WO2022016543A1

WO2022016543A1 - Method, device and computer readable medium of communication

Info

Publication number: WO2022016543A1
Application number: PCT/CN2020/104552
Authority: WO
Inventors: Jianguo Liu; Chunli Wu; Mads LAURIDSEN; Tao Tao
Original assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy; Nokia Technologies Oy
Current assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy; Nokia Technologies Oy
Priority date: 2020-07-24
Filing date: 2020-07-24
Publication date: 2022-01-27
Anticipated expiration: 2023-01-24
Also published as: CN114846855A; CN114846855B

Abstract

Embodiments of the present disclosure relate to methods, devices and computer readable storage media of communication. A second device transmits, to a first device, a first wake-up signal for a first mode of a discontinuous reception operation. The first device monitors the first wake-up signal, and if receiving the first wake-up signal with a wake-up indication, the first device performs the discontinuous reception operation in the second mode. In this way, an efficient mechanism can be provided for better support of the use of the second mode with low packet latency and low power consumption in licensed and unlicensed bands.

Description

METHOD, DEVICE AND COMPUTER READABLE MEDIUM OF COMMUNICATION

FIELD

Embodiments of the present disclosure generally relate to the field of telecommunication and in particular, to methods, devices and computer readable storage media of communication for a discontinuous reception (DRX) operation.

BACKGROUND

Power saving at a terminal device is always highly concerned. Generally, a DRX operation is performed to reduce physical downlink control channel (PDCCH) monitoring which consumes a significant amount of power. In a radio resource control (RRC) connected mode, there are two types of the DRX operation, i.e., a short DRX cycle and a long DRX cycle. If both the long DRX cycle and the short DRX cycle are configured for the terminal device, the short DRX cycle is used after a DRX inactivity timer runs out or a DRX Command medium access control (MAC) control element (CE) is received during the active time. Finally, the long DRX cycle is entered after the short DRX timer runs out.

For unlicensed deployment, a network device possibly cannot acquire a channel for transmission of a PDCCH and a physical downlink shared channel (PDSCH) for transmission of a MAC CE due to a downlink listen-before-talk (LBT) failure. In this case, the short DRX cycle cannot be started, and thus a traffic latency associated with the short DRX cycle will be increased.

SUMMARY

In general, example embodiments of the present disclosure provide a solution for a DRX operation.

In a first aspect, there is provided a method of communication. The method comprises: monitoring, at a first device and from a second device, a first wake-up signal for a first mode of a discontinuous reception operation; and in response to receiving the first wake-up signal with a wake-up indication, performing the discontinuous reception operation in a second mode of the discontinuous reception operation.

In a second aspect, there is provided a method of communication. The method comprises: monitoring, at a first device and from a second device, a first wake-up signal for a first mode of a discontinuous reception operation; in the absence of the first wake-up signal, determining whether a first failure in a downlink control channel occurs; and in accordance with a determination that the first failure occurs, performing a second monitoring of a second wake-up signal for a second mode of the discontinuous reception operation..

In a third aspect, there is provided a method of communication. The method comprises: transmitting, at a second device and to a first device, a first wake-up signal for a first mode of a discontinuous reception operation for performance of the discontinuous reception operation in a second mode by the first device in response to receiving the first wake-up signal with a wake-up indication.

In a fourth aspect, there is provided a method of communication. The method comprises: transmitting, at a second device and to a first device, a first wake-up signal for a first mode of a discontinuous reception operation for performance of the discontinuous reception operation in a second mode by the first device in the absence of the first wake-up signal due to a failure in a downlink control channel.

In a fifth aspect, there is provided a first device. The first device comprises: at least one processor; and at least one memory including computer program codes; the at least one memory and the computer program codes are configured to, with the at least one processor, cause the first device to perform the method according to at least one of the first and second aspects.

In a sixth aspect, there is provided a second device. The second device comprises: at least one processor; and at least one memory including computer program codes; the at least one memory and the computer program codes are configured to, with the at least one processor, cause the second device to perform the method according to at least one of the third and fourth aspects.

In a seventh aspect, there is provided a non-transitory computer readable medium. The non-transitory computer readable medium comprises program instructions for causing an apparatus to perform the method according to at least one of the first and second aspects.

In an eighth aspect, there is provided a non-transitory computer readable medium. The non-transitory computer readable medium comprises program instructions for causing an apparatus to perform the method according to at least one of the third and fourth aspects.

It is to be understood that the summary section is not intended to identify key or essential features of embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensible through the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

Some example embodiments will now be described with reference to the accompanying drawings, where:

Fig. 1 illustrates an example communication network in which example embodiments of the present disclosure may be implemented;

Fig. 2 illustrates a diagram of a DRX operation according to a conventional solution;

Fig. 3A illustrates a flowchart illustrating a process of communication for a DRX operation according to some embodiments of the present disclosure;

Fig. 3B illustrates a flowchart illustrating another process of communication for a DRX operation according to some embodiments of the present disclosure;

Fig. 4 illustrates a diagram of an example DRX operation according to example embodiments of the present disclosure;

Fig. 5 illustrates a diagram of another example DRX operation according to example embodiments of the present disclosure;

Fig. 6 illustrates a flowchart of an example method of communication implemented at a first device according to example embodiments of the present disclosure;

Fig. 7 illustrates a flowchart of another example method of communication implemented at a first device according to example embodiments of the present disclosure;

Fig. 8 illustrates a flowchart of another example method of communication implemented at a first device according to example embodiments of the present disclosure;

Fig. 9 illustrates a flowchart of an example method of communication implemented at a second device according to example embodiments of the present disclosure;

Fig. 10 illustrates a flowchart of another example method of communication implemented at a second device according to example embodiments of the present disclosure;

Fig. 11 illustrates a simplified block diagram of an apparatus that is suitable for implementing example embodiments of the present disclosure; and

FIG. 12 illustrates a block diagram of an example computer readable medium in accordance with example embodiments of the present disclosure.

Throughout the drawings, the same or similar reference numerals represent the same or similar element.

DETAILED DESCRIPTION

Principle of the present disclosure will now be described with reference to some example embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitation as to the scope of the disclosure. The disclosure described herein can be implemented in various manners other than the ones described below.

In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skills in the art to which this disclosure belongs.

References in the present disclosure to “one embodiment, ” “an embodiment, ” “an example embodiment, ” and the like indicate that the embodiment described may include a particular feature, structure, or characteristic, but it is not necessary that every embodiment includes the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

It shall be understood that although the terms “first” and “second” etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of example embodiments. As used herein, the term “and/or” includes any and all combinations of one or more of the listed terms.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a” , “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” , “comprising” , “has” , “having” , “includes” and/or “including” , when used herein, specify the presence of stated features, elements, and/or components etc., but do not preclude the presence or addition of one or more other features, elements, components and/or combinations thereof.

As used in this application, the term “circuitry” may refer to one or more or all of the following:

(a) hardware-only circuit implementations (such as implementations in only analog and/or digital circuitry) and

(b) combinations of hardware circuits and software, such as (as applicable) :

(i) a combination of analog and/or digital hardware circuit (s) with software/firmware and

(ii) any portions of hardware processor (s) with software (including digital signal processor (s) ) , software, and memory (ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and

(c) hardware circuit (s) and or processor (s) , such as a microprocessor (s) or a portion of a microprocessor (s) , that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.

This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and/or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

As used herein, the term “communication network” refers to a network following any suitable communication standards, such as Long Term Evolution (LTE) , LTE-Advanced (LTE-A) , Wideband Code Division Multiple Access (WCDMA) , High-Speed Packet Access (HSPA) , Narrow Band Internet of Things (NB-IoT) and so on. Furthermore, the communications between a terminal device and a network device in the communication network may be performed according to any suitable generation communication protocols, including, but not limited to, the first generation (1G) , the second generation (2G) , 2.5G, 2.75G, the third generation (3G) , the fourth generation (4G) , 4.5G, the future fifth generation (5G) communication protocols, and/or any other protocols either currently known or to be developed in the future. Embodiments of the present disclosure may be applied in various communication systems. Given the rapid development in communications, there will of course also be future type communication technologies and systems with which the present disclosure may be embodied. It should not be seen as limiting the scope of the present disclosure to only the aforementioned system.

As used herein, the term “network device” refers to a node in a communication network via which a terminal device accesses the network and receives services therefrom. The network device may refer to a base station (BS) or an access point (AP) , for example, a node B (NodeB or NB) , an evolved NodeB (eNodeB or eNB) , a NR NB (also referred to as a gNB) , a Remote Radio Unit (RRU) , a radio header (RH) , a remote radio head (RRH) , a relay, a low power node such as a femto, a pico, and so forth, depending on the applied terminology and technology.

The term “terminal device” refers to any end device that may be capable of wireless communication. By way of example rather than limitation, a terminal device may also be referred to as a communication device, user equipment (UE) , a Subscriber Station (SS) , a Portable Subscriber Station, a Mobile Station (MS) , or an Access Terminal (AT) . The terminal device may include, but not limited to, a mobile phone, a cellular phone, a smart phone, voice over IP (VoIP) phones, wireless local loop phones, a tablet, a wearable terminal device, a personal digital assistant (PDA) , portable computers, desktop computer, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, vehicle-mounted wireless terminal devices, wireless endpoints, mobile stations, laptop-embedded equipment (LEE) , laptop-mounted equipment (LME) , USB dongles, smart devices, wireless customer-premises equipment (CPE) , an Internet of Things (loT) device, a watch or other wearable, a head-mounted display (HMD) , a vehicle, a drone, a medical device and applications (e.g., remote surgery) , an industrial device and applications (e.g., a robot and/or other wireless devices operating in an industrial and/or an automated processing chain contexts) , a consumer electronics device, a device operating on commercial and/or industrial wireless networks, and the like. In the following description, the terms “terminal device” , “communication device” , “terminal” , “user equipment” and “UE” may be used interchangeably.

Fig. 1 illustrates an example communication network 100 in which embodiments of the present disclosure can be implemented. As shown in Fig. 1, the network 100 includes a first device 110 and a second device 120 serving the second device 120. For illustration, the first device 110 is shown as a terminal device and the second device 120 is shown as a network device. It is to be understood that the number of first and second devices as shown in Fig. 1 is only for the purpose of illustration without suggesting any limitations. The network 100 may include any suitable number of first and second devices adapted for implementing embodiments of the present disclosure.

As shown in Fig. 1, the first device 110 and the second device 120 may communicate with each other via a channel such as a wireless communication channel. The communications in the network 100 may conform to any suitable standards including, but not limited to, LTE, LTE-evolution, LTE-advanced (LTE-A) , wideband code division multiple access (WCDMA) , code division multiple access (CDMA) and global system for mobile communications (GSM) and the like. Furthermore, the communications may be performed according to any generation communication protocols either currently known or to be developed in the future. Examples of the communication protocols include, but not limited to, the first generation (1G) , the second generation (2G) , 2.5G, 2.75G, the third generation (3G) , the fourth generation (4G) , 4.5G, the fifth generation (5G) communication protocols.

Generally, the first device 110 needs to monitor a downlink control channel such as a PDCCH from the second device 120. The PDCCH monitoring consumes a significant amount of power at the first device 110. Thus, the first device 110 may be configured to perform a DRX operation.

Assuming that the first device 110 is in a RRC connected state with the second device 120. In some embodiments, the DRX operation may comprise two operation modes, i.e., a long DRX cycle and a short DRX cycle. Some services such as voice-over Internet protocol (IP) are characterized by periods of regular transmission and followed by periods of no or very little activity. To handle these services, the short DRX cycle can optionally be configured in addition to the long DRX cycle.

In a conventional solution, the short DRX cycle is used after a DRX inactivity timer runs out, and the long DRX cycle is entered after the short DRX timer runs out. In this solution, a terminal device will only start the DRX inactivity timer after a PDCCH occasion in which a PDCCH indicates a new uplink or downlink transmission, and then will start a DRX short cycle timer in the first symbol after an expiry of the DRX inactivity timer.

In another conventional solution, the short DRX cycle is used upon a DRX command MAC CE is received during the active time (e.g., when DRX on duration or DRX inactivity timer is running) , and the long DRX cycle is entered after the short DRX timer runs out. In this case, a terminal device needs to monitor a PDCCH during the active time of the long DRX cycle and check whether it receives the DRX command MAC CE from a network device. If receiving the DRX command MAC CE, the terminal device will start a DRX short cycle timer in the first symbol after the end of the DRX command MAC CE reception.

For unlicensed spectrum access, a LBT operation is required to be performed before transmission in unlicensed band according to the regulatory requirements in certain regions in order to achieve coexistence fairness with other radio access technologies (RATs) (e.g. new radio-unlicensed (NR-U) /license assisted access (LAA) /Wi-Fi) . For this, a channel should be considered to be occupied if other radio local area network (RLAN) transmissions are detected at a power level larger than a maximum energy detection (ED) threshold. In Release-16 NR-U, if a network device needs to access the channel for downlink transmission, it shall follow the downlink channel access procedure defined in TS 37.213. In this case, for unlicensed deployment, the network device possibly cannot acquire the channel for transmission of PDCCH and PDSCH for transmission of MAC CE due to a downlink LBT failure.

For example, in an existing mechanism, a wake-up signal (WUS) is provided to a terminal device via a PDCCH prior to the DRX on duration of the long DRX cycle. The WUS is also known as downlink control information (DCI) -based power saving signal (DCI with cyclic redundancy check (CRC) scrambled by a power saving-radio network temporary identifier (PS-RNTI) , also referred to as DCP) . In the basic implementation, the terminal device will wake up and monitor the PDCCH during the on duration if a wake-up indication bit of the WUS is 1, and the terminal device will not wake up if the wake-up indication bit is 0. Further, a ps-Wakeup bit can be defined to control whether the terminal device wakes up or not if the DCP is not detected. During standardization, it was agreed that the terminal device does not monitor for the DCP during the active time and that the WUS only applies to monitoring for DRX on duration belonging to the long DRX cycle.

In this case, the DCP is configured only for the long DRX cycle. Assume that a terminal device is configured to monitor the DCP prior to the long DRX cycle to determine whether to wake up or not. If the terminal device doesn’t detect the DCP due to a downlink LBT failure, and the ps-Wakeup bit indicates that the terminal device does not wake up, the terminal device will not wake up to monitor PDCCH during the DRX on duration. In this case, the terminal device will furthermore not start the DRX short cycle timer for use of the short DRX cycle, because neither the DRX inactivity timer expires nor the DRX command MAC CE is transmitted.

An example is described below with reference to Fig. 2. Fig. 2 illustrates a diagram 200 of a DRX operation according to a conventional solution. In this example, the terminal device is configured with both short DRX cycle and long DRX cycle. Assuming that a DRX inactive timer (denoted as drx-InactiveTimer) is set to 3 slots, an on duration timer (denoted as onDurationTimer) is set to 2 slots, a short DRX cycle (denoted as shortDrxCycle) is set to 5 slots, a long DRX cycle (denoted as longDrxCycle) is set to 10 slots, an offset for start of a short DRX cycle (denoted as drxStarOffset) is set to 0 and a short DRX cycle timer (denoted as drxShortCycleTimer) is set to 3 slots. Further, assuming that sign “S” denotes a LBT success for WUS, sign “I” denotes a LBT invalid for WUS, and sign “F” denotes a LBT failure for WUS.

As shown in Fig. 2, if the terminal device receives the WUS prior to the long DRX cycle in slot#0 of SFN#0, it will monitor PDCCH during active time of the long DRX cycle. If the terminal device receives any PDCCH for new uplink or downlink transmission in the slot#0 of the SFN#0, it will start the DRX inactivity timer. After the DRX inactivity timer expires, the terminal device will start the DRX short cycle timer from the slot#4 of SFN#0 and thus use the short DRX cycle. However, if the terminal device cannot receive the WUS prior to the long DRX cycle in SFN#2 due to a downlink LBT failure, as shown by 201, it will skip the PDCCH monitoring until next long DRX cycle. So, there is no chance to start the DRX short cycle timer for use of the short DRX cycle.

On the other hand, as a LBT is required to be performed before transmission, the network device is still possibly not able to acquire the channel for transmission of PDCCH during on duration of the long DRX cycle even if it transmits the WUS prior to the long DRX cycle. If the terminal device doesn’t receive PDCCH for indication of new uplink or downlink transmission or a DRX command MAC CE, the terminal device won’t start the DRX short cycle timer for use of the short DRX cycle. If the short DRX cycle is configured but cannot be used due to the LBT, it’s obvious that the traffic latency associated to the short DRX cycle will be increased.

As a solution in Release-16 NR, the ps-Wakeup bit can be defined to control whether the terminal device wakes up or not if the terminal device does not detect the DCP outside the active time. If the ps-Wakeup bit indicates wake up of the terminal device and the DCP associated with the long DRX cycle has not been received, the terminal device will start the DRX on duration timer after a DRX slot offset from the beginning of the subframe. Otherwise, the terminal device will skill PDCCH monitoring for the current DRX cycle for power saving. For unlicensed deployment, the ps-Wakeup bit can be defined to wake up the terminal device to monitor PDCCH during active time of the long DRX cycle even if the network device is blocked for WUS transmission prior to the long DRX cycle due to a downlink LBT failure.

The solution may cause extra power consumption as the terminal device needs to monitor the PDCCH during active time of long DRX cycle even if the network device would not schedule the terminal device. Furthermore, the network device needs to transmit the WUS to inform the terminal device not to wake-up even if it would not schedule the terminal device, which will introduce extra downlink resource overhead. Thus, the network device would not prefer to configure the ps-Wakeup bit for a DRX operation. As a result, the terminal device is still not able to use the short DRX cycle if the network device can’t get a channel for transmission of PDCCH during active time of the long DRX cycle due to a downlink LBT failure.

In order to solve the above and other potential problems, embodiments of the present disclosure provide an improved solution of communication for a DRX operation. For convenience, a long DRX cycle is also referred to as a first mode of DRX operation, and a short DRX cycle is also referred to as a second mode of DRX operation. According to an aspect of embodiments of the present disclosure, if a WUS (for convenience, also referred to as a first WUS herein) for the first mode is received and the WUS comprises a wake-up indication, the second mode will be started. In some embodiments, a message (for convenience, also referred to as a first message herein) indicating whether the second mode is to be started may be introduced. This aspect is applicable for licensed and unlicensed band or can be explicitly configurable whether to apply such behavior.

According to another aspect of embodiments of the present disclosure, if no first WUS for the first mode is received at the monitoring occasions or no PDCCH is received during on duration of the first mode after reception of the WUS, a monitoring (for convenience, also referred to as a second monitoring herein) of a WUS (for convenience, also referred to as a second WUS herein) for the second mode will be started in the case that the first WUS or PDCCH for the first mode is blocked, for example, due to a failure in a downlink control channel such as a downlink LBT failure. Otherwise, the terminal device can be specified or configured to skip further monitoring for the second mode. In some embodiments, a message (for convenience, also referred to as a third message herein) indicating whether the second monitoring is to be started may be introduced. This aspect is applicable for unlicensed band or can be explicitly configurable.

Thus, an efficient mechanism can be provided for better support of a short DRX cycle with low latency and power consumption in licensed and unlicensed bands. In this way, the short DRX cycle is enabled when transmission of either WUS or PDCCH associated with the long DRX cycle is blocked due to a failure in a downlink channel such as a downlink LBT failure.

Some example embodiments of the present disclosure will now be described in detail with reference to the figures. However, those skilled in the art would readily appreciate that the detailed description given herein with respect to these figures is for explanatory purpose as the present disclosure extends beyond theses limited embodiments.

Embodiments of the present disclosure may introduce or involve the following messages and information to control the use of the first and second modes:

1) a first message (for example, also referred to as a ps-ShortCycle-WakeUp message herein) as to whether the second mode is to be started. In some embodiments, the first message may comprise an indication bit. The value of the indication bit can be arbitrarily set.

2) a second message (for example, also referred to as a ps-Wakeup bit herein) as to whether the first device 110 wakes up in the first mode. In other words, it indicates whether the first monitoring herein of a downlink control channel in the first mode is to be started in absence of the WUS.

3) a third message (for example, also referred to as a ps-ShortCycle-WusMonitor message herein) as to whether the second monitoring of the second WUS is to be monitored. In some embodiments, the third message may comprise an indication bit. The value of the indication bit can be arbitrarily set.

4) information about occasions of monitoring the second WUS (for example, also referred to as search space set configuration for short DRX cycle herein) which indicates occasions of WUS monitoring for short DRX cycle.

Fig. 3A illustrates a flowchart 301 illustrating a process of communication for a DRX operation according to some embodiments of the present disclosure. For convenience, the following description will be made in connection with the context of Fig. 1. As shown in Fig. 3A, the second device 120 may transmit 301 a first WUS for a first mode of a DRX operation to the first device 110. In some embodiments, the first WUS may indicate the first device 110 to wake up. Alternatively, the first WUS may indicate the first device 110 to not wake up. For example, the first WUS may comprise an indication bit. In some embodiments, if the indication bit is 1, it is indicated that the first device 110 wakes up, and if the indication bit is 0, it is indicated that the first device 110 does not wake up. Of course, 1 of the indication bit may also be used to indicate that the first device 110 does not wake up, and 0 of the indication bit may also be used to indicate that the first device 110 wakes up. The present application does not make limitation for this.

In some embodiments, the second device 120 may also transmit 302 any of the above-listed messages and information to the first device 110. In some embodiments, the second device 120 may transmit any of these messages and information via a higher layer RRC signaling. In some embodiments, the second device 120 may transmit any of these messages and information via a lower layer physical signaling. For example, the second device 120 may configure the first message through a WUS or DCP associated with the first mode. It should be noted that the transmission of these messages and information can be performed in any other suitable ways.

The first device 110 monitors 303 the first WUS for the first mode. Assuming that the first device 110 receives the first WUS. In some embodiments, if the first device 110 receives the first WUS with a non-wake-up indication, the first device 110 may continue to monitor the first WUS.

If the first device 110 receives 304 the first WUS with a wake-up indication, the terminal device 120 performs 306 the DRX operation in a second mode of the DRX operation. That is, the short DRX cycle is used. In some embodiments, upon receiving the first WUS with the wake-up indication, the first device 110 may also start a DRX on duration timer for the first mode. In some embodiments, upon receiving the first WUS with the wake-up indication, the first device 110 may determine 305, from the first message, whether the second mode of the DRX operation is to be started, and if determining that the second mode is to be started, the terminal device 120 may perform 306 the DRX operation in the second mode.

In some embodiments, upon performing the DRX operation in the second mode, the first device 110 may start a short cycle timer for the second mode and monitor a downlink control channel such as a PDCCH according to short cycle until the short cycle timer expires. In this way, the short DRX cycle is enabled. In some alternative embodiments, the first device 110 may start the short cycle timer after an offset (denoted as drx-StartOffset herein) from the beginning of the subframe. For example, drx-StartOffset = [ (SFN × 10) + subframe number] modulo (drx-LongCycle) , where SFN denotes a system frame number, and drx-LongCycle denotes a length of the first mode. In some embodiments, the short cycle timer may be started upon reception of the WUS. In some embodiments, the short cycle timer may be started upon the starting of the OnDuration timer after the reception of the WUS. Of course, this is merely an example, and any other suitable ways are also feasible for the start of the short DRX cycle.

In some embodiments, duration of the short cycle timer can be determined in a predefined manner. For example, the duration of the short cycle timer may be the minimum value determined by min (drx-ShortCycleTimer, the remaining short DRX cycles available in the current long DRX cycle (i.e. until next OnDuration of the long DRX cycle) ) . Alternatively, the duration of the short cycle timer may be configured to be one of drx-ShortCycleTimer and the remaining short DRX cycles available in the current long DRX cycle. Of course, the duration of the short cycle timer may be determined by using a separately configured timer. As another example, the duration of the short cycle timer may be configured by a higher layer RRC signaling. In some alternative embodiments, the duration of the short cycle timer applied for the current short DRX cycle may be configured through the DCP or the WUS.

If determining from the first message that the second mode is not to be stated, the first device 110 may start 307 the first monitoring in the first mode. In some embodiments, the first device 110 may start a DRX on duration timer for the first mode and monitor the downlink control channel during the active time of the first mode.

During on duration of the first mode, the first device 110 may determine 308 whether the downlink control channel is blocked due to a failure in the downlink control channel. In other words, the first device 110 may perform transmission detection of the second device 120 to determine whether the second device 120 can get the channel during the active time of the first mode. In some embodiments, the first device 110 may perform the transmission detection in unlicensed band based on a downlink reference signal such as a demodulation reference signal (DMRS) or other reference signals. In some alternative embodiments, the first device 110 may perform the transmission detection in unlicensed band based on DCI such as group common (GC) -PDCCH or UE-specific PDCCH.

In some embodiments, if the first device 110 determines that the second device 120 gets a channel for transmission during active time of the first mode, the first device 110 may perform the DRX operation based on an existing procedure in Release 16 NR. For example, the first device 110 may start a DRX inactivity timer after the PDCCH occasion in which a PDCCH indicates a new downlink or uplink transmission, and may start the use of the second mode at the expiry of the DRX inactivity timer. Alternatively, the first device 110 may monitor the PDCCH during active time of the first mode, and if it receives a DRX command MAC CE from the second device 120, the first device 110 may start the use of the second mode in the first symbol after the end of DRX command MAC CE reception. Other details are omitted here to avoid confusing the present disclosure.

In some embodiments, if the first device 110 determines that the downlink control channel is blocked due to the failure in the downlink control channel during on duration of the first mode, the first device 110 may determine 308, from the third message, whether the second monitoring of the second WUS for the second mode is to be started.

In some embodiments, if determining from the third message that the second monitoring is to be started, the first device 110 may start 309 the second monitoring. In some embodiments, the first device 110 may determine occasions for the second monitoring. For example, the first device 110 may receive information about the occasions via a higher layer RRC signaling, and determine the occasions from the information. In some embodiments, the information may comprise a value of a configured timer. In some embodiments, the first device 110 may monitor the second WUS within the configured timer. In some alternative embodiments, the first device 110 may monitor the second WUS until next long cycle. In some alternative embodiments, the first device 110 may monitor the second WUS until the second WUS is received.

The second device 120 may transmit 310 the second WUS at the occasions. The first device 110 may determine 311 whether the second WUS is received at one of the occasions for the second monitoring. If determining that the second WUS is received at one of the occasions, the first device 110 may stop 312 the second monitoring at the occasions. In this way, power saving at the first device 110 is achieved by associating WUS monitoring at one occasion with multiple short DRX cycles. Then, the first device 110 may perform 313 the DRX operation in the second mode. The operation as shown by 313 is similar with that as shown by 306, and thus its details are omitted here.

In some embodiments, if determining that no second WUS is received at the occasions, the first device 110 may return to monitor the first WUS for the first mode. If determining from the third message that the second monitoring is not to be started, the first device 110 may also return to monitor the first WUS for the first mode. That is, the first device 110 may skip further monitoring of short DRX cycles until next long DRX cycle occurs.

An example is described below with reference to Fig. 4. Fig. 4 illustrates a diagram 400 of an example DRX operation according to example embodiments of the present disclosure. Assume that the first device 110 may detect the first WUS prior to the long DRX cycle but does not monitor transmission from the second device 120, e.g., due to a downlink LBT failure during active time of long DRX cycle, or if the first device 110 does not detect the first WUS prior to the long DRX cycle, e.g., due to a LBT failure, the first device 110 will be trigged to monitor the second WUS for short DRX cycles until next long DRX cycle.

In this example, assuming that a DRX inactive timer (denoted as drx-InactiveTimer) is set to 3 slots, an on duration timer (denoted as onDurationTimer) is set to 2 slots, a short DRX cycle (denoted as shortDrxCycle) is set to 5 slots, a long DRX cycle (denoted as longDrxCycle) is set to 20 slots, an offset for start of a short DRX cycle (denoted as drxStarOffset) is set to 0 and a short DRX cycle timer (denoted as drxShortCycleTimer) is set to 3 slots. Further, assuming that ps-ShortDrxCycle-WakeUp is configured with “FALSE” , which indicates that the first device 110 does not wake up, and assuming that ps-ShortDrxCycle-WusMonitor is configured with “TURE” , which indicates that a second monitoring for a second WUS is to be started. In addition, assuming that sign “x” for WUS denotes that the WUS is not detected, and sign “√” for WUS denotes that the WUS is detected. Assuming that sign “x” for drx-OnDurationTimer denotes that the OnDurationTimer is not started, and sign “√” for drx-OnDurationTimer denotes that the OnDurationTimer is started.

As shown in Fig. 4, after the second WUS is detected in slot#9 of SFN#0, the first device 110 will stop the second monitoring for short DRX cycles, and start the short cycle timer with duration of 2 short DRX cycles after the DCP reception, as denoted as Drx-ShortCycleTimerWus and shown by 401, and then monitor during on duration of short DRX cycles until the short cycle timer expires at the end of the SFN#1. It should be noted that the above-listed values in this example are merely an example, and do not make limitation for the present disclosure.

It should be note that actions shown in Fig. 3A are not always necessary for implementing embodiments of the present disclosure, and more or less actions may be adapted as needed. With the process in Fig. 3A, an efficient mechanism can be provided for better support of a short DRX cycle with low packet latency and low power consumption in licensed and unlicensed bands in the case that a WUS for a long DRX cycle is received.

Fig. 3B illustrates a flowchart 301 illustrating another process of communication for a DRX operation according to some embodiments of the present disclosure. For convenience, the following description will be made in connection with the context of Fig. 1. As shown in Fig. 3B, the second device 120 may transmit 320 a first WUS for a first mode of a DRX operation to the first device 110. The operation as shown by 320 is similar with that as shown by 301 in Fig. 3A, and thus its details are omitted here. In some embodiments, the second device 120 may also transmit 321 any of the above-listed messages and information to the first device 110. The operation as shown by 321 is similar with that as shown by 302 in Fig. 3A, and thus its details are also omitted here.

The first device 110 monitors 322 the first WUS for the first mode. Assuming that the first device 110 does not receive the first WUS. The first device 110 determines 323 whether the first WUS is blocked due to a failure (for convenience, also referred to as a first failure herein) of a downlink control channel. If determining that the first WUS is blocked due to the first failure, the first device 110 performs 327 a second monitoring of a second WUS for a second mode of the DRX operation.

In some embodiments, the first device 110 may determine 324 from the second message whether a first monitoring of a downlink control channel in the first mode is to be started. If determining from the second message that the first monitoring is to be stated, the first device 110 may perform 325 the DRX operation in the second mode. In this way, the short cycle is used. In some embodiments, upon determining the first monitoring is to be started, the first device 110 may determine from the first message whether the second mode is to be started. If determining that the second mode is to be started, the first device 110 may perform 325 the DRX operation in the second mode. If determining that the second mode is not to be started, the first device 110 may operate in a similar process as shown by 307-313 in Fig. 3A. Its details are not repeated here for concise.

In some embodiments, if determining from the second message that the first monitoring is not to be stated, the first device 110 may perform 327 the second monitoring of the second WUS. In some embodiments, upon determining that the first monitoring is not to be started, the first device 110 may determine 326 from the third message whether the second monitoring is to be started. If determining that the second monitoring is to be started, the first device 110 may perform 327 the second monitoring.

In some embodiments, the first device 110 may determine occasions for the second monitoring. For example, the first device 110 may receive information about the occasions via a higher layer RRC signaling, and determine the occasions from the information. In some embodiments, the information may comprise a value of a configured timer. In some embodiments, the first device 110 may monitor the second WUS within the configured timer. In some alternative embodiments, the first device 110 may monitor the second WUS until next long cycle. In some alternative embodiments, the first device 110 may monitor the second WUS until the second WUS is received.

The second device 120 may transmit 328 the second WUS at the occasions. The first device 110 may determine 329 whether the second WUS is received at one of the occasions for the second monitoring. If determining that the second WUS is received at one of the occasions, the first device 110 may stop 330 the second monitoring at the occasions. In this way, power saving at the first device 110 is achieved by associating WUS monitoring at one occasion with multiple short DRX cycles. Then, the first device 110 may perform 331 the DRX operation in the second mode. The operation as shown by 331 is similar with that as shown by 306 in Fig. 3A, and thus its details are omitted here for concise.

In some embodiments, if determining that no second WUS is received at the occasions, the first device 110 may return to monitor the first WUS for the first mode. If determining from the third message that the second monitoring is not to be started, the first device 110 may also return to monitor the first WUS for the first mode. That is, the first device 110 may skip further monitoring of short DRX cycles until next long DRX cycle occurs. The operations as shown by 327-331 are similar with that as shown by 309-313 in Fig. 3A, and their details are omitted here for concise.

An example is described below with reference to Fig. 5. Fig. 5 illustrates a diagram 500 of another example DRX operation according to example embodiments of the present disclosure. Assume that the first device 110 does not detect the first WUS prior to the long DRX cycle but the second message indicates that the first monitoring is to be started. In this example, assuming that a DRX inactive timer (denoted as drx-InactiveTimer) is set to 3 slots, an on duration timer (denoted as onDurationTimer) is set to 2 slots, a short DRX cycle (denoted as shortDrxCycle) is set to 5 slots, a long DRX cycle (denoted as longDrxCycle) is set to 20 slots, an offset for start of a short DRX cycle (denoted as drxStarOffset) is set to 0 and a short DRX cycle timer (denoted as drxShortCycleTimer) is set to 3 slots. Further, assuming that ps-ShortDrxCycle-WakeUp is configured with “TRUE” , which indicates that the first device 110 wakes up. In addition, assuming that sign “x” denotes that the first WUS is not detected, and sign “√” denotes a start of a short DRX cycle.

As shown in Fig. 5, the first device 110 may start drx-ShortCycleTimer with duration of 3 short DRX cycles from the beginning of on-duration occasion for the long DRX cycle (i.e. the slot#0 of SFN#0) in the case that the ps-ShortDrxCycle-WakeUp (i.e., the first message) indicates a start of the second mode, as shown by 501. It should be noted that the above-listed values in this example are merely an example, and do not make limitation for the present disclosure.

It should be note that actions shown in Fig. 3B are not always necessary for implementing embodiments of the present disclosure, and more or less actions may be adapted as needed. With the process in Fig. 3B, another efficient mechanism can be provided for better support of a short DRX cycle with low latency and power consumption in licensed and unlicensed bands in the case that no WUS for a long DRX cycle is received. Of course, in some alternative embodiments, the processes in Fig. 3A and 3B also can be combined in any suitable ways to achieve the control of DRX operation.

Corresponding to the processes described in Figs. 3A and 3B, embodiments of the present disclosure provide methods of communication implemented at a first device and at a second device. These methods will be described below with reference to Figs. 6 to 10.

Fig. 6 illustrates a flowchart of a method 600 of communication implemented at a first device according to example embodiments of the present disclosure. The method 600 can be implemented at the first device 110 shown in Fig. 1. For the purpose of discussion, the method 600 will be described with reference to Fig. 1. It is to be understood that method 600 may further include additional blocks not shown and/or omit some shown blocks, and the scope of the present disclosure is not limited in this regard.

As shown in Fig. 6, at block 610, the first device 110 monitors a first WUS for a first mode of a DRX operation. In some embodiments, the first device 110 may monitor the first WUS in any suitable manner. At block 620, the first device 110 determines whether the first WUS with a wake-up indication is received. In some embodiments, upon receiving a first WUS, the first device 110 may determine whether the first WUS comprises a wake-up indication. In some embodiments, the first WUS may comprise a non-wake-up indication, i.e., the first device 110 does not wake up. In these embodiments, the first device 110 may return to block 610 to continue to monitor the first WUS.

In some embodiments, the first WUS may comprise a wake-up indication, i.e., the first device 110 wakes up. In these embodiments, the first device 110 may start a DRX on duration timer for the first mode. In this way, the first mode is used, i.e., a long DRX cycle is started. Upon receiving the first WUS with a wake-up indication, the process proceeds to block 630. At block 630, the first device 110 performs the DRX operation in the second mode. In some embodiments, the first device 110 may start a timer (for convenience, also referred to as a second timer herein) for duration of the second mode. For example, the timer is a ShortCycleTimer as mentioned above. Then, the first device 110 may monitor a downlink control channel (such as a PDCCH) until the second timer expires. In this way, one or more short DRX cycles can be started.

In some alternative embodiments, the first device 110 may start the short cycle timer after an offset (denoted as drx-StartOffset) from the beginning of the subframe. For example, drx-StartOffset = [ (SFN × 10) + subframe number] modulo (drx-LongCycle) , where SFN denotes a system frame number, and drx-LongCycle denotes a length of the first mode. In some embodiments, the short cycle timer may be started upon reception of the WUS. In some embodiments, the short cycle timer may be started upon the starting of the OnDuration timer after the reception of the WUS. Of course, this is merely an example, and any other suitable ways are also feasible for the start of the short DRX cycle.

In some embodiments for block 630, the first device 110 may determine, from a first message (for example, ps-ShortCycle-WakeUp message) , whether a second mode of the DRX operation is to be started. In these embodiments, the first message is received from the second device 120 and indicates whether the second mode is to be started. In some embodiments, the first message may comprise an indication bit. A first value of the indication bit may indicate that the second mode is to be started, and a second value of the indication bit may indicate that the second mode is not to be started. The first and second values may be arbitrarily set. If determining that the second mode is to be started, the first device 110 may perform the DRX operation in the second mode. In this way, the short DRX cycle will be forcedly used.

In some embodiments, if determining that the second mode is not to be started, the first device 110 may start a first monitoring of a downlink control channel in the first mode. For example, the first device 110 may monitor a PDCCH in the first mode. In some embodiments, the first device 110 may perform transmission detection of the second device 120 so as to determine whether the second device 120 can get the channel during the active time of the first mode. In some embodiments, the first device 110 may perform the transmission detection in unlicensed band based on a downlink reference signal such as a DMRS. In some alternative embodiments, the first device 110 may perform the transmission detection in unlicensed band based on DCI such as GC-PDCCH or UE-specific PDCCH.

If determining that the downlink control channel is not blocked but the second device 120 does not transmit the DCP, the first device 110 may skip monitoring of a second WUS for the second mode and continue to monitor the first WUS for the first mode. In this case, the short DRX cycle is not used. If determining that a failure in the downlink control channel occurs, the first device 110 may perform the second monitoring.

In some embodiments, the first device 110 may determine from a third message (for example, ps-ShortCycle-WusMonitor message) whether the second monitoring is to be started. In some embodiments, the third message is received from the second device 120 via any suitable ways. If determining from the third message that the second monitoring is not to be stated, the first device 110 may return to monitor the first WUS. If determining from the third message that the second monitoring is to be stated, the first device 110 may perform the second monitoring.

In some embodiments, if determining that the second WUS is received at one of the occasions, the first device 110 may stop the second monitoring at the occasions. In this way, power saving at the first device 110 is enhanced by associating WUS monitoring at one occasion with multiple short DRX cycles. Then the first device 110 may perform the DRX operation in the second mode, as described with reference to block 630. Thereby, the short DRX cycle is used.

With the solution of Fig. 6, an enhanced DRX mechanism is provided for better support of short DRX cycle with low latency and power consumption in licensed and unlicensed bands in the case that a WUS for a long DRX cycle is received. Thereby, the use of short DRX cycle is enabled when transmission of a PDCCH associated to the long DRX cycle is blocked due to a failure in a downlink control channel such as a LBT failure.

Fig. 7 illustrates a flowchart of another method 700 of communication implemented at a first device according to example embodiments of the present disclosure. The method 700 can be implemented at the first device 110 shown in Fig. 1. For the purpose of discussion, the method 700 will be described with reference to Fig. 1. It is to be understood that method 700 may further include additional blocks not shown and/or omit some shown blocks, and the scope of the present disclosure is not limited in this regard.

As shown in Fig. 7, at block 710, the first device 110 monitors a first WUS for a first mode of a DRX operation. In some embodiments, the first device 110 may monitor the first WUS in any suitable manner. At block 720, the first device 110 determines whether the first WUS is blocked due to a failure (for convenience, also referred to as a first failure) in a downlink channel.

In some embodiments, the first device 110 may perform transmission detection of the second device 120 so as to determine whether the second device 120 can acquire the channel during the active time of the first mode. In some embodiments, the first device 110 may perform the transmission detection in unlicensed band based on a downlink reference signal such as a DMRS. In some alternative embodiments, the first device 110 may perform the transmission detection in unlicensed band based on DCI such as GC-PDCCH or UE-specific PDCCH.

If determining that the first WUS is not blocked but the second device 120 does not transmit the first WUS, the first device 110 may continue to monitor the first WUS for the first mode. In this case, the short DRX cycle is not used. If determining that the first failure occurs, that is, the first WUS is blocked due to the first failure, at block 730, the first device 110 performs a second monitoring of a second WUS for a second mode of the DRX operation.

In some embodiments, the first device 110 may determine occasions for the second monitoring. For example, the first device 110 may receive information about the occasions via a higher layer RRC signaling, and determine the occasions from the information. In some embodiments, the information may comprise a value of a configured timer (for convenience, also referred to as a first timer herein) . In some embodiments, the first device 110 may monitor the second WUS within the configured timer. In some alternative embodiments, the first device 110 may monitor the second WUS until next long cycle. In some alternative embodiments, the first device 110 may monitor the second WUS until the second WUS is received.

In some embodiments, if determining that the second WUS is received at one of the occasions, the first device 110 may stop the second monitoring at the occasions. In this way, power saving at the first device 110 is enhanced by associating WUS monitoring at one occasion with multiple short DRX cycles. Then the first device 110 may perform the DRX operation in the second mode. Thereby, the short DRX cycle is used.

In some embodiments, the first device 110 may start a timer (for convenience, also referred to as a second timer herein) for duration of the second mode. For example, the timer is a ShortCycleTimer as mentioned above. Then, the first device 110 may monitor a downlink control channel (such as a PDCCH) until the second timer expires. In this way, one or more short DRX cycles can be started. In some alternative embodiments, the first device 110 may start the second timer after an offset (denoted as drx-StartOffset) from the beginning of the subframe. For example, drx-StartOffset = [ (SFN × 10) + subframe number] modulo (drx-LongCycle) , where SFN denotes a system frame number, and drx-LongCycle denotes a length of the first mode. In some embodiments, the short cycle timer may be started upon reception of the WUS. In some embodiments, the short cycle timer may be started upon the starting of the OnDuration timer after the reception of the WUS. Of course, this is merely an example, and any other suitable ways are also feasible for the start of the short DRX cycle.

With the solution of Fig. 7, an enhanced DRX mechanism is provided for better support of short DRX cycle with low latency and power consumption in licensed and unlicensed bands in the case that no WUS for a long DRX cycle is received. Thereby, the use of short DRX cycle is enabled when transmission of a WUS associated to the long DRX cycle is blocked due to a failure in a downlink channel such as a LBT failure.

Fig. 8 illustrates a flowchart of another method 800 of communication implemented at a first device according to example embodiments of the present disclosure. The method 800 can be implemented at the first device 110 shown in Fig. 1. For the purpose of discussion, the method 800 will be described with reference to Fig. 1. It is to be understood that method 800 may further include additional blocks not shown and/or omit some shown blocks, and the scope of the present disclosure is not limited in this regard. This describes a solution combining the solutions of Figs. 6 and 7. It should be noted that it is merely an example, and does not make limitation for the present disclosure. The solutions described with reference to Figs. 6 and 7 can be used separately to support the use of short DRX cycle, and also can be combined to support the use of short DRX cycle. Although the combination is described in connection with Fig. 8, it can be carried out in any other suitable ways, and is not limited to that in Fig. 8.

At block 801, the first device 110 may determine whether a first WUS for a first mode of DRX operation (i.e., long DRX cycle) is received from the second device 120. If the first device 110 receives the first WUS, the process proceeds to block 802. At block 802, the first device 110 may determine whether the first WUS comprises a wake-up indication. If determining that the first WUS comprises a non-wake-up indication, the first device 110 will continue to monitor the first WUS. If determining that the first WUS comprises a wake-up indication, the first device 110 may start a DRX on duration timer for the long DRX cycle, and the process proceeds to block 803.

At block 803, the first device 110 may determine, from the first message (for example, ps-ShortCycle-WakeUp message) , whether a second mode of DRX operation (i.e., short DRX cycle) is to be started. In some embodiments, the first message is received from the second device 120 via any suitable ways. If determining that the second mode is to be started, At block 804, the first device 110 may perform the DRX operation in the second mode. In this way, the short DRX cycle will be used. In some embodiments, the first device 110 may start a timer (for example, a ShortCycleTimer, also referred to as a second timer for convenience) for duration of the second mode, and monitor a downlink control channel such as a PDCCH until the timer expires.

If the first device 110 does not receive the first WUS at block 801, the process proceeds to block 805. At block 805, the first device 110 may determine whether the first WUS is blocked due to a failure (also referred to as a first failure for convenience) in downlink channel. In some embodiments, the first device 110 may perform transmission detection of the second device 120 so as to determine whether the second device 120 can get the channel during the active time of the first mode. In some embodiments, the first device 110 may perform the transmission detection in unlicensed band based on a downlink reference signal such as a DMRS. In some alternative embodiments, the first device 110 may perform the transmission detection in unlicensed band based on DCI such as GC-PDCCH or UE-specific PDCCH.

If determining at block 805 that the first WUS is not blocked but the second device 120 does not transmit the first WUS, the first device 110 may return to block 801 and continue to monitor the first WUS for the first mode. In this case, the short DRX cycle is not used. If determining that the first failure occurs, that is, the first WUS is blocked due to the first failure, the process proceeds to block 806.

At block 806, the first device 110 may determine, from the second message (for example, ps-Wakeup bit) , whether a first monitoring of a downlink control channel is to be started. In some embodiments, the second message is received from the second device 120 via any suitable ways. If determining that the first monitoring is to be started, the first device 110 may also start a DRX on duration timer for the long DRX cycle, and the process proceeds to block 803. If determining that the first monitoring is not to be started, the process proceeds to block 809 which will be described later.

If determining at block 803 that the second mode is not to be started, the process proceeds to block 807. At block 807, the first device 110 may start the first monitoring of the downlink control channel (for example, a PDCCH) in the first mode. In some embodiments, the first device 110 may perform transmission detection of the second device 120 so as to determine whether the second device 120 can get the channel during the active time of the first mode. In some embodiments, the first device 110 may perform the transmission detection in unlicensed band based on a downlink reference signal such as a DMRS. In some alternative embodiments, the first device 110 may perform the transmission detection in unlicensed band based on DCI such as GC-PDCCH or UE-specific PDCCH.

If the first device 110 determines at block 808 that a failure (also referred to as a second failure for convenience) in a downlink control channel is not detected, i.e., the second device 120 gets a channel for transmission during on duration of the first mode, the process proceeds to block 814. At block 814, the first device 110 may perform the DRX operation based on an existing procedure in Release 16 NR. For example, the first device 110 may start a DRX inactivity timer after the PDCCH occasion in which a PDCCH indicates a new downlink or uplink transmission, and may start the use of the second mode at the expiry of the DRX inactivity timer. Alternatively, the first device 110 may monitor the PDCCH during active time of the first mode, and if it receives a DRX command MAC CE from the second device 120, the first device 110 may start the use of the second mode in the first symbol after the end of DRX command MAC CE reception. Other details are omitted here to avoid confusing the present disclosure.

If the first device 110 determines at block 808 that the second failure is detected, for example, a downlink LBT failure is detected during on duration of the first mode, the process proceeds to block 809. At block 809, the first device 110 may determine, from the third message (for example, ps-ShortCycle-WusMonitor message) , whether a second monitoring of a second WUS for the second mode is to be started. In some embodiments, the third message is received from the second device 120 via any suitable ways. If determining from the third message that the second monitoring is not to be stated, the first device 110 may return to monitor the first WUS at block 801.

If determining from the third message that the second monitoring is to be stated, the process proceeds to block 810. At block 810, the first device 110 may perform the second monitoring. In some embodiments, the first device 110 may determine occasions for the second monitoring. For example, the first device 110 may receive information about the occasions via a higher layer RRC signaling, and determine the occasions from the information. In some embodiments, the information may comprise a value of a configured timer (for convenience, also referred to as a first timer herein) . In some embodiments, the first device 110 may monitor the second WUS within the configured timer. In some alternative embodiments, the first device 110 may monitor the second WUS until next long cycle. In some alternative embodiments, the first device 110 may monitor the second WUS until the second WUS is received.

At block 811, the first device 110 may determine whether the second WUS is received at one of the occasions for the second monitoring. If determining that the second WUS is received at one of the occasions, at block 812, the first device 110 may stop the second monitoring at the occasions. In this way, power saving at the first device 110 is enhanced by associating WUS monitoring at one occasion with multiple short DRX cycles. Then the process proceeds to block 804, where the first device 110 performs the DRX operation in the second mode as described above. Thereby, the short DRX cycle is used.

With the solution of Fig. 8, an enhanced DRX mechanism is provided for better support of short DRX cycle with low packet latency and low power consumption in licensed and unlicensed bands, which enable use of short DRX cycle if transmission of either WUS or PDCCH associated to the long DRX cycle is blocked due to a failure in downlink channel.

Fig. 9 illustrates a flowchart of a method 900 of communication implemented at a second device according to example embodiments of the present disclosure. The method 900 can be implemented at the second device 120 shown in Fig. 1. For the purpose of discussion, the method 900 will be described with reference to Fig. 1. It is to be understood that method 900 may further include additional blocks not shown and/or omit some shown blocks, and the scope of the present disclosure is not limited in this regard.

As shown in Fig. 9, at block 910, the second device 120 transmits, to the first device 110, a first WUS for a first mode of DRX operation for performance of the DRX operation in a second mode by the first device 110 in response to receiving the first WUS with a wake-up indication. In some embodiments, the second device 120 may also transmit, to the first device 110, a first message (for example, ps-ShortCycle-WakeUp message) as to whether a second mode of DRX operation is to be started. In some embodiments, the second device 120 may transmit the first message through DCP associated with the first WUS. In some embodiments, the second device 120 may transmit the first message via a higher layer RRC signaling separately from the first WUS. It should be noted that the present application does not make limitation for the transmission of the first WUS and the first message.

In some embodiments, the second device 120 may transmit, to the first device 110, a second message (for example, ps-Wakeup bit) as to whether a first monitoring of a downlink control channel in the first mode is to be started. In some embodiments, the second device 120 may transmit the second message via a higher layer RRC signaling. In some embodiments, the second device 120 may transmit the second message via a lower layer physical signaling. It should be noted that the present application does not make limitation for the transmission of the second message.

In some embodiments, the second device 120 may transmit, to the first device 110, a third message (for example, ps-ShortCycle-WusMonitor message) as to whether a second monitoring of a second wake-up signal for the second mode is to be started. In some embodiments, the second device 120 may transmit the third message via a higher layer RRC signaling. In some embodiments, the second device 120 may transmit the third message via a lower layer physical signaling. It should be noted that the present application does not make limitation for the transmission of the third message.

In some embodiments, the second device 120 may transmit, to the first device 110, information (for example, search space set configuration for short DRX cycle) about occasions for the second monitoring, and transmit, to the first device 110, the second wake-up signal at one of the occasions. In some embodiments, the second device 120 may transmit the information about the occasions via a higher layer RRC signaling. It should be noted that the present application does not make limitation for the transmission of this information.

With configuration of the messages and information for controlling the use of the short DRX cycle, an efficient mechanism can be provided to control the use of the short DRX cycle when transmission of either WUS or PDCCH associated with the long DRX cycle is blocked due to a failure in a downlink control channel. Thus, the short DRX cycle is better supported with low packet latency and low power consumption in licensed and unlicensed bands.

Fig. 10 illustrates a flowchart of a method 1000 of communication implemented at a second device according to example embodiments of the present disclosure. The method 1000 can be implemented at the second device 120 shown in Fig. 1. For the purpose of discussion, the method 1000 will be described with reference to Fig. 1. It is to be understood that method 1000 may further include additional blocks not shown and/or omit some shown blocks, and the scope of the present disclosure is not limited in this regard.

As shown in Fig. 10, at block 1010, the second device 120 transmits, to the first device 110, a first WUS for a first mode of DRX operation for performance of the DRX operation in a second mode by the first device 110 in the absence of the first WUS due to a failure in downlink channel. In some embodiments, the second device 120 may also transmit, to the first device 110, a first message (for example, ps-ShortCycle-WakeUp message) as to whether a second mode of DRX operation is to be started. In some embodiments, the second device 120 may transmit the first message through DCP associated with the first WUS. In some embodiments, the second device 120 may transmit the first message via a higher layer RRC signaling separately from the first WUS. It should be noted that the present application does not make limitation for the transmission of the first WUS and the first message.

With configuration of the messages and information for controlling the use of the short DRX cycle, an efficient mechanism can be provided to control the use of the short DRX cycle when transmission of either WUS or PDCCH associated with the long DRX cycle is blocked due to a failure in a downlink channel such as a downlink LBT failure. Thus, the short DRX cycle is better supported with low latency and power consumption in licensed and unlicensed bands.

In some example embodiments, an apparatus capable of performing any of the method 600 (for example, the first device 110) may comprise means for performing the respective steps of the method 600. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

In some example embodiments, the apparatus comprises means for monitoring, at a first device and from a second device, a first wake-up signal for a first mode of a discontinuous reception operation; and means for in response to receiving the first wake-up signal with a wake-up indication, performing the discontinuous reception operation in a second mode of the discontinuous reception operation.

In some example embodiments, the means for performing the discontinuous reception operation in the second mode comprises: means for determining from a first message whether a second mode of the discontinuous reception operation is to be started, the first message received from the second device; and means for in accordance with a determination that the second mode is to be started, performing the discontinuous reception operation in the second mode.

In some example embodiments, the apparatus further comprises: means for in accordance with a determination from the first message that the second mode is not to be started, starting a first monitoring of a downlink control channel in the first mode; and means for in accordance with a determination that a failure in the downlink control channel occurs, performing a second monitoring of a second wake-up signal for the second mode.

In some example embodiments, the means for performing the second monitoring comprises: means for determining from a third message whether the second monitoring is to be started, the third message received from the second device; and means for in accordance with a determination that the second monitoring is to be started, performing the second monitoring.

In some example embodiments, the means for performing the second monitoring comprises: means for determining occasions for the second monitoring; and means for determining whether the second wake-up signal is received at one of the occasions. In these embodiments, the apparatus further comprises: means for in accordance with a determination that the second wake-up signal is received, stopping the second monitoring at the occasions; and means for performing the discontinuous reception operation in the second mode.

In some example embodiments, the means of determining whether the second wake-up signal is received comprises at least one of: means of monitoring, within a first timer, whether the second wake-up signal is received; means of monitoring whether the second wake-up signal is received until the end of the first mode; and means of monitoring whether the second wake-up signal is received until the second wake-up signal is received.

In some example embodiments, the means of performing the discontinuous reception operation in the second mode comprises: means of starting a second timer for duration of the second mode; and means of monitoring a downlink control channel until the second timer expires.

In some example embodiments, the first mode is a long cycle of the discontinuous reception operation, and the second mode is a short cycle of the discontinuous reception operation. In some example embodiments, the first device is a terminal device, and the second device is a network device.

In some example embodiments, an apparatus capable of performing any of the method 700 (for example, the first device 110) may comprise means for performing the respective steps of the method 700. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

In some example embodiments, the apparatus comprises: means for monitoring, at a first device and from a second device, a first wake-up signal for a first mode of a discontinuous reception operation; means for in the absence of the first wake-up signal, determining whether a first failure in a downlink control channel occurs; and means for in accordance with a determination that the first failure occurs, performing a second monitoring of a second wake-up signal for a second mode of the discontinuous reception operation.

In some example embodiments, the means for performing the second monitoring comprises: means for determining from a second message whether a first monitoring of a downlink control channel in the first mode is to be started, the second message received from the second device; and means for in accordance with a determination from the second message that the first monitoring is not to be started, performing the second monitoring.

In some example embodiments, the apparatus further comprises: means for in accordance with a determination from the second message that the first monitoring is to be started, determining from a first message whether a second mode of the discontinuous reception operation is to be started, the first message received from the second device; and means for in accordance with a determination that the second mode is to be started, performing the discontinuous reception operation in the second mode.

In some example embodiments, the apparatus further comprises: means for in accordance with a determination that the second mode is not to be started, starting a first monitoring of a downlink control channel in the first mode; and means for in accordance with a determination that a second failure in the downlink control channel occurs, performing the second monitoring.

In some example embodiments, the means for determining whether the second wake-up signal is received comprises at least one of: means for monitoring, within a first timer, whether the second wake-up signal is received; means for monitoring whether the second wake-up signal is received until the end of the first mode; and means for monitoring whether the second wake-up signal is received until the second wake-up signal is received.

In some example embodiments, the means for performing the discontinuous reception operation in the second mode comprises: means for starting a second timer for duration of the second mode; and means for monitoring a downlink control channel until the second timer expires.

In some example embodiments, an apparatus capable of performing any of the method 900 (for example, the second device 120) may comprise means for performing the respective steps of the method 900. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

In some example embodiments, the apparatus comprises means for transmitting, at a second device and to a first device, a first wake-up signal for a first mode of a discontinuous reception operation for performance of the discontinuous reception operation in a second mode by the first device in response to receiving the first wake-up signal with a wake-up indication.

In some example embodiments, an apparatus capable of performing any of the method 1000 (for example, the second device 120) may comprise means for performing the respective steps of the method 1000. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

In some example embodiments, the apparatus comprises means for transmitting, at a second device and to a first device, a first wake-up signal for a first mode of a discontinuous reception operation for performance of the discontinuous reception operation in a second mode by the first device in the absence of the first wake-up signal due to a failure in a downlink control channel.

In some example embodiments, the apparatus further comprises at least one of: means for transmitting, to the first device, a first message as to whether the second mode is to be started; means for transmitting, to the first device, a second message as to whether a first monitoring of a downlink control channel in the first mode is to be started; and means for transmitting, to the first device, a third message as to whether a second monitoring of a second wake-up signal for the second mode is to be started.

In some example embodiments, the apparatus further comprises: means for transmitting, to the first device, information about occasions for the second monitoring; and means for transmitting, to the first device, the second wake-up signal at one of the occasions.

FIG. 11 is a simplified block diagram of a device 1100 that is suitable for implementing embodiments of the present disclosure. The device 1100 may be provided to implement the first device or second device, for example first device 110 or the second device 120 as shown in Fig. 1. As shown, the device 1100 includes one or more processors 1110, one or more memories 1120 coupled to the processor 1110, and one or more communication modules 1140 (such as, transmitters and/or receivers) coupled to the processor 1110.

The communication module 1140 is for bidirectional communications. The communication module 1140 has at least one antenna to facilitate communication. The communication interface may represent any interface that is necessary for communication with other network elements.

The processor 1110 may be of any type suitable to the local technical network and may include one or more of the following: general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multicore processor architecture, as non-limiting examples. The device 1100 may have multiple processors, such as an application specific integrated circuit chip that is slaved in time to a clock which synchronizes the main processor.

The memory 1120 may include one or more non-volatile memories and one or more volatile memories. Examples of the non-volatile memories include, but are not limited to, a Read Only Memory (ROM) 1124, an electrically programmable read only memory (EPROM) , a flash memory, a hard disk, a compact disc (CD) , a digital video disk (DVD) , and other magnetic storage and/or optical storage. Examples of the volatile memories include, but are not limited to, a random access memory (RAM) 1122 and other volatile memories that will not last in the power-down duration.

A computer program 1130 includes computer executable instructions that are executed by the associated processor 1110. The program 1130 may be stored in the ROM 1124. The processor 1110 may perform any suitable actions and processing by loading the program 1130 into the RAM 1122.

The embodiments of the present disclosure may be implemented by means of the program 1130 so that the device 1100 may perform any process of the disclosure as discussed with reference to Figs. 3A to 10. The embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

In some embodiments, the program 1130 may be tangibly contained in a computer readable medium which may be included in the device 1100 (such as in the memory 1120) or other storage devices that are accessible by the device 1100. The device 1100 may load the program 1130 from the computer readable medium to the RAM 1122 for execution. The computer readable medium may include any types of tangible non-volatile storage, such as ROM, EPROM, a flash memory, a hard disk, CD, DVD, and the like. FIG. 12 shows an example of the computer readable medium 1200 in form of CD or DVD. The computer readable medium has the program 1130 stored thereon.

Generally, various embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. While various aspects of embodiments of the present disclosure are illustrated and described as block diagrams, flowcharts, or using some other pictorial representations, it is to be understood that the block, apparatus, system, technique or method described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer readable storage medium. The computer program product includes computer-executable instructions, such as those included in program modules, being executed in a device on a target real or virtual processor, to carry out the methods 600-1000 as described above with reference to Figs. 6-10. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. Machine-executable instructions for program modules may be executed within a local or distributed device. In a distributed device, program modules may be located in both local and remote storage media.

Program code for carrying out methods of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the program codes, when executed by the processor or controller, cause the functions/operations specified in the flowcharts and/or block diagrams to be implemented. The program code may execute entirely on a machine, partly on the machine, as a stand-alone software package, partly on the machine and partly on a remote machine or entirely on the remote machine or server.

In the context of the present disclosure, the computer program codes or related data may be carried by any suitable carrier to enable the device, apparatus or processor to perform various processes and operations as described above. Examples of the carrier include a signal, computer readable medium, and the like.

The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable medium may include but not limited to an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the computer readable storage medium would include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM) , a read-only memory (ROM) , an erasable programmable read-only memory (EPROM or Flash memory) , an optical fiber, a portable compact disc read-only memory (CD-ROM) , an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

Further, while operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Likewise, while several specific implementation details are contained in the above discussions, these should not be construed as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to particular embodiments. Certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable sub-combination.

Although the present disclosure has been described in languages specific to structural features and/or methodological acts, it is to be understood that the present disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

A method of communication comprising:

monitoring, at a first device and from a second device, a first wake-up signal for a first mode of a discontinuous reception operation; and

in response to receiving the first wake-up signal with a wake-up indication, performing the discontinuous reception operation in a second mode of the discontinuous reception operation.
The method of claim 1, wherein performing the discontinuous reception operation in the second mode comprises:

determining from a first message whether a second mode of the discontinuous reception operation is to be started, the first message received from the second device; and

in accordance with a determination that the second mode is to be started, performing the discontinuous reception operation in the second mode.
The method of claim 2, further comprising:

in accordance with a determination from the first message that the second mode is not to be started, starting a first monitoring of a downlink control channel in the first mode; and

in accordance with a determination that a failure in the downlink control channel occurs, performing a second monitoring of a second wake-up signal for the second mode.
The method of claim 3, wherein performing the second monitoring comprises:

determining from a third message whether the second monitoring is to be started, the third message received from the second device; and

in accordance with a determination that the second monitoring is to be started, performing the second monitoring.
The method of claim 3, wherein performing the second monitoring comprises:

determining occasions for the second monitoring; and

determining whether the second wake-up signal is received at one of the occasions, and

the method further comprising:

in accordance with a determination that the second wake-up signal is received, stopping the second monitoring at the occasions; and

performing the discontinuous reception operation in the second mode.
The method of claim 5, wherein determining whether the second wake-up signal is received comprises at least one of:

monitoring, within a first timer, whether the second wake-up signal is received;

monitoring whether the second wake-up signal is received until the end of the first mode; and

monitoring whether the second wake-up signal is received until the second wake-up signal is received.
The method of claim 1, wherein performing the discontinuous reception operation in the second mode comprises:

starting a second timer for duration of the second mode; and

monitoring a downlink control channel until the second timer expires.
The method of claim 1, wherein the first mode is a long cycle of the discontinuous reception operation, and the second mode is a short cycle of the discontinuous reception operation, and

wherein the first device is a terminal device, and the second device is a network device.
A method of communication comprising:

monitoring, at a first device and from a second device, a first wake-up signal for a first mode of a discontinuous reception operation;

in the absence of the first wake-up signal, determining whether a first failure in a downlink control channel occurs; and

in accordance with a determination that the first failure occurs, performing a second monitoring of a second wake-up signal for a second mode of the discontinuous reception operation.
The method of claim 9, wherein performing the second monitoring comprises:

determining from a second message whether a first monitoring of a downlink control channel in the first mode is to be started, the second message received from the second device; and

in accordance with a determination from the second message that the first monitoring is not to be started, performing the second monitoring.
The method of claim 10, further comprising:

in accordance with a determination from the second message that the first monitoring is to be started, determining from a first message whether a second mode of the discontinuous reception operation is to be started, the first message received from the second device; and

in accordance with a determination that the second mode is to be started, performing the discontinuous reception operation in the second mode.
The method of claim 11, further comprising:

in accordance with a determination that the second mode is not to be started, starting a first monitoring of a downlink control channel in the first mode; and

in accordance with a determination that a second failure in the downlink control channel occurs, performing the second monitoring.
The method of any of claims 9-12, wherein performing the second monitoring comprises:

determining from a third message whether the second monitoring is to be started, the third message received from the second device; and

in accordance with a determination that the second monitoring is to be started, performing the second monitoring.
The method of any of claims 9-12, wherein performing the second monitoring comprises:

determining occasions for the second monitoring; and

determining whether the second wake-up signal is received at one of the occasions, and

the method further comprising:

in accordance with a determination that the second wake-up signal is received, stopping the second monitoring at the occasions; and

performing the discontinuous reception operation in the second mode.
The method of claim 14, wherein determining whether the second wake-up signal is received comprises at least one of:

monitoring, within a first timer, whether the second wake-up signal is received;

monitoring whether the second wake-up signal is received until the end of the first mode; and

monitoring whether the second wake-up signal is received until the second wake-up signal is received.
The method of claim 14, wherein performing the discontinuous reception operation in the second mode comprises:

starting a second timer for duration of the second mode; and

monitoring a downlink control channel until the second timer expires.
The method of claim 9, wherein the first mode is a long cycle of the discontinuous reception operation, and the second mode is a short cycle of the discontinuous reception operation, and

wherein the first device is a terminal device, and the second device is a network device.
A method of communication, comprising:

transmitting, at a second device and to a first device, a first wake-up signal for a first mode of a discontinuous reception operation for performance of the discontinuous reception operation in a second mode by the first device in response to receiving the first wake-up signal with a wake-up indication.
A method of communication, comprising:

transmitting, at a second device and to a first device, a first wake-up signal for a first mode of a discontinuous reception operation for performance of the discontinuous reception operation in a second mode by the first device in the absence of the first wake-up signal due to a failure in a downlink control channel.
The method of claim 18 or 19, further comprising at least one of:

transmitting, to the first device, a first message as to whether the second mode is to be started;

transmitting, to the first device, a second message as to whether a first monitoring of a downlink control channel in the first mode is to be started; and

transmitting, to the first device, a third message as to whether a second monitoring of a second wake-up signal for the second mode is to be started.
The method of claim 18 or 19, further comprising:

transmitting, to the first device, information about occasions for the second monitoring; and

transmitting, to the first device, the second wake-up signal at one of the occasions.
The method of claim 18 or 19, wherein the first mode is a long cycle of the discontinuous reception operation, and the second mode is a short cycle of the discontinuous reception operation, and

wherein the first device is a terminal device, and the second device is a network device.
A first device, comprising:

at least one processor; and

at least one memory including computer program codes;

the at least one memory and the computer program codes are configured to, with the at least one processor, cause the first device to perform the method according to any of claims 1 to 17.
A second device, comprising:

at least one processor; and

at least one memory including computer program codes;

the at least one memory and the computer program codes are configured to, with the at least one processor, cause the second device to perform the method according to any of claims 18 to 22.
An apparatus of communication comprising:

means for monitoring, at a first device and from a second device, a first wake-up signal for a first mode of a discontinuous reception operation; and

means for in response to receiving the first wake-up signal with a wake-up indication, performing the discontinuous reception operation in a second mode of the discontinuous reception operation.
An apparatus of communication comprising:

means for monitoring, at a first device and from a second device, a first wake-up signal for a first mode of a discontinuous reception operation;

means for in the absence of the first wake-up signal, determining whether a first failure in a downlink control channel occurs; and

means for in accordance with a determination that the first failure occurs, performing a second monitoring of a second wake-up signal for a second mode of the discontinuous reception operation.
An apparatus of communication, comprising:

means for transmitting, at a second device and to a first device, a first wake-up signal for a first mode of a discontinuous reception operation for performance of the discontinuous reception operation in a second mode by the first device in response to receiving the first wake-up signal with a wake-up indication.
An apparatus of communication, comprising:

means for transmitting, at a second device and to a first device, a first wake-up signal for a first mode of a discontinuous reception operation for performance of the discontinuous reception operation in a second mode by the first device in the absence of the first wake-up signal due to a failure in a downlink control channel.
A non-transitory computer readable medium comprising program instructions for causing an apparatus to perform the method according to any of claims 1 to 17.
A non-transitory computer readable medium comprising program instructions for causing an apparatus to perform the method according to any of claims 18 to 22.