WO2022032634A1

WO2022032634A1 - Mechanism for transmission detection

Info

Publication number: WO2022032634A1
Application number: PCT/CN2020/109144
Authority: WO
Inventors: Jianguo Liu; Navin Hathiramani; Timo Lunttila; Karol Schober; Tao Tao; Mads LAURIDSEN
Original assignee: Nokia Shanghai Bell Co., Ltd.; Nokia Solutions And Networks Oy; Nokia Technologies Oy
Priority date: 2020-08-14
Filing date: 2020-08-14
Publication date: 2022-02-17
Also published as: CN114430918B; CN114430918A

Abstract

Example embodiments of the present disclosure relate to transmission detection. According to embodiments of the present disclosure, a serving cell determines a list of interfering cells from neighbour cells. The interfering cells on the list potentially block the serving cell to acquire the channel for transmission. With assistance information from the network, a device served by the serving cell monitors how long the interfering cells in the list occupy the channel after DL LBT failure is detected at the serving cell. Thereby, the device skips the transmission detection from the serving cell during the channel occupancy duration of at least one interference cell at least in the downlink slots. In this way, the power of the first device can be saved and it is more power efficient.

Description

MECHANISM FOR TRANSMISSION DETECTION

FIELD

Embodiments of the present disclosure generally relate to the field of telecommunication and in particular, to methods, devices, apparatuses and computer readable storage medium for transmission detection.

BACKGROUND

Discontinuous reception (DRX) is a method that is employed in various wireless technologies to allow a terminal device to turn its receiver off during periods of inactivity. DRX can be employed in both RRC idle mode and RRC connected mode. In RRC idle mode, the DRX cycle is based on the paging cycle, as the terminal device expects to only receive paging messages. In RRC connected mode, the terminal device needs to monitor physical downlink control channel (PDCCH) search space for possible indication of incoming traffic. Therefore, how to monitor the PDCCH properly is a very important aspect.

SUMMARY

In general, example embodiments of the present disclosure provide a solution for transmission detection.

In a first aspect, there is provided a first device. The first device comprises at least one processor; and at least one memory including computer program codes; the at least one memory and the computer program codes are configured to, with the at least one processor, cause the first device to receive from a second device assistance information at least including a list of interfering cells, the interfering cells having potential interference on a communication between the first device and the second device. The first device is further caused to obtain channel occupancy time of at least one interfering cell on the list based at least in part on the assistance information. The first device is also caused to cause a detection of transmission from the second device to be skipped within at least one downlink slot of the channel occupancy time.

In a second aspect, there is provided a second device. The second device comprises at least one processor; and at least one memory including computer program codes; the at least one memory and the computer program codes are configured to, with the at least one processor, cause the second device to determine a list of interfering cells which have potential interference on a communication between the second device and a first device. The second device is further caused to transmit to the first device assistance information at least including the list of interfering cells.

In a third aspect, there is provided a method. The method comprises receiving, at a first device and from a second device, assistance information at least including a list of interfering cells, the interfering cells having potential interference on a communication between the first device and the second device. The method also comprises obtaining channel occupancy time of at least one interfering cell on the list based at least in part on the assistance information. The method further comprises causing a detection of transmission from the second device to be skipped within at least one downlink slot of the channel occupancy time.

In a fourth aspect, there is provided a method. The method comprises determining, at a second device, a list of interfering cells which have potential interference on a communication between the second device and a first device. The method also comprises transmitting to the first device assistance information at least including the list of interfering cells.

In a fifth aspect, there is provided an apparatus. The apparatus comprise means for receiving, at a first device and from a second device, assistance information at least including a list of interfering cells, the interfering cells having potential interference on a communication between the first device and the second device; means for obtaining channel occupancy time of at least one interfering cell on the list based at least in part on the assistance information; and means for causing a detection of transmission from the second device to be skipped within at least one downlink slot of the channel occupancy time.

In a sixth aspect, there is provided an apparatus. The apparatus comprises means for determining, at a second device, a list of interfering cells which have potential interference on a communication between the second device and a first device; and means for transmitting to the first device assistance information at least including the list of interfering cells.

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

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

BRIEF DESCRIPTION OF THE DRAWINGS

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

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

Fig. 2 illustrates a signaling flow for applying uplink channel information to determine data processing model deployed for downlink use according to some example embodiments of the present disclosure;

Fig. 3 illustrates a flowchart of a method implemented at a first apparatus according to some example embodiments of the present disclosure;

Fig. 4 illustrates a flowchart of a method implemented at a second apparatus according to some other example embodiments of the present disclosure;

Fig. 5 illustrates a simplified block diagram of an apparatus that is suitable for implementing example embodiments of the present disclosure; and

Fig. 6 illustrates a block diagram of an example computer readable medium in accordance with some example embodiments of the present disclosure.

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

DETAILED DESCRIPTION

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

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

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

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

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

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

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

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

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

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

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

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

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

As used herein, the term “network device” refers to a node in a communication network via which a terminal device accesses the network and receives services therefrom. The network device may refer to a base station (BS) or an access point (AP) , for example, a node B (NodeB or NB) , an evolved NodeB (eNodeB or eNB) , a NR NB (also referred to as a gNB) , a Remote Radio Unit (RRU) , a radio header (RH) , a remote radio head (RRH) , a relay, an Integrated and Access Backhaul (IAB) node, a low power node such as a femto, a pico, a non-terrestrial network (NTN) or non-ground network device such as a satellite network device, a low earth orbit (LEO) satellite and a geosynchronous earth orbit (GEO) satellite, an aircraft network device, 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. In the following description, the terms “terminal device” , “terminal” , “user equipment” and “UE” may be used interchangeably.

As mentioned above, how to monitor the PDCCH properly is a very important. Study on UE power saving has been conducted by 3GPP. A key observation was that PDCCH monitoring is consuming a significant amount of UE power. It was shown that the UE power consumption can be reduced by PDCCH skipping. As observed, a large amount of UE’s power in modem composed of Radio Frequency (RF) chain and Base Band Unit (BBU) is consumed due to the PDCCH monitoring without any scheduled data.

A technology named “Wake-Up Signal (WUS) ” has been proposed, which dynamically control the UE’s PDCCH monitoring behavior depending on the data traffic. The power saving signal can indicate whether the UE skips the subsequent monitoring occasions within the DRX on duration or not. By this way, the UE will wake up to monitor PDCCH only when there is data targeted for the UE.

In New Radio Unlicensed (NR-U) communication systems, a radio equipment may be required to perform listen-before-talk (LBT) operation before transmission, according to the regulatory requirements, in order to achieve coexistence fairness with other Radio Access Technologies (RATs) (e.g. Wi-Fi) . For this, the equipment shall consider a channel to be occupied if other Radio Local Area Network (RLAN) transmissions are detected at a power level larger than a maximum Energy Detection (ED) threshold. According to some conventional technologies, if a gNB equipment needs to access the channel for downlink transmission, it shall follow the downlink channel access procedure. If a radio equipment passes LBT successfully, it can occupy the channel for a certain period of time. In conventional technologies, the maximum Channel Occupancy Time (COT) would vary with the channel access priority class and can last up to 10ms after the radio equipment grabs the channel with a successful LBT.

In NR-U, the gNB may broadcast the channel occupancy duration (i.e. COT) via Group Common Physical Downlink Control Channel (GC-PDCCH) when it acquires the channel. If a UE is configured by higher layers with a parameter “SlotFormatIndicator” , the UE monitors Downlink Control Information (DCI) format 2_0 with Cyclic Reduandancy Check (CRC) scrambled by SlotFormatIndicator-Radio Network Temporary Identifier (SFI-RNTI) . The DCI 2_0 would contain a pointer to value of semi-statically configured values by the serving cell. If the CO-DurationPerCell-r16 is not provided, the remaining channel occupancy duration for the serving cell is a number of slots, starting from a slot where the UE detects the DCI format 2_0, that the SFIindex field value provides corresponding slot formats. Note that the a SFI-index field value in a DCI format 2_0 indicates to a UE a slot format for each slot in a number of slots for each DL BWP or each uplink bandwidth part (UL BWP) starting from a slot where the UE detects the DCI format 2_0. The number of slots is equal to or larger than a PDCCH monitoring periodicity for DCI format 2_0.

For unlicensed deployment, a serving cell may suffer strong interference from one or more neighbouring cells and thus may not be able to acquire the channel due to DL LBT failure. This means that the serving cell may be blocked to access the channel during the channel occupancy time of one or more the neighbouring cell (s) . For example, assume that the neighbouring cell generates strong interference to the serving cell after transmission and causes LBT failure in the serving cell. After the neighbouring cell occupies the channel with duration of 5 slots (i.e. the COT is equal to 5 slots) , the serving cell would not be able to access the channel at least during the transmission of the neighbouring cell from slot# (n+1) to slot# (n+5) .

In Radio Resource Control (RRC) connected mode, a UE in NR-U needs to perform transmission detection from the serving cell during the active time. As noted above, the transmission detection behaviours like PDCCH monitoring may consume a significant amount of UE power. In fact, the UE can skip the unnecessary transmission detection from the serving cell during the channel occupancy time of the interfering neighbouring cells that cause DL LBT failure at the serving cell, which would be beneficial to UE power saving. For this, the UE shall know when and how long the serving cell would be blocked by the neighbouring cell.

As discussed above, the network can signal the wake-up indication to UE for controlling the PDCCH monitoring behaviours for UE power saving. However, whether the network indicates UE to skip the PDCCH monitoring usually depends on data traffic. Even if the serving cell is blocked due to DL LBT failure, the UE still needs to monitor the transmission from the serving cell like the PDCCH (e.g. at WUS occasions or within DRX OnDuration) or Channel State Information Reference Signal (CSI-RS) /Synchronization Signal Block (SSB) . Thus, it doesn’t address the problem identified above about transmission detection skipping for UE power saving due to DL LBT failure.

The network allocation vector (NAV) is a virtual carrier-sensing mechanism used with wireless network protocols such as IEEE 802.11 (Wi-Fi) . The virtual carrier-sensing is a logical abstraction which limits the need for physical carrier-sensing at the air interface in order to save power.

The NAV maintains a prediction of future traffic on the medium based on duration information. When the sender sends a Request to Send (RTS) the receiver waits one Short Inter-frame Space (SIFS) before sending Clear to Send (CTS) . Then the sender will wait again one SIFS before sending all the data. Again the receiver will wait a SIFS before sending acknowledgement (ACK) . So NAV is the duration from the first SIFS to the ending of ACK. During this time the medium is considered busy. The stations listening on the wireless medium read the duration field and set NAV which is an indicator for a station on how long it needs to defer from accessing the medium. To conserve power, the stations may enter a power-saving mode until the NAV is decremented to zero.

Herein, a station needs to hear transmission of RTS/CTS from other radio equipment (i.e. stations/AP) in the same BSS and learn how long it needs to defer from accessing the medium. However, the station may enter the power saving mode once the duration information is detected from other radio equipment regardless whether it will block the Access Point (AP) to acquire the channel.

In order to solve at least a part of the problems, a solution for transmission detection has been proposed. According to embodiments of the present disclosure, a serving cell determines a list of interfering cells from neighbour cells. The interfering cells on the list potentially block the serving cell to acquire the channel for transmission. With assistance information from the network, a device served by the serving cell monitors how long the interfering cells in the list occupy the channel after DL LBT failure is detected at the serving cell. Thereby, the device skips the transmission detection from the serving cell during the channel occupancy duration. In this way, the power of the first device can be saved and it is more power efficient.

Fig. 1 illustrates a schematic diagram of a communication environment 100 in which embodiments of the present disclosure can be implemented. The communication environment 100, which is a part of a communication network, further comprises a device 110-1, a device 110-2, ...., a device 110-N, which can be collectively referred to as “first device (s) 110. ” The communication environment 100 comprises a second device 120 and a third device 130. The second device 120 locates in a cell 121 which is a serving cell of the first device 110. The third device 130 locates in a cell 131 which is a neighbor cell of the cell 121. The first device 110 and the second device 120 can communicate with each other.

The communication environment 100 may comprise any suitable number of devices and cells. In the communication environment 100, the first device 110 and the second device 120 can communicate data and control information to each other. In the case that the first device 110 is the terminal device and the second device 120 is the network device, a link from the second device 120 to the first device 110 is referred to as a downlink (DL) , while a link from the first device 110 to the second device 120 is referred to as an uplink (UL) . The second device 120 and the first device 110 are interchangeable.

It is to be understood that the number of first devices and cells and their connections shown in Fig. 1 is given for the purpose of illustration without suggesting any limitations. The communication environment 100 may include any suitable number of devices and networks adapted for implementing embodiments of the present disclosure.

Communications in the communication environment 100 may be implemented according to any proper communication protocol (s) , comprising, but not limited to, cellular communication protocols of the first generation (1G) , the second generation (2G) , the third generation (3G) , the fourth generation (4G) and the fifth generation (5G) and on the like, wireless local network communication protocols such as Institute for Electrical and Electronics Engineers (IEEE) 802.11 and the like, and/or any other protocols currently known or to be developed in the future. Moreover, the communication may utilize any proper wireless communication technology, comprising but not limited to: Code Division Multiple Access (CDMA) , Frequency Division Multiple Access (FDMA) , Time Division Multiple Access (TDMA) , Frequency Division Duplex (FDD) , Time Division Duplex (TDD) , Multiple-Input Multiple-Output (MIMO) , Orthogonal Frequency Division Multiple (OFDM) , Discrete Fourier Transform spread OFDM (DFT-s-OFDM) and/or any other technologies currently known or to be developed in the future.

Example embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. Reference is now made to Fig. 2, which illustrates a signaling flow 200 for training a downlink data processing model with uplink channel information according to example embodiments of the present disclosure. For the purpose of discussion, the signaling flow 200 will be described with reference to Fig. 1. The signaling flow 200 may involve the first device 110-1, the second device 120 in the serving cell 121 and the third device 130 in the neighbor cell 131.

In some example embodiments, a set of DL RS resources may be configured to the second device 120 and/or the third device 130 for inter-cell energy measurements. In some example embodiments, the set of DL RS resources can be CSI-RS resources allocated to one or more neighbor cells (for example, the cell 131) . Alternatively or in addition, the set of DL RS resource may be SSB resources allocated to the one or more neighbor cells. In other embodiments, the set of DL RS resource may also the resources allocated to the one or more neighbor cells for Demodulation Reference Signal (DMRS) .

The third device 130 may transmit 2005 a reference signal to the second device 120. For example, the reference signal may be transmitted on the configured set of DL RS resources. In some example embodiments, the reference signal may be transmitted without other interference resources, for example, in a controlled environment. For example, the set of DL RS resources may be at a relatively clean band, which means there is a little interference from other devices on the band.

In some example embodiments, the second device 120 may measure 2010 an energy level on a channel from a neighbor cell 131. It should be noted that the second device 120 may measure energy on other channels from other neighbor cells. For only purpose of illustrations, embodiments of the present disclosure are described with the reference to the cell 131. In some example embodiments, the energy level may be measured by determining Reference Signal Received Power (RSRP) of the received reference signal. It should be noted that the energy level can be obtained by any other suitable measurements, for example, Reference Signal Received Quality (RSRQ) and/or Received Signal Strength Indicator (RSSI) .

The second device 120 determines 2015 a list of interfering cells. The list of interfering cells may have potential interference on a communication between the second device 120 and the first device 110-1. The interfering cells may cause the LBT failure of the serving cell 121 where the second device 120 locates. In some example embodiments, the list of interfering cells may be determined based on the measured energy level. For example, the measured energy level may be compared with an energy level threshold. If the measured energy level exceeds the energy level threshold, the cell 131 where the third device 130 locates may belong to the list of interfering cells. In some example embodiments, the energy level threshold may be the default energy detection threshold used for DL channel access procedure.

In other embodiments, an offset may be introduced. For example, the offset may be subtracted from the measured energy level, i.e., the measured energy level minus the offset. If the measured energy level minus the offset exceeds the energy level threshold, the second device 120 may determine that the cell 131 belongs to the list of interfering cells. In this way, the offset can be used to control the false alarm of DL LBT failure at the serving cell 121 caused by the interfering cell 131. In some example embodiments, the offset may be determined based on fading characteristics of the communication environment. Alternatively or in addition, the offset may also be determined based on confidence level required.

In some example embodiments, the list of interfering cells may be determined based on a channel quality between the first device 110-1 and the neighbor cell (for example, the cell 131) . The first device 110-1 may transmit a measurement report indicating the channel quality to the second device 120. For example, the first device 110-1 may transmit Radio Resource Management (RRM) measurements to the second device 120. The RRM measurements may comprise Channel Quality Indicator (CQI) . Alternatively or in addition, the RRM measurements may comprise RSRP. The RRM measurements may also comprise RSRQ and/or RSSI. The second device 120 may compare the channel quality with a quality threshold. If the channel quality exceeds the quality threshold, the cell 131 may be determined to belong to the list of interfering cells.

Alternatively or in addition, the list of interfering cells may be determined based on the above measured energy level and the above channel quality. For example, if the measured energy level exceeds the energy level threshold and the channel quality exceeds the quality threshold, the second device 120 may include the cell 131 as an interfering cell for the first device 110-1. It should be noted that the above mentioned offset may also be applicable in this situation.

The second device 120 may generate assistance information. In other embodiments, the second device 120 may obtain the assistance information from a core network device (for example, an Operation Administration and Maintenance (OAM) entity) . Alternatively, the assistance information may be obtained via an Xn interface with the interfering cells on the list. For example, the second device 120 may transmit 2020 a request for the assistance information to the third device 130. The third device 130 may transmit 2025 the requested assistance information to the second device 120.

The assistance information may comprise an interfering list indication which comprises identity information of the interfering cells. For example, the assistance information may comprise one or more of: a Physical Cell Identity (PCI) , a Cell Global Identity (CGI) , a Public Land Mobile Network (PLMN) identity or a Cell ID.

The assistance information may also comprise a configuration for decoding downlink control information (for example, DCI format 2_0) from the interfering cells. The configuration may comprise SFI-RNTI. Alternatively or in addition, the configuration may comprise DCI payload size. The CO-DurationPerCell-r16 information may also be included in the configuration. The configuration may comprise one or more of:a DMRS sequence, control resource set (COREST) or correspond SS-set aspects. It should be noted that the configuration can comprise any suitable information/parameters for decoding the downlink information.

In some example embodiments, the assistance information may comprise a configuration for sequence detection of the interfering cells on the list. For example, the assistance information may comprise the sequence index for indication of COT information.

Alternatively or in addition, the assistance information may comprise synchronization information for the interfering cells on the list. For example, timing synchronization information may be comprised in the assistance information. In addition, the assistance information may comprise frequency synchronization information.

The second device 120 transmits 2030 the assistance information to the first device 110-1. In some example embodiments, the assistance information may be transmitted in downlink control information. Alternatively, the assistance information may be transmitted via RRC signaling.

In some example embodiments, the first device 110-1 may obtain further assistance information from the third device 130. For example, the first device 110-1 may obtain the further assistance information based on System Information Block (SIB) received from the third device 130. The further assistance information may be similar to the assistance information. For example, the further assistance information may also comprise a configuration for decoding downlink information from the interfering cells. In some example embodiments, the further assistance information may comprise a configuration for sequence detection of the interfering cells on the list.

The first device 110-1 obtains 2040 Channel Occupancy Time (COT) (also referred to as channel occupancy duration) of at least one interfering cell (for example, the cell 131) on the list based at least in part on the assistance information. The first device 110-1 may obtain the channel occupancy duration of the cell 131 through decoding DCI format 2_0 or other signaling (e.g. sequence) based on the assistance information. Alternatively, the first device 110-1 may further acquire the information about the COT structure (DL or UL symbols) in a COT based on the DCI 2_0.

In some example embodiments, the first device 110-1 may buffer data when it monitors transmission from the second device 120. The first device 110-1 may be able to detect if the serving cell 121 is blocked due to LBT failure through transmission detection based on one or more of: CSI-RS, DMRS, or PDCCH. If the first device 110-1 fails to detect the transmission from the second device 120 due to the LBT failure, the first device 110-1 may monitor downlink information from the at least one interfering cell (for example, the cell 131) . The COT information may be obtained from the at least one interfering cell. The first device 110-1 may monitor the downlink information from the second device 120 until an expiration of a configured timer. For example, the configured timer may be default in the same slot where DL LBT failure is detected at the serving cell 121. Alternatively, the first device 110-1 may monitor the downlink information until the COT is detected for an interfering cell.

For an example, the first device 110-1 can monitor the interfering cells in the same slot where DL LBT fails at the serving cell. Once a COT is acquired for one interfering cell, the first device 110-1 may stop monitoring other interfering cells. In some example embodiments, the first device 110-1 can detect if a interfering cell is transmitting based on the DL RS (e.g. DMRS for GC-PDCCH, or the configured sequence) or based on decoding GC-PDCCH (e.g. DCI Format 2_0) . After the first device 110-1 detects transmission from a interfering cell (i.e. the interfering cell is occupying the channel for downlink transmission) , the first device 110-1 then may obtain the COT through decoding the GC-PDCCH with DCI format 2_0 based on the assistance information related to the interfering cell. Alternatively, the first device 110-1 then may obtain the COT through detecting the sequence based on the assistance information related to the interfering cell.

In some example embodiments, if the synchronization or/and configuration information for COT acquisition of the interfering cells are not configured in the assistance information transmitted by the second device 120, the first device 110-1 may further need to acquire the interfering cells assistance information using the interferer list indication to receive the configuration for decoding COT information of the interfering cell. For example, the first device 110-1 may transmit a request a configuration for decoding the downlink information to the at least one interfering cell (for example, the cell 131) . The first device 110-1 may receive the configuration from the least one interfering cell and decode the downlink information based on the configuration. The COT/channel occupancy duration may be obtained from the decoded downlink information.

For example, if the synchronization or/and configuration information for COT acquisition of the interfering cells are not configured in the assistance information transmitted by the second device 120, the first device 110-1 may further need to acquire the interfering cells assistance information using the interferer list indication to receive the configuration for decoding COT information of the interfering cell.

The first device 110-1 skips 2045 a detection of transmission from the second device 120 within at least one downlink slot of the channel occupancy time. In some example embodiments, the first device 110-1 may start a timer based on the channel occupancy duration. The first device 110-1 may suspend the detection of the transmission from the second device 120 during the timer. The first device 110-1 may resume the detection of the transmission after the timer expired. In some embodiments, the detection of the transmission may comprise a monitoring on a control channel for the transmission. The first device 110-1 may skip the monitoring on the control channel for the transmission within the channel occupancy time. Alternatively or in addition, the detection of the transmission may comprise a radio resource management (RRM) measurement associated with the second device 120. The first device 110-1 may not perform the RRM measurement associated with the second device 120. The RRM measurements may comprise Channel Quality Indicator (CQI) . Alternatively or in addition, the RRM measurements may comprise RSRP. The RRM measurements may also comprise RSRQ and/or RSSI.

According to embodiments of the present disclosure, an efficient power saving enabling technology is proposed. It can facilitate transmission detection skipping for the terminal device taking the channel occupancy information of the interfering cells into account. Further, it is more power efficient when compared to conventional mechanisms that the terminal device only knows if the network has obtained the channel based on real time LBT detection. Moreover, it may also achieve fast COT acquisition from the interfering cells with network assistance.

Fig. 3 shows a flowchart of an example method 300 implemented at a first device 110 in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 300 will be described from the perspective of the first device 110.

At block 310, the first device 110-1 receives assistance information from the second device 120. The assistance information at least includes a list of interfering cells. The interfering cells have potential interference on a communication between the first device 110-1 and the second device 120. In some example embodiments, the assistance information may be received in downlink control information. Alternatively, the assistance information may be received via RRC signaling. The assistance information may comprise an interfering list indication which comprises identity information of the interfering cells. For example, the assistance information may comprise one or more of: a PCI, a CGI, a PLMN identity or a Cell ID.

The assistance information may also comprise a configuration for decoding downlink control information (for example, DCI format 2_0) from the interfering cells. The configuration may comprise SFI-RNTI. Alternatively or in addition, the configuration may comprise DCI payload size. The CO-DurationPerCell-r16 information may also be included in the configuration. The configuration may comprise one or more of: a DMRS sequence, control resource set (CORESET) or correspond SS-set aspects. It should be noted that the configuration can comprise any suitable information/parameters for decoding the downlink information.

In some embodiments, the first device 110-1 may transmit a measurement report indicating the channel quality to the second device 120. For example, the first device 110-1 may transmit RRM measurements to the first device 110-1. The RRM measurements may comprise CQI. Alternatively or in addition, the RRM measurements may comprise RSRP. The RRM measurements may also comprise RSRQ and/or RSSI.

At block 320, the first device 110-1 obtains channel occupancy time of at least one interfering cell on the list based at least in part on the assistance information. The first device 110-1 may obtain the channel occupancy duration of the cell 131 through decoding DCI format 2_0 or other signaling (e.g. sequence) based on the assistance information. Alternatively, the first device 110-1 may further acquire the information about the COT structure (DL or UL symbols) in a COT based on the DCI 2_0.

At block 330, the first device 110-1 causes a detection of transmission from the second device 120 to be skipped within at least one downlink slot of the channel occupancy time. In some example embodiments, the first device 110-1 may start a timer based on the channel occupancy duration. The first device 110-1 may suspend the detection of the transmission from the second device 120 during the timer. The first device 110-1 may resume the detection of the transmission after the timer expired.

In some embodiments, the detection of the transmission may comprise a monitoring on a control channel for the transmission. The first device 110-1 may skip the monitoring on the control channel for the transmission within the channel occupancy time. Alternatively or in addition, the detection of the transmission may comprise a radio resource management (RRM) measurement associated with the second device 120. The first device 110-1 may not perform the RRM measurement associated with the second device 120. The RRM measurements may comprise Channel Quality Indicator (CQI) . Alternatively or in addition, the RRM measurements may comprise RSRP. The RRM measurements may also comprise RSRQ and/or RSSI.

Fig. 4 shows a flowchart of an example method 400 implemented at a second device 120 in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 400 will be described from the perspective of the second device 120. It should be noted that the dashed blocks are optional.

The second device 120 may receive a reference signal from the third device 130. For example, the reference signal may be transmitted on the configured set of DL RS resources. In some example embodiments, the reference signal may be transmitted without other interference resources, for example, in a controlled environment. For example, the set of DL RS resources may be at a relatively clean band, which means there is a little interference from other devices on the band.

In some example embodiments, the second device 120 may measure an energy level on a channel from a neighbor cell 131. It should be noted that the second device 120 may measure energy on other channels from other neighbor cells. For only purpose of illustrations, embodiments of the present disclosure are described with the reference to the cell 131. In some example embodiments, the energy level may be measured by determining Reference Signal Received Power (RSRP) of the received reference signal. It should be noted that the energy level can be obtained by any other suitable measurements, for example, Reference Signal Received Quality (RSRQ) and/or Received Signal Strength Indicator (RSSI) .

At block 410, the second device 120 determines a list of interfering cells. The interfering cells have potential interference on the communication between the second device 120 and the first device 110-1. The list of interfering cells may have potential interference on a communication between the second device 120 and the first device 110-1. The interfering cells may cause the LBT failure of the serving cell 121 where the second device 120 locates. In some example embodiments, the list of interfering cells may be determined based on the measured energy level. For example, the measured energy level may be compared with an energy level threshold. If the measured energy level exceeds the energy level threshold, the cell 131 where the third device 130 locates may belong to the list of interfering cells. In some example embodiments, the energy level threshold may be the default energy detection threshold used for DL channel access procedure.

In some example embodiments, the list of interfering cells may be determined based on a channel quality between the first device 110-1 and the neighbor cell (for example, the cell 131) . The second device 120 may receive a measurement report indicating the channel quality. For example, the second device 120 may receive Radio Resource Management (RRM) measurements from the first device 110-1. The RRM measurements may comprise Channel Quality Indicator (CQI) . Alternatively or in addition, the RRM measurements may comprise RSRP. The RRM measurements may also comprise RSRQ and/or RSSI. The second device 120 may compare the channel quality with a quality threshold. If the channel quality exceeds the quality threshold, the cell 131 may be determined to belong to the list of interfering cells.

The second device 120 may generate assistance information. In other embodiments, the second device 120 may obtain the assistance information from a core network device (for example, an Operation Administration and Maintenance (OAM) entity) . Alternatively, the assistance information may be obtained via an Xn interface with the interfering cells on the list. For example, the second device 120 may transmit 2020 a request for the assistance information to the third device 130.

The assistance information may comprise an interfering list indication which comprises identity information of the interfering cells. For example, the assistance information may comprise one or more of: a PCI, a CGI, a PLMN identity or a Cell ID.

The assistance information may also comprise a configuration for decoding downlink information (for example, DCI format 2_0) from the interfering cells. The configuration may comprise SFI-RNTI. Alternatively or in addition, the configuration may comprise DCI payload size. The CO-DurationPerCell-r16 information may also be included in the configuration. The configuration may comprise one or more of: a DMRS sequence, control resource set (CORESET) or correspond SS-set aspects. It should be noted that the configuration can comprise any suitable information/parameters for decoding the downlink information.

At block 420, the second device 120 transmits the assistance information to the first device 110-1. The assistance information at least includes the list of interfering cells. In some example embodiments, the assistance information may be transmitted in downlink control information. Alternatively, the assistance information may be transmitted via RRC signaling.

In some example embodiments, a first apparatus capable of performing any of the method 300 (for example, the first device 110) may comprise means for performing the respective operations of the method 300. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The first apparatus may be implemented as or included in the first device 110. In some example embodiments, the means may comprise at least one processor and at least one memory including computer program code. The at least one memory and computer program code are configured to, with the at least one processor, cause performance of the apparatus.

In some example embodiments, the apparatus comprises means for receiving, at a first device and from a second device, assistance information at least including a list of interfering cells, the interfering cells having potential interference on a communication between the first device and the second device; means for obtaining channel occupancy time of at least one interfering cell on the list based at least in part on the assistance information; and means for causing a detection of transmission from the second device to be skipped within at least one downlink slot of the channel occupancy time.

In some example embodiments, the assistance information further comprises at least one of: identity information of the interfering cells on the list, a configuration for decoding downlink control information from the interfering cells on the list, a configuration for sequence detection of the interfering cells on the list, or synchronization information of the interfering cells on the list.

In some example embodiments, the means for causing the detection of the transmission form the second device to be skipped comprises: means for starting a timer based on the channel occupancy time; and means for suspending the detection of the transmission from the second device during the timer.

In some example embodiments, the detection of the transmission comprises at least one of a monitoring on a control channel for the transmission, or a radio resource management measurement associated with the second device.

In some example embodiments, the means for obtaining the channel occupancy time comprises: means for in accordance with a determination that a failure occurs in detecting the transmission from the second device due to a listen-before-talk failure of the second device, monitoring downlink information from the at least one interfering cell; and means for obtaining the channel occupancy time based on the downlink information.

In some example embodiments, the means for monitoring the downlink information comprises means for monitoring the downlink information until an expiration of a configured timer; or means for monitoring the downlink information until the channel occupancy time is obtained.

In some example embodiments, the means for obtaining the channel occupancy time comprises means for transmitting to the at least one interfering cell a request for a configuration for decoding the downlink information; means for receiving from the at least one interfering cell information the configuration for decoding the downlink information; means for obtaining the channel occupancy time from the decoded downlink information.

In some example embodiments, the apparatus further comprises means for transmitting, to the second device, a measurement report indicating a channel quality between the first device and at least one neighbor cell.

In some example embodiments, a second first apparatus capable of performing any of the method 400 (for example, the second device 120) may comprise means for performing the respective operations of the method 400. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The first apparatus may be implemented as or included in the second device 120. In some example embodiments, the means may comprise at least one processor and at least one memory including computer program code. The at least one memory and computer program code are configured to, with the at least one processor, cause performance of the apparatus.

In some example embodiments, the apparatus comprises means for determining, at a second device, a list of interfering cells which have potential interference on a communication between the second device and a first device; and means for transmitting to the first device assistance information at least including the list of interfering cells.

In some example embodiments, the means for determining the list of interfering cells comprises means for measuring energy on a channel from a neighbor cell; means for comparing the measured energy with an energy threshold; and means for in accordance with a determination that the measured energy exceeds the energy threshold, determining that the neighbor cell belongs to the list of interfering cells.

In some example embodiments, the means for measuring the energy on the channel comprises means for obtaining a configuration indicating a set of resources for transmitting reference signals; means for detecting a reference signal from the neighbor cell based on the configuration; and means for measuring the energy of the detected reference signal.

In some example embodiments, the means for comparing the measured energy with the energy threshold comprises means for subtracting an offset from the measured energy; and means for comparing the subtracted measured energy with the energy threshold.

In some example embodiments, the means for determining the list of interfering cells comprises means for receiving from the first device a measurement report indicating a channel quality between the first device and the neighbor cell; means for comparing the channel quality with a quality threshold; and means for in accordance with a determination that the channel quality exceeds the quality threshold, determining that the neighbor cell belongs to the list of interfering cells.

Fig. 5 is a simplified block diagram of a device 500 that is suitable for implementing example embodiments of the present disclosure. The device 500 may be provided to implement a communication device, for example, the first device 110 or the second device 120 as shown in Fig. 1. As shown, the device 500 includes one or more processors 510, one or more memories 520 coupled to the processor 510, and one or more communication modules 540 coupled to the processor 510.

The communication module 540 is for bidirectional communications. The communication module 540 has one or more communication interfaces to facilitate communication with one or more other modules or devices. The communication interfaces may represent any interface that is necessary for communication with other network elements. In some example embodiments, the communication module 540 may include at least one antenna.

The processor 510 may be of any type suitable to the local technical network and may include one or more of the following: general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multicore processor architecture, as non-limiting examples. The device 500 may have multiple processors, such as an application specific integrated circuit chip that is slaved in time to a clock which synchronizes the main processor.

The memory 520 may include one or more non-volatile memories and one or more volatile memories. Examples of the non-volatile memories include, but are not limited to, a Read Only Memory (ROM) 524, an electrically programmable read only memory (EPROM) , a flash memory, a hard disk, a compact disc (CD) , a digital video disk (DVD) , an optical disk, a laser disk, and other magnetic storage and/or optical storage. Examples of the volatile memories include, but are not limited to, a random access memory (RAM) 522 and other volatile memories that will not last in the power-down duration.

A computer program 530 includes computer executable instructions that are executed by the associated processor 510. The program 530 may be stored in the memory, e.g., ROM 524. The processor 510 may perform any suitable actions and processing by loading the program 530 into the RAM 522.

Example embodiments of the present disclosure may be implemented by means of the program 530 so that the device 500 may perform any process of the disclosure as discussed with reference to Figs. 2 to 4. The example embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

In some example embodiments, the program 530 may be tangibly contained in a computer readable medium which may be included in the device 500 (such as in the memory 520) or other storage devices that are accessible by the device 500. The device 500 may load the program 530 from the computer readable medium to the RAM 522 for execution. The computer readable medium may include any types of tangible non-volatile storage, such as ROM, EPROM, a flash memory, a hard disk, CD, DVD, and other magnetic storage and/or optical storage. Fig. 6 shows an example of the computer readable medium 600 in form of an optical storage disk. The computer readable medium has the program 530 stored thereon.

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

The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer readable storage medium. The computer program product includes computer-executable instructions, such as those included in program modules, being executed in a device on a target physical or virtual processor, to carry out any of the methods as described above with reference to Figs. 3 to 8. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. Machine-executable instructions for program modules may be executed within a local or distributed device. In a distributed device, program modules may be located in both local and remote storage media.

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

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

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

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

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

Claims

A method comprising:

receiving, at a first device and from a second device, assistance information at least including a list of interfering cells, the interfering cells having potential interference on a communication between the first device and the second device;

obtaining channel occupancy time of at least one interfering cell on the list based at least in part on the assistance information; and

causing a detection of transmission from the second device to be skipped within at least one downlink slot of the channel occupancy time.
The method of claim 1, wherein the assistance information further comprises at least one of:

identity information of the interfering cells on the list,

a configuration for decoding downlink control information from the interfering cells on the list,

a configuration for sequence detection of the interfering cells on the list, or

synchronization information of the interfering cells on the list.
The method of claim 1, wherein causing the detection of the transmission from the second device to be skipped comprises:

starting a timer based on the channel occupancy time; and

suspending the detection of the transmission from the second device during the timer.
The method of claim 1, wherein the detection of the transmission comprises at least one of:

a monitoring on a control channel for the transmission, or

a radio resource management measurement associated with the second device.
The method of claim 1, wherein obtaining the channel occupancy time comprises:

in accordance with a determination that a failure occurs in detecting the transmission from the second device due to a listen-before-talk failure of the second device, monitoring downlink information from the at least one interfering cell; and

obtaining the channel occupancy time based on the downlink information.
The method of claim 5, wherein monitoring the downlink information comprises:

monitoring the downlink information until an expiration of a configured timer; or

monitoring the downlink information until the channel occupancy time is obtained.
The method of claim 5, wherein obtaining the channel occupancy time comprises:

transmitting to the at least one interfering cell a request for a configuration for decoding the downlink information;

receiving from the at least one interfering cell information the configuration for decoding the downlink information; and

obtaining the channel occupancy time from the decoded downlink information.
The method of claim 1, further comprising:

transmitting, to the second device, a measurement report indicating a channel quality between the first device and at least one neighbor cell.
The method of any one of claims 1-8, wherein the first device comprises a terminal device and the second device comprises a network device.
A method comprising:

determining, at a second device, a list of interfering cells which have potential interference on a communication between the second device and a first device; and

transmitting to the first device assistance information at least including the list of interfering cells.
The method of claim 10, wherein the assistance information further comprises at least one of:

identity information of the interfering cells on the list,

a configuration for decoding downlink control information of the interfering cells on the list,

a configuration for sequence detection of the interfering cells on the list, or

synchronization information of the interfering cells on the list.
The method of claim 10, wherein determining the list of interfering cells comprises:

measuring an energy level on a channel from a neighbor cell;

comparing the measured energy level with an energy level threshold; and

in accordance with a determination that the measured energy level exceeds the energy level threshold, determining that the neighbor cell belongs to the list of interfering cells.
The method of claim 12, wherein measuring the energy level on the channel comprises:

obtaining a configuration indicating a set of resources for transmitting reference signals;

detecting a reference signal from the neighbor cell based on the configuration; and

measuring the energy level of the detected reference signal.
The method of claim 12, wherein comparing the measured energy level with the energy level threshold comprises:

subtracting an offset from the measured energy level; and

comparing the subtracted measured energy level with the energy level threshold.
The method of claim 10, wherein determining the list of interfering cells comprises:

receiving from the first device a measurement report indicating a channel quality between the first device and the neighbor cell;

comparing the channel quality with a quality threshold; and

in accordance with a determination that the channel quality exceeds the quality threshold, determining that the neighbor cell belongs to the list of interfering cells.
The method of any one of claims 10-15, wherein the first device comprises a terminal device and the second device comprises a network device.
A first device comprising:

at least one processor; and

at least one memory including computer program codes;

the at least one memory and the computer program codes are configured to, with the at least one processor, cause the first device to perform the method according to any one of claims 1-9.
A second device comprising:

at least one processor; and

at least one memory including computer program codes;

the at least one memory and the computer program codes are configured to, with the at least one processor, cause the second device to perform the method according to any one of claims 10-16.
An apparatus comprising:

means for performing at least the method of any of claims 1-9 or the method of any of claims 10-16.
A computer readable medium comprising program instructions for causing an apparatus to perform the method of any of claims 1 to 9 or the method of any one of claims 10-16.