a divisional application of the Chinese invention patent application with application date of June 18, 2020 and application number 202080051227.2.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This patent application claims priority to Indian Provisional Patent Application No. 201941030272, filed by KHOSHNEVISAN et al. on July 26, 2019, titled “HYBRIDAUTOMATIC REPEAT REQUEST (HARQ) HANDLING FOR DISCONTINUOUS RECEPTION” and U.S. Patent Application No. 16 / 904,278, filed by KHOSHNEVISAN et al. on June 17, 2020, titled “HYBRIDAUTOMATIC REPEAT REQUEST (HARQ) HANDLING FOR DISCONTINUOUS RECEPTION”, each of which is assigned to the present assignee. Technical Field

[0004] The present disclosure relates generally to wireless communications and, more particularly, to hybrid automatic repeat request (HARQ) processing for discontinuous reception (DRX). Background Art

[0005] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, video, packet data, messaging, broadcast, etc. These systems may be able to support communication with multiple users by sharing available system resources (e.g., time, frequency, and power). Examples of such multiple access systems include fourth generation (4G) systems, such as long term evolution (LTE) systems, LTE advanced (LTE-A) systems, or LTE-A Pro systems, and fifth generation (5G) systems (which may be referred to as new radio (NR) systems). These systems may use techniques such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), or discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM). A wireless multiple access communication system may include multiple base stations or network access nodes, each of which simultaneously supports communication with multiple communication devices, which may be referred to as user equipment (UE). Summary of the invention

[0006] The systems, methods and devices of the present disclosure each have several innovative aspects, no single one of which is solely responsible for the desirable attributes disclosed herein.

[0007] An innovative aspect of the subject matter described in the present disclosure can be implemented in an apparatus for wireless communication. The apparatus may include a first interface and a processing system. The first interface may be configured to obtain a first downlink control information (DCI) message indicating a non-numeric value of a data-to-feedback timing indicator, wherein the first DCI message schedules a downlink data message, and the data-to-feedback timing indicator is associated with the feedback timing of the downlink data message. The processing system may be configured to activate a timer based on the first DCI message and based on the data-to-feedback timing indicator being a non-numeric value. The first interface may also be configured to obtain monitoring information of a downlink control channel when the timer is activated, and obtain a second DCI message indicating the feedback timing of the downlink data message based on the monitoring information of the downlink control channel.

[0008] Another innovative aspect of the subject matter described in the present disclosure can be implemented in a method for wireless communication at an apparatus for a user equipment (UE). The method may include: receiving a first DCI message indicating a non-numeric value of a data-to-feedback timing indicator, wherein the first DCI message schedules a downlink data message and the data-to-feedback timing indicator is associated with feedback timing of the downlink data message, activating a timer based on receiving the first DCI message and based on the data-to-feedback timing indicator being a non-numeric value, monitoring a downlink control channel while the timer is activated, and receiving a second DCI message indicating feedback timing of the downlink data message based on monitoring the downlink control channel.

[0009] Another innovative aspect of the subject matter described in the present disclosure can be implemented in an additional device for wireless communication at a UE. The device may include a processor, a memory coupled to the processor, and instructions stored in the memory. The instructions are executable by the processor to cause the device to receive a first DCI message indicating a non-numeric value of a data-to-feedback timing indicator, wherein the first DCI message schedules a downlink data message, and the data-to-feedback timing indicator is associated with feedback timing of the downlink data message, activate a timer based on receiving the first DCI message and based on the data-to-feedback timing indicator being a non-numeric value, monitor a downlink control channel when the timer is activated, and receive a second DCI message indicating feedback timing of the downlink data message based on monitoring the downlink control channel.

[0010] Another innovative aspect of the subject matter described in the present disclosure can be implemented in an additional apparatus for wireless communication at a UE. The apparatus can include means for: receiving a first DCI message indicating a non-numeric value for a data-to-feedback timing indicator, wherein the first DCI message schedules a downlink data message and the data-to-feedback timing indicator is associated with feedback timing for the downlink data message, activating a timer based on receiving the first DCI message and based on the data-to-feedback timing indicator being a non-numeric value, monitoring a downlink control channel while the timer is activated, and receiving a second DCI message indicating feedback timing for the downlink data message based on monitoring the downlink control channel.

[0011] Another innovative aspect of the subject matter described in the present disclosure can be implemented in a non-transitory computer-readable medium storing code for wireless communication at a UE. The code can include instructions executable by a processor to: receive a first DCI message indicating a non-numeric value for a data-to-feedback timing indicator, wherein the first DCI message schedules a downlink data message and the data-to-feedback timing indicator is associated with feedback timing of the downlink data message, activate a timer based on receiving the first DCI message and based on the data-to-feedback timing indicator being a non-numeric value, monitor a downlink control channel while the timer is activated, and receive a second DCI message indicating feedback timing of the downlink data message based on monitoring the downlink control channel.

[0012] Some implementations of the methods, apparatus, and non-transitory computer-readable media described herein may further include operations, features, components, or instructions for deactivating the timer based on receiving a second DCI message indicating feedback timing of the downlink data message.

[0013] In some implementations of the methods, apparatus, and non-transitory computer-readable media described herein, deactivating the timer may include operations, features, components, or instructions for deactivating the timer in a first symbol after receiving a second DCI message or in a first symbol after a feedback transmission corresponding to feedback timing indicated by the second DCI message.

[0014] Some implementations of the methods, apparatus, and non-transitory computer-readable media described herein may further include operations, features, components, or instructions for activating a timer, including activating the timer in a first symbol after receiving a first DCI message or in a first symbol after a scheduled downlink data message.

[0015] Some implementations of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for receiving a downlink data message based on a first DCI message, storing feedback information of the downlink data message based on the first DCI message indicating a non-numeric value, and sending a feedback message including feedback information of the downlink data message according to feedback timing indicated by a second DCI message.

[0016] In some implementations of the methods, apparatus, and non-transitory computer-readable media described herein, the feedback message may include a hybrid automatic repeat request (HARQ) acknowledgement (ACK) message.

[0017] Some implementations of the methods, apparatus, and non-transitory computer-readable media described herein may further include operations, features, components, or instructions for receiving a radio resource control (RRC) message indicating an active duration of the timer.

[0018] In some implementations of the methods, apparatus, and non-transitory computer-readable media described herein, the activity duration may be a first activity duration of a timer dedicated to receiving a DCI message indicating a non-numeric value, and the RRC message may further indicate a second activity duration of the timer.

[0019] In some implementations of the methods, apparatus, and non-transitory computer-readable media described herein, the timer may be a drx-RetransmissionTimerDL or a drx-InactivityTimer.

[0020] In some implementations of the methods, apparatus, and non-transitory computer-readable media described herein, a timer may be dedicated to a HARQ process for downlink data messages.

[0021] In some implementations of the methods, apparatus, and non-transitory computer-readable media described herein, the timer may be a retransmission timer for a downlink and may be associated with a HARQ identifier corresponding to a downlink data message.

[0022] Some implementations of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for: deactivating a timer based on the timer running within an active duration of the timer, entering a low power mode based on deactivating the timer, and avoiding monitoring of a downlink control channel while in low power mode.

[0023] In some implementations of the methods, apparatus, and non-transitory computer-readable media described herein, entering low power mode may also be based on the UE being outside of an ON duration of a discontinuous reception (DRX) mode and each timer corresponding to monitoring a downlink control channel being disabled.

[0024] Some implementations of the methods, apparatus, and non-transitory computer-readable media described herein may further include operations, features, components, or instructions for operating according to a DRX mode and monitoring a downlink control channel during an ON duration of the DRX mode, wherein a first DCI message may be received based on monitoring the downlink control channel during the ON duration.

[0025] Some implementations of the methods, apparatuses, and non-transitory computer-readable media described herein may further include operations, features, components, or instructions for sending a feedback message of a downlink data message according to feedback timing indicated by a second DCI message and activating a round trip time (RTT) timer in a first symbol after sending the feedback message. Some implementations of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for: activating a retransmission timer in a first symbol after expiration of the RTT timer based on a feedback message including a negative acknowledgement (NACK) of the downlink data message, and monitoring a downlink control channel when the retransmission timer may be activated.

[0026] In some implementations of the methods, apparatus, and non-transitory computer-readable media described herein, the RTT timer may be drx-HARQ-RTT-TimerDL and the retransmission timer may be drx-RetransmissionTimerDL.

[0027] Another innovative aspect of the subject matter described in the present disclosure can be implemented in an apparatus for wireless communication. The apparatus may include a first interface and a processing system. The processing system may be configured to determine a scheduled transmission opportunity of a feedback message containing feedback information of one or more downlink data messages, and activate a timer in a first symbol after the scheduled transmission opportunity of the feedback message. The first interface may be configured to obtain monitoring information of a downlink control channel when the timer is activated, and may obtain a DCI message requesting at least a portion of the feedback information of the one or more downlink data messages to be transmitted. The processing system may also be configured to deactivate the timer based on obtaining the DCI message.

[0028] Another innovative aspect of the subject matter described in the present disclosure can be implemented in a method for wireless communication at an apparatus for a UE. The method can include: determining a scheduled transmission opportunity for a feedback message, the feedback message including feedback information of one or more downlink data messages, activating a timer in a first symbol after the scheduled transmission opportunity for the feedback message, monitoring a downlink control channel while the timer is activated, receiving a DCI message requesting transmission of at least a portion of the feedback information of the one or more downlink data messages, and deactivating the timer based on receiving the DCI message.

[0029] Another innovative aspect of the subject matter described in the present disclosure can be implemented in an additional device for wireless communication at a UE. The device may include a processor, a memory coupled to the processor, and instructions stored in the memory. The instructions are executable by the processor to cause the device to determine a scheduled transmission opportunity for a feedback message, the feedback message including feedback information of one or more downlink data messages, activate a timer in a first symbol after the scheduled transmission opportunity for the feedback message, monitor a downlink control channel while the timer is activated, receive a DCI message requesting transmission of at least a portion of the feedback information of the one or more downlink data messages, and deactivate the timer based on receiving the DCI message.

[0030] Another innovative aspect of the subject matter described in the present disclosure can be implemented in an additional apparatus for wireless communication at a UE. The apparatus may include components for determining a scheduled transmission opportunity for a feedback message, the feedback message including feedback information for one or more downlink data messages, activating a timer in a first symbol after the scheduled transmission opportunity for the feedback message, monitoring a downlink control channel while the timer is activated, receiving a DCI message requesting transmission of at least a portion of the feedback information for the one or more downlink data messages, and deactivating the timer based on receiving the DCI message.

[0031] Another innovative aspect of the subject matter described in the present disclosure can be implemented in a non-transitory computer-readable medium storing code for wireless communication at a UE. The code may include instructions executable by a processor to: determine a scheduled transmission opportunity for a feedback message, the feedback message including feedback information for one or more downlink data messages, activate a timer in a first symbol after the scheduled transmission opportunity for the feedback message, monitor a downlink control channel while the timer is activated, receive a DCI message requesting transmission of at least a portion of the feedback information for the one or more downlink data messages, and deactivate the timer based on receiving the DCI message.

[0032] Some implementations of the methods, apparatus, and non-transitory computer-readable media described herein may further include operations, features, components, or instructions for performing a listen-before-talk (LBT) process to gain access to an uplink channel for a scheduled transmission opportunity and avoiding sending a feedback message in the scheduled transmission opportunity based on a failure of the LBT process.

[0033] In some implementations of the methods, apparatus, and non-transitory computer-readable media described herein, activating the timer may be based on avoiding sending the feedback message in a scheduled transmission opportunity.

[0034] Some implementations of the methods, apparatus, and non-transitory computer-readable media described herein may further include operations, features, components, or instructions for sending a feedback message in a scheduled transmission opportunity based on determining the scheduled transmission opportunity.

[0035] In some implementations of the methods, apparatus, and non-transitory computer-readable media described herein, the deactivation timer may also be based on receiving any DCI message, any DCI message scheduling the transmission of a downlink data message, a DCI message requesting the transmission of at least a portion of feedback information for one or more downlink data messages, or a combination thereof.

[0036] In some implementations of the methods, apparatus, and non-transitory computer-readable media described herein, the DCI message may be a second DCI message, and the methods, apparatus, and non-transitory computer-readable media described herein may further include operations, features, components, or instructions for receiving a first DCI message that schedules transmission of at least one downlink data message of one or more downlink data messages and includes a data-to-feedback timing indicator corresponding to the at least one downlink data message and indicating a scheduled transmission opportunity.

[0037] In some implementations of the methods, apparatus, and non-transitory computer-readable media described herein, a first group indicator of a first DCI message and a second group indicator of a second DCI message may include the same group indicator, a first new ACK-feedback group indicator (NFI) of the first DCI message and a second NFI of the second DCI message may include the same NFI, and the second DCI message may request transmission of at least a portion of feedback information of one or more downlink data messages based on the same group indicator and the same NFI.

[0038] In some implementations of the methods, apparatus, and non-transitory computer-readable media described herein, a first DCI message may include a first set of indicators, a second DCI message may include a feedback request for the first set of indicators, and the second DCI message may request transmission of at least a portion of feedback information for one or more downlink data messages based on the second DCI message including the feedback request for the first set of indicators.

[0039] In some implementations of the methods, apparatus, and non-transitory computer-readable media described herein, the feedback message may be a HARQ-ACK message.

[0040] Another innovative aspect of the subject matter described in the present disclosure can be implemented in an apparatus for wireless communication. The apparatus may include a first interface and a processing system. The first interface may be configured to output a first DCI message for transmission to a UE on a downlink control channel, the first DCI message indicating a non-numeric value of a data-to-feedback timing indicator, wherein the first DCI message schedules a downlink data message, and the data-to-feedback timing indicator is associated with the feedback timing of the downlink data message. The processing system may be configured to determine the active time for the UE to monitor the downlink control channel based on a timer, wherein the timer may be activated based on the first DCI message and the data-to-feedback timing indicator being a non-numeric value. The first interface may also be configured to output a second DCI message indicating the feedback timing of the downlink data message based on the determined active time for the UE to monitor the downlink control channel for transmission to the UE on the downlink control channel.

[0041] Another innovative aspect of the subject matter described in the present disclosure can be implemented in a method for wireless communication at an apparatus for a base station. The method may include sending a first DCI message indicating a non-numeric value of a data-to-feedback timing indicator to a UE on a downlink control channel, wherein the first DCI message schedules a downlink data message and the data-to-feedback timing indicator is associated with feedback timing of the downlink data message, determining an active time for the UE to monitor the downlink control channel based on a timer, wherein the timer is activated based on the first DCI message and the data-to-feedback timing indicator being a non-numeric value, and sending a second DCI message indicating feedback timing of the downlink data message to the UE on the downlink control channel based on the determined active time for the UE to monitor the downlink control channel.

[0042] Another innovative aspect of the subject matter described in the present disclosure can be implemented in an additional device for wireless communication at a base station. The device may include a processor, a memory coupled to the processor, and instructions stored in the memory. The instructions can be executed by the processor to cause the device to: send a first DCI message indicating a non-numeric value of a data-to-feedback timing indicator to a UE on a downlink control channel, wherein the first DCI message schedules a downlink data message, and the data-to-feedback timing indicator is associated with the feedback timing of the downlink data message, determine an active time for the UE to monitor the downlink control channel based on a timer, wherein the timer is activated based on the first DCI message and the data feedback timing indicator being a non-numeric value, and based on the determined active time for the UE to monitor the downlink control channel, send a second DCI message indicating the feedback timing of the downlink data message to the UE on the downlink control channel.

[0043] Another innovative aspect of the subject matter described in the present disclosure can be implemented in an additional apparatus for wireless communication at a base station. The apparatus may include means for: sending a first DCI message indicating a non-numeric value of a data-to-feedback timing indicator to a UE on a downlink control channel, wherein the first DCI message schedules a downlink data message and the data-to-feedback timing indicator is associated with feedback timing of the downlink data message, determining an active time for the UE to monitor the downlink control channel based on a timer, wherein the timer is activated based on the first DCI message and the data-to-feedback timing indicator being a non-numeric value, and sending a second DCI message indicating feedback timing of the downlink data message to the UE on the downlink control channel based on the determined active time for the UE to monitor the downlink control channel.

[0044] Another innovative aspect of the subject matter described in the present disclosure can be implemented in a non-transitory computer-readable medium storing code for wireless communication at a base station. The code can include instructions executable by a processor to: send a first DCI message indicating a non-numeric value of a data-to-feedback timing indicator to a UE on a downlink control channel, wherein the first DCI message schedules a downlink data message and the data-to-feedback timing indicator is associated with feedback timing of the downlink data message, determine an active time for the UE to monitor the downlink control channel based on a timer, wherein the timer is activated based on the first DCI message and the data feedback timing indicator being a non-numeric value, and send a second DCI message indicating feedback timing of the downlink data message to the UE on the downlink control channel based on the determined active time for the UE to monitor the downlink control channel.

[0045] In some implementations of the methods, apparatus, and non-transitory computer-readable media described herein, the timer may be a retransmission timer for a downlink and may be associated with a HARQ identifier corresponding to a downlink data message.

[0046] Some implementations of the methods, apparatus, and non-transitory computer-readable media described herein may further include operations, features, components, or instructions for sending an RRC message indicating an active duration of the timer.

[0047] In some implementations of the methods, apparatus, and non-transitory computer-readable media described herein, the activity duration may be a first activity duration of a timer dedicated to receiving a DCI message indicating a non-numeric value, and the RRC message may further indicate a second activity duration of the timer.

[0048] In some implementations of the methods, apparatus, and non-transitory computer-readable media described herein, the timer may be a drx-RetransmissionTimerDL or a drx-InactivityTimer.

[0049] Some implementations of the methods, apparatus, and non-transitory computer-readable media described herein may further include operations, features, components, or instructions for sending a downlink data message based on the first DCI message.

[0050] Another innovative aspect of the subject matter described in the present disclosure can be implemented in an apparatus for wireless communication. The apparatus may include a first interface and a processing system. The first interface may be configured to, for transmission to a UE on a downlink control channel, output a first DCI message, the first DCI message scheduling the transmission of a downlink data message, and including a data to feedback timing indicator corresponding to the downlink data message and indicating the scheduled transmission opportunity. The processing system may be configured to identify a feedback message that fails to successfully obtain feedback information including a downlink data message in a scheduled transmission opportunity, and determine the active time for the UE to monitor the downlink control channel based on a timer, wherein the timer is activated in the first symbol after the scheduled transmission opportunity. The first interface may also be configured to, for transmission to a UE on a downlink control channel, output a second DCI message, the second DCI message based on the determined active time for the UE to monitor the downlink control channel and identifying the failure to successfully receive the feedback message, requesting transmission of at least a portion of the feedback information of the downlink data message.

[0051] Another innovative aspect of the subject matter described in the present disclosure can be implemented in a method for wireless communication at an apparatus for a base station. The method can include sending a first DCI message to a UE on a downlink control channel, the first DCI message scheduling transmission of a downlink data message and including a data-to-feedback timing indicator corresponding to the downlink data message and indicating a scheduled transmission opportunity, identifying a feedback message including feedback information of the downlink data message that failed to be successfully received in the scheduled transmission opportunity, determining an active time for the UE to monitor the downlink control channel based on a timer, wherein the timer is activated in a first symbol after the scheduled transmission opportunity, and sending a second DCI message to the UE on the downlink control channel, the second DCI message requesting transmission of at least a portion of the feedback information of the downlink data message based on the determined active time for the UE to monitor the downlink control channel and identifying the failure to successfully receive the feedback message.

[0052] Another innovative aspect of the subject matter described in the present disclosure can be implemented in an additional device for wireless communication at a base station. The device may include a processor, a memory coupled to the processor, and instructions stored in the memory. The instructions can be executed by the processor so that the device sends a first DCI message to a UE on a downlink control channel, the first DCI message scheduling the transmission of a downlink data message and including a data-to-feedback timing indicator corresponding to the downlink data message and indicating a scheduled transmission opportunity, identifies a feedback message including feedback information of the downlink data message that failed to be successfully received in the scheduled transmission opportunity, determines an active time for the UE to monitor the downlink control channel based on a timer, wherein the timer is activated in a first symbol after the scheduled transmission opportunity, and sends a second DCI message to the UE on the downlink control channel, the second DCI message based on the determined active time for the UE to monitor the downlink control channel and identifying the failure to successfully receive the feedback message to request the transmission of at least a portion of the feedback information of the downlink data message.

[0053] Another innovative aspect of the subject matter described in the present disclosure can be implemented in an additional apparatus for wireless communication at a base station. The apparatus may include components for: sending a first DCI message to a UE on a downlink control channel, the first DCI message scheduling transmission of a downlink data message and including a data-to-feedback timing indicator corresponding to the downlink data message and indicating a scheduled transmission opportunity, identifying a feedback message including feedback information of the downlink data message that was not successfully received in the scheduled transmission opportunity, determining an active time for the UE to monitor the downlink control channel based on a timer, wherein the timer is activated in a first symbol after the scheduled transmission opportunity, and sending a second DCI message to the UE on the downlink control channel, the second DCI message requesting transmission of at least a portion of the feedback information of the downlink data message based on the determined active time for the UE to monitor the downlink control channel and identifying a failure to successfully receive the feedback message.

[0054] Another innovative aspect of the subject matter described in the present disclosure can be implemented in a non-transitory computer-readable medium storing code for wireless communication at a base station. The code can include instructions executable by a processor to: send a first DCI message to a UE on a downlink control channel, the first DCI message scheduling transmission of a downlink data message and including a data-to-feedback timing indicator corresponding to the downlink data message and indicating a scheduled transmission opportunity, identify a feedback message including feedback information of the downlink data message that was not successfully received in the scheduled transmission opportunity, determine an active time for the UE to monitor the downlink control channel based on a timer, wherein the timer is activated in a first symbol after the scheduled transmission opportunity, and send a second DCI message to the UE on the downlink control channel, the second DCI message requesting transmission of at least a portion of the feedback information of the downlink data message based on the determined active time for the UE to monitor the downlink control channel and identifying the failure to successfully receive the feedback message.

[0055] Some implementations of the methods, apparatus, and non-transitory computer-readable media described herein may further include operations, features, components, or instructions for sending an RRC message indicating an active duration of the timer.

[0056] Another innovative aspect of the subject matter described in the present disclosure can be implemented in an apparatus for wireless communication. The apparatus may include: a processing system configured to: receive a downlink control information (DCI) message including a data-to-feedback timing indicator, wherein the DCI message schedules a downlink data message and the data-to-feedback timing indicator is a value that does not indicate feedback timing; postpone feedback transmission of the downlink data message based on the value; activate a timer based on the value; enter an active mode when the timer is activated to monitor information of a downlink control channel; and enter an inactive mode when the timer expires to stop monitoring the downlink control channel.

[0057] Another innovative aspect of the subject matter described in the present disclosure can be implemented in an apparatus for wireless communication. The apparatus may include: a processing system configured to: output a downlink control information DCI message including a data-to-feedback timing indicator, wherein the DCI message schedules a downlink data message, and the data-to-feedback timing indicator is a value that does not indicate feedback timing; and determine an active time for a user equipment UE to monitor a downlink control channel based on a timer, wherein the timer is activated based on the value.

[0058] Another innovative aspect of the subject matter described in the present disclosure can be implemented in a method of wireless communication. The method may include: receiving a downlink control information (DCI) message including a data-to-feedback timing indicator, wherein the DCI message schedules a downlink data message and the data-to-feedback timing indicator is a value that does not indicate feedback timing; postponing feedback transmission of the downlink data message based on the value; activating a timer based on the value; entering an active mode when the timer is activated to monitor information of a downlink control channel; and entering an inactive mode when the timer expires to stop monitoring the downlink control channel.

[0059] Another innovative aspect of the subject matter described in the present disclosure can be implemented in a method for wireless communication. The method may include: sending a downlink control information DCI message including a data-to-feedback timing indicator, wherein the DCI message schedules a downlink data message, and the data-to-feedback timing indicator is a value that does not indicate feedback timing; and determining an active time for a user equipment UE to monitor a downlink control channel based on a timer, wherein the timer is activated based on the value.

[0060] Details of one or more implementations of the subject matter described in this disclosure are set forth in the accompanying drawings and the following description. Other features, aspects, and advantages will become apparent from the description, drawings, and claims. Please note that the relative dimensions of the following figures may not be drawn to scale. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 and 2 An example of a wireless communication system supporting a hybrid automatic repeat request (HARQ) process for discontinuous reception (DRX) is shown.

[0062] Figure 3A , Figure 3B , Figure 4A and Figure 4B An example of a timeline of a HARQ process supporting DRX is shown.

[0063] Figure 5 and Figure 6 An example of a process flow for a HARQ process supporting DRX is shown.

[0064] Figure 7 A block diagram of an example user equipment (UE) is shown.

[0065] Figure 8 A block diagram of an example base station (BS) is shown.

[0066] Figure 9-14 A flow chart illustrating an example method for handling HARQ with DRX operation is shown.

[0067] Like reference numbers and designations in the various drawings indicate like elements.

[0068] Specific implementation method

[0069] The following description is directed to certain implementations for the purpose of describing the innovative aspects of the present disclosure. However, one of ordinary skill in the art will readily recognize that the teachings herein may be applied in a variety of different ways. The implementations described may be implemented in a manner that is capable of being implemented in accordance with any IEEE 16.11 standard or any IEEE 802.11 standard, The present invention may be implemented in any device, system or network that sends and receives radio frequency (RF) signals using the standards, code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), global system for mobile communications (GSM), GSM / general packet radio service (GPRS), enhanced data GSM environment (EDGE), terrestrial trunked radio (TETRA), wideband CDMA (W-CDMA), evolution data optimized (EV-DO), 1xEV-DO, EV-DO Rev A, EV-DO Rev B, high speed packet access (HSPA), high speed downlink packet access (HSDPA), high speed uplink packet access (HSUPA), evolved high speed packet access (HSPA+), long term evolution (LTE), AMPS or other known signals for communicating within a wireless, cellular or Internet of Things (IoT) network, such as systems utilizing 3G, 4G or 5G, or further implementations of the technologies thereof.

[0070] In some systems, a user equipment (UE) may support a hybrid automatic repeat request (HARQ) process when operating in a discontinuous reception (DRX) mode. In the DRX mode, the UE may switch between an active state (e.g., during the active state, the UE monitors a downlink control information (DCI) message of a downlink control channel) and an inactive state. The UE may continue to operate in an active state based on one or more timers. For example, a timer set may maintain the active state of the UE while at least one timer in the timer set is running. Each timer may correspond to a specific activation trigger, a specific deactivation trigger, and a specific activity duration. Examples of timers that maintain an active state at the UE may include an ON duration timer, an inactive timer, and a retransmission timer. In some implementations, the UE may support other timers that may not maintain an active state, but may trigger the activation of other timers or operations, such as a round trip time (RTT) timer. If there is currently no timer running to maintain an active state at the UE, the UE may operate in a sleep mode (e.g., during the sleep mode, the UE may avoid monitoring a downlink control channel).

[0071] In some implementations, the UE may use a timer to maintain an active state based on receiving a DCI message of a data message, the DCI message of the data message having a non-numerical data-to-feedback timing indicator indicating the data message. In some examples, the data-to-feedback timing indicator may be a K1 value, wherein the K1 value indicates a time slot in which the UE may send feedback information of the data message. For example, the K1 value may specify the number of time slots after receiving a data message to send a corresponding feedback message. The non-numerical value of the feedback timing may trigger the UE to store the feedback information of the data message, and send the feedback information based on a subsequent DCI message specifying the actual feedback timing of the data message. In such an implementation, activating the timer based on receiving a DCI with a non-numerical K1 value may allow the UE to extend the active state and continue to monitor the downlink control channel to obtain a DCI message with a digital K1 value of the feedback timing. The UE may deactivate the timer based on receiving a DCI message indicating the actual feedback timing. In some examples, the timer may be dedicated to processing the non-numerical value of the data-to-feedback timing indicator. In some other examples, the timer may support multiple operations. For example, the timer may be an inactivity timer, a retransmission timer, or some similar timer that the UE reuses to handle operations such as non-numeric values ​​of data-to-feedback timing indicators. For example, such a timer may be triggered based on both receiving a DCI with a non-numeric K1 value and based on one or more other potential triggers (e.g., receiving a DCI indicating a new transmission, sending a negative acknowledgement (NACK) of HARQ feedback, etc.).

[0072] In some other implementations, the UE may use a timer to remain active after a feedback opportunity to support dynamic group-based HARQ messaging. In dynamic group-based HARQ messaging, the base station may use a DCI message to re-request feedback information from a previously scheduled feedback transmission. For example, if the base station fails to receive a scheduled feedback transmission for a data message group (e.g., based on a failed listen-before-talk (LBT) process at the UE or a misdetection at the base station), the base station may send a DCI message to re-request feedback information for the data message group. In such an implementation, activating a timer in the first symbol after a scheduled feedback opportunity may allow the UE to extend the active state and continue to monitor the downlink control channel to obtain a DCI message requesting scheduling of at least a portion of the feedback information sent in the feedback opportunity. The UE may deactivate the timer based on receiving one or more of a DCI message, a DCI message for a downlink transmission, or a DCI message requesting feedback information for a data message group after a scheduled feedback opportunity.

[0073] Specific implementations of the subject matter described in the present disclosure may be implemented to achieve one or more of the following potential advantages. In some implementations, utilizing a timer to extend the active state of a UE in specific scenarios (e.g., when processing non-numeric data to a feedback timing indicator, when supporting dynamic group-based HARQ messaging, or both) can significantly reduce the delay associated with HARQ feedback. For example, if a UE returns to an inactive state before receiving a DCI message indicating feedback timing for a data message or data message group, the UE may not send feedback information until the next DRX cycle. This may introduce significant delays to the HARQ feedback process, especially for relatively long DRX cycles. By activating a timer to remain active and continue to monitor the downlink control channel, the UE can receive a DCI message that schedules a feedback opportunity in the current DRX cycle, potentially supporting faster turnaround of feedback information. In addition, if a NACK is sent, this faster turnaround of feedback information can further support lower latency retransmissions of data from the base station, thereby potentially improving latency of other data-based processes at the UE.

[0074] Figure 1 An example of a wireless communication system 100 supporting hybrid automatic repeat request processing for discontinuous reception according to aspects of the present disclosure is shown. The wireless communication system 100 may include a base station 105, a UE 115, and a core network 130. In some examples, the wireless communication system 100 may be an LTE network, an LTE Advanced (LTE-A) network, an LTE-A Pro network, or a New Radio (NR) network. In some implementations, the wireless communication system 100 may support enhanced broadband communications, ultra-reliable (e.g., mission-critical) communications, low-latency communications, communications with low-cost and low-complexity devices, or any combination thereof.

[0075] The base stations 105 may be dispersed throughout a geographic area to form the wireless communication system 100, and may be devices of different forms or with different capabilities. The base stations 105 and the UEs 115 may communicate wirelessly via one or more communication links 125. Each base station 105 may provide a coverage area 110 over which the UEs 115 and the base stations 105 may establish communication links 125. The coverage area 110 may be an example of a geographic area over which the base stations 105 and the UEs 115 support signal communication according to one or more radio access technologies.

[0076] The UEs 115 may be dispersed throughout the coverage area 110 of the wireless communication system 100, and each UE 115 may be stationary or mobile, or both, at different times. The UEs 115 may be devices of different forms or with different capabilities. Figure 1 Some example UEs 115 are shown in FIG. Figure 1As shown, the UE 115 described herein may be able to communicate with various types of devices, such as other UEs 115, base stations 105, or network devices (e.g., core network nodes, relay devices, integrated access and backhaul (IAB) nodes, or other network devices).

[0077] The base stations 105 may communicate with the core network 130 or with each other, or both. For example, the base stations 105 may be connected to the core network 130 via a backhaul link 120 (e.g., via S1, N2, N3, or another interface). The base stations 105 may communicate with each other directly (e.g., directly between the base stations 105) or indirectly (e.g., via the core network 130), or both, via the backhaul link 120 (e.g., via X2, Xn, or other interfaces). In some examples, the backhaul link 120 may be or include one or more wireless links.

[0078] The one or more base stations 105 described herein may include or may be referred to by a person of ordinary skill in the art as a base station transceiver, a radio base station, an access point, a radio transceiver, a NodeB, an eNodeB (eNB), a next generation NodeB or a giga-NodeB (any of which may be referred to as a gNB), a Home NodeB, a Home eNodeB, or other suitable terminology.

[0079] UE 115 may include or may be referred to as a mobile device, a wireless device, a remote device, a handheld device, or a subscriber device, or some other suitable terminology, where in other examples, a "device" may also be referred to as a unit, a station, a terminal, or a client. UE 115 may also include or may be referred to as a personal electronic device such as a cellular phone, a personal digital assistant (PDA), a tablet computer, a laptop computer, or a personal computer. In some examples, UE 115 may include or be referred to as a wireless local loop (WLL) station, an IoT device, an Internet of Everything (IoE) device, a machine type communication (MTC) device, etc., which may be implemented in various objects such as home appliances, vehicles, meters, etc.

[0080] like Figure 1 As shown, the UE 115 described herein can communicate with various types of devices, such as other UEs 115 that can sometimes act as relays, as well as base stations 105 and network devices including macro eNBs or gNBs, small cell eNBs or gNBs, relay base stations, etc.

[0081] The UE 115 and the base station 105 may communicate wirelessly with each other via one or more communication links 125 through one or more carriers. The term "carrier" may refer to a set of radio spectrum resources having a defined physical layer structure for supporting the communication link 125. For example, a carrier for the communication link 125 may include a portion of a radio spectrum band (e.g., a bandwidth portion (BWP)) that operates according to a physical layer channel for a given radio access technology (e.g., LTE, LTE-A, LTE-A Pro, NR). Each physical layer channel may carry acquisition signaling (e.g., synchronization signals, system information, etc.), control signaling for coordinating carrier operations, user data, or other signaling. The wireless communication system 100 may support communication with the UE 115 using carrier aggregation or multi-carrier operation. The UE 115 may be configured with multiple downlink component carriers and one or more uplink component carriers according to the carrier aggregation configuration. Carrier aggregation may be used with both frequency division duplex (FDD) and time division duplex (TDD) component carriers.

[0082] The signal waveform transmitted via the carrier may be composed of multiple subcarriers (e.g., using multi-carrier modulation (MCM) techniques, such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT-S-OFDM)). In a system employing MCM techniques, a resource element may include a symbol period (e.g., the duration of a modulation symbol) and a subcarrier, where the symbol period and the subcarrier spacing are inversely related. The number of bits carried by each resource element may depend on the modulation scheme (e.g., the order of the modulation scheme, the codec rate of the modulation scheme, or both). Therefore, the more resource elements received by the UE 115 and the higher the order of the modulation scheme, the higher the data rate may be for the UE 115. Wireless communication resources may refer to a combination of radio spectrum resources, time resources, and spatial resources (e.g., spatial layers or beams), and the use of multiple spatial layers may further increase the data rate or data integrity used for communicating with the UE 115.

[0083] The time interval of the base station 105 or the UE 115 can be expressed as a multiple of a basic time unit. For example, the basic time unit can refer to T s =1 / (Δf max ·N f ) seconds sampling period, where Δf max It can represent the maximum supported subcarrier spacing, and N f The maximum supported discrete Fourier transform (DFT) size may be indicated. The time intervals of the communication resources may be organized according to radio frames each having a specified duration (e.g., 10 milliseconds (ms)). Each radio frame may be identified by a system frame number (SFN) (e.g., ranging from 0 to 1023).

[0084] Each frame may include multiple consecutively numbered subframes or time slots, and each subframe or time slot may have the same duration. In some implementations, the frame may be divided (e.g., in the time domain) into subframes, and each subframe may be further divided into multiple time slots. Alternatively, each frame may include a variable number of time slots, and the number of time slots may depend on the subcarrier spacing. Each time slot may include multiple symbol periods (e.g., depending on the length of the cyclic prefix preceding each symbol period). In some wireless communication systems, the time slot may be further divided into multiple mini-time slots containing one or more symbols. In addition to the cyclic prefix, each symbol period may contain one or more (e.g., N f ) sampling period. The duration of a symbol period may depend on the subcarrier spacing or frequency band of operation.

[0085] A subframe, slot, mini-slot, or symbol may be the smallest scheduling unit (e.g., in the time domain) of the wireless communication system 100 and may be referred to as a transmission time interval (TTI). In some implementations, the TTI duration (e.g., the number of symbol periods in a TTI) may be variable. Additionally or alternatively, the smallest scheduling unit of the wireless communication system 100 may be dynamically selected (e.g., in a burst of a shortened TTI (sTTI)).

[0086] Physical channels may be multiplexed on a carrier according to various techniques. Physical control channels and physical data channels may be multiplexed on a downlink carrier, for example, using a time division multiplexing (TDM) technique, a frequency division multiplexing (FDM) technique, or a hybrid TDM-FDM technique. A control region (e.g., a control resource set (CORESET)) of a physical control channel may be defined by a plurality of symbol periods and may extend across a system bandwidth or a subset of a system bandwidth of a carrier. One or more control regions (CORESETs) may be configured for a set of UEs 115. For example, a UE 115 may monitor or search a control region to obtain control information according to one or more search space sets, and each search space set may include one or more control channel candidates in one or more aggregation levels arranged in a cascaded manner. The aggregation level of a control channel candidate may refer to a plurality of control channel resources (e.g., control channel elements (CCEs)) associated with coded information of a control information format having a given payload size. A search space set may include a common search space set configured for sending control information to a plurality of UEs 115 and a UE-specific search space set for sending control information to a particular UE 115.

[0087] In some examples, the base stations 105 may be mobile, and thus provide communication coverage for mobile geographic coverage areas 110. In some examples, different geographic coverage areas 110 associated with different technologies may overlap, but the different geographic coverage areas 110 may be supported by the same base station 105. In some other examples, overlapping geographic coverage areas 110 associated with different technologies may be supported by different base stations 105. The wireless communication system 100 may include, for example, a heterogeneous network in which different types of base stations 105 provide coverage for various geographic coverage areas 110 using the same or different radio access technologies.

[0088] Some UEs 115 may be configured to employ a reduced power consumption operating mode, such as half-duplex communication (e.g., a mode that supports unidirectional communication via transmission or reception, but not simultaneous transmission and reception). In some examples, half-duplex communication may be performed at a reduced peak rate. Other energy-saving techniques for UE 115 include entering a power-saving deep sleep mode when not engaged in active communications, operating on a limited bandwidth (e.g., according to narrowband communications), or a combination of these techniques. For example, some UEs 115 may be configured to operate using a narrowband protocol type that is associated with a predefined portion or range (e.g., a subcarrier or resource block (RB) set) within a carrier, within a guard band of a carrier, or outside a carrier.

[0089] The wireless communication system 100 may be configured to support ultra-reliable communication or low-latency communication, or various combinations thereof. For example, the wireless communication system 100 may be configured to support ultra-reliable low-latency communication (URLLC) or mission-critical communication. UE115 may be designed to support ultra-reliable, low-latency or critical functions (e.g., mission-critical functions). Ultra-reliable communication may include private communication or group communication, and may be supported by one or more mission-critical services such as mission-critical push-to-talk (MCPTT), mission-critical video (MCVideo), or mission-critical data (MCData). Support for mission-critical functions may include service prioritization, and mission-critical services may be used for public safety or general commercial applications. The terms ultra-reliable, low-latency, mission-critical, and ultra-reliable low-latency may be used interchangeably herein.

[0090] In some implementations, the UE 115 may also communicate directly with other UEs 115 via a device-to-device (D2D) communication link 135 (e.g., using a peer-to-peer (P2P) or D2D protocol). One or more UEs 115 utilizing D2D communication may be within the geographic coverage area 110 of the base station 105. Other UEs 115 in such a group may be outside the geographic coverage area 110 of the base station 105 or unable to receive transmissions from the base station 105. In some implementations, a group of UEs 115 communicating via D2D communication may utilize a one-to-many (1:M) system in which each UE 115 transmits to each other UE 115 in the group. In some examples, the base station 105 facilitates the scheduling of resources for D2D communication. In some other implementations, D2D communication is performed between UEs 115 without involving the base station 105.

[0091] The core network 130 may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. The core network 130 may be an evolved packet core (EPC) or a 5G core (5GC), which may include at least one control plane entity (e.g., a mobility management entity (MME), an access and mobility management function (AMF)) for managing access and mobility and at least one user plane entity (e.g., a serving gateway (S-GW), a packet data network (PDN) gateway (P-GW), a user plane function (UPF)) for routing packets or interconnections to an external network. The control plane entity may manage non-access stratum (NAS) functions of UE 115 served by a base station 105 associated with the core network 130, such as mobility, authentication, and bearer management. User IP packets may be transmitted through user plane entities, which may provide IP address allocation and other functions. The user plane entity may be connected to a network operator IP service 150. The operator IP service 150 may include access to the Internet, (multiple) intranets, an IP multimedia subsystem (IMS), or a packet-switched streaming media service.

[0092] Some network devices, such as base stations 105, may include subcomponents, such as access network entities 140, which may be examples of access node controllers (ANCs). Each access network entity 140 may communicate with UE 115 through multiple other access network transport entities 145, which may be referred to as radio heads, smart radio heads, or transmit / receive points (TRPs). Each access network transport entity 145 may include one or more antenna panels. In some configurations, the various functions of each access network entity 140 or base station 105 may be distributed across various network devices (e.g., radio heads and ANCs) or merged into a single network device (e.g., base station 105).

[0093] The wireless communication system 100 may operate using one or more frequency bands, typically in the range of 300 megahertz (MHz) to 300 gigahertz (GHz). Typically, the region of 300 MHz to 3 GHz is referred to as the ultra-high frequency (UHF) region or decimeter band, because the wavelength range is approximately 1 decimeter to 1 meter long. UHF waves may be blocked or redirected by buildings and environmental features, but these waves may penetrate structures sufficiently for macro cells to provide service to UEs 115 located indoors. Transmissions using UHF waves may be associated with smaller antennas and shorter ranges (e.g., less than 100 kilometers) than transmissions using smaller frequencies and longer waves in the high frequency (HF) or very high frequency (VHF) portions of the spectrum with frequencies less than 300 MHz.

[0094] The wireless communication system 100 can utilize licensed and unlicensed radio spectrum bands. For example, the wireless communication system 100 can adopt license assisted access (LAA), LTE unlicensed (LTE-U) radio access technology, or NR technology in unlicensed bands such as the 5 GHz industrial, scientific, and medical (ISM) band. When operating in an unlicensed radio spectrum band, devices such as base stations 105 and UEs 115 can use carrier sensing for conflict detection and avoidance. In some implementations, operations in unlicensed bands can be based on carrier aggregation configurations and component carriers operating in licensed bands. Operations in unlicensed spectrum can include downlink transmissions, uplink transmissions, P2P transmissions, D2D transmissions, and the like.

[0095] The base station 105 or UE 115 may be equipped with multiple antennas, which can be used to employ technologies such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communications, or beamforming. The antennas of the base station 105 or UE 115 may be located in one or more antenna arrays or antenna panels, which may support MIMO operations, or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays may be co-located on an antenna assembly (e.g., an antenna tower). In some implementations, the antennas or antenna arrays associated with the base station 105 may be located in different geographical locations. The base station 105 may have an antenna array with several rows and columns of antenna ports, which the base station 105 may use to support beamforming for communications with the UE 115. Similarly, the UE 115 may have one or more antenna arrays, which may support various MIMO or beamforming operations. Additionally or alternatively, the antenna panel may support radio frequency beamforming for signals sent via the antenna ports.

[0096] Beamforming, which may also be referred to as spatial filtering, directional transmission, or directional reception, is a signal processing technique that may be used at a transmitting device or a receiving device (e.g., a base station 105 or a UE 115) to shape or direct an antenna beam (e.g., a transmit beam, a receive beam) along a spatial path between the transmitting device and the receiving device. Beamforming may be achieved by combining signals transmitted via antenna elements of an antenna array so that some signals propagating in a particular direction relative to the antenna array experience constructive interference and other signals experience destructive interference. Adjustments to signals transmitted via antenna elements may include the transmitting device or the receiving device applying an amplitude offset, a phase offset, or both to signals carried via antenna elements associated with the device. Adjustments associated with each antenna element may be defined by a set of beamforming weights associated with a particular direction (e.g., relative to the antenna array of the transmitting device or the receiving device, or relative to some other direction).

[0097] UE 115 and base station 105 may support retransmission of data to increase the likelihood of successfully receiving the data. Hybrid automatic repeat request (HARQ) feedback is a technique for increasing the likelihood of correctly receiving data through communication link 125. HARQ may include a combination of error detection (e.g., using cyclic redundancy check (CRC)), forward error correction (FEC), and retransmission (e.g., automatic repeat request (ARQ)). HARQ may improve the throughput of the MAC layer under poor radio conditions (e.g., low signal-to-noise ratio (SNR) conditions). In some implementations, a device may support same-slot HARQ feedback, wherein the device may provide HARQ feedback in a specific time slot for data received in a previous symbol in the time slot. In some other implementations, a device may provide HARQ feedback in a subsequent time slot or according to some other time interval.

[0098] In some wireless communication systems 100, UE 115 can work in DRX mode. In DRX mode, UE 115 can switch between active state (e.g., during active state, UE 115 monitors DCI messages of downlink control channels) and inactive or sleep state. UE 115 can continue to operate in active state based on one or more timers. For example, a timer set can maintain the active state of UE 115 when at least one timer in the timer set is running. Each timer can correspond to a specific activation trigger, a specific deactivation trigger, and a specific activity duration. Examples of timers that maintain active state at UE 115 can include ON duration timer, inactive timer, and retransmission timer. In some implementations, UE 115 can support other timers that may not maintain active state, but can trigger activation of other timers or operations, such as RTT timer. If there is no timer currently running to maintain active state at UE 115, UE 115 can operate in sleep mode (e.g., during sleep mode, UE 115 can avoid monitoring downlink control channels).

[0099] When operating in DRX mode, UE 115 may use a timer to support specific HARQ operations. In some implementations, UE 115 may use a timer to maintain an active state based on receiving a DCI message with a non-numerical data-to-feedback timing indicator (e.g., a K1 value) indicating a data message. For example, UE 115 may receive a DCI message with feedback timing of a data message from base station 105 based on maintaining an active state. In some other implementations, UE 115 may use a timer to maintain an active duration after a feedback opportunity to support HARQ messaging based on a dynamic group. For example, UE 115 may receive a DCI message from base station 105 requesting retransmission of feedback information previously scheduled for a feedback opportunity based on maintaining an active duration.

[0100] Figure 2 An example of a wireless communication system 200 supporting HARQ processing for DRX is shown. In some examples, the wireless communication system 200 can implement aspects of the wireless communication system 100. The wireless communication system 200 can include a base station 105-a and a UE 115-a, which can be reference Figure 1 Examples of corresponding base stations 105 and corresponding UEs 115 are described.

[0101] The base station 105-a and the UE 115-a can adopt DRX technology, wherein the UE 115-a can operate in DRX mode. In DRX mode, the UE 115-a has a time period during which receiving messages, sending messages, or both are not available to the UE 115-a. For example, the DRX mode can allow the UE 115-a to operate in two modes, an active mode and an inactive mode. In active mode, the UE 115-a can send data to the base station 105-a via the carrier 210, and can receive data from the base station 105-a via the carrier 205. In active mode, the UE 115-a can additionally or alternatively monitor downlink messages from the base station 105-a. However, in inactive mode, the UE 115-a cannot send data to the base station 105-a via the carrier 210, cannot receive data from the base station 105-a via the carrier 205, or both. In the inactive mode, the UE 115-a may operate in a low power state, such as a sleep state, in which data transmission and reception are disabled to allow the UE 115-a to conserve power. In some implementations, the low power state may support a reduced set of operations at the UE 115-a (e.g., receiving signals or beacons using a low power receiver).

[0102] Different modes, whether active or inactive, may occur periodically. For example, UE 115-a may operate in active mode for a period of time. UE 115-a may operate in inactive mode for another period of time. UE 115-a may cycle between active mode and inactive mode according to DRX scheduling or periodicity. In some implementations, the total amount of time spent by UE 115-a cycling between a first active mode and a second active mode (e.g., starting from a first active mode, through a first inactive mode, and to the beginning of a second active mode) may be referred to as a DRX cycle. When in DRX mode, UE 115-a may continuously perform DRX cycles. The operating capability of the media access control layer protocol data unit of UE 115-a may allow UE 115-a to operate in DRX mode. UE 115-a operating in DRX mode may allow UE 115-a to save power. For example, during inactive mode, UE 115-a may utilize less processing overhead and therefore use less power than during active mode. However, during active mode, UE 115-a may use more power than during inactive mode to accommodate higher processing overhead. A UE 115-a utilizing DRX mode may cycle between active and inactive modes or states (e.g., between an "awake" state and a "sleep" state), and thus UE 115-a may consume less power than a UE 115 operating continuously in active mode.

[0103] When the UE 115-a is operating in the DRX mode, the base station 105-a may send one or more downlink transmissions 215 to the UE 115-a via the carrier 205. For example, the base station 105-a may determine when the UE 115-a is expected to be active and may schedule the downlink transmissions 215 based on the determination. Although, in some examples, the base station 105-a may not accurately estimate when the UE 115-a is active (e.g., if the UE 115-a misses the triggering of a timer that keeps the UE 115-a active), such a determination by the base station 105-a may improve the reliability of the downlink transmissions 215 (e.g., based on a lower likelihood that the base station 105-a sends the downlink transmission 215 when the UE 115-a is inactive and may not be able to receive the downlink transmissions 215). The downlink transmissions 215 may include downlink control transmissions (e.g., physical downlink control channel (PDCCH) transmissions) and downlink data transmissions (e.g., physical downlink shared channel (PDSCH) transmissions). Downlink control channel transmissions may include downlink control information (DCI) in a DCI message. For example, a PDCCH transmission may include DCI 220-a, and a PDSCH transmission may include PDSCH 225-a. Base station 105-a may send DCI 220 and PDSCH 225 when UE 115 is in the ON duration. Thus, base station 105-a may have periodic transmission opportunities for downlink transmissions 215, but actual downlink transmissions 215 sent by base station 105-a may not be periodic.

[0104] In some examples, the downlink transmission 215 may include information for scheduling one or more feedback reports 230. For example, the downlink transmission 215 may include a DCI 220-a. In some implementations, the DCI 220-a may schedule a downlink transmission 215 (e.g., a PDSCH 225-a) and may include an indication of when the UE 115-a may send a feedback report 230 of a downlink data transmission to the base station 105-a via the carrier 210. The feedback report 230 may include information indicating whether the UE 115-a successfully received the information provided in the PDSCH 225 transmission to the UE 115-a. For example, a feedback message such as a HARQ-ACK message 235 may include positive acknowledgement (ACK) information, negative acknowledgement (NACK) information, or both, indicating successful reception and decoding (with an ACK) or unsuccessful reception and decoding (with a NACK) of the PDSCH 225. The feedback report 230 may be sent by the UE 115 - a to the base station 105 - a in an uplink control channel transmission, such as a physical uplink control channel (PUCCH) transmission, or an uplink data channel transmission, such as a physical uplink shared channel (PUSCH) transmission.

[0105] A UE 115-a operating in DRX mode may utilize a timer to schedule active and inactive time periods. For example, the UE 115-a may include a timer that may count down from a start time until the timer expires. The UE 115-a may receive a timer configuration from the base station 105-a that may include a duration for the timer. The UE 115-a may receive the timer configuration in a radio resource control (RRC) message from the base station 105-a. The UE 115-a may utilize a variety of different timers when operating in DRX mode.

[0106] In a first example, UE 115-a may include an ON duration timer, such as drx-onDurationTimer. The ON duration timer may determine a default amount of time that UE 115-a may be in active mode (e.g., during the ON duration of a DRX cycle). During active mode, UE 115-a may monitor downlink control messages that may schedule UE 115-a to send or receive data. In another example, UE 115-a may use an inactive timer such as drx-InactivityTimer. The inactive timer may determine the amount of time that UE 115-a remains in active mode after receiving DCI 220. In some implementations, the inactive timer may extend the ON duration of UE 115-a. For example, base station 105-a may send a PDCCH transmission (e.g., DCI 220) to UE 115-a. The inactive timer may extend the amount of time that UE 115-a remains in active mode after receiving a PDCCH transmission. The UE 115 - a may manage a single ON duration timer and a single inactivity timer (eg, these timers may not be HARQ process specific).

[0107] In another example, UE 115-a may use an RTT timer, such as drx-HARQ-RTT-TimerDL. The RTT timer may be used to determine the minimum duration before a downlink allocation for feedback retransmission may be received from base station 105-a. For example, UE 115-a may send a feedback report 230 to base station 105-a, which may include HARQ feedback (e.g., HARQ-ACK message 235). In response to the HARQ-ACK message 235, the minimum amount of time that UE 115-a may receive a retransmission or a retransmission request from base station 105-a may be determined by the RTT timer. The length of the RTT timer may be based on the round-trip delay of over-the-air (OTA) communications, the processing capabilities of base station 105-a, or both. In yet another example, UE 115-a may use a retransmission timer, such as drx-RetransmissionTimerDL. The retransmission timer may be used to determine the maximum amount of time that UE 115 may remain in active mode to monitor downlink retransmissions from base station 105-a. For example, UE 115-a may send a feedback report 230 (e.g., a HARQ-ACK message 235-a) to base station 105-a. Feedback report 230 may include a HARQ NACK. Base station 105-a may send a subsequent retransmission in response to the HARQ NACK. In this example, the amount of time that UE 115-a can monitor retransmissions from base station 105-a may be determined by a retransmission timer. In some implementations, an RTT timer and a retransmission timer may be used to determine the overall HARQ process timing that UE 115-a may operate. For example, an RTT timer may be used to determine the minimum amount of time before a retransmission can be received by UE 115-a and trigger activation of a retransmission timer, and the retransmission timer may determine the amount of time that UE 115-a can monitor retransmissions from base station 105-a (e.g., in subsequent downlink transmissions). UE 115-a may manage HARQ process-specific RTT and retransmission timers.

[0108] In some implementations, for a UE 115-a operating in DRX mode, the total active time (e.g., the time that the UE 115-a is not in inactive mode) may be based on a combination of timers described herein. The total active time may be based on at least one timer configured to keep the ON duration of the UE 115-a running. For example, if at least one of the ON duration timer, the inactive timer, and the retransmission timer is active, these timers may keep the UE 115-a in an active state. Once all of these timers are inactive (e.g., all running timers expire), the UE 115-a may return to an inactive state. However, in some examples, one or more timers may not be used to determine the total active time. For example, the RTT timer may not maintain the ON duration of the UE 115-a, but may indicate when to start the retransmission timer after the feedback transmission of the UE 115-a.

[0109] In some examples, DCI 220 may indicate a new uplink or downlink transmission by UE 115-a or base station 105-a. An indication of a new transmission may be received by UE 115-a in active mode in a downlink transmission 215 from base station 105-a. For example, DCI 220-a may include a message indicating that a subsequent new downlink message is scheduled for transmission to UE 115-a. In another example, DCI 220-a may indicate an uplink grant for a subsequent new uplink message to be sent by UE 115-a. In these examples, UE 115-a may continue to operate in active mode to receive subsequent transmissions from base station 105-a or to send subsequent transmissions to base station 105-a. An inactive timer may be triggered (started) after the last symbol of a PDCCH transmission (e.g., DCI 220-a) received from base station 105-a. In such an example, UE 115-a may remain in active mode until the inactive timer expires. Thus, the total time that UE 115-a can remain in active mode can be based on the ON duration timer and the inactivity timer.

[0110] In some examples, UE 115-a may receive an indication from base station 105-a indicating a scheduled downlink transmission from base station 105-a. UE 115-a may receive the indication from base station 105-a in a downlink transmission 215. The indication may be received in a DCI 220-a sent by base station 105-a. For example, base station 105-a may send DCI 220-a to UE 115-a, which may include an indication of a subsequent PDSCH 225-a transmission by base station 105-a. UE 115-a may attempt to receive and decode PDSCH 225-a, and may send a corresponding HARQ-ACK message 235-a with feedback information for PDSCH 225-a reception to base station 105-a. In such an example, UE 115-a may start an RTT timer to offset a retransmission timer from the HARQ-ACK message 235-a transmission. This may allow the UE 115-a to account for the OTA propagation time for the HARQ transmission to arrive at the base station 105-a and for subsequent retransmissions to arrive at the UE 115-a.In some examples, the RTT timer may be started after the last symbol of the HARQ-ACK message 235-a transmission to the base station 105-a.

[0111] In some implementations, the RTT timer may expire. This may occur naturally once the duration of the RTT timer is reached. When the RTT timer expires, a retransmission timer may be started. The retransmission timer may keep the UE 115-a in active mode, which may extend the time for the UE 115-a to receive retransmissions from the base station 105-a. The retransmission timer may start in the first symbol after the RTT timer expires. While the retransmission timer is running, the UE 115-a may remain in active mode and monitor retransmissions from the base station 105-a. For example, the UE 115-a may send a HARQ NACK to the base station 105-a in a HARQ-ACK message 235-a. The base station 105-a may receive the HARQ NACK or may not receive the HARQ-ACK message 235-a, triggering a retransmission of the corresponding PDSCH 225-a. For example, the base station 105-a may send a DCI 220-b indicating a retransmission of the PDSCH 225-a (e.g., in the PDSCH 225-b) while the retransmission timer is running. The UE 115-a may receive the retransmission based on the retransmission timer that keeps the UE 115-a active. In an implementation in which the UE 115-a does not receive further DCI 220 from the base station 105-a during the duration of the retransmission timer, the retransmission timer may expire naturally. In such an implementation, once the retransmission timer expires (e.g., if other inactivity parameters are also met), the UE 115-a may enter an inactive state.

[0112] In some examples, the UE 115-a may determine the timing of sending a subsequent feedback report 230 in response to the downlink transmission 215 based on a value provided in the DCI 220. For example, the DCI 220-a may include an indicator that defines the timing of the UE 115-a sending a corresponding HARQ-ACK message 235-a to the base station 105-a (where the HARQ-ACK message 235-a may indicate the reception of the PDSCH 225-a scheduled by the DCI 220-a). The indicator may be a data-to-feedback timing indicator, which may be additionally or alternatively referred to as a K1 value, a PDSCH-to-HARQ timing indicator, or both. In some examples, the K1 value may be a numerical value and may indicate the exact number of time slots (or TTIs) before the feedback report 230 is sent to the base station 105-a. For example, a K1 value of 3 may be indicated to the UE 115-a in the DCI 220-a. In this example, the K1 value indicates that three time slots after receiving the PDSCH 225-a, the UE 115-a can send a corresponding HARQ-ACK message 235-a to the base station 105-a.

[0113] However, in some examples, the K1 value may be non-numeric. The non-digital K1 value may be used to postpone the transmission of the feedback report 230. For example, the RRC parameter K1 may support sending an indicator to the UE 115-a to store the feedback report 230, rather than providing the timing of sending the feedback report 230. In this example, the base station 105-a may send a subsequent transmission, wherein the DCI may indicate when the stored feedback report 230 is sent to the base station 105-a. The feedback report triggered now may include the stored feedback report from the previous transmission. For example, the base station 105-a may send a DCI 220-a and a PDSCH 225-a to the UE 115-a. The DCI 220-a may include a non-digital K1 value. The non-digital K1 value may trigger the UE 115-a to store the feedback report associated with the reception of the PDSCH 225-a. The base station 105-a may then send a second DCI 220-b having a digital K1 value and indicating the feedback process of the PDSCH 225-a. The digital K1 value may trigger the UE 115 - a to send a HARQ-ACK message 235 - a to the base station 105 - a , which may include a stored feedback report associated with the receipt of the PDSCH 225 - a .

[0114] In some implementations, when operating in DRX mode, the UE 115-a may receive a DCI 220 with a non-digital K1 value. To support the UE 115-a to remain in active mode long enough to receive a second DCI 220 containing feedback timing information for delayed feedback, the UE 115-a may implement a timer upon identifying a non-digital K1 value in the DCI 200. The timer may be used to keep the UE 115-a in active mode, which may prevent the UE 115-a from entering an inactive mode. The timer may allow the UE 115-a to receive a digital K1 value in a subsequent downlink transmission so that the UE 115-a may send feedback before going to sleep.

[0115] In some examples, the wireless communication system 200 may support NR communications, which may allow static transmission modes (e.g., type 1) and dynamic transmission modes (e.g., type 2). In some implementations, the type 2 mode may allow multiple transmissions to be grouped by the UE 115-a. In such an implementation, multiple feedback codebooks (e.g., dynamic HARQ codebooks) may be supported, where ACK / NACK information for multiple PDSCHs 225 may be grouped together in the same codebook. The UE 115-a may send a single feedback report 230 for HARQ feedback for multiple downlink transmissions. For example, the type 2 codebook may allow information for multiple feedback reports 230 to be grouped into a single HARQ-ACK message 235 transmission. For example, the base station 105-a may send a first downlink transmission indicating a first downlink group to the UE 115-a. The base station 105-a may also send a second downlink transmission indicating the same downlink group to the UE 115-a. Based on the downlink transmissions corresponding to the same downlink group, the base station 105-a may indicate that feedback reports associated with the two downlink transmissions may be grouped into a single uplink transmission.The UE 115-a may send the grouped feedback report 230 to the base station 105-a.

[0116] For example, the base station 105-a may send a first downlink transmission 215, which may include a DCI 220-a and a PDSCH 225-a. The DCI 220-a may include information about a HARQ report (e.g., a HARQ-ACK message 235-a) to be sent back to the base station 105-a in response to the PDSCH 225-a scheduling. The information in the HARQ-ACK message 235-a may be based on a HARQ codebook, which may indicate whether the information in the PDSCH 225-a transmission is successfully received and decoded (using ACK) or not successfully received and decoded (using NACK). The DCI 220-a may include an indicator value that may be used to schedule subsequent HARQ-ACK messages 235-a by the UE 115-a. The indicator value may include a K1 value that may indicate the time slot in which the HARQ-ACK message 235-a will be sent to the base station 105-a. As previously described, the K1 value may be a numerical value or a non-numerical value. DCI 220-a may also include a group scheduling indication, including a group (G) value, a request (R) value, a downlink allocation index (DAI) value, a new ACK feedback group indicator (NFI) value, or some combination of these parameters. The G value may indicate the group to which the HARQ report is grouped. In some implementations, two groups may be supported, however, in some other implementations, more than two groups may be supported. The R value may indicate a request for feedback information of different groups. The DAI value may indicate the number of HARQ reports to be sent in the same group. In some implementations, the DAI value may be a counter DAI (cDAI) value, and the number of HARQ reports grouped in the same transmission may be counted incrementally. Additionally or alternatively, the DAI value may be a total DAI (tDAI) value, which may indicate the total number of HARQ reports grouped in the same transmission. In some implementations, a tDAI value may be included for a scheduled downlink group and a cDAI value may be included for a dynamic grouping, wherein the number of HARQ-ACK bits for the PDSCH group may be changed between consecutive requests for HARQ-ACK feedback. The NFI value may be a toggle bit and may indicate whether the same G value corresponds to a new feedback opportunity. For example, if the base station 105-a successfully receives HARQ feedback for the G=0 group, the base station 105-a may toggle the NFI bit for the next DCI 220 indicating the G=0 group, so that the UE 115-a may determine that the previous feedback for the G=0 group was successfully received by the base station 105-a. The UE 115-a may remove the feedback information stored for the group and restart aggregating the feedback information for the group with the new DCI 220.

[0117] The K1 value and the group-based indicator may be used to coordinate the transmission of multiple HARQ reports in the same feedback report 230. For example, the base station 105-a may send a first downlink transmission 215 including a DCI 220-a and a PDSCH 220-a. The DCI 220-a may include a K1 value of 3, a DAI value of 1, a G value of 0, an R value of 0, and an NFI value of 0. The base station 105-a may also send a second downlink transmission 215. The second downlink transmission 215 may include a DCI 220-b and a PDSCH 225-b. The DCI 220-b may include a K1 value of 2, a DAI value of 2, a G value of 0, an R value of 0, and an NFI value of 0. The two K1 values ​​may indicate that the corresponding HARQ reports may be sent in the same time slot (e.g., 3 time slots from the reception of the DCI 220-a and 2 time slots from the reception of the DCI 220-b). The DAI value of 2 may indicate that the HARQ feedback for PDSCH 225-b is the second HARQ feedback included in the reporting group (where the HARQ feedback for PDSCH 225-a is the first HARQ feedback for the group). The G value may indicate that two HARQ reports are in the same group (e.g., both HARQ reports correspond to group index 0), and the R value may indicate that HARQ feedback for group 0 is requested. The NFI value may indicate that there is no change in the report of the previous HARQ group (e.g., because the NFI bit is not switched between DCI 220). In this implementation, the HARQ report for the same PDSCH group may be carried by UE115-a in the same uplink transmission. For example, feedback for PDSCH 225-a and PDSCH 225-b may be sent in the same HARQ-ACK message 235-a, rather than being sent in separate transmissions of HARQ-ACK messages 235-a and 235-b. In this example, UE 115-a can send a single uplink transmission based on a HARQ codebook of grouped HARQ feedback reports. In this example, the HARQ codebook can specify multiple bits indicating HARQ ACK / NACK information for multiple PDSCHs 225 in the same PDSCH group. In some implementations, the number of bits can be changed, which can be based on the number of HARQ reports included in the uplink transmission. A UE 115-a that supports these features (e.g., HARQ-ACK based on dynamic groups) can signal the information to the base station 105-A. A base station 105-a that supports these features (e.g., HARQ-ACK based on dynamic groups) can decode information from UE 115-a and determine whether the PDSCH 225 in the PDSCH group is successfully received and decoded at UE 115-a.

[0118] In some implementations, the base station 105-a may be unable to receive a packetized HARQ feedback transmission from the UE 115-a. This may be due to a communication failure between the base station 105-a and the UE 115-a, or, if communicating in an unlicensed spectrum, due to a failure of the LBT protocol. In these implementations, the base station 105-a may use a subsequent downlink transmission 215 to initiate retrieval of the unreceived HARQ report. For example, the base station 105-a may send a third downlink transmission 215 including a DCI 220-c and a PDSCH 225-c. The DCI 220-c may include a K1 value of 2, a DAI value of 3, a G value of 0, an R value of 0, and an NFI value of 0. The K1 value may indicate that the UE 115-a may send a feedback report 230 two time slots after receiving the PDSCH 225-c. The UE 115-a may determine what information may be included in the feedback report. For example, information included in the DCI (e.g., DCI 220-c) in the third downlink transmission 215 can be compared with the DCI of the previous downlink transmission 215 (e.g., DCI 220-a and 220-b). The comparison can allow the UE 115-a to determine whether the HARQ information associated with the third downlink transmission can be sent together with the retransmission of the HARQ information associated with the first and second downlink transmissions. For example, a G value of 0 and an NFI value of 0 (e.g., a non-switched bit of the NFI value) in the third downlink group DCI 220-c can indicate that the HARQ report group has not changed. The DAI value of 3 can further indicate that the UE 115-a can include the corresponding HARQ information as a third HARQ ACK / NACK in the grouped HARQ report of the base station 105-a. The G value of 0 in the third DCI 220-c can indicate that the corresponding HARQ report can be grouped in the same HARQ-ACK message 235 as the previously grouped HARQ report. In this example, the next HARQ report (e.g., HARQ-ACK message 235-b or 235-c) may include feedback information of the packet transmitted by the HARQ report of the previously missed packet (e.g., HARQ-ACK message 235-a with feedback information of PDSCH 225-a and PDSCH 225-b).

[0119] In such an implementation, UE 115-a may send a single grouped HARQ report containing HARQ information associated with all three downlink transmissions corresponding to the same PDSCH group. For example, the grouped HARQ report may be encoded based on a HARQ codebook and may include multiple bits to indicate an ACK or NACK for receiving each downlink transmission. In some implementations, the number of downlink messages with feedback reported in the grouped HARQ report may determine the number of bits included in the codebook. For example, HARQ feedback for three PDSCHs 225 may use fewer bits than HARQ feedback for six PDSCHs 225.

[0120] In some implementations, UE 115-a may use dynamic group based HARQ feedback in DRX mode. In some such implementations, UE 115-a may send grouped HARQ reports while in active mode and may subsequently enter inactive mode. If base station 105-a does not successfully receive the grouped HARQ reports, UE 115-a may not be able to receive subsequent downlink transmissions from base station 105-a when UE 115-a is inactive. If UE 115-a does not receive the downlink transmission, it may not be able to determine that subsequent uplink transmission requests are associated with the lost group feedback (e.g., in the HARQ codebook). UE 115-a may not receive the downlink transmission until the next active period of a subsequent DRX cycle, which significantly increases the delay involved in providing feedback to base station 105-a. To extend the activity duration of UE 115-a, UE 115-a may implement a timer that may prevent UE 115-a from entering an inactive mode for a period of time following a scheduled transmission opportunity of a dynamically grouped HARQ-ACK message. The timer may allow UE 115-a to receive another DCI requesting retransmission feedback in a subsequent dynamically grouped HARQ message, thereby improving feedback latency for UE 115-a.

[0121] Figure 3A and 3B An example of a timeline 300 of a HARQ process supporting DRX is shown. Figure 3A A first example timeline 300-a is shown. In some examples, the feedback timeline 300-a can implement aspects of the wireless communication system 100 or 200. For example, the feedback timeline 300-a can correspond to the feedback timeline 300-a as described herein with reference to Figure 1 and 2 A processing timeline at UE 115 is described.

[0122] In some examples, UE 115 may operate in DRX mode. Figure 2 As discussed with respect to UE 115-a, a UE 115 operating in DRX mode may have an inactive period during which data transmission, data reception, or both are unavailable. When UE 115 operates in DRX mode, UE 115 may receive a downlink transmission from base station 105, which may include DCI 310-a (e.g., a first DCI message) and PDSCH 315-a (e.g., a data message). For example, when in an active state of DRX mode, UE 115 may receive a downlink transmission. In some implementations, DCI 310-a may include a field indicating when UE 115 sends a scheduling of feedback reports. In some examples, the field may be a data to feedback timing indicator, such as a PDSCH to HARQ timing indicator. In some implementations, the PDSCH to HARQ timing indicator may be referred to as a K1 value. The K1 value may correspond to the timing of feedback report 325. Feedback report 325 may indicate an ACK or NACK for receiving a downlink transmission (e.g., DCI 310-a, PDSCH 315-a, or both). For example, DCI 310-a may include a field indicating a transmission opportunity for UE 115 to send feedback report 325. In some examples, feedback report 325 may be an example of a HARQ-ACK message and may include HARQ ACK / NACK feedback for receiving DCI 310-a and PDSCH 315-a.

[0123] In some implementations, the K1 value may be a numeric value (e.g., 1, 2, 3, etc.). The numeric K1 value may indicate the number of time slots (or TTIs) in which the UE 115 may send the feedback report 325 after receiving the downlink transmission. However, in some examples, the K1 value may be a non-numeric value. Figure 2 As described, the non-numeric K1 value may trigger the UE 115 to store feedback report information associated with the downlink transmission. For example, the non-numeric K1 value indicated in the DCI 310-a may cause the UE 115 to store a HARQ ACK / NACK report associated with receiving the PDSCH 315-a (e.g., information of the feedback report 325).

[0124] If a non-numeric K1 value is received in the DCI, the UE 115 may monitor and receive a second downlink transmission (e.g., a second DCI message) indicating when the feedback report 325 is scheduled to be sent. The second downlink transmission may include or may be an example of DCI 310-b. The DCI 310-b may include a numeric K1 value, and the UE 115 may send the stored feedback report 325 in the time slot allocated by the numeric K1 value of the DCI 310-b.

[0125] However, in some examples, when UE 115 is operating in DRX mode, if UE 115 returns to an inactive mode (e.g., sleep mode) after receiving a first transmission, UE 115 may miss the transmission of DCI 310-b (or base station 105 may not schedule the transmission of DCI 310-b). For example, in inactive mode, UE 115 may not monitor the DCI of the downlink control channel and may accordingly not support the reception of DCI 310-b. In order for UE 115 to reliably receive DCI 310-b for scheduling feedback transmissions, UE 115 may remain in active mode after receiving the first transmission to avoid missing the reception of DCI 310-b containing a digital K1 value. UE 115 may implement a timer triggered by a non-digital K1 value to keep UE 115 in active mode and support continuous monitoring of the downlink control channel.

[0126] In some implementations, a timer may be used to keep the UE 115 in active mode. For example, the UE 115 may remain in active mode until one or more timers expire. The timer 305-a may be an example of a timer for keeping the UE 115 in active mode. As described herein, the timer 305-a may be triggered based on receiving a DCI 310-a including a non-digital K1 value for feedback timing. In some implementations, the timer 305-a may be started in the first symbol immediately after the scheduled reception of the PDSCH 315-a. However, in some other implementations, the timer 305-a may be started at a different time, such as a symbol immediately after the reception of the DCI 310-a. The UE 115 may remain in active state for the duration of the timer 305-a. Specifically, the active time of the UE 115 may include the active running time of the timer 305-a. When the UE 115 receives a DCI 310-b indicating the feedback timing for sending the feedback report 325 to the base station 105, the timer 305-a may end. However, in some implementations, timer 305-a may end at a different time, such as after sending a PUCCH or PUSCH transmission carrying feedback report 325. In some implementations, UE 115 may additionally implement RTT timer 330 and retransmission timer 335 to keep UE 115 in an active state to receive retransmissions (e.g., if feedback report 325 includes HARQ NACK). In some such implementations, the total active time that UE 115 may be in active mode may include the time of timer 305-a, the time of RRT timer 330, the time of retransmission timer 335, or some combination thereof. For example, the total active time of a DRX cycle of UE 115 may include non-overlapping portions of the running time of the ON duration timer, the inactivity timer, timer 305-a, and the retransmission timer 335.

[0127] Timer 305-a can be a timer dedicated to non-numerical K1 operations, or a timer that is repeatedly used for multiple operations. In a first example, timer 305-a can be a timer dedicated to processing non-numerical K1 values, such as a trigger timer (e.g., drx-DCItrigger-for-HARQ-Ack-TimerDL). The trigger timer can be activated for a specific HARQ feedback process. The trigger timer can set a new duration for which UE 115 can remain in active mode based on receiving a DCI 310-a with a non-numerical K1 parameter (e.g., in order to receive a subsequent DCI 310-b). In some implementations, the base station 105 can send a configuration of the trigger timer to UE 115 in a downlink transmission (e.g., in radio resource control (RRC) signaling). The duration of the trigger timer can be based on the HARQ feedback timing of UE 115 and base station 105, the value configured by base station 105, the DRX operation of UE 115, or some combination thereof. A HARQ process-specific trigger timer may be started in the first symbol following the scheduled PDSCH 315-a and may run until the timer duration expires, or may be disabled based on receipt of a timed DCI trigger (e.g., DCI 310-b) indicating HARQ-ACK feedback (e.g., sending feedback report 325) for the corresponding HARQ process.

[0128] In some other examples, the timer 305-a may be a repurposed timer that supports multiple operations. For example, the timer 305-a may be a retransmission timer, such as drx-RetransmissionTimerDL. Figure 2As described, the retransmission timer can be used to keep the UE 115 in active mode while monitoring the downlink retransmission from the base station 105. In order to support the monitoring of the retransmission in response to NACK, the retransmission timer 335 is started after the UE 115 sends the feedback report 325 (wherein the start of the retransmission timer 335 can be triggered based on the expiration of the RTT timer 330). Therefore, in some examples, during the time period before sending the feedback report 325, the retransmission timer can be used. In some implementations, the retransmission timer can support different durations (such as timer lengths) for different operations, which can be based on separate RCC parameters. For example, the base station 105 can configure the first retransmission timer duration and the second retransmission timer duration for the UE 115. When triggered by the expiration of the RTT timer 330, the UE 115 can activate the retransmission timer with the first timer duration, and when triggered by the DCI with a non-digital K1 value, the retransmission timer with the second timer duration can be activated. In such an implementation, the retransmission timer can be used as a timer 305-a by the UE 115, and is additionally used as a retransmission timer 335. In some examples, base station 105 may send an updated timer duration in a downlink transmission to UE 115. The duration of the timer may be based on HARQ feedback timing of UE 115 and base station 105, a timer duration indicated by base station 105, or both.

[0129] In some other examples, the timer 305-a may be an inactivity timer, such as drx-InactivityTimer. Figure 2As described, after receiving a DCI message indicating a new transmission (e.g., a new downlink transmission or a new uplink transmission), the inactive timer can be used to keep the UE 115 in active mode. In some implementations, the inactive timer can be started (or restarted) based on the indication of the new transmission. UE 115 can maintain a single inactive timer instead of maintaining an inactive timer for each HARQ process. Similar to the above, the inactive timer can be able to support different durations (e.g., timer lengths), which can be based on a separate RCC parameter configured by the base station 105. The inactive timer can be used as a timer 305-a by the UE 115 (e.g., in addition to supporting new transmissions). For example, the UE 115 can activate the inactive timer based on receiving a DCI indicating a new transmission (in the first operation of the inactive timer) or a DCI indicating a non-digital K1 value (in the second operation of the inactive timer). These different operations can correspond to the same or different timer durations. In some implementations, the base station 105 can send the duration of the updated inactive timer to the UE 115 in the downlink transmission. The duration of the timer may be based on the HARQ feedback timing of the UE 115 and the base station 105, the timer duration indicated by the base station 105, or both.

[0130] When the UE 115 stores feedback information for the HARQ process (e.g., based on the non-digital data-to-feedback timing indicator), implementing the timer 305-a to keep the UE 115 active can allow the UE 115 to successfully receive the DCI 310-b indicating the timing of the HARQ-ACK feedback for the HARQ process. Based on monitoring and receiving the DCI 310-b with the digital data-to-feedback timing indicator for the HARQ process, the UE 115 can send the feedback report 325 in the time slot corresponding to the digital value indicated in the DCI 310-b. Therefore, the timer 305-a can support the UE 115 operating in the DRX mode to effectively use the non-digital K1 value. For example, the timer 305-a can reduce the delay involved in sending the feedback report 325 because the UE 115 implementing the timer 305-a can continue to monitor the downlink control channel while the timer 305-a is running, and can receive the DCI 310-b based on the continuous monitoring. Without such a timer, the UE 115 may enter an inactive mode and may not receive a transmission opportunity for a feedback report until a subsequent DRX cycle, resulting in a significant delay in the feedback process.

[0131] Figure 3BA second example timeline 300-b is shown. In some examples, feedback timeline 300-b can implement aspects of wireless communication system 100 or 200. Timeline 300-b can operate similarly to timeline 300-a. For example, similar to timeline 300-a, UE 115 can operate in DRX mode. When UE 115 operates in DRX mode, UE 115 can receive downlink transmissions from base station 105, and the downlink transmissions can include DCI 310-c and PDSCH 315-b. In some implementations, DCI 310-c can include a field indicating when UE 115 can send a feedback report indicating an ACK or NACK for downlink data reception. The indication can be referred to as a K1 value, and the K1 value can be non-digital. The non-digital K1 value can trigger UE 115 to store feedback report information associated with DCI 310-c and PDSCH 315-b in a memory (e.g., deferring the transmission of the feedback report). As described herein, the non-numeric K1 value may additionally trigger the UE 115 to activate a timer 305 - b to keep the UE 115 monitoring the downlink control channel for the second DCI 310 - d .

[0132] like Figure 3B As shown, in some implementations, UE 115 may not receive a second downlink transmission (eg, Figure 3A In some such implementations, the UE 115 may not receive a digital K1 value for the HARQ process (e.g., based on a lack of DCI 310-d with a digital K1 value or based on the base station 105 not sending DCI 310-d with a digital K1 value). The UE 115 may continue to store the feedback report information until feedback timing for the HARQ process is received. However, as described in reference Figure 2 As described above, a UE 115 operating in DRX mode may cycle to an inactive mode to save power. The duration before a UE 115 enters an inactive mode (eg, sleep mode) may be determined by a set of timers managed by the UE 115.

[0133] UE 115 may manage timers similar to those used in timeline 300-a, including timers dedicated to non-digital K1 operations (e.g., trigger timers) or timers repurposed for multiple operations (e.g., retransmission timers or inactive timers). If a timer that maintains an active state expires and other condition sets are met (e.g., any other timer that maintains the active state of UE 115 (including timers for other HARQ processes) is deactivated), UE 115 may go to sleep (enter inactive mode). For example, in timeline 300-b, timer 305-b may expire after a certain amount of time, rather than upon receipt of a subsequent DCI 310-d. For example, base station 105 may not send DCI 310-d during the active time, or UE 115 may fail to receive DCI 310-d during the active time. Therefore, timer 305-b may run its entire duration before expiring. If other inactive conditions are met when timer 305-b expires, UE 115 may cycle to inactive mode. For example, the UE 115 may start a timer 305-b after a scheduled PDSCH 315-b (or after DCI 310-c is received), and the timer 305-b may run for a duration configured by the base station 105 for processing non-digital data to feedback timing indicators. If no other keep-alive timers are running at the UE 115 after the expiration of the timer 305-b, the UE 115 may enter an inactive mode and avoid monitoring of downlink control channels while operating in the inactive state. Operating in the inactive state may save processing power of the UE 115.

[0134] Figure 3A and 4B An example of a timeline 400 of a HARQ process supporting DRX is shown. Figure 4A A first example timeline 400-a is shown. In some examples, feedback timeline 400-a can implement aspects of wireless communication system 100 or 200. As shown in FIG. Figure 2 As described, feedback information for multiple downlink transmissions may be grouped into a single uplink transmission. According to the codebook 435, the feedback information may be sent as a HARQ-ACK message, which may include one or more ACKs, one or more NACKs, or both. For example, the UE 115 may group the HARQ ACK / NACKs into a single HARQ codebook 435 and send the HARQ ACK / NACKs to the base station 105 in the feedback report 430.

[0135] As reference Figure 2As described, the DCI contained in the multiple downlink transmissions received at the UE 115 may be used to coordinate the information sent in the uplink transmission (e.g., uplink feedback transmission) by the UE 115. For example, a K1 value, a DAI value (e.g., cDAI, tDAI, or both), a G value, an R value, an NFI value, or some combination thereof may be sent in a DCI message to the UE 115. The UE 115 may compare these values ​​and determine which HARQ ACK / NACK information may be grouped together and returned in a single feedback report 430 based on the shared HARQ codebook 435.

[0136] In some implementations, the UE 115 may receive a first downlink transmission, which may include a DCI 410-a and a PDSCH 415-a in a first time slot 405-a. The DCI 410a may schedule transmission of the PDSCH 415-a and may include a K1 value of 3, a DAI value of 1, a G value of 0, an R value of 0, and an NFI value of 0. In addition, the UE 115 may receive a second downlink transmission, which may include a DCI 410-b and a PDSCH 415-b in a second time slot 405-b. The DCI 410-b may schedule transmission of the PDSCH 415-b and may include a K1 value of 2, a DAI value of 2, a G value of 0, an R value of 0, and an NFI value of 0. The UE 115 may receive the downlink transmission based on operating in an active state during a DRX cycle.

[0137] The received DCI value may be used to determine how to send HARQ ACK / NACK information for the received downlink transmission. For example, the DCI value may indicate to the UE 115 that the first and second downlink transmissions are grouped together and feedback information associated with the first and second downlink transmissions is sent using a single HARQ codebook 435-a. The grouping may be based on a comparison of the K1 value, DAI value, G value, R value, NFI value, or some combination thereof for the downlink group. For example, a G value of 0 may indicate that two DCIs 410 correspond to the same group with a group index of 0, a DAI value may indicate that the first DCI 410-a is used for the first HARQ process of the group, a second DCI 410-b is used for the second HARQ process of the group, an NFI value may indicate that the feedback information of these DCIs 410 corresponds to the same HARQ-ACK feedback group of the group, and a K1 value indicates that the feedback for the two transmissions is scheduled for the same time slot 405-d. The UE 115 can enter feedback information for the two downlink transmissions into the HARQ codebook 435-a based on these DCI values, and can send a single feedback report 430-a to the base station 105 in a single uplink transmission based on the HARQ codebook 435-a in the fourth time slot 405-d (in this example, one time slot after the empty time slot 405-c based on the K1 value).

[0138] In some implementations, the base station 105 may not successfully receive and decode the feedback report 430-a. This may be due to LBT failure at the UE 115 (where the feedback report 430-a is not sent in the scheduled transmission opportunity of the feedback report 430-a) or misdetection at the base station 105. In such an implementation, the HARQ ACK / NACK information in the HARQ codebook 435-a may not be received by the base station 105. In order to re-request the HARQ ACK / NACK information, the base station 105 may send a third downlink transmission to the UE 115, which may include DCI 410-c, PDSCH 415-c, or both. The K1 value, DAI value, G value, R value, NFI value, or some combination thereof of the third downlink transmission may be compared with these values ​​of the first and second downlink transmissions. The UE 115 may determine whether at least a portion of the information from the previously scheduled group feedback report 430-a is requested to be transmitted in an additional feedback report (not shown) scheduled by the third downlink transmission.

[0139] As reference Figure 2 As described, UE 115 may operate in DRX mode. When operating in DRX mode, UE 115 may be active in one or more time periods and inactive in other time periods. In some implementations, UE 115 operating in DRX mode may enter inactive mode after a scheduled transmission opportunity of feedback report 430-a. For example, if UE 115 fails to send feedback report 430-a based on failure to access an uplink channel in an unlicensed spectrum, or if UE 115 sends feedback report 430-a without any NACK, UE 115 may not activate any timer to keep UE 115 in an active state. In some such implementations, a third downlink transmission (such as DCI 410-c) may not be received by UE 115. If base station 105 determines to re-request the HARQ-ACK information originally scheduled for the feedback report 430-a transmission opportunity, UE 115 may receive the request during the next active mode of UE 115 (e.g., in a subsequent DRX cycle). This may introduce significant delays to both the UE 115 and the base station 105 because the DRX timing may delay the transmission of the feedback report 430 to the base station 105 based on the UE 115 returning to sleep after the feedback report 430-a transmission opportunity.

[0140] Due to the group-based feedback capability of UE 115, UE 115 can implement timer 450-a to remain active and continue to monitor the downlink control channel. Base station 105 can successfully re-request feedback information (e.g., HARQ ACK / NACK bits) using the third DCI 410-c based on UE 115 monitoring the downlink control channel. This re-request can be accomplished by the base station 105 sending a non-switched NFI value (e.g., 0) for group 0 in DCI 410-c, which can indicate a request for the next feedback report transmission to include previously lost feedback information for group 0 (e.g., feedback information in HARQ codebook 435-a). Alternatively, the re-request can be accomplished using an R value to request feedback for another PDSCH group, which can include group 0 corresponding to feedback information in HARQ codebook 435-a. By implementing timer 450-a, UE 115 can effectively extend its active time to support receiving the third DCI 410-c and the corresponding feedback retransmission request.

[0141] In some implementations, the timer 450-a may be used for a feedback process (or other similar feedback process) of a UE 115 configured with dynamic group-based HARQ. For example, the timer 450-a may be used to keep the UE 115 in an active mode after a scheduled transmission opportunity of a feedback message (e.g., feedback report 430-a). The UE 115 may remain in an active mode (e.g., sending and receiving data, monitoring a downlink control channel, etc.) until the timer 450-a expires (and until another set of criteria is met). In some implementations, the timer 450-a may be started in the first symbol immediately after the opportunity to send the feedback report 430-a. However, in some other implementations, the timer 450-a may be started at a different time. In some implementations, the UE 115 configured with dynamic group-based HARQ-ACK may activate the timer 450-a after each feedback transmission opportunity. In some other implementations, if the UE 115 sends the feedback report 430-a in the scheduled feedback transmission opportunity, the UE 115 may not activate the timer 450-a. During the duration of timer 450-a, UE 115 may remain in an active state, and the active time of UE 115 may include the active time of timer 450-a. Timer 450-a may be stopped when the timer duration of timer 450-a expires or when a DCI trigger is identified (e.g., after PDCCH reception ends). For example, in some implementations, timer 450-a may be stopped when UE 115 receives any DCI 410. In some other implementations, timer 450-a may be stopped when UE 115 receives DCI 410 (e.g., PDSCH 415) that schedules downlink data transmission. In yet other implementations, when the UE 115 receives a DCI 410-c indicating that the PDSCH 415-c and including an indication that the HARQ ACK / NACK feedback for the PDSCH 415-c can be grouped in the same grouped feedback report as the previously scheduled feedback report 430-a, the timer 450-a can be stopped (e.g., based on an NFI value, a G value, an R value, a DAI value, or a combination thereof as previously discussed).

[0142] Using the timer 450-a to keep the UE 115 in an active state may allow the UE 115 to successfully receive the third DCI 410-c. This may allow the UE 115 to group together the missing feedback information from the first downlink transmission, the second downlink transmission, or a combination thereof with the information from the third downlink transmission. Thus, the timer 450-a may support the UE 115 operating in the DRX mode to efficiently transmit group-based feedback.

[0143] Figure 4BA second example timeline 400-b is shown. In some examples, feedback timeline 400-b can implement aspects of wireless communication system 100 or 200. Similar to timeline 400-a, feedback information for multiple downlink transmissions can be grouped into a single uplink transmission, which can include HARQ ACK / NACK. The HARQ ACK / NACK can be grouped into a single HARQ codebook 435 and sent to base station 105 in a single uplink transmission. The DCI 410 received by UE 115 can be used to coordinate information sent by UE 115 in uplink transmissions. For example, DCI parameters such as K1 values, DAI values ​​(cDAI, tDAI, or both), G values, R values, and NFI values ​​can indicate to UE 115 how to group PDSCH 415 for feedback. The UE 115 may compare these values ​​and use the shared HARQ codebook 435-b to determine which HARQ ACK / NACK information may be grouped and returned in a single uplink transmission (eg, feedback report 430-b).

[0144] Similar to timeline 400-a, UE 115 may receive a first downlink transmission, which may include DCI 410-d and PDSCH 415-d in a first time slot 405-e. The first downlink transmission may include a K1 value of 3, a DAI value of 1, a G value of 0, an R value of 0, and an NFI value of 0. Similarly, UE 115 may receive a second downlink transmission, which may include DCI 410-e and PDSCH 415-e in a second time slot 405-f. The second downlink transmission may include a K1 value of 2, a DAI value of 2, a G value of 0, an R value of or 0, and an NFI value of 0. These values ​​may be used to determine that HARQ ACK / NACK information associated with receiving the first and second downlink data transmissions may be grouped into a single HARQ codebook 435-b. The UE 115 may send feedback information to the base station 105 in a fourth time slot 405 - h (after the third time slot 405 - g based on the K1 value) in a single feedback report 430 - b based on the HARQ codebook 435 - b.

[0145] Similar to timeline 400-a, feedback report 430-b may not be received by base station 105, which may be due to LBT failure at UE115 or misdetection at base station 105. Accordingly, HARQ ACK / NACK information in HARQ codebook 435-a may not be received by base station 105. Similar to timeline 400-a, UE 115 may operate in DRX mode and may be active during a time period and inactive during other time periods. UE 115 may implement timer 450-b to extend the active time of UE115 and allow reception of a third downlink transmission that effectively requests some HARQ ACK / NACK bits that were previously scheduled to be sent. The timer 450-b may not be specific to any particular HARQ process.

[0146] Timer 450-b can be used to keep UE 115 in active mode, and UE 115 can remain in active mode, at least until timer 450-b expires. Timer 450-b can be started in the first symbol immediately following the scheduled transmission opportunity of feedback report 430-b. However, in some implementations, timer 450-b can be started at a different time. Similarly, in some implementations, if feedback report 430-b is sent by UE 115 due to a successful LBT process, timer 450-b may not be started. UE 115 can remain in active state for the duration of timer 450-b. However, in some examples, timer 450-b can expire after a certain amount of time (the duration of the timer, which can be configured by base station 105 via RRC or other signaling). For example, while timer 450-b is running, UE 115 may not receive another DCI 410. In some other examples, UE 115 may receive DCI 410 that may indicate an uplink grant or DCI for another feedback group, both of which, in some implementations, may not trigger expiration of timer 450-b (e.g., according to a deactivation trigger configured for timer 450-b). Thus, timer 450-b may run and expire for the duration of timer 450-b. If no other timers are running that maintain an active state of UE 115 after timer 450-b expires, UE 115 may enter an inactive mode and stop monitoring the downlink control channel based on the expiration of the timer.

[0147] Figure 5 An example of a process flow 500 for HARQ processing supporting DRX is shown. For example, the process flow 500 may show that the UE 115-b and the base station 105-b process a DCI message with non-digital data to the feedback timing indicator K1. The UE 115-b and the base station 105-b may be reference Figure 1 and 2 Examples of corresponding wireless devices described. Figure 3A and Figure 3B As described, UE115-b may maintain a timer. The following alternative examples may be implemented, where some of the steps are performed in a different order than described or not performed at all. In some implementations, the steps may include additional features not mentioned below, or further steps may be added.

[0148] At 505, the base station 105-b may send a DCI message to the UE 115-b on a downlink control channel. The DCI message may indicate a non-numeric value (e.g., a K1 value) of a data-to-feedback timing indicator, wherein the DCI message schedules a downlink data message and the data-to-feedback indicator is associated with the feedback timing of the downlink data message. The non-numeric value may be an example of a negative number, a null value, or some similar value that does not indicate actual feedback timing. At 510, the base station 105-b may send a downlink data message to the UE 115-b. The UE 115-b may attempt to receive and decode the downlink data message. The UE 115-b may determine feedback information (e.g., HARQ feedback, such as ACK or NACK) of the downlink data message based on whether the data message is successfully received and decoded, and the UE 115-b may store the feedback information in a memory based on the non-numeric value of the data-to-feedback timing indicator.

[0149] At 515, UE 115-b may activate a timer based on receiving the DCI message at 505 and based on the data-to-feedback timing indicator being a non-numeric value. UE 115-b may activate the timer in the first symbol after receiving the DCI message or in the first symbol after a scheduled downlink data message. The timer may keep UE 115-b in active mode. For example, at 520, when the timer is activated, UE 115-b may monitor a downlink control channel. In some implementations, the timer may be an example of drx-DCItrigger-for-HARQ-ACK-TimerDL or some similar timer. In some other implementations, the timer may be an example of drx-RetransmissionTimerDL, drx-InactivityTimer, or some similar timer.

[0150] At 525, the base station 105-b may determine an active timer for the UE 115-b to monitor the downlink control channel based on the timer, wherein the timer is activated based on the DCI and the data-to-feedback timing indicator being a non-numeric value. At 530, the base station 105-b may send a second DCI message indicating feedback timing of the downlink data message to the UE 115-b on the downlink control channel. The base station 105-b may determine the timing of sending the second DCI message based on the active time of the UE 115-b monitoring the downlink control channel. The second DCI message may use a digital data-to-feedback timing indicator to indicate the actual feedback timing (e.g., a specific time slot) of the feedback transmission.

[0151] At 530, when the timer is activated, based on monitoring of the downlink control channel, the UE 115-b may receive a second DCI message indicating feedback timing of the downlink data message. In some implementations, at 535, the UE 115-b may deactivate the timer based on receiving the second DCI message indicating feedback timing of the downlink data message. The timer may be deactivated in the first symbol after receiving the second DCI message or in the first symbol after the feedback transmission. For example, at 540, the UE 115-b may send a feedback message (e.g., a HARQ-ACK message) of the downlink data message to the base station 105-b based on the feedback timing indicated in the second DCI message received at 530.

[0152] Figure 6 An example of a process flow 600 for HARQ processing supporting DRX is shown. For example, the process flow 600 may show that the UE 115 and the base station 105 process feedback when the UE 115 is configured with dynamic group-based HARQ-ACK. The UE 115-c and the base station 105-c may be reference Figure 1 , Figure 2 and Figure 5 Examples of corresponding wireless devices described. Figure 4A and Figure 4B As described, UE115-c may maintain a timer. The following alternative examples may be implemented, where some of the steps are performed in a different order than described or not performed at all. In some implementations, the steps may include additional features not mentioned below, or further steps may be added.

[0153] At 605, the base station 105-c may send one or more DCI messages on a downlink control channel to the UE 115-c, the one or more DCI messages scheduling transmission of downlink data messages and including a data-to-feedback timing indicator indicating the scheduled transmission opportunities. For example, based on the corresponding DCI message, each downlink data message may be associated with the same PDSCH group for HARQ feedback. At 610, the base station 105-c may additionally send one or more downlink data messages to the UE 115-c.

[0154] At 615, the UE 115 may determine a scheduled transmission opportunity for a feedback message that includes feedback information for the set of downlink data messages (e.g., downlink data messages corresponding to the same PDSCH group scheduled for feedback). At 620, the UE 115 may attempt to send the feedback message to the base station 105-c in the scheduled transmission opportunity. In some implementations, based on the failed LBT process, the UE 115-c may not be able to obtain access to an uplink channel to send feedback. In some other implementations, the base station 105-c may not be able to successfully receive and decode the feedback message at 620.

[0155] At 625, the UE 115 may activate a timer in the first symbol after the scheduled transmission opportunity of the feedback message. In some implementations, the UE 115 may activate the timer based on operating with a dynamic group based HARQ-ACK. In some other implementations, the UE 115 may activate the timer based on a LBT process failure and no feedback message is sent. At 630, when the timer is activated, the UE 115 may monitor the downlink control channel.

[0156] At 635, the base station 105-c may identify a failure to successfully receive a feedback message in a scheduled transmission opportunity (e.g., based on a LBT failure or misdetection at the base station 105-c). The missed feedback message may include feedback information for a downlink data message. At 640, the base station 105-c may determine an active timer for the UE 115-c to monitor the downlink control channel based on a timer, wherein the timer is activated in a first symbol after the scheduled transmission opportunity.

[0157] At 645, the base station 105-c may send a second DCI message to the UE 115-c on the downlink control channel, the second DCI message requesting transmission (e.g., re-requesting transmission or requesting retransmission) of at least a portion of feedback information for a downlink data message based on the activity time determined for the UE 115-c and based on failure to receive the feedback message. At 650, the UE 115 may deactivate the timer based on receiving any DCI message, any DCI message scheduling transmission of a downlink data message, a specific DCI message requesting transmission of at least a portion of feedback information for one or more downlink data messages, or a combination thereof. At 655, the UE 115 may send a feedback message (e.g., a HARQ-ACK message) to the base station 105 based on the second DCI received at 645.

[0158] Figure 7 A block diagram of an example UE 115 is shown. The UE 115 (e.g., device 705) can be a component of the system 700 for HARQ processing supporting DRX. The device 705 can include components for two-way voice and data communications, including components for sending and receiving communications, such as a communication manager 710, an input / output (I / O) controller 715, a transceiver 720, an antenna 725, a memory 730, a processor 740, and a timer manager 750. These components can communicate electronically via one or more buses (e.g., bus 745).

[0159] In some implementations, the communication manager 710 may receive a first DCI message indicating a non-numeric value (e.g., a K1 value) for a data-to-feedback timing indicator, wherein the first DCI message schedules a downlink data message and the data-to-feedback timing indicator is associated with feedback timing of the downlink data message. The timer manager 750 may activate the timer based on receiving the first DCI message and based on the data-to-feedback timing indicator being a non-numeric value. The communication manager 710 may monitor a downlink control channel while the timer is activated, and may receive a second DCI message indicating feedback timing of the downlink data message (e.g., using a numeric K1 value) based on monitoring the downlink control channel. The timer manager 750 may deactivate the timer based on receiving a second DCI message indicating feedback timing of the downlink data message.

[0160] In some other implementations, the communication manager 710 may determine a scheduled transmission opportunity for a feedback message that includes feedback information for one or more downlink data messages. The timer manager 750 may activate a timer in a first symbol after the scheduled transmission opportunity for the feedback message. The communication manager 710 may monitor a downlink control channel while the timer is activated and may receive a DCI message requesting transmission of at least a portion of the feedback information for the one or more downlink data messages. The timer manager 750 may deactivate the timer based on receiving the DCI message.

[0161] I / O controller 715 can manage input and output signals of device 705. I / O controller 715 can also manage peripheral devices that are not integrated into device 705. In some implementations, I / O controller 715 can represent a physical connection or port to an external peripheral device. In some implementations, I / O controller 715 can utilize a communication interface such as a or another known operating system. In some other implementations, the I / O controller 715 may represent or interact with a modem, keyboard, mouse, touch screen, or similar device. In some implementations, the I / O controller 715 may be implemented as part of a processor. In some implementations, a user may interact with the device 705 via the I / O controller 715 or via hardware components controlled by the I / O controller 715.

[0162] The transceiver 720 may communicate bidirectionally via one or more antennas, wired or wireless links as described above. For example, the transceiver 720 may represent a wireless transceiver and may communicate bidirectionally with another wireless transceiver. The transceiver 720 may also include a modem for modulating packets and providing the modulated packets to an antenna for transmission, and demodulating packets received from an antenna. In some implementations, the communication manager 710 may be a component of the transceiver 720 or connected to the transceiver 720.

[0163] In some examples, a wireless device may include a single antenna 725. However, in some other examples, a device may have more than one antenna 725, which may be capable of sending or receiving multiple wireless transmissions simultaneously.

[0164] The memory 730 may include random access memory (RAM) and read-only memory (ROM). The memory 730 may store computer-readable computer executable code 735, which includes instructions that, when executed, cause the processor to perform various functions described herein. In some implementations, the memory 730 may contain a basic I / O system (BIOS), etc., which may control basic hardware or software operations, such as interaction with peripheral components or devices.

[0165] The processor 740 may include an intelligent hardware device (e.g., a general-purpose processor, a digital signal processor (DSP), a central processing unit (CPU), a microcontroller, an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some implementations, the processor 740 may be configured to operate the memory array using a memory controller. In some other implementations, the memory controller may be integrated into the processor 740. The processor 740 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 730) to cause the device 705 to perform various functions (e.g., functions or tasks supporting HARQ in DRX mode).

[0166] The code 735 may include instructions to implement aspects of the present disclosure, including instructions to support wireless communications. The code 735 may be stored in a non-transitory computer-readable medium such as a system memory or other type of memory. In some examples, the code 735 may not be directly executed by the processor 740, but may cause a computer (when compiled and executed) to perform the functions described herein.

[0167] Additionally or alternatively, the device 705 may include one or more interfaces and a processing system. The processing system may be in electronic communication with the one or more interfaces. In some implementations, the interface and the processing system may be components of a chip or a modem, which may be a component of the device 705. The processing system and the one or more interfaces may include aspects of the communication manager 710, the timer manager 750, the memory 730, the processor 740, or a combination thereof. The processing system and the one or more interfaces may also be in electronic communication with the I / O controller 715, the transceiver 720, the one or more antennas 725, or a combination thereof (e.g., via the bus 745).

[0168] For example, the first interface may be configured to obtain information from other components of the device 705. The second interface may be configured to output information to other components of the device 705. Information may be sent and received in the form of coded or uncoded bits. The processing system may perform any number of processes to modify or determine the information output from the second interface.

[0169] In some implementations, the processing system may be configured to obtain, through the first interface, a first DCI message indicating a non-numeric value of a data-to-feedback timing indicator, wherein the first DCI message schedules a downlink data message and the data-to-feedback timing indicator is associated with feedback timing of the downlink data message. The processing system may be configured to activate a timer based on obtaining the first DCI message and the data-to-feedback timing indicator being a non-numeric value, and the processing system may obtain, through the first interface, monitoring information of a downlink control channel when the timer is activated. The processing system may also be configured to obtain, through the first interface, a second DCI message indicating feedback timing of the downlink data message based on the monitoring information of the downlink control channel.

[0170] In some other implementations, the processing system may be configured to determine a scheduled transmission opportunity of a feedback message containing feedback information of one or more downlink data messages, activate a timer in a first symbol after the scheduled transmission opportunity of the feedback message, and obtain monitoring information of a downlink control channel through a first interface when the timer is activated. The processing system may be configured to obtain a DCI message requesting transmission of at least a portion of the feedback information of the one or more downlink data messages through the first interface, and may deactivate the timer based on obtaining the DCI message.

[0171] Figure 8 A block diagram of an example base station 105 is shown. The base station 105 (e.g., device 805) can be a component of the system 800 for HARQ processing supporting DRX. The device 805 can include components for two-way voice and data communications, including components for sending and receiving communications, such as a communication manager 810, a network communication manager 815, a transceiver 820, an antenna 825, a memory 830, a processor 840, and an inter-station communication manager 845. These components can communicate electronically via one or more buses (e.g., bus 850).

[0172] In some implementations, the communication manager 810 may send a first DCI message to the UE 115 on a downlink control channel, the first DCI message indicating a non-numeric value of a data-to-feedback timing indicator, wherein the first DCI message schedules a downlink data message and the data-to-feedback timing indicator is associated with feedback timing of the downlink data message. The communication manager 810 may also determine an active time for the UE 115 to monitor the downlink control channel based on a timer, wherein the timer is activated based on the first DCI message and the data feedback timing indicator being a non-numeric value, and based on the determined active time for the UE 115 to monitor the downlink control channel, send a second DCI message indicating feedback timing of the downlink data message to the UE 115 on the downlink control channel.

[0173] In some other implementations, the communication manager 810 may send a first DCI message to the UE 115 on a downlink control channel, the first DCI message scheduling transmission of a downlink data message and including a data-to-feedback timing indicator corresponding to the downlink data message and indicating a scheduled transmission opportunity. The communication manager 810 may identify that a feedback message including feedback information of the downlink data message was not successfully received in the scheduled transmission opportunity, determine an active time for the UE 115 to monitor the downlink control channel based on a timer, wherein the timer is activated in a first symbol after the scheduled transmission opportunity, and send a second DCI message to the UE 115 on the downlink control channel, the second DCI message requesting transmission of at least a portion of the feedback information of the downlink data message based on the determined active time for the UE 115 to monitor the downlink control channel and identifying that the feedback message was not successfully received.

[0174] The network communications manager 815 may manage communications with the core network 130 (eg, via one or more wired backhaul links). For example, the network communications manager 815 may manage the delivery of data communications for client devices such as one or more UEs 115.

[0175] The transceiver 820 may communicate bidirectionally via one or more antennas, wired or wireless links as described above. For example, the transceiver 820 may represent a wireless transceiver and may communicate bidirectionally with another wireless transceiver. The transceiver 820 may also include a modem for modulating packets and providing the modulated packets to an antenna for transmission, and demodulating packets received from an antenna. In some implementations, the communication manager 810 may be a component of the transceiver 820 or connected to the transceiver 720.

[0176] In some examples, a wireless device may include a single antenna 825. However, in some other examples, a device may have more than one antenna 825, which may be capable of transmitting or receiving multiple wireless transmissions simultaneously.

[0177] The memory 830 may include RAM, ROM, or a combination thereof. The memory 830 may store computer readable code 835, which includes instructions that, when executed by a processor (e.g., processor 840), cause the device to perform various functions described herein. In some implementations, the memory 830 may include a BIOS, etc., which may control basic hardware or software operations, such as interaction with peripheral components or devices.

[0178] The processor 840 may include an intelligent hardware device (e.g., a general purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some implementations, the processor 840 may be configured to operate a memory array using a memory controller. In some examples, the memory controller may be integrated into the processor 840. The processor 840 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 830) to cause the device 805 to perform various functions (e.g., functions or tasks of HARQ processing supporting DRX).

[0179] The inter-site communication manager 845 may manage communications with other base stations 105 and may include a controller or scheduler for controlling communications with UE 115 in collaboration with other base stations 105. For example, the inter-site communication manager 845 may coordinate scheduling of transmissions to UE 115 for various interference mitigation techniques such as beamforming or joint transmission. In some examples, the inter-site communication manager 845 may provide an X2 interface within an LTE / LTE-A wireless communication network technology to provide communications between base stations 105.

[0180] The code 835 may include instructions to implement aspects of the present disclosure, including instructions to support wireless communications. The code 835 may be stored in a non-transitory computer-readable medium such as a system memory or other type of memory. In some implementations, the code 835 may not be directly executed by the processor 840, but may cause a computer (when compiled and executed) to perform the functions described herein.

[0181] Additionally or alternatively, the device 805 may include one or more interfaces and a processing system. The processing system may be in electronic communication with the one or more interfaces. In some implementations, the interface and the processing system may be components of a chip or a modem, which may be a component of the device 805. The processing system and the one or more interfaces may include aspects of a communication manager 810, a memory 830, a processor 840, or a combination thereof. The processing system and the one or more interfaces may also be in electronic communication with a network communication manager 815, an inter-station communication manager 845, a transceiver 820, one or more antennas 825, or a combination thereof (e.g., via a bus 850).

[0182] For example, the first interface can be configured to output information to other components of the device 805. The second interface can be configured to obtain information from other components of the device 805. Information can be sent and received in the form of encoded or unencoded bits. The processing system can perform any number of processes to modify or determine the information output from the second interface.

[0183] In some implementations, the processing system may be configured to output a first DCI message to the UE 115 on a downlink control channel through the first interface, the first DCI message indicating a non-numeric value of a data-to-feedback timing indicator, wherein the first DCI message schedules a downlink data message and the data-to-feedback timing indicator is associated with feedback timing of the downlink data message. The processing system may also be configured to determine an active time for the UE 115 to monitor the downlink control channel based on a timer, wherein the timer is activated based on the first DCI message and the data-to-feedback timing indicator being a non-numeric value, and based on the determined active time for the UE to monitor the downlink control channel, output a second DCI message indicating feedback timing of the downlink data message to the UE 115 on the downlink control channel through the first interface.

[0184] In some other implementations, the processing system may be configured to output a first DCI message to the UE 115 on a downlink control channel through the first interface, the first DCI message scheduling transmission of a downlink data message and including a data-to-feedback timing indicator corresponding to the downlink data message and indicating a scheduled transmission opportunity. The processing system may also be configured to identify a feedback message that failed to successfully obtain feedback information including the downlink data message in the scheduled transmission opportunity, determine an active time for the UE 115 to monitor the downlink control channel based on a timer, wherein the timer is activated in a first symbol after the scheduled transmission opportunity, and output a second DCI message to the UE 115 on the downlink control channel through the first interface, the second DCI message requesting transmission of at least a portion of the feedback information of the downlink data message based on the determined active time for the UE 115 to monitor the downlink control channel and identifying a failure to successfully receive the feedback message.

[0185] Fig. 9 A flow chart illustrating an example method 900 for handling HARQ with DRX operation is shown. The operations of the method 900 may be implemented by the UE 115 or components thereof, as described herein. For example, the operations of the method 900 may be implemented by reference to Figure 7 The communication manager, timer manager, or both described in the embodiments of the present invention may be used to perform the functions described below. In some implementations, the UE 115 may execute an instruction set to control the functional elements of the UE 115 to perform the functions described below. Additionally or alternatively, the UE 115 may use dedicated hardware to perform aspects of the functions described below.

[0186] At 905, UE 115 may receive a first DCI message indicating a non-numeric value of a data-to-feedback timing indicator, wherein the first DCI message schedules a downlink data message and the data-to-feedback timing indicator is associated with feedback timing of the downlink data message. The operations of 905 may be performed according to the methods described herein.

[0187] At 910, the UE 115 may activate a timer based on receiving a first DCI message and based on the data-to-feedback timing indicator being a non-numeric value. The operation of 910 may be performed according to the methods described herein. At 915, when the timer is activated, the UE 115 may monitor a downlink control channel. The operation of 915 may be performed according to the methods described herein.

[0188] At 920, based on monitoring of the downlink control channel, UE 115-b may receive a second DCI message indicating feedback timing of the downlink data message. The operations at 920 may be performed according to the methods described herein.

[0189] Fig.10 A flow chart illustrating an example method 1000 for handling HARQ with DRX operation is shown. The operations of the method 1000 may be implemented by the UE 115 or components thereof, as described herein. For example, the operations of the method 1000 may be implemented by reference to Figure 7 The communication manager, timer manager, or both described in the embodiments of the present invention may be used to perform the functions described below. In some implementations, the UE 115 may execute an instruction set to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE 115 may use dedicated hardware to perform aspects of the functions described below.

[0190] At 1005, UE 115 may receive a first DCI message indicating a non-numeric value of a data-to-feedback timing indicator, wherein the first DCI message schedules a downlink data message and the data-to-feedback timing indicator is associated with feedback timing of the downlink data message. The operations of 1005 may be performed according to the methods described herein.

[0191] At 1010, UE 115 may activate a timer based on receiving a first DCI message and based on the data-to-feedback timing indicator being a non-numeric value. The operations of 1010 may be performed according to the methods described herein. At 1015, when the timer is activated, UE 115 may monitor a downlink control channel. The operations of 1015 may be performed according to the methods described herein.

[0192] At 1020, based on monitoring of the downlink control channel, UE 115-b may receive a second DCI message indicating feedback timing of a downlink data message. The operation of 1020 may be performed according to the methods described herein. At 1025, UE 115 may deactivate the timer based on receiving a second downlink control information message indicating feedback timing of the downlink data message. The operation of 1025 may be performed according to the methods described herein.

[0193] Fig.11 A flow chart illustrating an example method 1100 for handling HARQ with DRX operation is shown. The operations of the method 1100 may be implemented by the UE 115 or components thereof, as described herein. For example, the operations of the method 1100 may be implemented by reference to Figure 7 The communication manager, timer manager, or both described in the embodiments of the present invention may be used to perform the functions described below. In some implementations, the UE 115 may execute an instruction set to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE 115 may use dedicated hardware to perform aspects of the functions described below.

[0194] At 1105, UE 115 may determine a scheduled transmission opportunity for a feedback message including feedback information for one or more downlink data messages. The operations of 1105 may be performed according to the methods described herein. At 1110, UE 115 may activate a timer in a first symbol after the scheduled transmission opportunity for the feedback message. The operations of 1110 may be performed according to the methods described herein.

[0195] At 1115, when the timer is activated, the UE 115 may monitor the downlink control channel. The operations of 1115 may be performed according to the methods described herein. At 1120, the UE 115 may receive a DCI message requesting at least a portion of feedback information for transmitting one or more downlink data messages. The operations of 1120 may be performed according to the methods described herein. At 1125, the UE 115 may deactivate the timer based on receiving the DCI message. The operations of 1125 may be performed according to the methods described herein.

[0196] Fig.12 A flow chart illustrating an example method 1200 for handling HARQ with DRX operation is shown. The operations of the method 1200 may be implemented by the UE 115 or components thereof, as described herein. For example, the operations of the method 1200 may be implemented by reference to Figure 7 The communication manager, timer manager, or both described in the embodiments of the present invention may be used to perform the functions described below. In some implementations, the UE 115 may execute an instruction set to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE 115 may use dedicated hardware to perform aspects of the functions described below.

[0197] At 1205, UE 115 may determine a scheduled transmission opportunity for a feedback message, the feedback message including feedback information for one or more downlink data messages. The operations of 1205 may be performed according to the methods described herein. At 1210, UE 115 may perform an LBT procedure to obtain access to an uplink channel for the scheduled transmission opportunity. The operations of 1210 may be performed according to the methods described herein. At 1215, based on a failure of the LBT procedure, UE 115 may avoid sending the feedback message in the scheduled transmission opportunity. The operations of 1215 may be performed according to the methods described herein. At 1220, UE 115 may activate a timer in a first symbol after the scheduled transmission opportunity for the feedback message based on avoiding sending the feedback message in the scheduled transmission opportunity. The operations of 1220 may be performed according to the methods described herein.

[0198] At 1225, when the timer is activated, UE 115 may monitor the downlink control channel. The operation of 1225 may be performed according to the methods described herein. At 1230, UE 115 may receive a DCI message requesting at least a portion of feedback information for transmitting one or more downlink data messages. The operation of 1230 may be performed according to the methods described herein. At 1235, the UE may deactivate the timer based on receiving the DCI message. The operation of 1235 may be performed according to the methods described herein.

[0199] Fig.13 A flow chart illustrating an example method 1300 for handling HARQ with DRX operation is shown. The operations of the method 1300 may be implemented by the base station 105 or components thereof, as described herein. For example, the operations of the method 1300 may be implemented by reference to Figure 8 In some implementations, the base station may execute an instruction set to control functional elements of the base station to perform the functions described herein. Additionally or alternatively, the base station may use dedicated hardware to perform aspects of the functions described below.

[0200] At 1305, the base station 105 may send a first DCI message on a downlink control channel to the UE 115, the first DCI message indicating a non-numeric value of a data-to-feedback timing indicator, wherein the first DCI message schedules a downlink data message, and the data-to-feedback timing indicator is associated with feedback timing of the downlink data message. The operations of 1305 may be performed according to the methods described herein.

[0201] At 1310, the base station 105 may determine an active time for the UE 115 to monitor the downlink control channel based on a timer, wherein the timer is activated based on the first DCI message and the data-to-feedback timing indicator being a non-numeric value. The operations of 1310 may be performed according to the methods described herein.

[0202] At 1315, the base station 105 may send a second DCI message to the UE 115 on the downlink control channel, the second DCI message indicating feedback timing of the downlink data message based on the determined active time of the UE 115 monitoring the downlink control channel. The operation of 1315 may be performed according to the methods described herein.

[0203] Fig.14 A flow chart illustrating an example method 1400 for handling HARQ with DRX operation is shown. The operations of the method 1400 may be implemented by the base station 105 or components thereof, as described herein. For example, the operations of the method 1400 may be implemented by reference to Figure 8 In some implementations, the base station may execute an instruction set to control the functional elements of the base station 105 to perform the functions described herein. Additionally or alternatively, the base station 105 may use dedicated hardware to perform aspects of the functions described below.

[0204] At 1405, the base station 105 may send a first DCI message to the UE 115 on a downlink control channel, the first DCI message scheduling transmission of a downlink data message and including a data-to-feedback timing indicator corresponding to the downlink data message and indicating a scheduled transmission opportunity. The operations of 1405 may be performed according to the methods described herein.

[0205] At 1410, the base station 105 may identify a feedback message that failed to successfully receive feedback information including a downlink data message in a scheduled transmission opportunity. The operations of 1410 may be performed according to the methods described herein.

[0206] At 1415, the base station 105-c may determine an active time for the UE 115 to monitor the downlink control channel based on a timer, wherein the timer is activated in a first symbol after a scheduled transmission opportunity. The operations of 1415 may be performed according to the methods described herein.

[0207] At 1420, the base station 105 may send a second DCI message to the UE 115 on the downlink control channel, the second DCI message requesting transmission of at least a portion of feedback information of the downlink data message based on the determined activity time of the UE monitoring the downlink control channel and identifying the failure to successfully receive the feedback message. The operation of 1420 may be performed according to the method described herein.

[0208] As used herein, a phrase referring to "at least one" of a list of items refers to any combination of those items, including single members. For example, "at least one of a, b, or c" is intended to cover: a, b, c, ab, ac, bc, and abc.

[0209] The various illustrative logics, logic blocks, modules, circuits, and algorithmic processes described in conjunction with the implementations disclosed herein may be implemented as electronic hardware, computer software, or a combination of both. The interchangeability of hardware and software has been generally described in terms of functionality and illustrated in the various illustrative components, blocks, modules, circuits, and processes described above. Whether such functionality is implemented in hardware or software depends on the specific application and the design constraints imposed on the overall system.

[0210] The hardware and data processing apparatus for implementing the various illustrative logics, logic blocks, modules, and circuits described in conjunction with the aspects disclosed herein may be implemented or executed with a general purpose single-chip or multi-chip processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, or any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, for example, a DSP and a microprocessor, a plurality of microprocessors, a combination of one or more microprocessors combined with a DSP core, or any other such configuration. In some implementations, specific processes and methods may be performed by circuits specific to a given function.

[0211] In one or more aspects, the functions described may be implemented in hardware, digital electronic circuitry, computer software, firmware (including the structures disclosed in this specification and their equivalents), or any combination thereof. Implementations of the subject matter described in this specification may also be implemented as one or more computer programs, i.e., one or more modules of computer program instructions, encoded on a computer storage medium for execution by a data processing device or for controlling the operation of the data processing device.

[0212] If implemented in software, these functions can be stored as one or more instructions or codes on a computer-readable medium or transmitted through a computer-readable medium. The process of the method or algorithm disclosed herein can be implemented in a processor executable software module that can reside on a computer-readable medium. Computer-readable media include computer storage media and communication media, and communication media include any medium that can transfer a computer program from one place to another. The storage medium can be any available medium that a computer can access. As an example and not a limitation, such a computer-readable medium may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, disk storage or other magnetic storage device, or any other medium that can be used to store the required program code in the form of an instruction or data structure and can be accessed by a computer. In addition, any connection can be properly referred to as a computer-readable medium. Disks and optical disks as used herein include compact disks (CDs), laser disks, optical disks, digital versatile disks (DVDs), floppy disks and blue-ray disks, wherein disks are generally used to reproduce data magnetically, and optical disks are used to reproduce data optically with lasers. The above combination should also be included in the scope of computer-readable media. Additionally, the operations of a method or algorithm may reside as one or any combination or set of codes and instructions on a machine-readable medium and a computer-readable medium, which may be incorporated into a computer program product.

[0213] Various modifications to the implementations described in this disclosure will be apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects without departing from the spirit or scope of this disclosure. Therefore, the claims are not intended to be limited to the implementations shown herein, but are to be accorded the broadest scope consistent with this disclosure, the principles, and the novel features disclosed herein.

[0214] In addition, one of ordinary skill in the art will readily understand that the terms "upper" and "lower" are sometimes used to facilitate description of the drawings and indicate relative positions corresponding to the orientation of the drawings on a correctly oriented page and may not reflect the correct orientation of any device implemented.

[0215] Certain features described in this specification in the context of separate implementations may also be implemented in combination in a single implementation. Conversely, various features described in the context of a single implementation may also be implemented in multiple implementations, either individually or in any suitable subcombination. Furthermore, while the features described above may be described as functioning in certain combinations, or even initially claimed as such, in some cases one or more features from the claimed combination may be deleted from the combination, and the claimed combination may be directed to a subcombination or a variation of a subcombination.

[0216] Similarly, although the operations are described in a particular order in the accompanying drawings, this should not be understood as requiring such operations to be performed in the particular order or sequence shown, or requiring all illustrated operations to be performed to achieve the desired results. In addition, the accompanying drawings may schematically depict more than one example process in the form of a flow chart. However, other operations not described may be combined in the schematically illustrated example process. For example, one or more additional operations may be performed before, after, simultaneously, or between any of the illustrated operations. In some cases, multitasking and parallel processing may be advantageous. In addition, the separation of various system components in the above-described implementations should not be understood as requiring such separation in all implementations, and it should be understood that the described program components and systems may generally be integrated in a single software product or packaged into multiple software products. In addition, other implementations are within the scope of the following claims. In some cases, the actions described in the claims may be performed in different orders, and still obtain desirable results.

Claims

1. A device for wireless communication, comprising: A processing system configured to: receiving a downlink control information (DCI) message including a data-to-feedback timing indicator, wherein the DCI message schedules a downlink data message and the data-to-feedback timing indicator is a value that does not indicate feedback timing; deferring transmission of feedback of the downlink data message based on the value; activating a timer based on the value; entering an active mode when the timer is activated to monitor information of a downlink control channel; and When the timer expires, the inactive mode is entered to stop monitoring the downlink control channel.

2. The device according to claim 1, wherein: The value is a negative number.

3. The device according to claim 1, wherein: The timer comprises a retransmission timer for downlink retransmission and is associated with a hybrid automatic repeat request HARD procedure corresponding to the downlink data message.

4. The device according to claim 3, wherein: The timer includes drx-RetransmissionTimerDL.

5. The device according to claim 1, wherein: The processing system is also configured to: outputting a feedback message for the downlink data message according to the feedback timing indicated by the second DCI message; and After the feedback message is output, a round trip timer is activated in the first symbol.

6. The device according to claim 5, wherein: The processing system is also configured to: activating a retransmission timer in a first symbol after expiration of the round trip timer based on a feedback message including a negative acknowledgement (NACK) of the downlink data message; and When the retransmission timer is activated, the downlink control channel is monitored.

7. The device according to claim 6, wherein: The round trip time timer comprises drx-HARQ-RTT-TimerDL; and The retransmission timer includes drx-RetransmissionTimerDL.

8. The device according to claim 1, wherein: The processing system is also configured to: The timer is deactivated based on receiving the second DCI message indicating the feedback timing for the downlink data message.

9. The device according to claim 8, wherein: Deactivating the timer includes deactivating the timer in a first symbol after receiving a second DCI message or in a first symbol after feedback transmission corresponding to the feedback timing indicated by the second DCI message.

10. The device according to claim 1, wherein: The processing system is also configured to: receiving the downlink data message based on the DCI message; storing feedback information for the downlink data message based on the DCI message indicating the value; as well as A feedback message including the feedback information for the downlink data message is output according to the feedback timing indicated by the second DCI message.

11. The device according to claim 10, wherein: The feedback message includes a hybrid automatic repeat request HARQ confirmation message.

12. The device according to claim 1, wherein: The processing system is also configured to: A radio resource control (RRC) message is received indicating an activity duration of the timer.

13. The device according to claim 12, wherein: The active duration comprises a first active duration of the timer dedicated to receiving a DCI message indicating the value; and The RRC message also indicates a second active duration of the timer.

14. The device according to claim 1, wherein: The timer is dedicated to a hybrid automatic repeat request (HARQ) process of the downlink data message.

15. The device according to claim 1, wherein: The processing system is also configured to: deactivating the timer based on the timer running within an active duration of the timer; entering a low power mode based on deactivating the timer; and While in the low power mode, monitoring of the downlink control channel is avoided.

16. The device according to claim 15, wherein: The processing system is also configured to: Entering the low power mode is also based on the user equipment UE being out of an ON time duration of a discontinuous reception (DRX) mode, and each timer corresponding to monitoring the downlink control channel is deactivated.

17. The device according to claim 1, wherein: The processing system is also configured to: operating according to a discontinuous reception (DRX) mode; and The downlink control channel is monitored during an ON duration of the DRX mode, wherein the DCI message is received based on monitoring the downlink control channel during the ON duration of the DRX mode.

18. The apparatus according to claim 1, comprised in a user equipment (UE).

19. An apparatus for wireless communication, comprising: A processing system configured to: outputting a downlink control information (DCI) message including a data-to-feedback timing indicator, wherein the DCI message schedules a downlink data message and the data-to-feedback timing indicator is a value that does not indicate feedback timing; and An activity time for the user equipment UE to monitor the downlink control channel is determined based on a timer, wherein the timer is activated based on the value.

20. The device according to claim 19, wherein The value is a negative number.

21. The apparatus of claim 19, wherein: The timer comprises a retransmission timer for downlink retransmission and is associated with a hybrid automatic repeat request HARD procedure corresponding to the downlink data message.

22. The device according to claim 19, wherein The processing system is also configured to: A radio resource control (RRC) message is output indicating an active duration of the timer.

23. The apparatus of claim 22, wherein: The active duration comprises a first active duration of the timer dedicated to receiving a DCI message indicating the value; and The RRC message also indicates a second active duration of the timer.

24. The device according to claim 19, wherein The processing system is also configured to: The downlink data message is output based on the DCI message.

25. A method for wireless communication, comprising: receiving a downlink control information (DCI) message including a data-to-feedback timing indicator, wherein the DCI message schedules a downlink data message and the data-to-feedback timing indicator is a value that does not indicate feedback timing; deferring transmission of feedback of the downlink data message based on the value; activating a timer based on the value; entering an active mode when the timer is activated to monitor information of a downlink control channel; and When the timer expires, the inactive mode is entered to stop monitoring the downlink control channel.

26. The method according to claim 25, wherein: The value is a negative number.

27. The method of claim 25, wherein: The timer comprises a retransmission timer for downlink retransmission and is associated with a hybrid automatic repeat request HARD procedure corresponding to the downlink data message.

28. A method for wireless communication, comprising: sending a downlink control information (DCI) message including a data-to-feedback timing indicator, wherein the DCI message schedules a downlink data message and the data-to-feedback timing indicator is a value that does not indicate feedback timing; and An activity time for the user equipment UE to monitor the downlink control channel is determined based on a timer, wherein the timer is activated based on the value.

29. The method according to claim 28, wherein: The value is a negative number.

30. The method of claim 28, wherein: The timer comprises a retransmission timer for downlink retransmission and is associated with a hybrid automatic repeat request HARD procedure corresponding to the downlink data message.

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