WO2023010481A1

WO2023010481A1 - Methods, devices and computer storage media for communication

Info

Publication number: WO2023010481A1
Application number: PCT/CN2021/111047
Authority: WO
Inventors: Gang Wang
Original assignee: Nec Corporation
Priority date: 2021-08-05
Filing date: 2021-08-05
Publication date: 2023-02-09

Abstract

A method comprises: determining to trigger for a first device to switch from a first channel access mode to a second channel access mode based on at least one of the following, the second channel access mode being different from the first channel access mode: detection of consistent channel access failures in a first detection time interval; detection of channel occupancy events based on received signal strength measurements in a second detection time interval; and detection of feedback information for uplink transmissions in a third detection time interval. In this way, a mechanism of channel access mode in millimeter wave bands can be proposed to achieve flexible and effective channel occupancy.

Description

METHODS, DEVICES AND COMPUTER STORAGE MEDIA FOR COMMUNICATION

TECHNICAL FIELD

Embodiments of the present disclosure generally relate to the field of telecommunication, and in particular, to methods, devices and computer storage media for channel access mode switching in millimeter wave bands.

BACKGROUND

Mobile communication involves the transmissions between a terminal device and a network device. Before performing transmission (s) , the terminal device or the network device may evaluate the availability of a channel for performing transmissions with channel access procedures, such as a Listen-before-Talk (LBT) mechanism or a clear channel assessment (CCA) , to improve the transmission performance.

For the regions where the channel access procedures is not mandated, it has been discussed that the network device and the terminal device may be operated in different channel access modes.

SUMMARY

In general, example embodiments of the present disclosure provide methods, devices and computer storage media for channel access mode switching in millimeter wave bands.

In a first aspect, there is provided a method. The method comprises determining to trigger for a first device to switch from a first channel access mode to a second channel access mode based on at least one of the following, the second channel access mode being different from the first channel access mode: detection of consistent channel access failures in a first detection time interval; detection of channel occupancy events based on received signal strength measurements in a second detection time interval; and detection of feedback information for uplink transmissions in a third detection time interval.

In a second aspect, there is provided a method. The method comprises receiving, from a first device, an indication associated with at least one of the following: detection of consistent channel access failures of the first device in a first detection time interval; detection of channel occupancy events of the first device based on received signal strength measurements in a second detection time interval; detection of feedback information for uplink transmissions of the first device in a third detection time interval; or a first device is to be switched from a first channel access mode to a second channel access mode, the second channel access mode being different from the first channel access mode; and determining to trigger for the first device to switch from a first channel access mode to a second channel access mode based on the indication.

In a third aspect, there is provided a first device. The first device comprises a processor and a memory. The memory is coupled to the processor and stores instructions thereon. The instructions, when executed by the processor, cause the first device to perform the method according to the first aspect of the present disclosure.

In a fourth aspect, there is provided a second device. The second device comprises a processor and a memory. The memory is coupled to the processor and stores instructions thereon. The instructions, when executed by the processor, cause the second device to perform the method according to the second aspect of the present disclosure.

In a fifth aspect, there is provided a computer readable medium having instructions stored thereon. The instructions, when executed on at least one processor, cause the at least one processor to perform the method according to any of the first and the second aspects.

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

BRIEF DESCRIPTION OF THE DRAWINGS

Through the more detailed description of some embodiments of the present disclosure in the accompanying drawings, the above and other objects, features and advantages of the present disclosure will become more apparent, wherein:

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

FIG. 2 shows a flowchart of an example method of channel access mode switching in millimeter wave bands in accordance with some embodiments of the present disclosure;

FIG. 3 shows a flowchart of an example method of channel access mode switching in millimeter wave bands in accordance with some embodiments of the present disclosure;

FIG. 4 shows a flowchart of an example method of channel access mode switching in millimeter wave bands in accordance with some embodiments of the present disclosure;

FIG. 5 shows a flowchart of an example method of channel access mode switching in millimeter wave bands in accordance with some embodiments of the present disclosure;

FIG. 6 is a simplified block diagram of a device that is suitable for implementing embodiments of the present disclosure.

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

DETAILED DESCRIPTION

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

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

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

It shall be understood that although the terms “first” and “second” etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish functionalities of various elements. As used herein, the term “and/or” includes any and all combinations of one or more of the listed terms.

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

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

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

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

Although functionalities described herein can be performed, in various example embodiments, in a fixed and/or a wireless network node, in other example embodiments, functionalities may be implemented in a user equipment apparatus (such as a cell phone or tablet computer or laptop computer or desktop computer or mobile IoT device or fixed IoT device) . This user equipment apparatus can, for example, be furnished with corresponding capabilities as described in connection with the fixed and/or the wireless network node (s) , as appropriate. The user equipment apparatus may be the user equipment and/or or a control device, such as a chipset or processor, configured to control the user equipment when installed therein. Examples of such functionalities include the bootstrapping server function and/or the home subscriber server, which may be implemented in the user equipment apparatus by providing the user equipment apparatus with software configured to cause the user equipment apparatus to perform from the point of view of these functions/nodes.

The term “circuitry” used herein may refer to hardware circuits and/or combinations of hardware circuits and software. For example, the circuitry may be a combination of analog and/or digital hardware circuits with software/firmware. As a further example, the circuitry may be any portions of hardware processors with software including digital signal processor (s) , software, and memory (memories) that work together to cause an apparatus, such as a terminal device or a network device, to perform various functions. In a still further example, the circuitry may be hardware circuits and or processors, such as a microprocessor or a portion of a microprocessor, that requires software/firmware for operation, but the software may not be present when it is not needed for operation. As used herein, the term circuitry also covers an implementation of merely a hardware circuit or processor (s) or a portion of a hardware circuit or processor (s) and its (or their) accompanying software and/or firmware.

FIG. 1 shows an example communication network 100 in which embodiments of the present disclosure can be implemented. The network 100 includes a network device 120 and terminal devices 110-1, 110-2…, 110-N served by the network device 120. The serving area of the network device 120 is called as a cell 102. Hereinafter, the terminal devices 110-1, 110-2…, 110-N may be collectively referred to as “UE 110” , “terminal device 110” or “first device 110” and the network device 120 may also be referred to “second device 120” or “gNB 120” .

It is to be understood that the number of network devices and terminal devices is only for the purpose of illustration without suggesting any limitations. The communication network 100 may include any suitable number of network devices and terminal devices adapted for implementing embodiments of the present disclosure.

In the communication network 100, the network device 120 can communicate/transmit data and control information to the terminal device 110 and the terminal device 110 can also communicate/transmit data and control information to the network device 120. A link from the network device 120 to the terminal device 110 is referred to as a downlink (DL) , while a link from the terminal device 110 to the network device 120 is referred to as an uplink (UL) . DL may comprise one or more logical channels, including but not limited to a Physical Downlink Control Channel (PDCCH) and a Physical Downlink Shared Channel (PDSCH) . UL may comprise one or more logical channels, including but not limited to a Physical Uplink Control Channel (PUCCH) and a Physical Uplink Shared Channel (PUSCH) .

Depending on the communication technologies, the network 100 may be a Code Division Multiple Access (CDMA) network, a Time Division Multiple Address (TDMA) network, a Frequency Division Multiple Access (FDMA) network, an Orthogonal Frequency-Division Multiple Access (OFDMA) network, a Single Carrier-Frequency Division Multiple Access (SC-FDMA) network or any others. Communications discussed in the network 100 may use conform to any suitable standards including, but not limited to, NR, Long Term Evolution (LTE) , LTE-Evolution, LTE-Advanced (LTE-A) , Wideband Code Division Multiple Access (WCDMA) , Code Division Multiple Access (CDMA) , CDMA2000, and Global System for Mobile Communications (GSM) and the like. Furthermore, the communications may be performed according to any generation communication protocols either currently known or to be developed in the future. Examples of the communication protocols include, but not limited to, the first generation (1G) , the second generation (2G) , 2.5G, 2.75G, the third generation (3G) , the fourth generation (4G) , 4.5G, the fifth generation (5G) communication protocols. The techniques described herein may be used for the wireless networks and radio technologies mentioned above as well as other wireless networks and radio technologies. For clarity, certain aspects of the techniques are described below for LTE, and LTE terminology is used in much of the description below.

As used herein, the term “channel” may refer to a carrier or a part of a carrier consisting of a contiguous set of resource blocks (RBs) on which a channel access procedure is performed in shared spectrum.

As used herein, the term “channel access procedure” may refer to a procedure based on sensing that evaluates the availability of a channel for performing transmissions. The basic unit for sensing may be a sensing slot with a sensing slot duration T _sl. For example, the sensing slot duration T _sl may be considered to be idle if an eNB/gNB or a UE senses the channel during the sensing slot duration and determines that the detected power for at least certain duration within the sensing slot duration (such as 4μs) is less than energy detection threshold X _thresh. Otherwise, the sensing slot duration T _sl may be considered to be busy.

As used herein, the term “Listen Before Talk (LBT) ” , “Category 4 (Cat4) LBT” , “Category 2 (Cat2) LBT” , “clear channel assessment (CCA) ” or “enhanced clear channel assessment (eCCA) ” may refer to the channel access procedure described above. For example, the Cat 4 LBT procedure may be similar to the Type 1 Uplink (UL) /Downlink (DL) channel access procedure or Clear Channel Access (CCA) . As a further example, the Cat 2 LBT procedure may be similar to the Type 2/2A/2B/2C UL/DL channel access procedures.

As used herein, the term “channel occupancy” may refer to transmission (s) on channel (s) by eNB/gNB/UE (s) after performing the corresponding channel access procedures.

For regions where LBT is not mandated, the gNB may indicate to the UE this gNB-UE connection is operating in LBT mode or no-LBT mode, namely, LBT is necessary for the operation in LBT mode, and LBT is unnecessary for the operation in no-LBT mode. For a frequency range in mmWave band under corresponding regulation in a certain region, the indication of operation mode may be per UE, per cell or per beam, and carried as part of system information, a L1 signaling or dedicated RRC signaling in an implicit or explicit way. The system information can be MIB and/or SIB1.

For the channel occupancy initiated by gNB/UE for DL/UL transmission without LBT procedure, the following UL/DL transmission after DL/UL transmission needs to satisfy the corresponding requirement of UE/gNB’s LBT operating mode. The Cat 4 LBT procedure may be similar to the Type 1 UL/DL channel access procedure in 3GPP or CCA check. The Cat 2 LBT procedure may be similar to the Type 2/2A/2B/2C UL/DL channel access procedures in 3GPP.

It has been proposed that both channel access with LBT mechanism (s) and a channel access mechanism without LBT can be supported for the gNB and the UE to initiate a channel occupancy. It is also possible that the gNB and the UE may be switched between one channel access mode and the other channel access mode. For example, the gNB and the UE may be switched between a channel access with LBT and channel access without LBT. To this aim, the mechanism for triggering the switching process may still need to be discussed.

In the solution of the present invention, the UE may determine to trigger for a first device to switch from a first channel access mode to a second channel access mode based on at least one of the following : detection of consistent channel access failures in a first detection time interval; detection of channel occupancy events based on received signal strength measurements in a second detection time interval; and detection of feedback information for uplink transmissions in a third detection time interval.

In this way, a mechanism of channel access mode in millimeter wave bands can be proposed to achieve flexible and effective channel occupancy.

Principle and implementations of the present disclosure will be described in detail below with reference to FIGs. 2-5.

Now the reference is made to FIG. 2, which illustrates a flowchart of an example method 200 in accordance with some embodiments of the present disclosure. The method 200 can be implemented at a UE 110 as shown in FIG. 1. It is to be understood that the method 200 may include additional blocks not shown and/or may omit some blocks as shown, and the scope of the present disclosure is not limited in this regard.

As describe above, for regions where LBT is not mandated, the gNB may indicate to the UE this gNB-UE connection is operating in LBT mode or no-LBT mode. The indication of operation mode may be per UE, per cell or per beam.

The indication may be provided as part of system information (such as MIB, SIB1 etc. ) , physical layer signal/signaling (such as DMRS, DCI, MSG2/4 etc. ) or dedicated RRC signalling in an implicit or explicit way.

Based on the indication received from the gNB 120, the UE 110 may perform the channel access procedure with different channel access mode, such as LBT mode or no-LBT mode.

As described above, it is also possible that the UE 110 may switch between LBT mode operation and no-LBT mode operation, for example, in a case where the channel state has been changed. The UE 110 may determine whether the conditions for triggering the switching are satisfied based on specific measurements or detections.

At block 210 in FIG. 2, the UE 110 may determine to trigger for a first device to switch from a first channel access mode to a second channel access mode based on at least one of the following: detection of consistent channel access failures in a first detection time interval; detection of channel occupancy events based on received signal strength measurements in a second detection time interval; and detection of feedback information for uplink transmissions in a third detection time interval.

Hereinafter, various cases for channel access mode switching may be further described in detail as below. Specifically, the channel access mode switching can be referred to as a switching from LBT mode operation to no-LBT mode operation or a switching from no-LBT mode operation to LBT mode operation.

In some embodiments, if UE is operating in LBT mode, the lower layer of UE may perform an LBT procedure prior to a UL transmission to initiate a channel occupancy or share/continue the Channel Occupancy Time (COT) initiated by gNB/UE.

When lower layer performs an LBT procedure before a transmission and the transmission is not performed, an LBT failure indication is sent to the Medium Access Control (MAC) entity from lower layers. When LBT is not performed by the lower layers, LBT failure indication is not received from lower layers.

As an option, when the UE is operating in LBT mode, the detection of the consistent LBT failures can be considered for triggering the channel access mode switching. In general, when the number of the LBT failures occurred within a constrained time interval exceeds or equals to a LBT failure threshold, the UE may determine that a consistent LBT failure has been occurred. As used herein, the term “exceed” may refer to “is greater than” .

Now the reference is made to FIG. 3, which illustrates a flowchart of an example method 300 in accordance with some embodiments of the present disclosure. The method 300 can be implemented at a UE 110 as shown in FIG. 1. It is to be understood that the method 300 may include additional blocks not shown and/or may omit some blocks as shown, and the scope of the present disclosure is not limited in this regard.

As shown in FIG. 3, if the UE is operating in LBT mode, at block 310, the UE 110 may perform plurality of LBT procedures within a first detection time interval. The first detection time interval may be considered as a long term detection window.

At block 320, the UE 110 may determine whether the number of the plurality of LBT procedures reaches a threshold number of LBT procedures allowed to be performed within the first detection time interval. If the number of the plurality of LBT procedures reaches a maximal number of LBT procedures allowed to be performed within the first detection time interval, at block 330, the UE 110 may determine a ratio of the number of the consistent channel access failures occurred in the plurality of channel access procedures to the number of the plurality of channel access procedures. At block 340, if the UE 110 determines that the ratio is lower than a threshold ratio, which may be referred to as a consistent LBT failure threshold ratio, As used herein, the term “reach” may refer to “equal to”. at block 350, the UE 110 may determine that the UE 110 is to be switched from LBT mode operation to no-LBT mode operation.

In this case, a long term consistent LBT failure may be detected per serving cell by counting consistent LBT failures indications in a relatively long period of time, i.e., the first detection time interval as mentioned above. The UE 110 may be configured with two parameters in the lbt-LongtermSensingConfig for long term sensing per serving cell, namely lbt-consistentFailureMaxRatio, which is used for the long term channel congestion detection and indicates an allowed maximal ratio of the consistent LBT failures within the long term consistent LBT failure detection period, and lbt-LongtermDectectionMaxCount, which is also for the long term channel congestion detection and indicates an maximal number of LBT procedures allowed to be performed within the long term consistent LBT failure detection period.

The parameter “lbt-consistentFailureMaxRatio” can be referred to the consistent failure threshold number as described above, which can be set to 1, 2, 3, 4, 5, 10, 15 and 20. The parameter “lbt-LongtermDectectionMaxCount” can be referred to the threshold number of LBT procedures allowed to be performed within the first detection time interval as described above, which can be set to 256, 512, 1024, 2048, 4096, 8192, or 16384.

Furthermore, the counter CONSISTENT_LBT_FAILURE_COUNTER can be introduced for counting the consistent LBT failures, which may initially set to 0. Moreover, the counter ALL_LBT_COUNTER can be configured for the UE 110 to count the LBT procedures performed by UE 110, which may also be initially set to 0.

In some embodiments, for each activated serving cell configured with lbt-LongtermSensingConfig, the process of the long term consistent LBT failure detection procedure performed by a UE operating in LBT mode may be listed as below:

Table 1: Long term consistent LBT failure detection procedure

In some embodiments, the UE 110 may also determine the number of consistent LBT failures occurred in the first detection time interval, which may be considered as a long term detection window. If the number of consistent LBT failures occurred in the first detection time interval exceeds or equals to a threshold number, the UE 110 may determine that the UE 110 is to be switched from LBT mode operation to no-LBT mode operation.

Furthermore, for certain UE, a long term consistent LBT failure detection procedure as mentioned above may also be performed in the gNB. Then, gNB may comprehensively determine whether and when to indicate that UE shall switch from LBT mode to no-LBT mode through physical layer indication (such as MIB, SIB information) and/or RRC signalling.

The Received Signal Strength Indicator (RSSI) and the channel occupancy measurements is supported in Release 16. The UE in LBT mode may measure and report on the configured resources on the indicated frequency. Based on a long term RSSI and channel occupancy measurements, the congestion level of intended channel in a relatively long period of time can be reflected to some extents. The channel congestion level may be used at least as a part of basis/condition to determine the operating mode for the UE.

Therefore, as another option, when the UE is operating in LBT mode, the detection of the received signal strength measurements can be considered for triggering the channel access mode switching.

Now the reference is made to FIG. 4, which illustrates a flowchart of an example method 400 in accordance with some embodiments of the present disclosure. The method 400 can be implemented at a UE 110 as shown in FIG. 1. It is to be understood that the method 400 may include additional blocks not shown and/or may omit some blocks as shown, and the scope of the present disclosure is not limited in this regard.

As shown in FIG. 4, if UE is operating in LBT mode, at block 410, the UE 110 may obtain results of the received signal strength measurements performed within a second detection time interval. Herein the term “the second detection time interval” may be referred to as a reporting time interval associated with the received signal strength measurements. In this case, a UE may be configured with IE ReportInterval including a reporting time interval with a greater value, such as 10240 ms, 20480 ms, 40960 ms and so on.

Furthermore, IE measResults with an enhanced field measResultForRSSI may be configured for UE performing long term RSSI and channel occupancy measurements as below.

Table 2: IE measResults with an enhanced field measResultForRSSI

A counter for channel occupancy “ChannelOccupancy_COUNTER” can be introduced for counting the measured channel occupancy, which can be initially set to 0. If the UE 110 determines a measured RSSI result exceeds or equals to a channel occupancy threshold, the counter for channel occupancy may be incremented by 1.

Meanwhile, a timer of the consistent channel occupancy for the consistent channel occupancy detection can be started or restarted. The timer of the consistent channel occupancy may be referred to as a parameter “consistentChannleOccupancyTimer” in the consistentChannelOccupancyConfig for consistent channel occupancy detection per serving cell, which may be set to 10 ms, 20 ms, 40 ms, 80 ms, 160 ms, 320 ms, 640 ms, 1280 ms, 2560 ms.

Within the time interval -when the timer of consistent channel occupancy is not expired, if the UE 110 determines that the number of the detected channel occupancy events exceeds or equals to a threshold number, the UE 110 may determine that a consistent channel occupancy event has been occurred. A counter of consistent channel occupancy “consistentchannelOccupancy_COUNTER” can be introduced for counting the occurred channel occupancy events within the time interval when the timer of consistent channel occupancy is not expired, which can be initially set to 0.

At block 420, the UE 110 may determine the number of a first plurality of the channel occupancy events occurred within the second detection time interval, i.e., the reporting time interval based on the results of the received signal strength measurements. The number of a first plurality of the channel occupancy events occurred within the second detection time interval can be counted by the counter for channel occupancy “ChannelOccupancy_COUNTER” , which can be initially set to 0.

At block 430, the UE 110 may determine whether one or more consistent channel occupancy events occurred in the first plurality of the channel occupancy events. If the UE determines that one or more consistent channel occupancy events occurred in the first plurality of the channel occupancy events, at block 440, the UE 110 may determine the number of a second plurality of channel occupancy events involved in the consistent channel occupancy events.

For determining the number of a second plurality of channel occupancy events involved in the consistent channel occupancy events, the UE 110 may determine whether the number of at least one portion of the first plurality of the channel occupancy events occurred within the second detection time interval, i.e., the reporting time interval exceeds or equals to a threshold number based on the results of the received signal strength measurements. The threshold number herein may be referred to as a parameter “channelOccupancyInstanceMaxCount” in the consistentChannelOccupancyConfig for consistent channel occupancy detection per serving cell, which may be set to 4, 8, 16, 32, 64, 128, 256, 512, 1024.

If the UE 110 determines that at least one portion of the number of the first plurality of the channel occupancy events occurred within the second detection time interval reaches the threshold number, the UE 110 may determine whether a previous consistent channel occupancy event has been triggered. In this case, an indicator is introduced for indicating whether a new consistent channel occupancy event is triggered. If the indicator equals to one, a new consistent channel occupancy event is triggered. If the indicator equals to zero, a previous consistent channel occupancy event has been triggered. Hereinafter the indication may also be referred to as a parameter “NewConsistentChannelOccupancyIndication. ”

In other words, if the UE determines that the indicator equals to one, the UE may determine that the consistent channel occupancy event triggered when the number of the first plurality of the channel occupancy events occurred within the second detection time interval reaches the threshold number is a new consistent channel occupancy event. Otherwise, the consistent channel occupancy event triggered when the number of the first plurality of the channel occupancy events occurred within the second detection time interval exceeds the threshold number is not a new consistent channel occupancy event.

If the UE 110 determines that a new consistent channel occupancy event is triggered, the UE 110 may also determine the number of a second plurality of channel occupancy events involved in the consistent channel occupancy events based on the threshold number of “channelOccupancyInstanceMaxCount” and the counting number of the “consistentchannelOccupancy_COUNTER. ”

Specifically, the number of a second plurality of channel occupancy events involved in the consistent channel occupancy events can be equal to the threshold number of “channelOccupancyInstanceMaxCount” plus the counting number of the “consistentchannelOccupancy_COUNTER” .

Furthermore, the indicator can be set to zero until the new triggered consistent channel occupancy event terminates.

If the UE 110 determines that a previous consistent channel occupancy event has been triggered, the UE 110 may also determine the number of a second plurality of channel occupancy events involved in the consistent channel occupancy events based on the counting number of the “consistentchannelOccupancy_COUNTER” plus one.

Furthermore, the indicator can be set to one until the current consistent channel occupancy event terminates.

Based on the number of the first plurality of the channel occupancy events occurred within the second detection time interval, the number of the second plurality of channel occupancy events involved in the consistent channel occupancy events and the number of the RSSI measurements, at block 450, the UE may determine a channel occupancy ratio and the consistent channel occupancy ratio.

For example, in some embodiments, at the end of the report interval, rssi-Result-r16, consistentChannelOccupancy and channelOccupancy-r16 are derived based on the measurements within report interval, which may be referred to the consistent channel occupancy ratio and the channel occupancy ratio respectively.

Specifically, channelOccupancy is the rounded percentage of sample values which are beyond the configured channelOccupancyThreshold within all the sample values in the associated reportInterval. consistentChannelOccupancy is the rounded percentage of sample values when the consecutive RSSI results were beyond the configured channelOccupancyThreshold for the associated reportInterval, namely the rounded percentage of sample values which are counted in consistentchannelOccupancy_COUNTER within all the sample values in the associated reportInterval.

At block 460, if the UE 110 determines that the channel occupancy ratio is lower than a threshold level and/or the consistent channel occupancy ratio is lower than a threshold level, at block 470, the UE 110 may determine that the UE 110 is to be switched from LBT mode operation to no-LBT mode operation.

Specifically, according to the consistentChannelOccupancy and channelOccupancy for a long report interval, the operation mode of UE may be determined based on predefined thresholds which may be named as channelCongestionThreshold and consistentChannelCongestionThreshold. If consistentChannelOccupancy and/or channelOccupancy are greater than or equals to associated thresholds respectively, the UE should hold LBT mode, otherwise, UE may switch to no-LBT mode.

In some embodiments, the process of the long term RSSI detection procedure performed by a UE operating in LBT mode may be listed as below:

Table 3: Long term RSSI detection procedure

In some embodiments, the execution of long term RSSI and consistent channel occupancy detection procedure may be requested by gNB, or autonomously performed by UE and reported to gNB. Correspondingly, UE may determine its operating mode based on above channel occupancy measurement procedure or report the measurement result and comply with the indication from gNB.

For the UE operating in no-LBT mode, a fallback mechanism from no-LBT mode to LBT mode is necessary for UE to adapt to the variable channel occupancy status, especially for the fair co-existence with the other systems. Although channel status obtained by channel sensing is not available in such case, the channel congestion level could be reflected in the form of HARQ-ACK feedbacks.

Therefore, the UE 110 determine whether the UE 110 is to be switched from a LBT mode to a no-LBT mode based on the HARQ feedback information.

For the purpose of channel congestion level detection, HARQ-ACK feedback for PUSCH (s) transmissions are expected to be provided to UE (s) explicitly or implicitly where explicit HARQ-ACK is determined based on the valid HARQ-ACK feedback in a corresponding CG-DFI, and implicit HARQ-ACK feedback is determined based on the indication for a new transmission or retransmission in the DCI scheduling PUSCH (s) .

Furthermore, a long detection interval HARQ-ACK_DetectionInterval with a duration can also be configured, which can also be referred to as a third detection time interval below.

In some embodiments, the UE 110 may determine respective numbers of acknowledgement feedbacks received in multiple sets of the transmissions performed on at least one band width part (BWP) configured for the UE 110. If the UE 110 determines that a ratio of the respective numbers of acknowledgement feedbacks to respective numbers of feedbacks for the multiple sets of the transmissions is lower than a threshold ratio, the UE 110 may determine that the UE 110 is to be switched from no-LBT mode operation to LBT mode operation.

In some embodiments, the threshold ratio may be defined by a predetermined parameter HARQ-ACK_Threshold. In some embodiments, the at least one BWP may be referred to all UL BWPs configured for the UE 110 with PRACH occasions on same carrier in this serving cell.

In a case where the serving cell of the UE 110 is SpCell, the UE 110 may determine the first number of acknowledgement feedbacks received in a first set of transmissions performed on a first BWP in the at least one BWP within a third detection time interval. If the UE 110 determines that a ratio of the first number of acknowledgement feedbacks to the number of feedbacks received in the first set of transmissions is lower than a threshold ratio, the UE 110 may switch an operating BWP of the UE 110 from the first BWP to a second BWP in the at least one BWP and determine a second number of acknowledgement feedbacks received in a second set of transmissions performed on the second BWP. If the UE 110 determines that a ratio of the second number of acknowledgement feedbacks to the number of feedbacks received in the second set of transmissions is lower than a threshold ratio, the UE 110 may determine that the UE 110 is to be switched from no-LBT mode operation to LBT mode operation.

In some embodiments, the process of HARQ feedback information detection procedure can be listed as below:

Table 4: The HARQ feedback information detection procedure

In some embodiments, if the severe channel congestion has been indicated for a Serving Cell, the UE may trigger a fallback from no-LBT mode to LBT mode by itself. Alternatively, a switching request or cell congestion indication may be sent to the gNB, and then gNB may comprehensively determine whether and when to indicate that UE shall switch from LBT mode to no-LBT mode through physical layer indication (such as MIB, SIB information) and/or RRC signalling.

As another option, the RSSI measurement may also be considered for the fallback mechanism from no-LBT mode to LBT mode. A UE may be configured with IE ReportInterval with a greater value, such as 10240 ms, 20480 ms, 40960 ms and so on.

For a certain report interval, UE performs RSSI measurements according to the corresponding RSSI measurement timing configuration (RMTC) .

In some embodiments, the UE 110 may determine respective results of multiple sets of received signal strength measurements detected on at least one BWP configured for the UE 110. If the UE 110 determines that the respective average levels of the respective results for the at least one BWP exceed or equal to a fourth threshold level, the UE 110 may determine that the UE 110 is to be switched from no-LBT mode operation to LBT mode operation.

In some embodiments, the fourth threshold number may be defined by a predetermined parameter rssi-resultThreshold.. In some embodiments, the at least one BWP may be referred to all UL BWPs configured for the UE 110 with PRACH occasions on same carrier in this serving cell.

In a case where the serving cell of the UE 110 is SpCell, if the UE 110 determines that a first average level of the results of a first set of received signal strength measurements on a first BWP in the at least one BWP within the reporting interval exceeds or equals to the rssi-resultThreshold, the UE 110 may switch an operating BWP of the UE 110 from the first BWP to a second BWP in the at least one BWP and determine a second average level of the results of a first set of received signal strength measurements on a second BWP in the at least one BWP within the reporting interval. If the UE 110 determines that the average level of the results exceeds or equals to the rssi-resultThreshold, the UE 110 may determine that the UE 110 is to be switched from no-LBT mode operation to LBT mode operation.

In some embodiments, the UE 110 may determine respective numbers of multiple sets of channel occupancy events detected on at least one BWP configured for the UE 110. If the UE 110 determines, based on the respective numbers of multiple sets of channel occupancy events, that respective channel congestion levels for the at least one BWP exceed or equal to a fifth threshold level, the UE 110 may determine that the UE 110 is to be switched from no-LBT mode operation to LBT mode operation.

In some embodiments, the fifth threshold level may be defined by a predetermined parameter channelCongestionThreshold. In some embodiments, the at least one BWP may be referred to all UL BWPs configured for the UE 110 with PRACH occasions on same carrier in this serving cell.

In a case where the serving cell of the UE 110 is SpCell, if the UE 110 determines that a first channel congestion level based on the number of a first set of channel occupancy events detected on a first BWP in the at least one BWP within the reporting interval exceeds or equals to the channelCongestionThreshold, the UE 110 may switch an operating BWP of the UE 110 from the first BWP to a second BWP in the at least one BWP and determine a second channel congestion level based on the number of a second set of channel occupancy events detected on a second BWP in the at least one BWP within the reporting interval. If the UE 110 determines that the second channel congestion level exceeds or equals to the channelCongestionThreshold, the UE 110 may determine that the UE 110 is to be switched from no-LBT mode operation to LBT mode operation.

In some embodiments, the process of RSSI measurement detection procedure can be listed as below:

Table 5: The RSSI measurement detection procedure

In some embodiments, if the severe channel congestion has been indicated for a Serving Cell, the UE 110 may trigger a fallback from no-LBT mode to LBT mode by itself. Alternatively, a switching request or cell congestion indication may be sent to the gNB 120, and then gNB 120 may comprehensively determine whether and when to indicate that UE shall switch from LBT mode to no-LBT mode through physical layer indication (such as MIB, SIB information) and/or RRC signalling.

Depending on the capability and implement of UE 110, the proposed mechanism as described above may be applied separately or concurrently. At the same time, the proposed mechanism as described above may also be performed in the gNB 120 (subject to the operating mode of gNB 120) to determine the operation mode of UE 110 in a more comprehensive way.

For above-mentioned case for channel access mode switching, if the UE 110 determines that the UE 110 is to be switched from the current channel access mode to another channel access mode, the UE 110 may transmit an indication that the UE 110 is to be switched from the current channel access mode to another channel access mode to the gNB 120. The gNB 120 may determine whether the channel access mode of the UE 110 is to be switched partially depend on the indication.

FIG. 5 illustrates a flowchart of an example method 500 in accordance with some embodiments of the present disclosure. The method 500 can be implemented at a gNB 120 as shown in FIG. 1. It is to be understood that the method 500 may include additional blocks not shown and/or may omit some blocks as shown, and the scope of the present disclosure is not limited in this regard.

At block 510, the gNB 120 receives from the UE 110, an indication associated with at least one of the following: detection of consistent channel access failures of the UE 110 in a first detection time interval; detection of channel occupancy events of the UE 110 based on received signal strength measurements in a second detection time interval; detection of feedback information for uplink transmissions of the UE 110 in a third detection time interval; or a UE 110 is to be switched from a first channel access mode to a second channel access mode, the second channel access mode being different from the first channel access mode.

At block 520, the gNB 120 determines a trigger for the UE 110 to switch from a first channel access mode to a second channel access mode based on the indication.

Details for channel access in millimeter wave bands according to the present disclosure have been described with reference to FIGs. 1-5. Now an example implementation of the first device 110 will be discussed below. In some embodiments, the first device 110 comprises circuitry configured to: determine to trigger for a first device to switch from a first channel access mode to a second channel access mode based on at least one of the following, the second channel access mode being different from the first channel access mode: detection of consistent channel access failures in a first detection time interval; detection of channel occupancy events based on received signal strength measurements in a second detection time interval; and detection of feedback information for uplink transmissions in a third detection time interval.

In some embodiments, the first device 110 comprises circuitry configured to in a case that a channel access procedure is required to be performed by the first device in the first channel access mode and the channel access procedure is not required to be performed by the first device in the second channel access mode, perform a plurality of channel access procedures with the first channel access mode within the first detection time interval; in accordance with a determination that the number of the plurality of channel access procedures reaches a threshold number of channel access procedures allowed to be performed within the first detection time interval, determine a ratio of the number of the consistent channel access failures occurred in the plurality of channel access procedures to the number of the plurality of channel access procedures; and in accordance with a determination that the ratio is lower than a threshold ratio, determine that the first device is to be switched from the first channel access mode to the second channel access mode.

In some embodiments, the threshold number of channel access procedures allowed to be performed within the first detection time interval is set to any of 256, 512, 1024, 2048, 4096, 8192, or 16384.

In some embodiments, the consistent failure threshold number is set to 4, 8, 16, 32, 64, 128, 256.

In some embodiments, the first device 110 comprises circuitry configured to in a case that a channel access procedure is required to be performed by the first device in the first channel access mode and the channel access procedure is not required to be performed by the first device in the second channel access mode, determining whether a ratio of the number of consistent channel access failures occurred in the first detection time interval to the number of the plurality of channel access procedures in the first detection time interval exceeds or equals to a first threshold number; and in accordance with a determination that the number of consistent channel access failures occurred in the first detection time interval exceeds or equals to the first threshold ratio, determining that the first device is to be switched from the first channel access mode to the second channel access mode.

In some embodiments, the first device 110 comprises circuitry configured to in a case that a channel access procedure is required to be performed by the first device in the first channel access mode and the channel access procedure is not required to be performed by the first device in the second channel access mode, determine that the first device is to be switched from the first channel access mode to the second channel access mode, in accordance with a determination of at least one of the following: a channel occupancy ratio associated with the channel occupancy events is lower than a first threshold level; or a consistent channel occupancy ratio associated with consistent channel occupancy events is lower than a second threshold level.

In some embodiments, the first device 110 comprises circuitry configured to determine the number of a first plurality of channel occupancy events occurred within the second detection time interval based on the results of the received signal strength measurements; in accordance with a determination that the first plurality of channel occupancy events occurred within the second detection time interval include one or more consistent channel occupancy events, determine the number of a second plurality of channel occupancy events involved in the one or more consistent channel occupancy events within the second detection time interval; determine the channel occupancy ratio based on the number of the first plurality of channel occupancy events and the number of the received signal strength measurements; and determine the consistent channel occupancy ratio based on the number of the second plurality of channel occupancy events involved in the one or more consistent channel occupancy events and the number of the received signal strength measurements.

In some embodiments, the first device 110 comprises circuitry configured to in accordance with a determination that the number of a portion of the first plurality of channel occupancy events within a time interval of a timer of consistent channel occupancy exceeds or equals to a second threshold number, determine the consistent channel occupancy event is triggered.

In some embodiments, the first device 110 comprises circuitry configured to in accordance with a determination that at least one portion of the number of the first plurality of channel occupancy events exceeds or equals to a fourth threshold number and a new consistent channel occupancy event is triggered, determine the number of the second plurality of the channel occupancy events involved in the new triggered consistent channel occupancy event based on the fourth threshold number and a counting number of channel occupancy events involved in the new consistent channel occupancy events.

In some embodiments, the first device 110 comprises circuitry configured to set an indicator to zero until the new triggered consistent channel occupancy event terminates, the indicator indicating whether a new consistent channel occupancy event is triggered.

In some embodiments, the first device 110 comprises circuitry configured to in accordance with a determination that at least one portion of the number of the first plurality of channel occupancy events exceeds or equals to a fourth threshold number and a new consistent channel occupancy event fails to be triggered, determine the number of the second plurality of the channel occupancy events involved in the consistent channel occupancy events based on a counting number of channel occupancy events involved in a consistent channel occupancy events that has been triggered previously.

In some embodiments, the first device 110 comprises circuitry configured to set an indicator to zero, the indicator indicating whether a new consistent channel occupancy event is triggered

In some embodiments, the first device 110 comprises circuitry configured to in accordance with a determination that a result of a first received signal strength measurement in the received signal strength measurements exceeds or equals to a third threshold level, start or restart the timer of consistent channel occupancy.

In some embodiments, the first device 110 comprises circuitry configured to in a case that a channel access procedure is required to be performed by the first device in the second channel access mode and the channel access procedure is not required to be performed by the first device in the first channel access mode, determine respective numbers of acknowledgement feedbacks received in multiple sets of the transmissions performed on at least one band width part configured for the first device; in accordance with determination that a ratio of the respective numbers of acknowledgement feedbacks to respective numbers of feedbacks received in the multiple sets of the transmissions is lower than a threshold ratio, determine that the first device is to be switched from the first channel access mode to the second channel access mode.

In some embodiments, the first device 110 comprises circuitry configured to determine a first number of acknowledgement feedbacks received in a first set of transmissions performed on a first band width part in the at least one band width part within a third detection time interval; in accordance with a determination that a ratio of the first number of acknowledgement feedbacks to the number of feedbacks received in the first set of transmissions is lower than the threshold ratio, determine a second number of acknowledgement feedbacks received in a second set of transmissions performed on a second band width part in the at least one band width part by switching an operating band width part of the first device from the first band width part to the second band width part; and in accordance with a determination that a ratio of the second number of acknowledgement feedbacks to the number of feedbacks received in the second set of transmissions is lower than the threshold ratio, determine that the first device is to be switched from the first channel access mode to the second channel access mode.

In some embodiments, the first device 110 comprises circuitry configured to in a case that a channel access procedure is required to be performed by the first device in the second channel access mode and the channel access procedure is not required to be performed by the first device in the first channel access mode, obtain respective results of multiple sets of received signal strength measurements detected on at least one band width part configured for the first device; and in accordance with a determination that the respective average levels of the respective results for the at least one band width part exceed or equal to a fourth threshold level, determine that the first device is to be switched from the first channel access mode to the second channel access mode.

In some embodiments, the first device 110 comprises circuitry configured to determine a first average level of the results of a first set of received signal strength measurements on a first band width part in the at least one band width part within a first detection time interval; in accordance with a determination that the first average level exceeds or equals to the fourth threshold level, determine a second average level of the results of a second set of received signal strength measurements on a second band width part in the at least one band width part within the first detection time interval by switching an operating band width part of the first device from the first band width part to the second band width part; and in accordance with a determination that the second average level exceeds or equals to the fourth threshold level, determine that the first device is to be switched from the first channel access mode to the second channel access mode.

In some embodiments, the first device 110 comprises circuitry configured to in a case that a channel access procedure is required to be performed by the first device in the second channel access mode and the channel access procedure is not required to be performed by the first device in the first channel access mode, determine the respective numbers of multiple sets of channel occupancy events detected on at least one band width part configured for the first device; in accordance with a determination, based on the respective numbers of multiple sets of channel occupancy events, that respective channel congestion levels for the at least one band width part exceed or equal to a fifth threshold level, determine that the first device is to be switched from the first channel access mode to the second channel access mode.

In some embodiments, the first device 110 comprises circuitry configured to determine a first channel congestion level based on the number of a first set of channel occupancy events detected on a first band width part in the at least one band width part within a second detection time interval; in accordance with a determination that the first channel congestion level exceeds or equals to the fifth threshold level , determine a second channel congestion level based on the number of a second set of channel occupancy events detected on a second band width part in the at least one band width part within the second detection time interval by switching an operating band width part of the first device from the first band width part to the second band width part; and in accordance with a determination that the second channel congestion level exceeds or equals to the fifth threshold level, determine that the first device is to be switched from the first channel access mode to the second channel access mode.

In some embodiments, the first device 110 comprises circuitry configured to in accordance with a determination that the first device is to be switched from the first channel access mode to the second channel access mode, transmit, to a second device, an indication that the first device is to be switched from the first channel access mode to the second channel access mode.

Now an example implementation of the second device 120 will be discussed below. In some embodiments, the second device 120 comprises circuitry configured to: receive, from a first device, an indication associated with at least one of the following: detection of consistent channel access failures of the first device in a first detection time interval; detection of channel occupancy events of the first device based on received signal strength measurements in a second detection time interval; detection of feedback information for uplink transmissions of the first device in a third detection time interval; or a first device is to be switched from a first channel access mode to a second channel access mode, the second channel access mode being different from the first channel access mode; and determine to trigger for the first device to switch from a first channel access mode to a second channel access mode based on the indication.

FIG. 6 is a simplified block diagram of a device 600 that is suitable for implementing embodiments of the present disclosure. The device 600 can be considered as a further example implementation of the gNB 120 or the UE 110 as shown in FIG. 1. Accordingly, the device 600 can be implemented at or as at least a part of the gNB 120 or the UE 110.

As shown, the device 600 includes a processor 610, a memory 620 coupled to the processor 610, a suitable transmitter (TX) and receiver (RX) 640 coupled to the processor 610, and a communication interface coupled to the TX/RX 640. The memory 610 stores at least a part of a program 630. The TX/RX 640 is for bidirectional communications. The TX/RX 640 has at least one antenna to facilitate communication, though in practice an Access Node mentioned in this application may have several ones. The communication interface may represent any interface that is necessary for communication with other network elements, such as X2 interface for bidirectional communications between eNBs, S1 interface for communication between a Mobility Management Entity (MME) /Serving Gateway (S-GW) and the eNB, Un interface for communication between the eNB and a relay node (RN) , or Uu interface for communication between the eNB and a terminal device.

The program 630 is assumed to include program instructions that, when executed by the associated processor 610, enable the device 600 to operate in accordance with the embodiments of the present disclosure, as discussed herein with reference to FIGs. 2 to 5. The embodiments herein may be implemented by computer software executable by the processor 610 of the device 600, or by hardware, or by a combination of software and hardware. The processor 610 may be configured to implement various embodiments of the present disclosure. Furthermore, a combination of the processor 610 and memory 620 may form processing means 650 adapted to implement various embodiments of the present disclosure.

The memory 620 may be of any type suitable to the local technical network and may be implemented using any suitable data storage technology, such as a non-transitory computer readable storage medium, semiconductor based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory, as non-limiting examples. While only one memory 620 is shown in the device 600, there may be several physically distinct memory modules in the device 600. The processor 610 may be of any type suitable to the local technical network, and may include one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multicore processor architecture, as non-limiting examples. The device 600 may have multiple processors, such as an application specific integrated circuit chip that is slaved in time to a clock which synchronizes the main processor.

Generally, various embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. While various aspects of embodiments of the present disclosure are illustrated and described as block diagrams, flowcharts, or using some other pictorial representation, it will be appreciated that the blocks, 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 some combination thereof.

The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer readable storage medium. The computer program product includes computer-executable instructions, such as those included in program modules, being executed in a device on a target real or virtual processor, to carry out the process or method as described above with reference to FIGs. 2-5. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. Machine-executable instructions for program modules may be executed within a local or distributed device. In a distributed device, program modules may be located in both local and remote storage media.

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

The above program code may be embodied on a machine readable medium, which may be any tangible medium that may contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device. The machine readable medium may be a machine readable signal medium or a machine readable storage medium. A machine readable medium may include but not limited to an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the machine readable storage medium would include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM) , a read-only memory (ROM) , an erasable programmable read-only memory (EPROM or Flash memory) , an optical fiber, a portable compact disc read-only memory (CD-ROM) , an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

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

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

Claims

A method comprising:

determining to trigger for a first device to switch from a first channel access mode to a second channel access mode based on at least one of the following, the second channel access mode being different from the first channel access mode:

detection of consistent channel access failures in a first detection time interval;

detection of channel occupancy events based on received signal strength measurements in a second detection time interval; and

detection of feedback information for uplink transmissions in a third detection time interval.
The method of Claim 1, wherein a channel access procedure is required to be performed by the first device in the first channel access mode and the channel access procedure is not required to be performed by the first device in the second channel access mode, and wherein determining the trigger for the first device to switch from the first channel access mode to the second channel access mode comprises:

performing a plurality of channel access procedures with the first channel access mode within the first detection time interval;

in accordance with a determination that the number of the plurality of channel access procedures reaches a threshold number of channel access procedures allowed to be performed within the first detection time interval, determining a ratio of the number of the consistent channel access failures occurred in the plurality of channel access procedures to the number of the plurality of channel access procedures;

in accordance with a determination that the ratio is lower than a threshold ratio, determining that the first device is to be switched from the first channel access mode to the second channel access mode.
The method of Claim 2, wherein the threshold number of channel access procedures allowed to be performed within the first detection time interval is set to any of 256, 512, 1024, 2048, 4096, 8192, or 16384.
The method of Claim 2, wherein the consistent failure threshold number is set to 4, 8, 16, 32, 64, 128, 256.
The method of Claim 1, wherein a channel access procedure is required to be performed by the first device in the first channel access mode and the channel access procedure is not required to be performed by the first device in the second channel access mode, and wherein determining the trigger for the first device to switch from the first channel access mode to the second channel access mode comprises:

determining whether a ratio of the number of consistent channel access failures occurred in the first detection time interval to the number of channel access procedures performed in the first detection time interval exceeds or equals to a first threshold ratio; and

in accordance with a determination that a ratio of the number of consistent channel access failures occurred in the first detection time interval to the number of channel access procedures performed in the first detection time interval exceeds or equals to the first threshold number, determining that the first device is to be switched from the first channel access mode to the second channel access mode.
The method of Claim 1, wherein a channel access procedure is required to be performed by the first device in the first channel access mode and the channel access procedure is not required to be performed by the first device in the second channel access mode, and wherein determining the trigger for the first device to switch from the first channel access mode to the second channel access mode comprises:

determining that the first device is to be switched from the first channel access mode to the second channel access mode, in accordance with a determination of at least one of the following:

a channel occupancy ratio associated with the channel occupancy events is lower than a first threshold level; or

a consistent channel occupancy ratio associated with consistent channel occupancy events is lower than a second threshold level.
The method of Claim 6, further comprising:

determining the number of a first plurality of channel occupancy events occurred within the second detection time interval based on the results of the received signal strength measurements;

in accordance with a determination that the first plurality of channel occupancy events occurred within the second detection time interval include one or more consistent channel occupancy events, determining the number of a second plurality of channel occupancy events involved in the one or more consistent channel occupancy events within the second detection time interval;

determining the channel occupancy ratio based on the number of the first plurality of channel occupancy events and the number of the received signal strength measurements; and

determining the consistent channel occupancy ratio based on the number of the second plurality of channel occupancy events involved in the one or more consistent channel occupancy events and the number of the received signal strength measurements.
The method of Claim 7, further comprising:

in accordance with a determination that the number of a portion of the first plurality of channel occupancy events within a time interval of a timer of consistent channel occupancy exceeds or equals to a second threshold number, determining the consistent channel occupancy event is triggered.
The method of Claim 7, wherein determining the number of the second plurality of the channel occupancy events involved in the one or more consistent channel occupancy events comprises:

in accordance with a determination that at least one portion of the number of the first plurality of channel occupancy events exceeds or equals to a fourth threshold number and a new consistent channel occupancy event is triggered, determining the number of the second plurality of the channel occupancy events involved in the new triggered consistent channel occupancy event based on the fourth threshold number and a counting number of channel occupancy events involved in the new consistent channel occupancy events.
The method of Claim 9, further comprising:

setting an indicator to zero until the new triggered consistent channel occupancy event terminates, the indicator indicating whether a new consistent channel occupancy event is triggered.
The method of Claim 7, wherein determining the number of the channel occupancy events involved in the one or more consistent channel occupancy events comprises:

in accordance with a determination that at least one portion of the number of the first plurality of channel occupancy events exceeds or equals to a fourth threshold number and a new consistent channel occupancy event fails to be triggered, determining the number of the second plurality of the channel occupancy events involved in the consistent channel occupancy events based on a counting number of channel occupancy events involved in a consistent channel occupancy events that has been triggered previously.
The method of Claim 11, further comprising:

setting an indicator to zero, the indicator indicating whether a new consistent channel occupancy event is triggered.
The method of Claim 8, further comprising:

in accordance with a determination that a result of a first received signal strength measurement in the received signal strength measurements exceeds or equals to a third threshold level, starting or restarting the timer of consistent channel occupancy.
The method of Claim 1, wherein a channel access procedure is required to be performed by the first device in the second channel access mode and the channel access procedure is not required to be performed by the first device in the first channel access mode, and wherein determining the trigger for the first device to switch from the first channel access mode to the second channel access mode comprises:

determining respective numbers of acknowledgement feedbacks received in multiple sets of the transmissions performed on at least one band width part configured for the first device; and

in accordance with determination that a ratio of the respective numbers of acknowledgement feedbacks to the number of feedbacks received in the multiple sets of the transmissions is lower than a threshold ratio, determining that the first device is to be switched from the first channel access mode to the second channel access mode.
The method of Claim 14, wherein the first device is operated in a primary cell, wherein determining that the first device is to be switched from the first channel access mode to the second channel access mode comprises:

determining a first number of acknowledgement feedbacks received in a first set of transmissions performed on a first band width part in the at least one band width part within a third detection time interval;

in accordance with a determination that a ratio of the first number of acknowledgement feedbacks to the number of feedbacks received in the first set of transmissions is lower than the threshold ratio, determining a second number of acknowledgement feedbacks received in a second set of transmissions performed on a second band width part in the at least one band width part by switching an operating band width part of the first device from the first band width part to the second band width part; and

in accordance with a determination that a ratio of the second number of acknowledgement feedbacks to the number of feedbacks received in the second set of transmissions is lower than the threshold ratio, determining that the first device is to be switched from the first channel access mode to the second channel access mode.
The method of Claim 1, The method of Claim 1, wherein a channel access procedure is required to be performed by the first device in the second channel access mode and the channel access procedure is not required to be performed by the first device in the first channel access mode, and wherein determining the trigger for the first device to switch from the first channel access mode to the second channel access mode comprises:

obtaining respective results of multiple sets of received signal strength measurements detected on at least one band width part configured for the first device; and

in accordance with a determination that the respective average levels of the respective results for the at least one band width part exceed or equal to a fourth threshold level, determining that the first device is to be switched from the first channel access mode to the second channel access mode.
The method of Claim 16, wherein the first device is operated in a primary cell, wherein determining that the first device is to be switched from the first channel access mode to the second channel access mode comprises:

determining a first average level of the results of a first set of received signal strength measurements on a first band width part in the at least one band width part within a first detection time interval;

in accordance with a determination that the first average level exceeds or equals to the fourth threshold level, determining a second average level of the results of a second set of received signal strength measurements on a second band width part in the at least one band width part within the first detection time interval by switching an operating band width part of the first device from the first band width part to the second band width part; and

in accordance with a determination that the second average level exceeds or equals to the fourth threshold level, determining that the first device is to be switched from the first channel access mode to the second channel access mode.
The method of Claim 1, wherein a channel access procedure is required to be performed by the first device in the second channel access mode and the channel access procedure is not required to be performed by the first device in the first channel access mode, and wherein determining the trigger for the first device to switch from the first channel access mode to the second channel access mode comprises:

determining the respective numbers of multiple sets of channel occupancy events detected on at least one band width part configured for the first device; and

in accordance with a determination, based on the respective numbers of multiple sets of channel occupancy events, that respective channel congestion levels for the at least one band width part exceed or equal to a fifth threshold level, determining that the first device is to be switched from the first channel access mode to the second channel access mode.
The method of Claim 18, wherein the first device is operated in a primary cell, wherein determining that the first device is to be switched from the first channel access mode to the second channel access mode comprises:

determining a first channel congestion level based on the number of a first set of channel occupancy events detected on a first band width part in the at least one band width part within a second detection time interval;

in accordance with a determination that the first channel congestion level exceeds or equals to the fifth threshold level, determining a second channel congestion level based on the number of a second set of channel occupancy events detected on a second band width part in the at least one band width part within the second detection time interval by switching an operating band width part of the first device from the first band width part to the second band width part; and

in accordance with a determination that the second channel congestion level exceeds or equals to the fifth threshold level, determining that the first device is to be switched from the first channel access mode to the second channel access mode.
The method of Claim 1, further comprising:

in accordance with a determination that the first device is to be switched from the first channel access mode to the second channel access mode, transmitting, to a second device, an indication that the first device is to be switched from the first channel access mode to the second channel access mode.
A method comprising:

receiving, from a first device, an indication associated with at least one of the following:

detection of consistent channel access failures of the first device in a first detection time interval;

detection of channel occupancy events of the first device based on received signal strength measurements in a second detection time interval;

detection of feedback information for uplink transmissions of the first device in a third detection time interval; or

a first device is to be switched from a first channel access mode to a second channel access mode, the second channel access mode being different from the first channel access mode; and

determining to trigger for the first device to switch from a first channel access mode to a second channel access mode based on the indication.
A first device, comprising:

a processor configured to:

determine to trigger for a first device to switch from a first channel access mode to a second channel access mode based on at least one of the following, the second channel access mode being different from the first channel access mode:

detection of consistent channel access failures in a first detection time interval;

detection of channel occupancy events based on received signal strength measurements in a second detection time interval; and

detection of feedback information for uplink transmissions in a third detection time interval.
A second device, comprising:

a processor configured to:

receive, from a first device, an indication associated with at least one of the following:

detection of consistent channel access failures of the first device in a first detection time interval;

detection of channel occupancy events of the first device based on received signal strength measurements in a second detection time interval;

detection of feedback information for uplink transmissions of the first device in a third detection time interval; or

a first device is to be switched from a first channel access mode to a second channel access mode, the second channel access mode being different from the first channel access mode; and

determine to trigger for the first device to switch from a first channel access mode to a second channel access mode based on the indication.
A non-transitory computer readable medium comprising program instructions for causing an apparatus to perform at least the method of any of claims 1-20 or the method of claim 21.