CN114846855A

CN114846855A - Communication method, apparatus and computer readable medium

Info

Publication number: CN114846855A
Application number: CN202080006829.6A
Authority: CN
Inventors: 刘建国; 吴春丽; M·劳里德森; 陶涛
Original assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy
Current assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy
Priority date: 2020-07-24
Filing date: 2020-07-24
Publication date: 2022-08-02
Anticipated expiration: 2040-07-24
Also published as: CN114846855B; WO2022016543A1

Abstract

Embodiments of the present invention relate to a communication method, apparatus, and computer-readable storage medium. The second device transmits a first wake-up signal for a first mode of discontinuous reception operation to the first device. The first device listens for a first wake-up signal and, if the first wake-up signal with a wake-up indication is received, the first device performs discontinuous reception operation in the second mode. In this way, an efficient mechanism may be provided to better support the use of the second mode with low packet delay and low power consumption in both the licensed and unlicensed bands.

Description

Communication method, apparatus and computer readable medium

Technical Field

Embodiments of the present invention relate generally to the field of telecommunications, and more particularly, relate to a communication method, apparatus, and computer-readable storage medium for Discontinuous Reception (DRX) operation.

Background

Power saving of terminal devices has been a high concern. Generally, a DRX operation is performed to reduce a Physical Downlink Control Channel (PDCCH) listening that consumes a large amount of power. In a Radio Resource Control (RRC) connected mode, there are two types of DRX operation, i.e., short DRX cycle operation and long DRX cycle operation. If a long DRX cycle and a short DRX cycle are configured for the terminal device, the short DRX cycle is used after a DRX inactivity timer expires or a DRX command Medium Access Control (MAC) Control Element (CE) is received during an active time. Finally, the long DRX cycle is entered after the short DRX timer expires.

For unlicensed deployments, the network device may not be able to acquire a channel to transmit a Physical Downlink Shared Channel (PDSCH) and PDCCH for transmission of MAC CEs due to downlink Listen Before Talk (LBT) failure. In this case, the short DRX cycle cannot start, and thus traffic delay associated with the short DRX cycle will increase.

Disclosure of Invention

In general, example embodiments of the present invention provide schemes for DRX operation.

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

In a second aspect, a method of communication is provided. The method comprises the following steps: listening, at a first device, for a first wake-up signal of a first mode of discontinuous reception operation from a second device; determining whether a first failure occurs in a downlink control channel without a first wake-up signal; and performing a second listening for a second wake-up signal for a second mode of discontinuous reception operation if it is determined that the first failure occurs.

In a third aspect, a method of communication is provided. The method comprises the following steps: at the second device, a first wake-up signal for a first mode of discontinuous reception operation is transmitted to the first device to perform 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, a method of communication is provided. The method comprises the following steps: the method further includes transmitting, at the second device, a first wake-up signal for a first mode of discontinuous reception operation to the first device to perform the discontinuous reception operation in a second mode by the first device without the first wake-up signal due to a failure in a downlink control channel.

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

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

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

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

It should be understood that this summary is not intended to identify key or essential features of the embodiments of the disclosure, nor is it intended to limit the scope of the disclosure. Other features of the present disclosure will become readily apparent from the following description.

Drawings

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

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

fig. 2 illustrates a diagram of DRX operation according to a conventional scheme;

figure 3A shows a flow diagram illustrating a communication procedure for DRX operation according to some embodiments of the present disclosure;

figure 3B shows a flow diagram illustrating another communication procedure for DRX operation, in accordance with some embodiments of the present disclosure;

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

fig. 5 illustrates a diagram of another example DRX operation, according to an example embodiment of the present disclosure;

fig. 6 shows a flowchart of an example communication method implemented at a first device, according to an example embodiment of the present disclosure;

fig. 7 shows a flow diagram of another example communication method implemented at a first device, according to an example embodiment of the present disclosure;

fig. 8 shows a flow diagram of another example communication method implemented at a first device, according to an example embodiment of the present disclosure;

fig. 9 shows a flowchart of an example communication method implemented at a second device, according to an example embodiment of the present disclosure;

fig. 10 shows a flowchart of another example communication method implemented at a second device, according to an example embodiment of the present disclosure;

FIG. 11 shows a simplified block diagram of an apparatus suitable for implementing an example embodiment of the present disclosure; and

FIG. 12 shows a block diagram of an example computer-readable medium, according to an example embodiment of the present disclosure.

Throughout the drawings, the same or similar reference numerals denote the same or similar elements.

Detailed Description

The principles of the present disclosure will now be described with reference to a few exemplary embodiments. It is to be understood that these examples are described solely for the purpose of illustration and to assist those skilled in the art in understanding and practicing the invention, and are not intended to suggest any limitation as to the scope of the invention. The disclosure described herein may be implemented in a variety of ways other than those 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 skill in the art to which this invention belongs.

References in the specification to "one embodiment," "an example embodiment," etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include 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 will be understood that, although the terms first, 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 may be termed a second element, and, similarly, a second element may 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 items.

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," "contains" and/or "including," when used herein, specify the presence of stated features, elements, and/or components, but do not preclude the presence or addition of one or more other features, elements, components, and/or groups 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 (e.g., implementations in only analog and/or digital circuitry) and

(b) a combination of hardware circuitry and software, for example (as applicable):

(i) combinations of analog and/or digital hardware circuitry and software/firmware, and

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

(c) hardware circuitry and/or a processor, such as a microprocessor or a portion of a microprocessor, that requires software (e.g., firmware) for operation but may not be present when software is not required for operation.

This definition of circuitry applies to all uses of the term in this application, including all uses in any claims. As another example, as used in this application, the term circuitry also encompasses implementations in which only 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. For example, the term circuitry, if applicable to a particular claim element, also encompasses a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in a server, a cellular network device, or other computing or network device.

As used herein, the term "communication network" refers to a network that conforms to any suitable communication standard, such as Long Term Evolution (LTE), LTE-advanced (LTE-a), Wideband Code Division Multiple Access (WCDMA), High Speed Packet Access (HSPA), narrowband internet of things (NB-IoT), and so forth. Further, communication between terminal devices and network devices in the communication network may be performed according to any suitable generation communication protocol, including, but not limited to, first generation (1G), second generation (2G), 2.5G, 2.75G, third generation (3G), fourth generation (4G), 4.5G, future fifth generation (5G) communication protocols, and/or any other protocol currently known or to be developed in the future. Embodiments of the present invention may be applied to various communication systems. In view of the rapid development of communications, there will of course also be future types of communication techniques and systems in which the present invention may be implemented. And should not be construed as limiting the scope of the disclosure to only the above-described systems.

As used herein, the term "network device" refers to a node in a communication network through which a terminal device accesses the network and receives services therefrom. A network device may refer to a Base Station (BS) or an Access Point (AP), e.g., a NodeB (NodeB or NB), an evolved NodeB (eNodeB or eNB), an NR NB (also known as a gNB), a Remote Radio Unit (RRU), a Radio Head (RH), a Remote Radio Head (RRH), a relay, a low power node such as a femto cell (femto), pico cell (pico), etc., depending on the terminology and technology applied.

The term "terminal device" refers to any terminal device capable of wireless communication. By way of example, and not 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 devices may include, but are not limited to, mobile phones, cell phones, smart phones, voice over IP (VoIP) phones, wireless local loop phones, tablets, wearable terminal devices, Personal Digital Assistants (PDAs), portable computers, desktop computers, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback devices, in-vehicle wireless terminal devices, wireless endpoints, mobile stations, notebook embedded devices (LEEs), notebook installed devices (LMEs), USB dongles, smart devices, wireless client devices (CPEs), internet of things (IoT) devices, watches or other wearable devices, Head Mounted Displays (HMDs), vehicles, drones, medical devices and applications (e.g., tele-surgery), industrial devices and applications (e.g., robots and/or other wireless devices operating in an industrial and/or automated processing chain context), Consumer electronics devices, devices 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 may 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 should be understood that the number of first devices and second devices shown in fig. 1 is for illustrative purposes only and does not imply any limitation. Network 100 may include any suitable number of first and second devices suitable 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. Communications in network 100 may conform to any suitable standard including, but not limited to, LTE evolution, LTE-advanced (LTE-a), Wideband Code Division Multiple Access (WCDMA), Code Division Multiple Access (CDMA), global system for mobile communications (GSM), and the like. Further, the communication may be performed in accordance with any generation communication protocol currently known or developed in the future. Examples of communication protocols include, but are not limited to, first generation (1G), second generation (2G), 2.5G, 2.75G, third generation (3G), fourth generation (4G), 4.5G, and fifth generation (5G) communication protocols.

In general, the first device 110 needs to listen for a downlink control channel, e.g., PDCCH, from the second device 120. PDCCH monitoring consumes a lot of power at the first device 110. Accordingly, the first device 110 may be configured to perform DRX operation.

Assume that the first device 110 and the second device 120 are in an RRC connected state. In some embodiments, DRX operation may include two modes of operation, namely a long DRX cycle and a short DRX cycle. Some services, such as voice over Internet Protocol (IP), are characterized by: a period of regular transmission is followed by a period of no or little activation. To handle these services, the short DRX cycle may be optionally configured in addition to the long DRX cycle.

In a conventional scheme, a short DRX cycle is used after a DRX inactivity timer expires, and a long DRX cycle is entered after the short DRX timer expires. In this scheme, the terminal device will start the DRX inactivity timer only after the PDCCH indicates a PDCCH occasion for a new uplink or downlink transmission, and will then start the DRX short cycle timer in the first symbol after the DRX inactivity timer expires.

In another conventional scheme, a short DRX cycle is used when a DRX command MAC CE is received during an active time (e.g., when a DRX active period or a DRX inactivity timer is running), and a long DRX cycle is entered after the short DRX timer is exhausted. In this case, the terminal device needs to monitor the PDCCH during the active time of the long DRX cycle and check whether it receives a DRX command MAC CE from the network device. If a DRX command MAC-CE is received, the terminal equipment starts a DRX short cycle timer in the first symbol after the DRX command MAC CE is received.

For unlicensed spectrum access, LBT operations need to be performed prior to transmission in the unlicensed band, according to regulatory requirements in certain regions, to achieve coexistence fairness with other Radio Access Technologies (RATs), such as unlicensed (NR-U) of new radios/Licensed Assisted Access (LAA)/Wi-Fi. To this end, a channel should be considered occupied if other Radio Local Area Network (RLAN) transmissions are detected at a power level greater than a maximum Energy Detection (ED) threshold. In release 16NR-U, if a network device needs to access a channel for downlink transmission, the downlink channel access procedure defined in TS 37.213 should be followed. In this case, for an unlicensed deployment, the network device may not be able to acquire a channel to transmit PDCCH and PDSCH for transmission of MAC CEs due to downlink LBT failure.

For example, in existing mechanisms, a wake-up signal (WUS) is provided to the terminal device via the PDCCH prior to the DRX active period of the long DRX cycle. WUS is also referred to as Downlink Control Information (DCI) based power save signal (DCI with Cyclic Redundancy Check (CRC) scrambled by a power save radio network temporary identifier (PS-RNTI), also referred to as DCP). In a basic implementation, if the wake-up indication bit for the WUS is 1, the terminal device will wake up and monitor the PDCCH during the active period, and if the wake-up indication bit is 0, the terminal device will not wake up. If no DCP is detected, a ps wakeup bit may be defined to control whether the end device wakes up. It is agreed in the standardization process that the terminal device does not monitor DCP during active time and WUS is only adapted to monitor DRX on periods belonging to long DRX cycles.

In this case, the DCP is configured only for the long DRX cycle. Assume that the terminal device is configured to monitor the DCP before the long DRX cycle to determine whether to wake up. If the terminal device does not detect the DCP due to downlink LBT failure and the ps-Wakeup bit indicates that the terminal device is not awake, the terminal device will not wake up to monitor the PDCCH during DRX valid periods. In this case, the terminal device will further not start the DRX short cycle timer for use of the short DRX cycle, since neither the DRX inactivity timer expires nor the DRX command MAC-CE is not transmitted.

An example is described below with reference to fig. 2. Fig. 2 illustrates a diagram 200 of DRX operation according to a conventional scheme. In this example, the terminal device is configured with both short and long DRX cycles. Assume that a DRX inactivity timer (denoted as DRX inactivity timer) is set to 3 slots, an active period timer (denoted as onDurationTimer) is set to 2 slots, a short DRX cycle (denoted as shortdrx cycle) is set to 5 slots, a long DRX cycle (denoted as longdrx cycle) is set to 10 slots, a start offset (denoted as drxstartoffset) of the short DRX cycle is set to 0, and a short DRX cycle timer (denoted as drxShortCycleTimer) is set to 3 slots. Further, assume that the symbol "S" indicates success of LBT of WUS, the symbol "I" indicates invalidity of LBT of WUS, and the symbol "F" indicates failure of LBT of WUS.

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

On the other hand, since LBT needs to be performed before transmission, even if the network device sends WUS before the long DRX cycle, it may still be impossible to acquire a channel to transmit PDCCH during the active period of the long DRX cycle. If the terminal device does not receive a PDCCH indicating a new uplink or downlink transmission or a DRX command MAC-CE, the terminal device does not start a DRX short cycle timer to use a short DRX cycle. If the short DRX cycle is configured but cannot be used due to LBT, it is apparent that the traffic delay associated with the short DRX cycle will increase.

As a solution in release 16NR, if the terminal device does not detect DCP outside the activation time, a ps-Wakeup bit may be defined to control whether the terminal device wakes up. If the ps-Wakeup bit indicates the wake-up of the terminal device and a DCP associated with a long DRX cycle has not been received, the terminal device will start a DRX active period timer after a DRX slot offset from the beginning of the subframe. Otherwise, the terminal device will skip PDCCH monitoring for the current DRX cycle to save power. For unlicensed deployments, the ps-Wakeup bit may be defined to wake up the terminal device to monitor PDCCH during the active time of the long DRX cycle, even if the network device is prevented from WUS transmission due to downlink LBT failure before the long DRX cycle.

This scheme may also result in additional power consumption, since the terminal device needs to monitor the PDCCH during the active time of the long DRX cycle even if the terminal device is not scheduled by the network device. Furthermore, even if the network device does not schedule the terminal device, the network device needs to send a WUS to inform the terminal device not to wake up, which introduces additional downlink resource overhead. Therefore, the network device does not want to configure the ps-Wakeup bit for DRX operation. As a result, if the network device cannot acquire a channel to transmit PDCCH during the active time of the long DRX cycle due to downlink LBT failure, the terminal device still cannot use the short DRX cycle.

To address the above and other potential problems, embodiments of the present invention provide an improved scheme for communication for DRX operation. For convenience, the long DRX cycle is also referred to as a first mode of DRX operation, and the short DRX cycle is also referred to as a second mode of DRX operation. According to one aspect of an embodiment of the invention, if a WUS for a first mode (also referred to herein as a first WUS for convenience) is received and the WUS includes a wake-up indication, a second mode will be started. In some embodiments, a message (also referred to herein as a first message for convenience) may be introduced indicating whether the second mode is to be started. This aspect applies to both licensed and unlicensed bands, or whether such behavior applies may be explicitly configurable.

According to another aspect of embodiments of the present disclosure, if a first WUS for a first mode is not received at a monitoring opportunity, or a PDCCH is not received during a valid period of the first mode after the WUS is received, monitoring (for convenience, also referred to herein as second monitoring) of a WUS for a second mode (also referred to herein as second WUS) will be initiated if 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 may be designated or configured to skip further listening for the second mode. In some embodiments, a message (also referred to herein as a third message for convenience) may be introduced indicating whether or not to initiate the second listening. This aspect may be applicable to unlicensed frequency bands or may be explicitly configurable.

Accordingly, an efficient mechanism may be provided to better support short DRX cycles with low latency and low power consumption in both licensed and unlicensed bands. In this way, the short DRX cycle is enabled when transmission of the WUS or PDCCH associated with the long DRX cycle is prevented due to a failure in the downlink channel (e.g., downlink LBT failure).

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

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

1) a first message (e.g., also referred to herein as a ps-ShortCycle-WakeUp message) regarding whether the second mode is to be initiated. In some embodiments, the first message may include an indication bit. The value of the indication bit may be arbitrarily set.

2) A second message (e.g., also referred to herein as a ps-Wakeup bit) regarding whether the first device 110 is awake in the first mode. In other words, it indicates whether a first listening to the downlink control channel in the first mode is to be initiated without WUS.

3) A third message (e.g., also referred to herein as a ps-ShortCycle-WusMonitor message) regarding whether to listen for a second listen of the second WUS. In some embodiments, the third message may include an indication bit. The value of the indication bit may be arbitrarily set.

4) Information regarding the timing of listening to the second WUS (e.g., also referred to herein as a search space set configuration for short DRX cycles), which indicates the timing of WUS listening for short DRX cycles.

Fig. 3A shows a flowchart 301 illustrating a communication procedure for DRX operation according to some embodiments of the present disclosure. For convenience, the following description will be made in 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 DRX operation to the first device 110. In some embodiments, the first WUS may instruct the first device 110 to wake up. Alternatively, the first WUS may indicate not to wake up the first device 110. For example, the first WUS may include an indication bit. In some embodiments, if the indication bit is 1, the first device 110 is indicated to wake up, and if the indication bit is 0, the first device 110 is indicated not to wake up. Of course, an indication bit of 1 may also be used to indicate that the first device 110 is not awake, and an indication bit of 0 may also be used to indicate that the first device 110 is awake. This is not limited by the present application.

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

The first device 110 listens 303 for the first WUS for the first mode. Assume that the first device 110 receives a first WUS. In some embodiments, if the first device 110 receives a first WUS with a non-awake indication, the first device 110 may continue listening for the first WUS.

If the first device 110 receives 304 a first WUS with a wake-up indication, the terminal device 120 performs 306 a DRX operation in a second mode of DRX operation. That is, a short DRX cycle is used. In some embodiments, the first device 110 may also start a DRX valid period timer for the first mode upon receiving the first WUS with the wake-up indication. 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 to initiate a second mode of DRX operation, and if it is determined that the second mode is to be initiated, the terminal device 120 may perform 306DRX operation in the second mode.

In some embodiments, when 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 the 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 a short period timer after an offset from the beginning of the subframe (denoted herein as drx-StartOffset). For example, drx-StartOffset ═ [ (SFN × 10) + subframe number ] mod (drx-LongCycle), where SFN represents a system frame number and drx-LongCycle represents the length of the first mode. In some embodiments, a short period timer may be started after the WUS is received. In some embodiments, the short cycle timer may be started after the WUS is received, after the validity period timer is started. Of course, this is merely an example and any other suitable means for initiating the short DRX cycle is possible.

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

If it is determined from the first message that the second mode is not to be activated, the first device 110 may initiate 307 a first listening in the first mode. In some embodiments, the first device 110 may start a DRX active period timer for the first mode and listen to a downlink control channel during active times of the first mode.

During the active period 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 may acquire the channel during the active time of the first mode. In some embodiments, the first device 110 may perform transmission detection in the unlicensed frequency band based on a downlink reference signal, such as a demodulation reference signal (DMRS) or other reference signal. In some alternative embodiments, the first device 110 may perform transmission detection in the unlicensed frequency band based on DCI such as a Group Common (GC) -PDCCH or a UE-specific PDCCH.

In some embodiments, if the first device 110 determines that the second device 120 obtains a channel for transmission during the active time of the first mode, the first device 110 may perform DRX operation based on existing procedures in release 16 NR. For example, the first device 110 may start a DRX inactivity timer after the PDCCH indicates a PDCCH occasion for a new downlink transmission or uplink transmission, and may start using the second mode when the DRX inactivity timer expires. Alternatively, the first device 110 may monitor the PDCCH during the active time of the first mode, and if the first device 110 receives the DRX command MAC CE from the second device 120, the first device 110 may start using the second mode in the first symbol after the DRX command MAC CE reception ends. Other details are omitted herein to avoid obscuring the disclosure.

In some embodiments, if the first device 110 determines that the downlink control channel is blocked due to a failure in the downlink control channel during the active period of the first mode, the first device 110 may determine 308 from the third message whether to initiate a second listening to a second WUS for the second mode.

In some embodiments, the first device 110 may initiate 309 a second listen if it is determined from the third message that the second listen is to be initiated. In some embodiments, the first device 110 may determine an opportunity for the second listen. For example, the first device 110 may receive information about the occasion via higher layer RRC signaling and determine the occasion according to the information. In some embodiments, the information may include a value of a configured timer. In some embodiments, the first device 110 may listen for the second WUS within a configured timer. In some alternative embodiments, the first device 110 may listen for the second WUS until the next long period. In some alternative embodiments, the first device 110 may listen for the second WUS until the second WUS is received.

The second device 120 may transmit 310 a second WUS at the opportunity. The first device 110 may determine 311 whether the second WUS is received at one of the opportunities for the second listen. If it is determined that a second WUS is received at one of the opportunities, the first device 110 may cease 312 the second listening at the opportunity. In this way, power savings at the first device 110 are achieved by associating WUS listening at one occasion with multiple short DRX cycles. The first device 110 may then perform 313DRX operation in the second mode. The operation shown at 313 is similar to that shown at 306, and therefore the details thereof are omitted here.

In some embodiments, if it is determined that the second WUS is not received at these occasions, the first device 110 may return to listen for the first WUS for the first mode. The first device 110 may also return to listen to the first WUS for the first mode if it is determined from the third message that the second listening is not initiated. That is, the first device 110 may skip further listening for the short DRX cycle until the 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 an example embodiment of the present disclosure. Assuming that the first device 110 may detect the first WUS before the long DRX cycle, but does not monitor for transmissions from the second device 120, e.g., due to downlink LBT failure during the active time of the long DRX cycle, or if the first device 110 does not detect the first WUS before the long DRX cycle, e.g., due to LBT failure, the first device 110 will be triggered to monitor the second WUS for the short DRX cycle until the next long DRX cycle.

In this example, assume that a DRX inactivity timer (denoted as DRX-inactivity timer) is set to 3 slots, an active duration timer (denoted as onDurationTimer) is set to 2 slots, a short DRX cycle (denoted as shortdrx cycle) is set to 5 slots, a long DRX cycle (denoted as longdrx cycle) is set to 20 slots, a start offset (denoted as drxstartoffset) of the short DRX cycle is set to 0, and a short DRX cycle timer (denoted as drxShortCycleTimer) is set to 3 slots. Further, assume that ps-ShortDrxCycle-WakeUp is configured to "FALSE", which means that the first device 110 is not awake, and assume that ps-ShortDrxCycle-WusMonitor is configured to "tune", which means that a second listen is to be initiated for the second WUS. In addition, it is assumed that the symbol "x" for WUS indicates that WUS is not detected, and the symbol "√" for WUS indicates that WUS is detected. Assume that the symbol "x" for drx-OnDurationTimer indicates that the OnDurationTimer is not started, and the symbol "√ for drx-OnDurationTimer indicates that the OnDurationTimer is started.

As shown in fig. 4, after detecting the second WUS in slot #9 of SFN #0, the first device 110 will stop the second listening for the short DRX cycle and start a short cycle timer with a period of 2 short DRX cycles after DCP reception, denoted as DRX-ShortCycleTimerWus and shown as 401, and then listen during the active period of the short DRX cycle until the short cycle timer expires at the end of SFN # 1. It should be noted that the above-mentioned value in this example is only an example and does not limit the present disclosure.

It should be noted that the acts illustrated in fig. 3A are not always necessary to implement embodiments of the present disclosure, and that more or fewer acts may be adjusted as desired. With the process in fig. 3A, an efficient mechanism can be provided to better support short DRX cycles with low packet delay and low power consumption in both licensed and unlicensed bands, in case WUS for long DRX cycles is received.

Fig. 3B shows a flowchart 301 illustrating another communication procedure for DRX operation according to some embodiments of the present disclosure. For convenience, the following description will be made in 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 DRX operation to the first device 110. The operation shown by 320 is similar to that shown by 301 in fig. 3A, and thus the details thereof are omitted here. In some embodiments, the second device 120 may also send 321 any of the messages and information listed above to the first device 110. The operation shown by 321 is similar to that shown by 302 in fig. 3A, and therefore the details thereof are also omitted here.

The first device 110 listens 322 to the first WUS for the first mode. Assume 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 of a downlink control channel (also referred to herein as a first failure for convenience). If it is determined that the first WUS is blocked due to the first failure, the first device 110 performs 327 a second listening to the second WUS for a second mode of DRX operation.

In some embodiments, the first device 110 may determine 324 from the second message whether to initiate a first listening to the downlink control channel in the first mode. If it is determined from the second message that the first listening is to be initiated, the first device 110 may perform 325DRX operation in the second mode. Thus, a short cycle time is used. In some embodiments, after determining to initiate the first listening, the first device 110 may determine from the first message whether to initiate the second mode. If it is determined that the second mode is to be initiated, the first device 110 may perform 325DRX operation in the second mode. If it is determined that the second mode is not to be initiated, the first device 110 may operate in a similar process as shown in 307-. For the sake of brevity, details thereof are not repeated here.

In some embodiments, the first device 110 may perform 327 a second snoop for the second WUS if it is determined from the second message that the first snoop is not initiated. In some embodiments, upon determining not to initiate the first listening, the first device 110 may determine 326 from the third message whether to initiate the second listening. If it is determined that a second snoop is to be initiated, the first device 110 may perform 327 the second snoop.

In some embodiments, the first device 110 may determine an opportunity for the second listen. For example, the first device 110 may receive information about the occasion via higher layer RRC signaling and determine the occasion according to the information. In some embodiments, the information may include a value of a configured timer. In some embodiments, the first device 110 may listen for the second WUS within a configured timer. In some alternative embodiments, the first device 110 may listen for the second WUS until the next long period. In some alternative embodiments, the first device 110 may listen for the second WUS until the second WUS is received.

The second device 120 may transmit 328 the second WUS at the opportunity. The first device 110 may determine 329 whether the second WUS is received at one of the opportunities for the second listen. If it is determined that a second WUS is received at one of the opportunities, the first device 110 may cease 330 the second listening at the opportunity. In this way, power savings at the first device 110 are achieved by associating one opportunity of WUS listening with multiple short DRX cycles. The first device 110 may then perform 331DRX operation in the second mode. The operation shown by 331 is similar to that shown by 306 in fig. 3A, and therefore, for the sake of brevity, details thereof are omitted here.

In some embodiments, if it is determined that the second WUS is not received at these occasions, the first device 110 may return to listen for the first WUS for the first mode. The first device 110 may also return to listen for the first WUS for the first mode if it is determined from the third message that the second listen is not initiated. That is, the first device 110 may skip further monitoring for the short DRX cycle until the next long DRX cycle occurs. The operations illustrated by 327-.

An example is described below with reference to fig. 5. Fig. 5 illustrates a diagram 500 of another example DRX operation in accordance with an example embodiment of the present disclosure. Assume that the first device 110 does not detect the first WUS before the long DRX cycle, but the second message indicates that the first listening is to be initiated. In this example, assume that a DRX inactivity timer (denoted as DRX-inactivity timer) is set to 3 slots, an active duration timer (denoted as onDurationTimer) is set to 2 slots, a short DRX cycle (denoted as shortdrx cycle) is set to 5 slots, a long DRX cycle (denoted as longdrx cycle) is set to 20 slots, a start offset (denoted as drxstartoffset) of the short DRX cycle is set to 0, and a short DRX cycle timer (denoted as drxShortCycleTimer) is set to 3 slots. Further, assume that ps-ShortDrxCycle-WakeUp is configured as "TRUE", which means that the first device 110 wakes up. Further, assume that the symbol "x" indicates that the first WUS is not detected, and the symbol "√" indicates the start of a short DRX cycle.

As shown in fig. 5, in case that ps-ShortDrxCycle-WakeUp (i.e., the first message) indicates the start of the second mode, the first device 110 may start DRX-ShortCycleTimer at a period of 3 short DRX cycles from the start of the active period for the long DRX cycle (i.e., slot #0 of SFN #0), as shown in 501. It should be noted that the above-described value in the present embodiment is merely an example, and does not limit the present disclosure.

It should be noted that the acts illustrated in fig. 3B are not always necessary to implement embodiments of the present disclosure, and that more or fewer acts may be adjusted as desired. With the process in fig. 3B, another efficient mechanism may be provided to better support short DRX cycles with low latency and power consumption in both the licensed and unlicensed bands without receiving WUS for long DRX cycles. Of course, in some alternative embodiments, the processes in fig. 3A and 3B may also be combined in any suitable manner to enable control of DRX operation.

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

Fig. 6 shows a flow diagram of a communication method 600 implemented at a first device, according to an example embodiment of the present disclosure. The method 600 may be implemented at the first device 110 shown in fig. 1. For discussion purposes, the method 600 will be described with reference to fig. 1. It should be understood that method 600 may also include additional blocks not shown and/or omit some of the blocks shown, and the scope of the present disclosure is not limited in this respect.

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

In some embodiments, the first WUS may include a wake indication, i.e., the first device 110 wakes up. In these embodiments, the first device 110 may start the DRX valid period timer for the first mode. In this way, the first mode is used, i.e. the long DRX cycle is started. After receiving the first WUS with the wake indication, the process proceeds to block 630. At block 630, the first device 110 performs DRX operation in the second mode. In some embodiments, the first device 110 starts a timer (also referred to herein as the second timer for convenience) for a period of the second mode. For example, the timer is a ShortCycleTimer as described above. The first device 110 may then monitor a downlink control channel (e.g., PDCCH) until the second timer expires. In this way, one or more short DRX cycles may be initiated.

In some alternative embodiments, the first device 110 may start a short period timer after an offset from the beginning of the subframe (denoted as drx-StartOffset). For example, drx-StartOffset ═ [ (SFN × 10) + subframe number ] mod (drx-LongCycle), where SFN represents a system frame number and drx-LongCycle represents the length of the first mode. In some embodiments, a short period timer may be started after the WUS is received. In some embodiments, the short cycle timer may be started after the WUS is received, after the validity period timer is started. Of course, this is merely an example and any other suitable means for initiating the short DRX cycle is possible.

In some embodiments for block 630, the first device 110 may determine from the first message (e.g., the ps-ShortCycle-WakeUp message) whether to initiate the second mode of DRX operation. In these embodiments, the first message is received from the second device 120 and indicates whether the second mode is to be initiated. In some embodiments, the first message may include an indication bit. A first value of the indication bit may indicate that the second mode is to be enabled and a second value of the indication bit may indicate that the second mode is not to be enabled. The first value and the second value may be arbitrarily set. If it is determined that the second mode is to be initiated, the first device 110 may perform a DRX operation in the second mode. Thus, the short DRX cycle will be forcibly used.

In some embodiments, the first device 110 may initiate a first listening to the downlink control channel in the first mode if it is determined that the second mode is not initiated. For example, the first device 110 may monitor the PDCCH in the first mode. In some embodiments, the first device 110 may perform transmission detection of the second device 120 to determine whether the second device 120 may acquire the channel during the activation time of the first mode. In some embodiments, the first device 110 may perform transmission detection in the unlicensed frequency band based on a downlink reference signal, such as a DMRS. In some alternative embodiments, the first device 110 may perform transmission detection in the unlicensed frequency band based on DCI such as a GC-PDCCH or a UE-specific PDCCH.

If it is determined that the downlink control channel is not blocked but the second device 120 is not transmitting the DCP, the first device 110 may skip listening for the second WUS for the second mode and continue listening for the first WUS for the first mode. In this case, the short DRX cycle is not used. The first device 110 may perform the second listening if it is determined that the failure occurs in the downlink control channel.

In some embodiments, first device 110 may determine from the third message (e.g., the ps-ShortCycle-WusMonitor message) whether to initiate the second listen. In some embodiments, the third message is received from the second device 120 by any suitable means. If it is determined from the third message that the second listening is not initiated, the first device 110 may return to listen to the first WUS. The first device 110 may perform the second listening if it is determined from the third message that the second listening is to be initiated.

If it is determined that a second WUS is received at one of the opportunities, the first device 110 may cease 330 second listening at those opportunities. In this way, power savings at the first device 110 are achieved by associating one opportunity of WUS listening with multiple short DRX cycles. The first device 110 may then perform DRX operation in the second mode, as described with reference to block 630. Thus, a short DRX cycle is used.

With the scheme of fig. 6, an enhanced DRX mechanism is provided to better support short DRX cycles with low latency and low power consumption in both licensed and unlicensed bands, in case WUS is received for long DRX cycles. Thus, the use of a short DRX cycle is enabled when transmission of a PDCCH associated with a long DRX cycle is prevented due to a failure in the downlink control channel, e.g., an LBT failure.

Fig. 7 shows a flow diagram of another method 700 of communication implemented at a first device, according to an example embodiment of the present disclosure. The method 700 may be implemented at the first device 110 shown in fig. 1. For purposes of discussion, the method 700 will be described with reference to fig. 1. It should be understood that method 700 may also include additional blocks not shown and/or omit some of the blocks shown, and the scope of the present disclosure is not limited in this respect.

As shown in fig. 7, at block 710, the first device 110 listens to a first WUS for a first mode of DRX operation. In some embodiments, the first device 110 may listen to 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 (also referred to as a first failure for convenience) in the downlink channel.

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

If it is determined that the first WUS is not blocked but the second device 120 does not transmit the first WUS, the first device 110 may continue listening for the first WUS for the first mode. In this case, the short DRX cycle is not used. If it is determined that the first failure occurs, i.e., the first WUS is blocked due to the first failure, the first device 110 performs a second listening to a second WUS, which is a second mode for DRX operation, at block 730.

In some embodiments, the first device 110 may determine an opportunity for the second listen. For example, the first device 110 may receive information about the occasion via higher layer RRC signaling and determine the occasion according to the information. In some embodiments, this information may include the value of the configured timer (also referred to herein as the first timer for convenience). In some embodiments, the first device 110 may listen for the second WUS within a configured timer. In some alternative embodiments, the first device 110 may listen for the second WUS until the next long period. In some alternative embodiments, the first device 110 may listen for the second WUS until the second WUS is received.

In some embodiments, if it is determined that a second WUS is received at one of the opportunities, the first device 110 may stop the second listening at the opportunity. In this way, power savings for the first device 110 are improved by associating WUS listening at one opportunity with multiple short DRX cycles. The first device 110 may then perform DRX operation in the second mode. Thus, a short DRX cycle is used.

In some embodiments, the first device 110 may start a timer (also referred to herein as a second timer for convenience) for a period of the second mode. For example, the timer is a ShortCycleTimer as described above. The first device 110 may then monitor a downlink control channel (e.g., PDCCH) until the second timer expires. In this way, one or more short DRX cycles may be initiated. In some alternative embodiments, the first device 110 may start the second timer after an offset from the beginning of the subframe (denoted drx StartOffset). For example, drx-StartOffset ═ [ (SFN × 10) + subframe number ] mod (drx-LongCycle), where SFN represents a system frame number and drx-LongCycle represents the length of the first mode. In some embodiments, a short period timer may be started after the WUS is received. In some embodiments, the short cycle timer may be started after the WUS is received, after the validity period timer is started. Of course, this is merely an example and any other suitable means for initiating the short DRX cycle is possible.

With the scheme of fig. 7, an enhanced DRX mechanism is provided to better support short DRX cycles with low latency and low power consumption in both licensed and unlicensed bands without receiving WUS for long DRX cycles. Thus, the use of a short DRX cycle is enabled when transmission of a WUS associated with a long DRX cycle is prevented due to a failure in the downlink channel, e.g., an LBT failure.

Fig. 8 shows a flow diagram of another method 800 of communication implemented at a first device, according to an example embodiment of the present disclosure. The method 800 may be implemented at the first device 110 shown in fig. 1. For discussion purposes, the method 800 will be described with reference to fig. 1. It should be understood that method 800 may also include additional blocks not shown and/or omit some of the blocks shown, and the scope of the present disclosure is not limited in this respect. This describes a scheme combining the schemes of fig. 6 and 7. It should be noted that this is only an example and does not limit the disclosure. The schemes described with reference to fig. 6 and 7 may be used alone or in combination to support the use of the short DRX cycle. Although this combination is described in connection with fig. 8, it may be performed in any other suitable manner and is not limited to the manner 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., a long DRX cycle) is received from the second device 120. If the first device 110 receives the first WUS, the process passes to block 802. At block 802, the first device 110 may determine whether the first WUS includes a wake-up indication. If it is determined that the first WUS includes a non-wake indication, the first device 110 will continue to listen for the first WUS. If it is determined that the first WUS includes a wake-up indication, the first device 110 may start a DRX valid period 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 (e.g., the ps-ShortCycle-WakeUp message) whether to initiate the second mode of DRX operation (i.e., the short DRX cycle). In some embodiments, the first message is received from the second device 120 by any suitable means. If it is determined that the second mode is to be initiated, the first device 110 may perform DRX operation in the second mode at block 804. Thus, a short DRX cycle will be used. In some embodiments, the first device 110 may start a timer (e.g., ShortCycleTimer, also referred to as a second timer for convenience) for a period of the second mode and monitor a downlink control channel, such as the 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 the downlink channel. In some embodiments, the first device 110 may perform transmission detection of the second device 120 to determine whether the second device 120 may acquire the channel during the activation time of the first mode. In some embodiments, the first device 110 may perform transmission detection in the unlicensed frequency band based on a downlink reference signal, such as a DMRS. In some alternative embodiments, the first device 110 may perform transmission detection in the unlicensed frequency band based on DCI such as a GC-PDCCH or a UE-specific PDCCH.

If it is determined in 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 listening for the first WUS for the first mode. In this case, the short DRX cycle is not used. If a first failure is determined to have occurred, i.e., the first WUS is blocked due to the first failure, the process passes to block 806.

At block 806, the first device 110 may determine whether to initiate first listening to the downlink control channel based on the second message (e.g., the ps-Wakeup bit). In some embodiments, the second message is received from the second device 120 by any suitable means. The first device 110 may also start a DRX valid period timer for the long DRX cycle if it is determined to start the first listening, and the process proceeds to block 803. If it is determined that the first snoop is not to be initiated, the process proceeds to block 809, which will be described later.

If it is determined at block 803 that the second mode is not enabled, the process proceeds to block 807. At block 807, the first device 110 may initiate a first listening to a downlink control channel (e.g., PDCCH) in a first mode. In some embodiments, the first device 110 may perform transmission detection of the second device 120 to determine whether the second device 120 may acquire the channel during the activation time of the first mode. In some embodiments, the first device 110 may perform transmission detection in the unlicensed frequency band based on a downlink reference signal, such as a DMRS. In some alternative embodiments, the first device 110 may perform transmission detection in the unlicensed frequency band based on DCI such as a GC-PDCCH or a 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 the downlink control channel was not detected, i.e., the second device 120 acquired a channel for transmission during the active period of the first mode, the process proceeds to block 814. At block 814, the first device 110 may perform DRX operation based on existing procedures in release 16 NR. For example, the first device 110 may start a DRX inactivity timer after the PDCCH indicates a PDCCH occasion for a new downlink or uplink transmission, and may begin use of the second mode after the DRX inactivity timer expires. Alternatively, the first device 110 may monitor the PDCCH during the active time of the first mode, and if the first device 110 receives the 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 DRX command MAC CE reception ends. Other details are omitted herein to avoid obscuring the disclosure.

If the first device 110 determines at block 808 that a second failure is detected, e.g., a downlink LBT failure is detected during the active period of the first mode, the process proceeds to block 809. At block 809, the first device 110 may determine from the third message (e.g., the ps-ShortCycle-WusMonitor message) whether to initiate a second listen for a second WUS in the second mode. In some embodiments, the third message is received from the second device 120 by any suitable means. If it is determined from the third message that the second listen is not to be initiated, the first device 110 may return to listen to the first WUS at block 801.

If it is determined from the third message that a second snoop is to be initiated, the process passes to block 810. At block 810, the first device 110 may perform a second listen. In some embodiments, the first device 110 may determine an opportunity for the second listen. For example, the first device 110 may receive information about the occasion via higher layer RRC signaling and determine the occasion according to the information. In some embodiments, this information may include the value of the configured timer (also referred to herein as the first timer for convenience). In some embodiments, the first device 110 may listen for the second WUS within a configured timer. In some alternative embodiments, the first device 110 may listen for the second WUS until the next long period. In some alternative embodiments, the first device 110 may listen for the second WUS until the second WUS is received.

At block 811, the first device 110 may determine whether the second WUS was received at one of the opportunities for second listening. If it is determined at block 812 that a second WUS is received at one of the opportunities, the first device 110 may cease the second listening at that opportunity. In this way, power savings at the first device 110 are improved by associating WUS listening at one occasion with multiple short DRX cycles. The process then proceeds to block 804 where the first device 110 performs DRX operation in the second mode as described above. Thus, a short DRX cycle is used.

With the scheme of fig. 8, an enhanced DRX mechanism is provided to better support short DRX cycles with low delay and low power consumption in both licensed and unlicensed bands, which enables the use of short DRX cycles when the transmission of WUS or PDCCH associated with a long DRX cycle is blocked due to a failure in the downlink channel.

Fig. 9 shows a flow chart of a communication method 900 implemented at a second device according to an example embodiment of the present disclosure. The method 900 may be implemented at the second device 120 shown in fig. 1. For discussion purposes, the method 900 will be described with reference to fig. 1. It should be understood that method 900 may also include additional blocks not shown and/or omit some of the blocks shown, and the scope of the present disclosure is not limited in this respect.

As shown in fig. 9, at block 910, the second device 120 transmits a first WUS for a first mode of DRX operation to the first device 110 to perform 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 send a first message (e.g., a ps-ShortCycle-WakeUp message) to the first device 110 regarding whether to initiate the second mode of DRX operation. In some embodiments, the second device 120 may transmit the first message through the DCP associated with the first WUS. In some embodiments, the second device 120 may send the first message separately from the first WUS via higher layer RRC signaling. It should be noted that the transmission of the first WUS and the first message is not limited by the present application.

In some embodiments, the second device 120 may send a second message (e.g., a ps-Wakeup bit) to the first device 110 regarding whether to initiate a first listening to the downlink control channel in the first mode. In some embodiments, the second device 120 may send the second message via higher layer RRC signaling. In some embodiments, second device 120 may send the second message via lower layer physical signaling. It should be noted that the present application does not limit the transmission of the second message.

In some embodiments, second device 120 may send a third message (e.g., a ps-ShortCycle-WusMonitor message) to first device 110 regarding whether to initiate a second listen for a second wake-up signal for the second mode. In some embodiments, the second device 120 may send the third message via higher layer RRC signaling. In some embodiments, the second device 120 may send the third message via lower layer physical signaling. It should be noted that the present application does not limit the transmission of the third message.

In some embodiments, the second device 120 may send information to the first device 110 regarding occasions for the second listening (e.g., search space set configuration for short DRX cycle) and send a second wake-up signal to the first device 110 at one of the occasions. In some embodiments, the second device 120 may send information about these occasions via higher layer RRC signaling. It should be noted that the present application is not limited to the transmission of this information.

By configuring messages and information for controlling the use of the short DRX cycle, an efficient mechanism may be provided to control the use of the short DRX cycle when transmission of the WUS or PDCCH associated with the long DRX cycle is prevented due to a failure in the downlink control channel. Therefore, the short DRX cycle is better supported with low packet delay and low power consumption in the licensed and unlicensed bands.

Fig. 10 shows a flowchart of a method 1000 of communication implemented at a second device, according to an example embodiment of the present disclosure. The method 1000 may be implemented at the second device 120 shown in fig. 1. For purposes of discussion, the method 1000 will be described with reference to fig. 1. It should be understood that method 1000 may also include additional blocks not shown and/or omit some of the blocks shown, and the scope of the present disclosure is not limited in this respect.

As shown in fig. 10, at block 1010, the second device 120 transmits a first WUS for a first mode of DRX operation to the first device 110 to perform DRX operation in a second mode by the first device 110 without the first WUS due to a failure in a downlink channel. In some embodiments, the second device 120 may also send a first message (e.g., a ps-ShortCycle-WakeUp message) to the first device 110 regarding whether to initiate the second mode of DRX operation. In some embodiments, the second device 120 may transmit the first message through the DCP associated with the first WUS. In some embodiments, the second device 120 may send the first message separately from the first WUS via higher layer RRC signaling. It should be noted that the transmission of the first WUS and the first message is not limited by the present application.

In some embodiments, the second device 120 may send a second message (e.g., a ps-Wakeup bit) to the first device 110 regarding whether to initiate the first listening to the downlink control channel in the first mode. In some embodiments, the second device 120 may send the second message via higher layer RRC signaling. In some embodiments, second device 120 may send the second message via lower layer physical signaling. It should be noted that the present application does not limit the transmission of the second message.

In some example embodiments, an apparatus (e.g., first device 110) capable of performing any of method 600 may include means for performing the various steps of method 600. The components may be implemented in any suitable form. For example, the components may be implemented in circuits or software modules.

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

In some example embodiments, the means for performing discontinuous reception operation in the second mode comprises: means for determining from a first message received from the second device whether to initiate a second mode of discontinuous reception operation; and means for performing a discontinuous reception operation in the second mode if it is determined that the second mode is to be activated.

In some example embodiments, the apparatus further comprises: means for initiating a first listening to a downlink control channel in the first mode if it is determined from the first message that the second mode is not to be initiated; and means for performing a second listening for a second wake-up signal if it is determined that a failure has occurred in the downlink control channel, the second wake-up signal being for a second mode.

In some example embodiments, the means for performing the second listening comprises: means for determining whether to initiate the second listening from a third message, the third message received from the second device; and means for performing the second snoop if it is determined that the second snoop is to be initiated.

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

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 listening whether the second wake-up signal is received until the first mode ends; and means for listening whether the second wake-up signal is received until the second wake-up signal is received.

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

In some example embodiments, the first mode is a long period of discontinuous reception operation and the second mode is a short period of 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 (e.g., first device 110) capable of performing any of method 700 may include means for performing the various steps of method 700. The components may be implemented in any suitable form. For example, the components may be implemented in circuits or software modules.

In some example embodiments, the apparatus comprises: means for listening, at a first device, for a first wake-up signal from a second device for a first mode of discontinuous reception operation; means for determining whether a first failure occurs in a downlink control channel without the first wake-up signal; and means for performing a second listen for a second wake-up signal if the first failure is determined to have occurred, the second wake-up signal being a second mode for discontinuous reception operation.

In some example embodiments, the means for performing the second listening comprises: means for determining whether to initiate first listening to a downlink control channel in a first mode based on a second message received from the second device; and means for performing the second snoop if it is determined from the second message that the first snoop is not to be initiated.

In some example embodiments, the apparatus further comprises: means for determining from the first message whether to initiate a second mode of discontinuous reception operation if it is determined from the second message that the first listen is to be initiated, the first message received from the second device; and means for performing discontinuous reception operation in the second mode if it is determined that the second mode is to be initiated.

In some example embodiments, the apparatus further comprises: means for initiating first listening for a downlink control channel in the first mode if it is determined that the second mode is not initiated; and means for performing the second listening if it is determined that a second failure has occurred in the downlink control channel.

In some example embodiments, the means for performing the second listening comprises: means for determining whether to initiate the second listen from a third message, the third message received from the second device; and means for performing the second snoop if it is determined that the second snoop is to be initiated.

In some example embodiments, the means for performing the second listening comprises: means for determining an opportunity for a second listen; 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 stopping the second listen at the opportunity if it is determined that the second wake-up signal is received; and means for performing discontinuous reception operation in the second mode.

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

In some example embodiments, the first mode is a long cycle of discontinuous reception operation and the second mode is a short cycle of 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 (e.g., second device 120) capable of performing any of method 900 may include means for performing the various steps of method 900. The components may be implemented in any suitable form. For example, the components may be implemented in circuits or software modules.

In some example embodiments, the apparatus includes means for transmitting, at the second device, a first wake-up signal for a first mode of discontinuous reception operation to the first device to perform 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 (e.g., second device 120) capable of performing any of method 1000 may include means for performing the various steps of method 1000. The components may be implemented in any suitable form. For example, the components may be implemented in circuits or software modules.

In some example embodiments, the apparatus includes means for transmitting, at the second device, a first wake-up signal for a first mode of discontinuous reception operation to the first device to perform 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 sending a first message to the first device as to whether to initiate the second mode; means for transmitting a second message to the first device regarding whether to initiate first listening to a downlink control channel in a first mode; and means for sending a third message to the first device as to whether to initiate a second listen for a second wake-up signal, the second wake-up signal being for a second mode.

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

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

The communication module 1140 is used for bi-directional communication. The communication module 1140 has at least one antenna to facilitate communication. A communication interface may represent any interface necessary to communicate with other network elements.

By way of non-limiting example, processor 1110 may be of any type suitable for a local technology 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 a multi-core processor architecture. Device 1100 may have multiple processors, such as application specific integrated circuit chips, that are time dependent from a clock synchronized to the host processor.

The memory 1120 may include one or more non-volatile memories and one or more volatile memories. Examples of non-volatile memory include, but are not limited to, Read Only Memory (ROM)1124, Electrically Programmable Read Only Memory (EPROM), flash memory, a hard disk, a Compact Disc (CD), a Digital Video Disc (DVD), and other magnetic and/or optical storage. Examples of volatile memory include, but are not limited to, Random Access Memory (RAM)1122, and other volatile memory that does not persist for periods of power down.

Computer programs 1130 include computer-executable instructions that are executed by an associated processor 1110. The program 1130 may be stored in the ROM 1124. Processor 1110 may perform any suitable actions and processes by loading program 1130 into RAM 1122.

Embodiments of the present disclosure may be implemented by program 1130, such that device 1100 may perform any of the processes of the present invention as discussed with reference to fig. 3A-10. Embodiments of the present invention may also be implemented by hardware or by a combination of software and hardware.

In some embodiments, program 1130 may be tangibly embodied in a computer-readable medium, which may be included in device 1100 (e.g., in memory 1120) or other storage device accessible to device 1100. The device 1100 may load the program 1130 from the computer-readable medium into the RAM 1122 for execution. The computer readable medium may include any type of tangible, non-volatile storage such as ROM, EPROM, flash memory, a hard disk, a CD, a DVD, etc. Fig. 12 shows an example of a computer readable medium 1200 in the form of a CD or DVD. The computer readable medium has program 1130 stored thereon.

In general, the various embodiments of the invention 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 the embodiments of the disclosure are illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that the block diagrams, apparatus, systems, techniques or methods 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 combinations thereof.

The present invention also provides at least one computer program product tangibly stored on a non-transitory computer-readable storage medium. The computer program product comprises computer-executable instructions, such as instructions included in program modules, that are executed in a device on a target real or virtual processor to perform the method 600 as described above with reference to fig. 6-10. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform particular tasks or implement particular abstract data types. In various embodiments, the functionality of the program modules may be combined or divided among program modules as desired. Machine-executable instructions for program modules may be executed within local or distributed devices. In a distributed facility, program modules may be located in both local and remote memory storage media.

Program code for carrying out methods of the present invention 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 functions/operations specified in the flowchart and/or block diagram are implemented when the program codes are executed by the processor or controller. The program code may execute entirely on the machine, partly on the machine and partly on a remote machine or entirely on the remote machine or server as a stand-alone software package.

In the context of the present disclosure, computer program code or related data may be carried by any suitable carrier to enable a device, apparatus or processor to perform various processes and operations as described above. Examples of a 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 is 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 a 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 described 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 some cases, multitasking and parallel processing may be advantageous. Likewise, while several specific implementation details are included in the above discussion, these should not be construed as limitations on the scope of the disclosure, but rather as descriptions of specific features of particular embodiments. Certain features that are described in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination.

Although the disclosure has been described in language specific to structural features and/or methodological acts, it is to be understood that the 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

1. A method of communication, comprising:

at a first device, listening for a first wake-up signal from a second device, the first wake-up signal being for a first mode of 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.

2. The method of claim 1, wherein performing the discontinuous reception operation in the second mode comprises:

determining from a first message received from the second device whether to initiate the second mode of discontinuous reception operation; and

performing the discontinuous reception operation in the second mode if it is determined that the second mode is to be activated.

3. The method of claim 2, further comprising:

initiating a first listening to a downlink control channel in the first mode if it is determined from the first message that the second mode is not to be initiated; and

performing a second listening for a second wake-up signal, the second wake-up signal being for the second mode, if it is determined that a failure has occurred in the downlink control channel.

4. The method of claim 3, wherein performing the second listen comprises:

determining whether to initiate the second listening from a third message, the third message received from the second device; and

performing the second snoop if it is determined that the second snoop is to be initiated.

5. The method of claim 3, wherein performing the second listen comprises:

determining an opportunity for the second listen; and

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

The method further comprises the following steps:

stopping the second listening at the opportunity if it is determined that the second wake-up signal is received; and

performing the discontinuous reception operation in the second mode.

6. The method of claim 5, wherein determining whether the second wake-up signal is received comprises at least one of:

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

monitoring whether the second wake-up signal is received or not until the first mode is ended; and

and monitoring whether the second wake-up signal is received or not until the second wake-up signal is received.

7. The method of claim 1, wherein performing the discontinuous reception operation in the second mode comprises:

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

monitoring a downlink control channel until the second timer expires.

8. The method of claim 1, wherein the first mode is a long period of the discontinuous reception operation and the second mode is a short period of the discontinuous reception operation, an

Wherein the first device is a terminal device and the second device is a network device.

9. A method of communication, comprising:

at a first device, listening for a first wake-up signal from a second device, the first wake-up signal being for a first mode of discontinuous reception operation;

determining whether a first failure occurs in a downlink control channel without the first wake-up signal; and

performing a second listen for a second wake-up signal for a second mode of the discontinuous reception operation if the first fault is determined to occur.

10. The method of claim 9, wherein performing the second listen comprises:

determining from a second message, the second message received from the second device, whether to initiate first listening to a downlink control channel in the first mode; and

performing the second snoop if it is determined from the second message that the first snoop is not initiated.

11. The method of claim 9, further comprising:

determining from a first message, the first message received from the second device, whether to initiate the second mode of discontinuous reception operation if it is determined from the second message that the first listening is to be initiated; and

12. The method of claim 11, further comprising:

initiating first listening to a downlink control channel in the first mode if it is determined that the second mode is not initiated; and

performing the second listening if it is determined that a second failure occurs in the downlink control channel.

13. The method of any of claims 9-12, wherein performing the second listening comprises:

14. The method of any of claims 9-12, wherein performing the second listening comprises:

determining an opportunity for the second listen; and

The method further comprises the following steps:

performing the discontinuous reception operation in the second mode.

15. The method of claim 14, wherein determining whether the second wake-up signal is received comprises at least one of:

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

16. The method of claim 14, wherein performing the discontinuous reception operation in the second mode comprises:

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

monitoring a downlink control channel until the second timer expires.

17. The method of claim 9, wherein the first mode is a long period of the discontinuous reception operation and the second mode is a short period of the discontinuous reception operation, an

18. A method of communication, comprising:

at a second device, transmitting a first wake-up signal to a first device, the first wake-up signal being for a first mode of discontinuous reception operation, to perform, by the first device, the discontinuous reception operation in a second mode in response to receiving the first wake-up signal with a wake-up indication.

19. A method of communication, comprising:

at a second device, a first wake-up signal is transmitted to a first device, the first wake-up signal being for a first mode of discontinuous reception operation to perform the discontinuous reception operation in a second mode by the first device without the first wake-up signal due to a failure in a downlink control channel.

20. The method of claim 18 or 19, further comprising at least one of:

sending a first message to the first device, the first message being about whether to initiate the second mode;

transmitting a second message to the first device, the second message being about whether to initiate first listening to a downlink control channel in the first mode; and

sending a third message to the first device, the third message regarding whether to initiate a second listen for a second wake-up signal, the second wake-up signal being for the second mode.

21. The method of claim 18 or 19, further comprising:

transmitting information about an occasion for the second listening to the first device; and

transmitting the second wake-up signal to the first device at one of the occasions.

22. 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

23. A first device, comprising:

at least one processor; and

at least one memory including computer program code;

the at least one memory and the computer program code configured to, with the at least one processor, cause the first device to perform the method of any of claims 1-17.

24. A second device comprising:

at least one processor; and

at least one memory including computer program code;

the at least one memory and the computer program code configured to, with the at least one processor, cause the second apparatus to perform the method of any of claims 18-22.

25. A communication device, comprising:

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

means for performing the discontinuous reception operation in a second mode of the discontinuous reception operation in response to receiving the first wake-up signal with a wake-up indication.

26. A communication device, comprising:

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

means for determining whether a first failure occurs in a downlink control channel without the first wake-up signal; and

means for performing a second listen for a second wake-up signal for a second mode of the discontinuous reception operation if the first failure is determined to occur.

27. A communication device, comprising:

means for transmitting, at a second device, a first wake-up signal to a first device to perform, by the first device, discontinuous reception operation in a second mode in response to receiving the first wake-up signal with a wake-up indication, the first wake-up signal for a first mode of the discontinuous reception operation.

28. A communication device, comprising:

means for transmitting, at a second device, a first wake-up signal to a first device to perform discontinuous reception operation in a second mode by the first device without the first wake-up signal due to a failure in a downlink control channel, the first wake-up signal being for a first mode of the discontinuous reception operation.

29. A non-transitory computer readable medium comprising program instructions for causing an apparatus to perform the method of any one of claims 1 to 17.

30. A non-transitory computer readable medium comprising program instructions for causing an apparatus to perform the method of any one of claims 18 to 22.