WO2022122908A1

WO2022122908A1 - A method for accessing a channel and related wireless nodes

Info

Publication number: WO2022122908A1
Application number: PCT/EP2021/084977
Authority: WO
Inventors: Rickard Ljung
Original assignee: Sony Group Corporation; Sony Europe B.V.
Priority date: 2020-12-10
Filing date: 2021-12-09
Publication date: 2022-06-16

Abstract

Disclosed is a method, performed by a first wireless node, for accessing a channel between the first wireless node and a second wireless node. The method comprises determining during a channel occupancy time acquired by the first wireless node and/or the second wireless node, a channel sensing metric of a channel condition. The method comprises configuring, based on the channel sensing metric, an upcoming clear channel access procedure and/or one or more parameters of an upcoming channel occupancy time.

Description

A METHOD FOR ACCESSING A CHANNEL AND RELATED WIRELESS NODES

The present disclosure pertains to the field of wireless communications. The present disclosure relates to a method for accessing a channel and related wireless nodes.

BACKGROUND

In an unlicensed spectrum, a clear channel access, CCA, procedure is conducted by a wireless node prior to acquiring the channel for a transmission for a time period called a channel occupancy time, COT.

As communication technology advances in, for example, exploiting higher frequencies, there is a need for improving the CCA procedure and/or communications during the COT. For example, in 3^rd Generation Partnership Project, 3GPP, communications in very high frequencies are envisioned. New Radio, NR, technology supports frequencies up to 52GHz. It may be envisioned to devise protocols to use frequencies above 52GHz. Unlicensed spectrum communication can also be used at higher frequencies, such as above 52 GHz.

Operating at high frequencies allows for deploying various techniques, including exploiting the unlicensed spectrum.

SUMMARY

Various techniques that may be deployed comprise beamforming and/or a higher time granularity. An unlicensed spectrum allocation and/or communication on unlicensed bands can be used at higher frequencies, such as above 52 GHz. In 3GPP Release 17, the 60GHz band is being considered and therefore the standard needs to be adapted to meet the regulations for unlicensed access in these frequencies.

In the unlicensed spectrum, a clear channel access, CCA, procedure is conducted by a wireless node prior to acquiring the channel for a transmission. When the CCA is successful, the wireless node is allowed to transmit using the cleared spectrum for a maximum channel occupancy time, COT as illustrated in Fig. 2. In the legacy technique illustrated in Fig. 2, there is no link or connection between measurements being performed on an unlicensed/open spectrum during an already acquired transmission time window (e.g. COT) and the next CCA or the next transmission time window (e.g. COT). However, measurements may be used for the channel access framework determining transmission opportunities for a next transmission time window.

Accordingly, there is a need for devices and methods for accessing a channel, which mitigate, alleviate or address the shortcomings existing and improve the CCA procedure and/or characteristics of the COT in an unlicensed spectrum as well as interference management.

Disclosed is a wireless node comprising memory circuitry, processor circuitry, and a wireless interface. The wireless node is configured to perform any of the methods disclosed herein.

It is an advantage of the present disclosure that the disclosed method and the disclosed wireless node provide unlicensed access enhancements with interference mitigation. The disclosed wireless node may benefit from a sensing activity added during a COT acquired by the wireless node and/or its counterpart wireless node (which may be seen as a time window of active communication on a shared and/or unlicensed access channel), so as to improve an upcoming CCA procedure and/or an upcoming COT. For example, the sensing activity during the acquired channel occupancy time may lead to determining a level of interference on the radio channel during an advantageous time window. The acquired COT is an advantageous time window for sensing in that the channel during the acquired COT is available or cleared for the wireless node that has acquired the COT, and allow to detect for example a hidden node problem, and/or interferences due to channel fading and/or wireless node mobility. The sensing activity disclosed herein may be integrated seamlessly by using the higher time granularity possible at high frequencies and/or by using beamforming. The sensing activity disclosed herein is exploited to configure and improve an upcoming clear channel access procedure and/or one or more parameters of an upcoming COT, for example by using beamforming and/or antenna configurations and/or selecting advantageous CCA types and/or CCA parameters. This may lead to a reduced latency via e.g. a reduced time used for CCA, and/or an improved system performance via an improved interference management.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and advantages of the present disclosure will become readily apparent to those skilled in the art by the following detailed description of examples thereof with reference to the attached drawings, in which:

Fig. 1 is a diagram illustrating an example wireless communication system comprising an example first wireless node and an example second wireless node according to this disclosure,

Fig. 2 is a diagram illustrating an example communication with an example legacy channel access procedure to acquire a channel occupancy time,

Fig. 3 is a diagram illustrating an example communication between an example first wireless node and an example second wireless node according to this disclosure, Fig. 4 is a flow-chart illustrating an example method, performed by a first wireless node, for accessing a channel between the first wireless node and a second wireless node according to this disclosure,

Fig. 5 is a block diagram illustrating an example first wireless node as an example wireless device according to this disclosure, and

Fig. 6 is a block diagram illustrating an example second wireless node as an example network node according to this disclosure.

DETAILED DESCRIPTION

Various examples and details are described hereinafter, with reference to the figures when relevant. It should be noted that the figures may or may not be drawn to scale and that elements of similar structures or functions are represented by like reference numerals throughout the figures. It should also be noted that the figures are only intended to facilitate the description of the examples. They are not intended as an exhaustive description of the disclosure or as a limitation on the scope of the disclosure. In addition, an illustrated example needs not have all the aspects or advantages shown. An aspect or an advantage described in conjunction with a particular example is not necessarily limited to that example and can be practiced in any other examples even if not so illustrated, or if not so explicitly described.

The figures are schematic and simplified for clarity, and they merely show details which aid understanding the disclosure, while other details have been left out. Throughout, the same reference numerals are used for identical or corresponding parts.

Fig. 1 is a diagram illustrating an example wireless communication system 1 comprising an example first wireless node and an example second wireless node according to this disclosure.

As discussed in detail herein, the present disclosure relates to a wireless communication system 1 comprising a cellular system, for example, a 3GPP wireless communication system. The wireless communication system 1 comprises a first wireless node and/or a second wireless node.

A wireless node disclosed herein may be seen as a node configured to communicate using a wireless communication system, such as system 1 . In one or more examples, a wireless node is a wireless device (such as wireless device 300), such as a mobile device and/or a user equipment, UE. In one or more examples, a wireless node is a network node, such as a radio access network node operating in the radio access network, RAN, such as a base station, an evolved Node B, eNB, gNB in NR. In one or more examples, the RAN node is a functional unit which may be distributed in several physical units.

In one or more examples, the first wireless node is a wireless device (such as wireless device 300) and the second wireless node is a network node, such as network node 400. In one or more examples, the first wireless node is a network node, such as network node 400 and the second wireless node is a wireless device (such as wireless device 300).

The wireless communication system 1 described herein may comprise one or more wireless nodes 300, 300A, and 400.

In one or more examples, the first wireless node 300, 300A may be configured to communicate with the second wireless node 400 via a wireless link (or radio access link) 10, 10A. It should be noted that although various examples may be given for operation on specific radio frequencies, with example antenna configuration possibilities, with example modulation formats and with example radio communication protocols, the methods and examples disclosed may be applied to any radio communication frequency, antenna configuration possibility, modulation format and signaling protocol version.

It may be appreciated that operating at high frequencies simply allows a more efficient application of the disclosed technique(s). For example, operating at high frequencies (such as above 52GHz) allows for deploying various techniques. For example, at high frequencies (such as above 52GHz), spatial/directional transmissions can be deployed. For example, at high frequencies, each antenna element can be relatively small in size due to the reduced wavelength. Typically, beamforming with multiple antenna elements is easier because the implementation complexity for applying beamforming is reduced. It may be appreciated that a need to improve a link budget via directional transmissions and reception increases due to the larger attenuation of signals at the mentioned high frequencies.

Another aspect of communication using higher frequencies is that for e.g. an Orthogonal Frequency Division Multiplexing, OFDM, system, typically the OFDM symbol length (in time) is reduced when frequency domain is increased. Using FFT, an increase in frequency domain means a reduction in time domain. In terms of protocols, this impacts the timing in absolute values, for each symbol. In other words, an OFDM symbol for these high frequencies is seen as very short in time, and a switching between different symbols (or even a couple of symbols) may lead to very low switching delays.

The usage of unlicensed spectrum allocations I communication on unlicensed bands can be applied also to higher frequencies. In 3GPP Release 17, the 60GHz band is being considered and therefore the standard needs to be adapted to meet the regulations for unlicensed access in these frequencies. Higher frequencies may also impose different unlicensed bands other than the already defined unlicensed 60GHz band.

An unlicensed spectrum may be seen as a spectrum that is shared and/or open in that there is, as such, no owner of the spectrum controlling the access to the spectrum. In other words, there is no central coordination for accessing the unlicensed spectrum. Fig. 2 shows a diagram illustrating an example communication with an example channel access procedure to acquire a channel occupancy time. In an unlicensed spectrum, a clear channel access, CCA, procedure is conducted by a wireless node prior to acquiring the channel for a transmission. When the CCA is successful, the wireless node is allowed to transmit using the cleared spectrum for a maximum channel occupancy time, COT as illustrated in Fig. 2.

For example, a wireless node has an intention (illustrated by 20 in Fig. 2) to communicate over an channel of the unlicensed spectrum and performs a clear channel access, CCA, procedure 21 to assess the availability of the channel, prior to acquiring the channel for communication. For example, when the channel is deemed available for communication upon completion of the CCA procedure, the wireless node accesses the channel for an allowed channel occupancy time, COT, 22. Communication on the channel may be performed during the acquired COT (such as a COT window).

The CCA procedure 21 , may be among different types mentioned in 3GPP TS 27.213 v16.1.0 for unlicensed LTE and NR communications. In other words, various CCA procedures may be deployed.

The CCA procedure assesses the availability of the channel based on measurements made only during the time window when the CCA procedure is performed.

The legacy technique therefore lacks possibilities to take measurements during a COT into account for an upcoming CCA, which may lead to difficulties in considering interference situations and/or may make a CCA procedure unnecessarily long.

The present disclosure provides for how to adapt a CCA, and/or a COT when exploiting one or more of the following techniques: directive transmissions/receptions, high time granularity and unlicensed access. In other words, the various techniques may present challenges but also possibilities for improvements. For example, a total level of interference within the system may be analyzed and managed when one or more of the various techniques, such as short time scales, directive transmissions and/or beam management, are used.

Fig. 3 is a diagram illustrating an example communication between an example first wireless node and an example second wireless node according to this disclosure. As shown in Fig. 3, a wireless node accessing an unlicensed band may, according to spectrum regulations and/or radio protocol specifications, be required to perform a clear channel assessment (CCA) prior to accessing the channel. In one or more examples, the CCA may be referred to as a listen before talk procedure, and it may require one or more sensing periods which needs to be performed prior to any communication on the channel.

For example, a wireless node tries to access the channel (such as the communication channel), in an unlicensed spectrum, when a wireless node has an intention 30 to transmit (such as based on higher layer application), then follows the CCA procedure 31 (such as listen before talk, LBT).

For example, a wireless node performing the CCA procedure may be required to conduct comparisons of the level of detected energy on the channel during the sensing with an energy detection threshold. For example, when a sensing activity concludes that the channel is unavailable or busy or occupied, a transmission may not be allowed at that point. For example, instead, a waiting procedure may be applied, and one or more additional sensing activities may be applied. Various examples of CCA procedures may be applied, and the timing of sensing and waiting may differ.

It may be appreciated that during a CCA procedure, the wireless node is expected to be silent (e.g. not to perform any transmissions) during the CCA sensing period, since it is not yet concluded whether or not the wireless node is allowed to perform any transmission on the channel. In other examples of CCA procedures, only specific control signaling for CCA management may be transmitted before finalization of the CCA procedure and the channel is deemed available. When the CCA is successful (i.e., the channel is available or free), the wireless node may be allowed to access the channel for time window, which may be referred to as the channel occupancy time 33, COT. For example, once the channel is deemed available based on the CCA procedure, the wireless node is allowed to transmit, and the granted transmission may be performed during a maximum time duration which may be denoted as a channel occupancy time, COT. The COT indicates the time period during which the wireless node has gained a right to occupy the channel based on the CCA procedure performed. The length of the COT may differ, for example depending on the type of CCA procedure conducted, or the type of signaling transmitted on the channel.

In one or more examples of the present disclosure, during the channel occupancy time, the wireless node obtains or determines one or more channel sensing metrics, for example by performing one or more sensing activities (such as measurements) 33A, 33B, 33C, 33D, 33E. The sensing during the acquired COT may be configured to use at least one different antenna configuration than a transmission conducted within the already acquired channel occupancy time.

A sensing activity 33A-33E within COT 33 may be used to determine one or more channel sensing metrics indicative of a channel condition of the channel during the acquired COT 33. The channel condition may be indicative of interference. The channel sensing metric may be a level of interference on the channel. The sensing activities may be used to determine the characteristics (for example, antenna configuration, beam directions, beam width, beam configurations, and/or time for upcoming COT) for an upcoming CCA procedure 34 followed by an upcoming COT 35.

In an ideal situation, the sensing activity 33A-33E during the COT 33 is expected to naturally result in detecting no energy (above the noise floor), since the channel is targeted to be used by the wireless node that acquired the COT 33 and other devices should be silent (i.e. not communicate). However, in reality, there may be other nodes transmitting energy that can be detected as interference, e.g. due to neighbor cell transmissions or so-called hidden node problems and other aspects such as varying channel fading and/or device mobility. It is to be noted that these aspects are even more prominent in a high frequency scenario. For example, beam widths are relatively small in high frequencies so even a minimal change of a location or a beam may impact the interference detected by another node in the system.

With the disclosed functionality of channel sensing within a COT, the disclosed method can be applied as a criterion to determine the CCA procedure 34 to be utilized after the COT 33. In various examples, a CCA procedure may be selected amongst different types of CCA procedures for an upcoming CCA occasion, such as CCA 34. In one or more examples, the disclosed method can be used to determine whether the wireless node shall be required to perform a CCA prior to the next COT. In one or more examples the disclosed method can be used to determine whether the wireless node shall be allowed to perform a CCA in a given time period after a finalized COT.

In one or more examples, the disclosed wireless node may configure the upcoming CCA

34 by selecting antenna configurations, and/or by selecting a type of CCA and/or one or more CCA parameters.

In one or more examples, the disclosed wireless node may configure the upcoming COT

35 by adjusting the time window of the channel occupancy time.

For example, sensing slot(s) (e.g. for sensing acti vity(ies)) can be included within a channel occupancy time, for the purpose of determining an allowed channel access type or parameter determination for a next channel access procedure. A sensing slot within a channel occupancy time may be of a given value in microseconds. The sharing of a channel occupancy time may be regulated via sensing slots within the COT. An interference tolerance threshold can be used for a sensing slot within a COT. The sensing slot is considered to be “accepted” or “acceptable” if the detected power for at least X ps within the sensing slot duration is below the interference tolerance threshold. For example, communications between wireless nodes (such as transmissions initiated by a network node and/or a wireless device) where a sensing within previous slot has concluded that interference is not accepted or not acceptable based on detecting interference above lnterference_tolerance_threshold. For example, communications between wireless nodes (such as transmissions initiated by a network node and/or a wireless device) where a sensing within previous slot has been concluded as accepted or acceptable based on detecting interference below lnterference_tolerance_threshold.

Fig. 4 shows a flow diagram of an example method 100, performed by a first wireless node for accessing a channel between the first wireless node and a second wireless node according to the disclosure.

In one or more example methods, the method 100 comprises performing S102 a clear channel assessment of the channel, CCA.

In one or more example methods, the method 100 comprises acquiring S104 a channel occupancy time, COT, for communication between the first wireless node and the second wireless node upon a successful clear channel assessment. For example, the CCA is successful when the channel is deemed available or free based on measurements, such as detected energy level in comparison with an energy detection threshold. The COT indicates the time period during which the wireless node has gained a right to occupy the channel based on the CCA procedure performed. The length of the COT may differ, e.g. depending on the type of CCA procedure conducted, or the type of signaling transmitted on the channel. There may be a COT or a Maximum Channel Occupancy Time, MCOT, during which the first wireless node can use the channel and which, upon expiry, the first wireless node is to release the channel (such as channel resources or radio channel).

A clear channel assessment refers to a mechanism used by a wireless node to identify other transmissions in the channel, typically via an energy detection methodology or energy detect procedure. The regulations may specify one or more energy detection thresholds to use for CCA and other requirements on procedures for when and how long time the wireless node needs to perform the energy detection. For example, when the first wireless node wishes to resume transmission, the first wireless node is required to reperform a clear channel assessment to access the channel again.

The method 100 comprises determining S106 during a channel occupancy time acquired by the first wireless node and/or the second wireless node, a channel sensing metric of a channel condition. Stated differently, the first wireless node may obtain (such as via measurements performed by the first wireless node, such as via reception of measurements) during a channel occupancy time acquired by the first wireless node and/or the second wireless node, a channel sensing metric of a channel condition. In one or more example methods, the determining S106 comprises measuring the channel to determine the channel sensing metric.

In other words, the channel occupancy time may be acquired by the first wireless node and/or the second wireless node via a successful CCA procedure performed by the first wireless node and/or the second wireless node. For example, the channel sensing metric of the channel condition may be determined within the acquired channel occupancy time. In some example, the channel sensing metric may be based on measurements performed in an earlier COT.

A channel condition used herein may be seen as condition of the channel, such as radio condition. The channel condition may be indicative of the radio condition in the vicinity of the first wireless node. Alternatively, or additionally, the channel sensing metric may be seen as a parameter indicative of the radio condition in the vicinity of a first wireless node. For example, the channel condition may be indicative of the radio environment. For example, the channel sensing metric may be indicative of noise interference and/or coexistence condition experienced by the first wireless node or by a wireless node intended to be the receiver of an upcoming transmission.

For example, the channel sensing metric may comprise one or more of: a channel condition parameter, a channel state parameter, a coexistence parameter, a noise parameter, an interference parameter, a collision parameter, a measurements parameter, an error rate (e.g. a frame error rate, a bit error rate), and a COT sharing parameter etc.

It may be envisaged to determine a first channel sensing metric, and optionally a second channel sensing metric. The second channel sensing metric may be a different type of metric than the first channel sensing metric.

The method 100 comprises configuring S108, based on the channel sensing metric, an upcoming clear channel access procedure.

The disclosed method may lead to an interference detection within a wireless network operating on a shared spectrum wherein a wireless node is configured to perform channel sensing within a channel occupancy time already acquired by the wireless node, wherein the sensing is used for configuring an upcoming clear channel access procedure outside the acquired channel occupancy time.

In one or more example methods, the configuring S108 comprises selecting S108A, for the upcoming clear channel access procedure, a type of channel access procedure amongst a plurality of channel access procedures. It may be appreciated that the results of the sensing may be used as a criterion for determining the type of the upcoming CCA. For example, the type of channel access procedure may be A1 , A2, B1 , B2 Type 1 UL, Type 2UL provided in TS 37.123 v.16.3.0 or TS 37.213 v.16.3.0.

In one or more example methods, the configuring S108 comprises configuring S108B one or more parameters of the upcoming clear channel access procedure, comprising one or more of: a contention window parameter, one or more time parameters, one or more counter parameters, one or more parameters indicative of channel access priority class, and one or more channel occupancy times (such as a maximum COT as described in table 4.1 .1.1 of TS 37.123 v. 16.3.0 or TS 37.213 v.16.3.0). For example, the time parameter is a defer duration Td. For example, as provided in TS 37.123 v. 16.3.0 or TS 37.213 v.16.3.0, the defer duration Td consists of duration Tf =16ps immediately followed by m_p consecutive sensing slot durations T_si , and Tf includes an idle sensing slot duration Tsi at start of Tf. For example, the first wireless node may transmit a transmission after first sensing the channel to be idle during the sensing slot durations of a defer duration Td and after the counter parameter N is zero in step 4. The counter parameter N may be adjusted by sensing the channel for additional sensing slot duration(s) according to the steps below for example:

1 ) set Ninit, where Ninit is a random number uniformly distributed between 0 and CW_P , and go to step 4;

2) if N>0 and the eNB/gNB chooses to decrement the counter, set N=N-1 ;

3) sense the channel for an additional sensing slot duration, and if the additional sensing slot duration is idle, go to step 4; else, go to step 5;

4) if N=0, stop; else, go to step 2.

5) sense the channel until either a busy sensing slot is detected within an additional defer duration Td or all the sensing slots of the additional defer duration Td are detected to be idle; 6) if the channel is sensed to be idle during all the sensing slot durations of the additional defer duration N=Nj_nit, go to step 4; else, go to step 5.

In one or more example methods, the configuring S108 comprises determining S108C an antenna configuration for use in the upcoming clear channel access procedure. In one or more example methods, the configuring S108 comprises determining S108C an antenna configuration by the first wireless node for use in the upcoming clear channel access procedure. In one or more example methods, the antenna configuration comprises one or more of: a beam configuration and a direction configuration. In some examples, the first wireless node may use different antenna configurations (such as beams) for the sensing, compared to the beams used for reception of control and/or data transmissions during the COT. This way, the first wireless node can determine the interference level for different directions (for example other directions and/or with a broader angle) than the direction currently used for the communication in the COT. In some examples, the beam management for the sensing may be controlled by the network node (e.g. a base station). In some examples, the first wireless node may use such different antenna configurations to determine that one or more antenna configurations is to be used in an upcoming sensing period of the upcoming CCA procedure. This way, the sensing during the COT can be used to configure one or more directions and/or beams for the upcoming CCA procedure. For example, triggers to use an antenna configuration in an upcoming CCA procedure may be due to an especially high or an especially low level of interference detected during the sensing within the COT.

Additionally, or alternatively, the method 100 comprises configuring S108, based on the channel sensing metric, one or more parameters of an upcoming channel occupancy time. In one or more example methods, the one or more parameters comprise a time window of the upcoming channel occupancy time. Configuring S108, based on the channel sensing metric, one or more parameters of an upcoming channel occupancy time may comprise adjusting a time window of the upcoming channel occupancy time. This may provide the effect of using a longer COT in situations where the CCA is successful and low interference level within COT has been detected.

In one or more example methods, the upcoming clear channel access procedure comprises a subsequent clear channel access procedure following the acquired channel occupancy time. In other words, the upcoming clear channel access procedure is, for example, performed after the acquired channel occupancy time. It may be envisaged that the channel sensing metric determined during the acquired COT may be used for K upcoming CCAs and/or M upcoming COTs. It may be envisaged that K and/or M are suitably selected based on a coherence time of the channel.

In one or more example methods, the channel sensing metric comprises one or more of: a detected energy level on the channel, and a level of interference on the channel. The detected energy level may be used to determine the presence of another wireless node operating on the channel based on detecting the total energy level of the energy on the channel. Such energy detection procedure may therefore result in detecting that other wireless node(s) is transmitting. The level of interference may be measured using the signal to interference plus noise ratio.

In one or more example methods, the determining S106 is performed based on a measurement in-between two communications during the acquired channel occupancy time, COT. For example, the measurement may be performed in between two transmissions by the first wireless node. For example, the measurement may be performed in-between two receptions by the first wireless node. In some examples, the increased time granularity from high frequency transmissions can be utilized to perform this interference measurement within time slots in-between transmissions from the same wireless node. For example, in OFDM, because a sensing slot can be very short, the wireless node can perform channel sensing during one slot in which the device is not transmitting, for example in a period when the wireless node (e.g. UE) otherwise (without the sensing) would be performing a so-called connected mode Discontinuous Reception, DRX. For example, instead of performing a power save activity (such as DRX), the wireless node may be configured to perform an interference measurement, to manage the next CCA period after the currently utilized COT.

In one or more example methods, the determining S106 comprises receiving S106A the channel sensing metric from the second wireless node. In one or more examples, the first wireless node may receive the channel sensing metric from the second wireless node at any time. In one or more examples, the first wireless node may receive during the acquired COT the channel sensing metric from the second wireless node.

In one or more example methods, the channel sensing metric is indicative of measurements performed in an earlier channel occupancy time. For example, the earlier COT is earlier than the acquired COT of S106, which may be the current COT. It may be envisaged that the channel sensing metric was determined in a previous COT, but is received, by the first node, at any time. The channel sensing metric may, in some example, be indicative of measurement performed in the presently acquired COT of S106.

For example, the disclosed procedure may, in some examples, be a part of a so-called handshaking CCA procedure. A handshaking CCA procedure involves signaling between two or more wireless nodes to e.g. perform channel sensing not only at transmitter side, but also in at least one receiver side. In some examples, the disclosed procedure can be used in combination with handshaking CCA signaling procedure, for example to exchange information indicative of measurements performed in an earlier COT. For example, the transmitter side may transmit a first signaling to an intended receiver and the intended receiver may respond with such measurement results.

In one or more example methods, the method 100 comprises receiving S105 control signalling indicating to the first wireless node to determine the channel sensing metric within the acquired channel occupancy time. In one or more example methods, the control signalling is indicative of a time resource and/or a frequency resource for channel sensing. In one or more example methods, the control signalling comprises a control parameter. In one or more example methods, the control parameter comprises downlink control information, DCL For example, the determination of the channel sensing metric of the channel condition, during a channel occupancy time acquired by the first wireless node and/or the second wireless node may be seen as an inclusion of sensing slots into the acquired COT. For example, the inclusion of sensing slots into the acquired COT may be implemented as a modification of the physical layer specifications that determines the usage of time/frequency resources, such as in the scheduling. For example, the downlink control information, DCI, may be used to indicate and/or schedule a sensing period (as illustrated TS 38.212 v16.3.0). For example, the DCI may be configured to indicate the time for the sensing, and optionally the frequency range. For example, the DCI may be configured to indicate a beam specific indication.

In one or more example methods, the first wireless node is a wireless device and the second wireless node is a network node.

In one or more example methods, the first wireless node is a network node and the second wireless node is a wireless device.

The present disclosure provides a method, performed by a second wireless node, for supporting access, by a first wireless node and/or the second wireless node, of a channel between the second wireless node and the first wireless node. The method performed by the second wireless node comprises determining, during a channel occupancy time acquired by the first wireless node and/or the second wireless node, a channel sensing metric indicative of a channel condition of the channel; and transmitting the channel sensing metric to the first wireless node. In other words, the second wireless node may measure the channel during the acquired COT and may determine the channel sensing metric indicative of the channel condition of the channel. For example, the second wireless node may transmit the channel sensing metric to the first wireless node for configuration of an upcoming procedures such as CCA and/or COT. The channel sensing metric may be based on measurement performed during the presently acquired COT and may be transmitted, at any time, e.g. during the presently acquired COT or later, during a subsequent acquired COT.

Fig. 5 shows a block diagram of an example first wireless node, acting as a wireless device 300 according to the disclosure. The wireless device 300 comprises memory circuitry 301 , processor circuitry 302, and a wireless interface 303. The first wireless device 300 may be configured to perform any of the methods disclosed in Fig. 4. In other words, the wireless device 300 may be configured to enhance access to a channel between the wireless device and a network node.

The wireless device 300 is configured to communicate with a second wireless node, such as the network node 400 disclosed herein, using a wireless communication system (such as using a wireless interface 303). The wireless device 300 is configured to determine (such as by using a processor circuitry 302), during a channel occupancy time acquired by the first wireless node and/or the second wireless node, a channel sensing metric of a channel condition.

The wireless device 300 is configured to configure (such as by using the processor circuitry 302), based on the channel sensing metric, an upcoming clear channel access procedure and/or one or more parameters of an upcoming channel occupancy time. The wireless interface 303 is configured for wireless communications via a wireless communication system, such as an IEEE system and/or a 3GPP system, such as a 3GPP system supporting one or more of: Long Term Evolution, LTE, New Radio, NR, Narrowband loT, NB-loT, and Long Term Evolution - enhanced Machine Type Communication, LTE-M.

The wireless device 300 is optionally configured to perform any of the operations disclosed in Fig. 4 (such as any one or more of S102, S104, S105, S106A, S108A, S108B, S108C). The operations of the wireless device 300 may be embodied in the form of executable logic routines (for example, lines of code, software programs, etc.) that are stored on a non-transitory computer readable medium (for example, memory circuitry 301) and are executed by processor circuitry 302).

Furthermore, the operations of the wireless device 300 may be considered a method that the wireless device 300 is configured to carry out. Also, while the described functions and operations may be implemented in software, such functionality may also be carried out via dedicated hardware or firmware, or some combination of hardware, firmware and/or software.

Memory circuitry 301 may be one or more of a buffer, a flash memory, a hard drive, a removable media, a volatile memory, a non-volatile memory, a random access memory (RAM), or other suitable device. In a typical arrangement, memory circuitry 301 may include a non-volatile memory for long term data storage and a volatile memory that functions as system memory for processor circuitry 302. Memory circuitry 301 may exchange data with processor circuitry 302 over a data bus. Control lines and an address bus between memory circuitry 301 and processor circuitry 302 also may be present (not shown in Fig. 5). Memory circuitry 301 is considered a non-transitory computer readable medium.

Memory circuitry 301 may be configured to store information, such as channel sensing metrics, and/or control parameters. Fig. 6 shows a block diagram of an example second wireless node, acting as network node 400 according to the disclosure. The network node 400 comprises memory circuitry 401 , processor circuitry 402, and a wireless interface 403. The network node 400 may be configured to perform any of the methods disclosed in Fig. 4. In other words, the network node 400 may be configured for enhancing channel access.

The network node 400 is configured to communicate with a first wireless node, such as the wireless device 300 disclosed herein, using a wireless communication system (such as using a wireless interface 403).

The wireless interface 403 is configured for wireless communications via a wireless communication system, such as an IEEE system and/or a 3GPP system, such as a 3GPP system supporting one or more of: Long Term Evolution, LTE, New Radio, NR, Narrowband loT, NB-loT, and Long Term Evolution - enhanced Machine Type Communication, LTE-M.

The network node 400 is configured to determine (such as by using a processor circuitry 402), during a channel occupancy time acquired by the first wireless node and/or the second wireless node, a channel sensing metric of a channel condition.

The network node 400 is configured to configure (such as by using the processor circuitry 402), based on the channel sensing metric, an upcoming clear channel access procedure and/or one or more parameters of an upcoming channel occupancy time.

The network node is optionally configured to transmit (such as by using a wireless interface 403) channel sensing metrics to the wireless device.

Processor circuitry 402 is optionally configured to perform any of the operations disclosed in Fig. 4 (such as any one or more of S102, S104, S105, S106A, S108A, S108B, S108C). The operations of the network node 400 may be embodied in the form of executable logic routines (for example, lines of code, software programs, etc.) that are stored on a non- transitory computer readable medium (for example, memory circuitry 401 ) and are executed by processor circuitry 402).

Furthermore, the operations of the network node 400 may be considered a method that the network node 400 is configured to carry out. Also, while the described functions and operations may be implemented in software, such functionality may also be carried out via dedicated hardware or firmware, or some combination of hardware, firmware and/or software. Memory circuitry 401 may be one or more of a buffer, a flash memory, a hard drive, a removable media, a volatile memory, a non-volatile memory, a random access memory (RAM), or other suitable device. In a typical arrangement, memory circuitry 401 may include a non-volatile memory for long term data storage and a volatile memory that functions as system memory for processor circuitry 402. Memory circuitry 401 may exchange data with processor circuitry 402 over a data bus. Control lines and an address bus between memory circuitry 401 and processor circuitry 402 also may be present (not shown in Fig. 6). Memory circuitry 401 is considered a non-transitory computer readable medium.

Memory circuitry 401 may be configured to store information, such as channel sensing metrics, and/or control parameters.

Examples of methods and products (wireless nodes) according to the disclosure are set out in the following items:

Item 1. A method, performed by a first wireless node, for accessing a channel between the first wireless node and a second wireless node, the method comprising: determining (S106), during a channel occupancy time acquired by the first wireless node and/or the second wireless node, a channel sensing metric of a channel condition; and configuring (S108), based on the channel sensing metric, an upcoming clear channel access procedure and/or one or more parameters of an upcoming channel occupancy time.

Item 2. The method according to item 1 , wherein the configuring (S108) comprises selecting (S108A), for the upcoming clear channel access procedure, a type of channel access procedure amongst a plurality of channel access procedures.

Item 3. The method according to item 1 or 2, wherein the configuring (S108) comprises configuring (S108B) one or more parameters of the upcoming clear channel access procedure, comprising one or more of: a contention window parameter, one or more time parameter, one or more counter parameters, one or more parameters indicative of channel access priority class, and one or more channel occupancy times.

Item 4. The method according to any of the previous items, wherein the configuring (S108) comprises determining (S108C) an antenna configuration for use in the upcoming clear channel access procedure.

Item 5. The method according to item 4, wherein the antenna configuration comprises one or more of: a beam configuration and a direction configuration.

Item 6. The method according to any of the previous items, wherein the upcoming clear channel access procedure comprises a subsequent clear channel access procedure following the acquired channel occupancy time.

Item 7. The method according to any of the previous items, wherein the channel sensing metric comprises one or more of: a detected energy level on the channel, and a level of interference on the channel.

Item 8. The method according to any of the previous items, wherein the determining (S106) is performed based on a measurement in-between two communications during the acquired channel occupancy time.

Item 9. The method according to any of the previous items, wherein the determining (S106) comprises receiving (S106A) the channel sensing metric from the second wireless node.

Item 10. The method according to any of the previous items, wherein the channel sensing metric is indicative of measurements performed in an earlier channel occupancy time.

Item 11 . The method according to any of the previous items, the method comprising: performing (S102) a clear channel assessment of the channel, upon a successful clear channel assessment, acquiring (S104) the channel occupancy time for communication between the first wireless node and the second wireless node.

Item 12. The method according to any of the previous items, wherein the one or more parameters comprise a time window of the upcoming channel occupancy time.

Item 13. The method according to any of the previous items, the method comprising receiving (S105) control signalling indicating to the first wireless node to determine the channel sensing metric within the acquired channel occupancy time.

Item 14. The method according to item 13, wherein the control signalling is indicative of a time resource and/or a frequency resource for channel sensing.

Item 15. The method according to any of items 13-14, wherein the control signalling comprises a control parameter.

Item 16. The method according to any of the previous items, wherein the first wireless node is a wireless device and the second wireless node is a network node.

Item 17. The method according to any of items 1-15, wherein the first wireless node is a network node and the second wireless node is a wireless device.

Item 18. A method, performed by a second wireless node, for supporting access, by a first wireless node and/or the second wireless node, of a channel between the second wireless node and the first wireless node, the method comprising:

- determining, during a channel occupancy time acquired by the first wireless node and/or the second wireless node, a channel sensing metric indicative of a channel condition of the channel; and

- transmitting the channel sensing metric to the first wireless node. Item 19. A wireless node comprising memory circuitry, processor circuitry, and a wireless interface, wherein the wireless node is configured to perform any of the methods according to any of items 1-17 or item 18.

The use of the terms “first”, “second”, “third” and “fourth”, “primary”, “secondary”, “tertiary” etc. does not imply any particular order, but are included to identify individual elements. Moreover, the use of the terms “first”, “second”, “third” and “fourth”, “primary”, “secondary”, “tertiary” etc. does not denote any order or importance, but rather the terms “first”, “second”, “third” and “fourth”, “primary”, “secondary”, “tertiary” etc. are used to distinguish one element from another. Note that the words “first”, “second”, “third” and “fourth”, “primary”, “secondary”, “tertiary” etc. are used here and elsewhere for labelling purposes only and are not intended to denote any specific spatial or temporal ordering. Furthermore, the labelling of a first element does not imply the presence of a second element and vice versa.

It may be appreciated that Figs. 1-6 comprise some circuitries or operations which are illustrated with a solid line and some circuitries or operations which are illustrated with a dashed line. Circuitries or operations which are comprised in a solid line are circuitries or operations which are comprised in the broadest example. Circuitries or operations which are comprised in a dashed line are examples which may be comprised in, or a part of, or are further circuitries or operations which may be taken in addition to circuitries or operations of the solid line examples. It should be appreciated that these operations need not be performed in order presented. Furthermore, it should be appreciated that not all of the operations need to be performed. The example operations may be performed in any order and in any combination.

It is to be noted that the word "comprising" does not necessarily exclude the presence of other elements or steps than those listed.

It is to be noted that the words "a" or "an" preceding an element do not exclude the presence of a plurality of such elements.

It should further be noted that any reference signs do not limit the scope of the claims, that the examples may be implemented at least in part by means of both hardware and software, and that several "means", "units" or "devices" may be represented by the same item of hardware. The various example methods, devices, nodes and systems described herein are described in the general context of method steps or processes, which may be implemented in one aspect by a computer program product, embodied in a computer- readable medium, including computer-executable instructions, such as program code, executed by computers in networked environments. A computer-readable medium may include removable and non-removable storage devices including, but not limited to, Read Only Memory (ROM), Random Access Memory (RAM), compact discs (CDs), digital versatile discs (DVD), etc. Generally, program circuitries may include routines, programs, objects, components, data structures, etc. that perform specified tasks or implement specific abstract data types. Computer-executable instructions, associated data structures, and program circuitries represent examples of program code for executing steps of the methods disclosed herein. The particular sequence of such executable instructions or associated data structures represents examples of corresponding acts for implementing the functions described in such steps or processes.

Although features have been shown and described, it will be understood that they are not intended to limit the claimed disclosure, and it will be made obvious to those skilled in the art that various changes and modifications may be made without departing from the scope of the claimed disclosure. The specification and drawings are, accordingly, to be regarded in an illustrative rather than restrictive sense. The claimed disclosure is intended to cover all alternatives, modifications, and equivalents.

Claims

24

1 . A method, performed by a first wireless node, for accessing a channel between the first wireless node and a second wireless node, the method comprising: determining (S106), during a channel occupancy time acquired by the first wireless node and/or the second wireless node, a channel sensing metric of a channel condition; and configuring (S108), based on the channel sensing metric, an upcoming clear channel access procedure and/or one or more parameters of an upcoming channel occupancy time.

2. The method according to claim 1 , wherein the configuring (S108) comprises selecting (S108A), for the upcoming clear channel access procedure, a type of channel access procedure amongst a plurality of channel access procedures.

3. The method according to claim 1 or 2, wherein the configuring (S108) comprises configuring (S108B) one or more parameters of the upcoming clear channel access procedure, comprising one or more of: a contention window parameter, one or more time parameter, one or more counter parameters, one or more parameters indicative of channel access priority class, and one or more channel occupancy times.

4. The method according to any of the previous claims, wherein the configuring (S108) comprises determining (S108C) an antenna configuration for use in the upcoming clear channel access procedure.

5. The method according to claim 4, wherein the antenna configuration comprises one or more of: a beam configuration and a direction configuration.

6. The method according to any of the previous claims, wherein the upcoming clear channel access procedure comprises a subsequent clear channel access procedure following the acquired channel occupancy time. The method according to any of the previous claims, wherein the channel sensing metric comprises one or more of: a detected energy level on the channel, and a level of interference on the channel. The method according to any of the previous claims, wherein the determining (S106) is performed based on a measurement in-between two communications during the acquired channel occupancy time. The method according to any of the previous claims, wherein the determining (S106) comprises receiving (S106A) the channel sensing metric from the second wireless node. The method according to any of the previous claims, wherein the channel sensing metric is indicative of measurements performed in an earlier channel occupancy time. The method according to any of the previous claims, the method comprising: performing (S102) a clear channel assessment of the channel, upon a successful clear channel assessment, acquiring (S104) the channel occupancy time for communication between the first wireless node and the second wireless node. The method according to any of the previous claims, wherein the one or more parameters comprises a time window of the upcoming channel occupancy time. 13. The method according to any of the previous claims, the method comprising receiving (S105) control signalling indicating to the first wireless node to determine the channel sensing metric within the acquired channel occupancy time.

14. The method according to claim 13, wherein the control signalling is indicative of a time resource and/or a frequency resource for channel sensing.

15. The method according to any of claims 13-14, wherein the control signalling comprises a control parameter.

16. The method according to any of the previous claims, wherein the first wireless node is a wireless device, and the second wireless node is a network node.

17. The method according to any of claims 1-15, wherein the first wireless node is a network node, and the second wireless node is a wireless device.

18. A method, performed by a second wireless node, for supporting access, by a first wireless node and/or the second wireless node, of a channel between the second wireless node and the first wireless node, the method comprising:

- transmitting the channel sensing metric to the first wireless node.

19. A wireless node comprising memory circuitry, processor circuitry, and a wireless interface, wherein the wireless node is configured to perform any of the methods according to any of claims 1-17 or claim 18.