Sharing channel occupancy time by user equipment performing sidelink communication in unlicensed spectrum

Abstract

A user equipment (UE) for a wireless communication network, such as a 3rd Generation Partnership Project (3GPP) network, is described. The UE is configured to perform sidelink (SL) communications using a channel comprising resources from an unlicensed spectrum, and to occupy the channel within a channel occupancy time (COT). The UE is configured to receive one or more control messages, wherein at least one of the control messages is related to one or more upcoming SL transmissions through one or more network entities of the wireless communication network. The UE is configured to determine at least one network entity with upcoming transmissions using one or more control messages among the one or more network entities and share a COT with the at least one network entity.

Description

[0001] The present invention relates to the field of wireless communication systems or networks, and more particularly to direct communication between user devices via a sidelink using resources in an unlicensed spectrum (also referred to as SL-U). Embodiments relate to sharing of channel occupancy time by user devices for sidelink communication using resources from the unlicensed spectrum.

[0002] FIG. 1 is a schematic diagram of an example of a terrestrial wireless network 100. As shown in FIG. 1(a), the terrestrial wireless network 100 includes a core network 102 and one or more radio access networks RAN. 1 , RAN 2 ,...RAN N Figure 1(b) shows the radio access network RAN n Schematic diagram of an example of a radio access network RAN n It can include one or more base stations gNB 1 To gNB 5 Each base station serves a specific area around the base station, which is composed of corresponding cells 106 1 To 106 5 Schematically represented. The base station provides services to users within the cell. One or more base stations can provide services to users in licensed and / or unlicensed frequency bands. The term base station (BS) refers to gNB in ​​5G networks, eNB in ​​UMTS / LTE / LTE-A / LTE-APro, or BS in other mobile communication standards. Users can be fixed devices or mobile devices. The wireless communication system can also be accessed by mobile or fixed IoT devices connected to the base station or user. Mobile devices or fixed devices can include physical devices, ground-based vehicles (such as robots or cars), aerial vehicles (such as manned or unmanned aerial vehicles (UAVs), the latter also known as drones), buildings and other items or devices with embedded electronic devices, software, sensors, actuators, etc., and network connections that enable these devices to collect and exchange data through existing network infrastructure. Figure 1(b) shows an exemplary view of five cells, however, the RAN n More or fewer such cells may be included, and the RAN n It may also include only one base station. Figure 1(b) shows two user UEs 1 and UE 2 , also known as user equipment (device) or user equipment (equipment), which are in the cell 106 2 and by the base station gNB 2 Another user UE 3 Displayed by the base station gNB 4 Serving Residential Areas 106 4In. Arrow 108 1 , 108 2 and 108 3 Schematic diagram of a method for transferring data from a user UE 1 ,UE 2 and UE 3 Transmitted to the base station gNB 2 、gNB 4 Or for the base station gNB 2 、gNB 4 Transmit data to user UE 1 ,UE 2 ,UE 3 This can be done in a licensed band or an unlicensed band. In addition, FIG. 1( b) shows that cell 106 4 Two further devices 110 1 and 110 2 , such as IoT devices, which can be fixed devices or mobile devices. Device 110 1 Via base station gNB 4 Access to the wireless communication system to receive and send data, as indicated by arrow 112 1 Schematic representation. Device 110 2 Via user UE 3 Access to the wireless communication system, as indicated by arrow 112 2 Schematic representation. Corresponding base station gNB 1 To gNB 5 For example, via the S1 interface, via the corresponding backhaul link 114 1 To 114 5 Connected to the core network 102, the backhaul link 114 1 To 114 5 In FIG1( b ), the core network 102 is schematically represented by an arrow pointing to “core”. The core network 102 may be connected to one or more external networks. The external network may be the Internet, or a private network such as an intranet or any other type of campus network, such as a private WiFi communication system or a 4G or 5G mobile communication system. In addition, the corresponding base station gNB 1 To gNB 5 Some or all of the may be connected, for example, via an S1 or X2 interface or an XN interface in NR, via a corresponding backhaul link 116 1 Up to 116 5 Connected to each other, backhaul link 116 1 Up to 116 5This is schematically represented by the arrows pointing to “gNBs” in Figure 1(b). The sidelink channel allows direct communication between UEs, also known as device-to-device (D2D) communication. The sidelink interface in 3GPP is named PC5.

[0003] For data transmission, a physical resource grid may be used. The physical resource grid may include a set of resource elements to which various physical channels and physical signals are mapped. For example, the physical channels may include a physical downlink shared channel PDSCH, a physical uplink shared channel PUSCH and a physical sidelink shared channel PSSCH (carrying user specific data, also referred to as downlink, uplink and sidelink payload data), a physical broadcast channel PBCH and a physical sidelink broadcast channel PSBCH (carrying, for example, a master information block (MIB) and one or more system information blocks (SIBs), one or more sidelink information blocks (SLIBs), if supported, a physical downlink control channel PDCCH, a physical uplink control channel PUCCH and a physical sidelink control channel PSSCH (carrying, for example, downlink control information DCI, uplink control information UCI and sidelink control information SCI), and a physical sidelink feedback channel PSFCH (carrying PC5 feedback responses). The sidelink interface may support 2-stage SCI, which involves a first control region containing some parts of the SCI, also referred to as the first stage SCI, and optionally, a second control region containing a second part of the control information, also referred to as the second stage SCI.

[0004] For the uplink, the physical channel may further include a physical random access channel PRACH or RACH, which the UE uses to access the network once it is synchronized and obtains the MIB and SIB. Physical signals may include reference signals or symbols (RS), synchronization signals, etc. The resource grid may include a frame or radio frame with a specific duration in the time domain and a given bandwidth in the frequency domain. A frame may have a certain number of subframes of a predetermined length, such as 1 millisecond. Each subframe may include one or more time slots of 12 or 14 OFDM symbols, depending on the cyclic prefix (CP) length. The frame may also have a smaller number of OFDM symbols, for example, when utilizing a shortened transmission time interval (sTTI, shortened transmission time interval) or a micro-slot / non-slot-based frame structure that includes only a few OFDM symbols.

[0005] The wireless communication system may be any single tone or multi-carrier system using frequency division multiplexing, such as an orthogonal frequency division multiplexing (OFDM) system, an orthogonal frequency division multiple access (OFDMA) system, or any other signal based on an inverse fast Fourier transform IFFT with or without a cyclic prefix CP, such as a discrete Fourier transform-spread OFDM (DFT-s-OFDM). Other waveforms may also be used, such as multiple access non-orthogonal waveforms, such as filter bank multi-carrier (FBMC), generalized frequency division multiplexing (GFDM), or universal filter multi-carrier (UFMC). The wireless communication system may, for example, operate according to 3GPP LTE, LTE-advanced, LTE-advanced Pro, or 5G or 3GPP New Radio (NR), or operate within LTE Unlicensed (LTE-U) or New Radio Unlicensed (NR-U) (specified in the LTE specification and the NR specification).

[0006] The wireless network or communication system depicted in FIG. 1 may be a heterogeneous network with different overlapping networks, such as a macro cell network, each macro cell including a macro base station (such as a base station gNB 1 To gNB 5 ) and a network of small cell base stations (not shown in FIG. 1 ), such as femto or pico base stations. In addition to the above-mentioned terrestrial wireless networks, there are also non-terrestrial wireless communication networks NTN, including space transceivers such as satellites and / or airborne transceivers such as unmanned aircraft systems. The non-terrestrial wireless communication network or system can operate in a similar manner to the terrestrial system described above with reference to FIG. 1 , for example according to LTE-Advanced Pro or 5G or New Radio NR.

[0007] In a mobile communication network, for example, in a network as described above with reference to FIG. 1 (such as an LTE or 5G / NR network), there may be UEs that communicate directly with each other through one or more side link SL channels, for example, using a PC5 / PC3 interface or WiFi direct connection. UEs that communicate directly with each other through side links may include vehicles that communicate directly with other vehicles (V2V communication), vehicles that communicate with other entities of a wireless communication network (V2X communication), such as roadside units RSU, roadside entities (such as traffic lights, traffic signs, or pedestrians). Depending on the specific network configuration, the RSU may have the functionality of a BS or the functionality of a UE. Other UEs may not be vehicle-related UEs and may include any of the above-mentioned devices. These devices may also communicate directly with each other using SL channels, i.e., D2D communication.

[0008] When considering two UEs communicating directly with each other via a sidelink, the two UEs may be served by the same base station, such that the base station may provide sidelink resource allocation configuration or assistance to the UEs. For example, both UEs may be within the coverage area of ​​a base station, such as one of the base stations shown in FIG1 . This is referred to as the “in coverage” scenario. Another scenario is referred to as the “out of coverage” scenario. It should be noted that “out of coverage” does not mean that the two UEs are necessarily outside of one of the cells shown in FIG1 , but rather that these UEs:

[0009] - may not be connected to the base station, e.g. they are not in an RRC connected state, such that the UE does not receive any sidelink resource allocation configuration or assistance from the base station, and / or

[0010] - may be connected to a base station, but due to one or more reasons, the base station may not provide sidelink resource allocation configuration or assistance to the UE, and / or

[0011] -May be connected to base stations that may not support NR V2X services, such as GSM, UMTS, LTE base stations.

[0012] FIG2( a) is a schematic diagram of a coverage scenario in which two UEs communicating directly with each other are both connected to a base station. The coverage area of ​​the base station gNB is schematically represented by a circle 200, which corresponds substantially to the cell schematically represented in FIG1 . The UEs communicating directly with each other include a first vehicle 202 and a second vehicle 204, both of which are located within the coverage area 200 of the base station gNB. Both vehicles 202 and 204 are connected to the base station gNB, and furthermore, they are directly connected to each other via a PC5 interface. Scheduling and / or interference management of V2V traffic is assisted by the gNB via control signaling over the Uu interface, which is the radio interface between the base station and the UE. In other words, the gNB provides SL resource allocation configuration or assistance to the UE, and the gNB allocates resources to be used for V2V communication via a side link. This configuration is also referred to as a mode 1 configuration in NR V2X or a mode 3 configuration for LTE V2X. Thus, in Mode 1, a SL UE (e.g., UE 202) is connected to the gNB via a Uu interface, and the gNB coordinates resources of UE 202 to be used to transmit control and / or data to another UE (e.g., UE 204) via a SL interface (which is referred to as PC5 in NR).

[0013] FIG2( b) is a schematic diagram of an out-of-coverage scenario, in which UEs communicating directly with each other are either not connected to a base station, although they may be physically located within a cell of a wireless communication network, or some or all of the UEs communicating directly with each other are connected to a base station, but the base station does not provide SL resource allocation configuration or assistance. Three vehicles 206, 208, and 210 are shown as communicating directly with each other via a side link, for example, using a PC5 interface. The scheduling and / or interference management of V2V traffic is based on an algorithm implemented between vehicles. This configuration is also referred to as a Mode 2 configuration in NR V2X or as a Mode 4 configuration in LTE V2X. As described above, the scenario in FIG2( b), which is an out-of-coverage scenario, does not necessarily mean that the corresponding Mode 2 UE in NR or Mode 4 UE in LTE is outside the coverage 200 of the base station, but means that the corresponding Mode 2 UE in NR or Mode 4 UE in LTE is not served by the base station, is not connected to a base station in the coverage area, or is connected to a base station but does not receive SL resource allocation configuration or assistance from the base station. Therefore, there may be a situation where, in addition to UEs 202, 204 of NR mode 1 or LTE mode 3, UEs 206, 208, 210 of NR mode 2 or LTE mode 4 may exist within the coverage area 200 shown in FIG. 2(a). In addition, FIG. 2(b) schematically illustrates an out-of-coverage UE that uses a relay device to communicate with the network. For example, UE 210 may communicate with UE 212 via a side link, and UE 212 may be connected to the gNB via a Uu interface. Therefore, UE 212 may relay information between the gNB and UE 210. Therefore, SL UEs (e.g., UEs 206-210) do not need to have a connection to the gNB, and, for example, when transmitting from UE 206 to UE 208, sensing and access resource allocation or random access-based resource allocation are performed. However, in order to successfully exchange data, basic configuration needs to be available to UEs 206-210. Such information may be pre-configured or may be configured when the UE is within the coverage of the gNB. To this end, the gNB may provide basic configuration, such as basic information, which may be propagated via a broadcast channel, for example, using a system information block (SIB). The BS may also assist the Mode 2 UE to provide basic information about which resource pool (RP) to use or may serve as a synchronization source.

[0014] Although Figures 2(a) and 2(b) illustrate vehicle UEs, it should be noted that the described in-coverage and out-of-coverage scenarios also apply to non-vehicle UEs. In other words, any UE (such as a handheld device) that communicates directly with another UE using an SL channel can be in-coverage and out-of-coverage.

[0015] In the above scenario of a vehicle user equipment (UE), a plurality of such user equipment may form a user equipment group, also referred to as a group, and communication between members within or between groups may be performed via a side link interface (such as a PC5 interface) between user equipment. For example, the above scenario using a vehicle user equipment may be applied to the field of the transportation industry, in which a plurality of vehicles equipped with vehicle user equipment may be grouped together, for example, through a remote driving application. Other use cases in which a plurality of user equipment may be grouped together for side link communication with each other include, for example, factory automation and power distribution. In the case of factory automation, a plurality of mobile or fixed machines within a factory may be equipped with user equipment and grouped together for side link communication, for example for controlling the operation of the machines, such as motion control of a robot. In the case of power distribution, entities within a distribution network may be equipped with corresponding user equipment, which may be grouped together within a certain area of ​​the system to communicate with each other via side link communication, thereby allowing monitoring of the system and allowing handling of distribution network faults and power outages.

[0016] It should be noted that the information in the above section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art already known to a person of ordinary skill in the art.

[0017] Based on the above, it may be necessary to improve or enhance the side link in the wireless communication system or network.

[0018] Now, embodiments of the present invention are described in further detail with reference to the accompanying drawings:

[0019] FIG1 is a schematic diagram of an example of a terrestrial wireless network;

[0020] Figure 2(a) is a schematic diagram of a scene within the coverage area;

[0021] Figure 2(b) is a schematic diagram of a scenario outside the coverage area;

[0022] Figure 3 is a schematic diagram of a wireless communication system for implementing an embodiment of the present invention, the wireless communication system comprising a transmitter (such as a base station) and one or more receivers (such as user equipment (UE));

[0023] Figure 4 illustrates COT sharing in the case where a responding UE simultaneously receives SCI and data from an initiating UE and uses the COT for transmission to a further UE;

[0024] Figure 5 illustrates COT sharing in the case where a responding UE receives only SCI associated with data transmitted by an initiating UE and transmits to further UEs using COT;

[0025] Figure 6 The figure shows a wireless communication system including a user equipment and a base station according to an embodiment of the present invention;

[0026] Figure 7 illustrates an example of UE sharing a COT with future reservation; and

[0027] Figure 8 The figure shows an example of a computer system on which the units or modules described according to the method of the present invention and the steps of the method can be executed.

[0028] Embodiments of the present invention will now be described in more detail with reference to the accompanying drawings, wherein the same or similar elements are designated with the same reference numerals.

[0029] In a mobile communication system or network, such as those described above with reference to FIG. 1 , for example, in an LTE or 5G / NR network, corresponding entities may communicate using one or more frequency bands. A frequency band includes a starting frequency, an ending frequency, and all intermediate frequencies between the starting frequency and the ending frequency. In other words, the starting frequency, the ending frequency, and the intermediate frequencies may define a certain bandwidth, such as 20 MHz. A frequency band may also be referred to as a carrier or subcarrier, a bandwidth part (BWP), a subband, a subchannel, etc.

[0030] When a single frequency band is used, the communication may be referred to as single-band operation, for example, the UE sends / receives radio signals to / from another network entity on a frequency within the frequency band (eg, a 20 MHz band).

[0031] When two or more frequency bands are used, the communication may be referred to as multi-band operation or as wideband operation or as carrier aggregation operation. The frequency bands may have different bandwidths or may have the same bandwidth, such as 20 MHz. For example, in the case where the frequency bands have the same bandwidth, the UE may send / receive radio signals to / from another network entity at frequencies within two or more 20 MHz frequency bands, so that the frequency range of the radio communication may be a multiple of 20 MHz. The two or more frequency bands may be continuous / adjacent frequency bands, or part or all of the frequency bands may also be separated in the frequency domain.

[0032] Multi-band operation may include frequency bands in the licensed spectrum, frequency bands in the unlicensed spectrum, or frequency bands in both the licensed spectrum and the unlicensed spectrum.

[0033] Carrier aggregation (CA) is an example of using two or more frequency bands in the licensed spectrum and / or in the unlicensed spectrum. Mixed combinations are also possible, for example, one or more frequency bands in the licensed band and one or more frequency bands in the unlicensed band. In addition, CA can also be used to aggregate additional carriers in only one direction, for example as supplementary carriers to improve transmission via UL, DL or SL.

[0034] 5G New Radio (NR) can support operation in an unlicensed spectrum so that single-band operation or multi-band operation can include bands or sub-bands in the unlicensed spectrum. The unlicensed spectrum may include bands with potential IEEE802.11 coexistence, such as bands within the 5 GHz and / or 6 GHz spectrum. For example, due to regulatory requirements, NR-U can support bandwidths of integer multiples of 20 MHz. Sub-band segmentation can be performed to minimize interference to coexisting systems (such as IEEE802.11 systems), which can operate in the same band with one or more channels with the same nominal bandwidth (such as a 20 MHz channel). Other examples of coexistence systems may use sub-bands with sub-band sizes and nominal frequencies different from those of the above-mentioned IEEE 802.11 systems. For example, the unlicensed spectrum may include a 5 GHz band, a 6 GHz band, a 24 GHz band, and a 60 GHz band. Examples of these unlicensed bands include the Industrial, Scientific and Medical (ISM) radio bands, which are reserved internationally for the use of radio frequency energy for industrial, scientific and medical purposes other than telecommunications.

[0035] During operation using unlicensed sub-bands, Listen-before-talk (LBT) can be performed individually on a per-sub-band basis. This may result in a situation where one or more sub-bands are busy or occupied due to interference, for example from other communication systems co-existing on the same band, such as other public land mobile networks (PLMNs) or systems operating according to the IEEE 802.11 specification or systems operating according to the ETSI Broadband Radio Access Network (BRAN) specification. In this situation, the transmitter (transmitting gNB or transmitting UE) is only allowed to transmit on sub-bands that are detected to be not busy (also referred to as idle or unoccupied sub-bands). For example, for transmissions spanning more than 20 MHz in the 5 GHz operational unlicensed band, the transmitter (such as a gNB or UE) performs LBT individually on each sub-band. Once the LBT results are available for each subband, the device (e.g., gNB in ​​the downlink DL or UE in the uplink UL) is allowed to transmit on those subbands determined to be idle or unoccupied, i.e., on the winning subbands. Transmission is not allowed on subbands that are occupied, busy, or not winning.

[0036] In order to access resources or channels in the unlicensed spectrum, a so-called NR-U channel access is performed, which utilizes a channel access procedure, which is a procedure based on the assessment of the availability of a channel for performing transmissions. The basic unit for sensing may be a sensing slot with a certain duration, e.g., T si =9μs. If the base station or UE senses the channel during the sensing time slot duration and determines that the power detected is less than the energy detection threshold for at least a certain time (such as 4μs) within the sensing time slot duration, then the sensing time slot duration T is considered to be si is idle. Otherwise, the sensing slot duration is considered to be busy. When the channel is available or not busy, one or more transmissions can be performed on the channel, and the so-called channel occupancy refers to one or more transmissions performed by the base station or UE on one or more channels after performing the corresponding channel access procedure. The channel occupancy time COT refers to the total time that the base station or UE and any other base station or UE can share the channel occupancy to perform one or more transmissions on the channel after the base station or UE performs the channel access procedure CAP.

[0037] To determine the channel occupancy time, if the transmission gap is less than or equal to a certain period (eg, 25 μs), the gap duration is counted into the channel occupancy time. The channel occupancy time may be shared by the transmission between the base station and the corresponding UE.

[0038] There may be several types of channel access procedures (CAP), for example:

[0039] - The duration that a Type 1 CAP sensed channel needs to be idle before transmission can be random. For example, the base station or UE can determine an initial counter N that is randomly selected to be between 0 and CW. p Among them, CW min,p ≤CW p ≤CW max,p , C.W. min,p and CW max,p Limited by the channel access procedure class (CAPC), when the channel is sensed to be idle for a certain period of time, the value of N is reduced, and transmission is performed only when N reaches 0.

[0040] - Type 2A: The duration that the sensed channel needs to be idle before transmission may be determined, and the channel may need to be idle for two sensing slots (eg at the beginning and end) within a sensing interval of a first duration (eg 25 μs).

[0041] - Type 2B: The duration that the sensed channel needs to be idle before transmission may be determined, and the channel may need to be idle for one sensing slot within a sensing interval of a second duration (eg, 16 μs) shorter than the first duration.

[0042] - Type 2C: This type does not perform any sensing on the channel before transmission, and the duration of the corresponding transmission may have a predefined duration, for example, a maximum of 584 μs. This may also be referred to as a non-LBT CAP.

[0043] Once the UE performs the channel access procedure CAP, the UE occupies the given frequency band or channel on which it performs the CAP and the COT starts. The UE is also referred to as an initiating UE. The initiating UE may also share the COT with another gNB or with another UE (also referred to as a responding UE) in the case of a sidelink communication SL-U using resources from an unlicensed spectrum (such as an unlicensed SL resource pool SL-U RP, including multiple resources from an unlicensed spectrum to be used for SL transmission). For a sidelink communication SL-U using unlicensed spectrum, when the initiating UE shares the COT with another or responding UE (also referred to as UE-to-UE COT sharing), despite the fact that the responding UE uses the shared COT on which the initiating UE has performed a CAP (such as LBT), the responding UE needs to use the CAP to check the availability of the shared channel. The CAP adopted by the responding UE may be shorter than the CAP adopted by the initiating UE, for example a shorter LBT, such as the type 2A CAP or type 2B CAP referenced above. In the case where the responsive UE sends feedback (such as PSFCH), since the feedback only spans two or three codewords, the feedback can be classified as a short transmission, and the UE can also perform a Type 2C CAP without performing any LBT, such as a no-LBT CAP.

[0044] Traditionally, UE-to-UE COT sharing is considered for two scenarios or alternatives:

[0045] - Alternative 1:

[0046] In case that the responding SL-UE is a target receiver of PSSCH data transmission performed by the COT initiating UE during the COT, the responding SL-UE may utilize the COT shared by the COT initiating UE.

[0047] - Alternative 2:

[0048] In case that the responding SL-UE is a target receiver of control message transmission (eg, SCI) performed by the COT initiating UE during the COT, the responding SL-UE may utilize the COT shared by the COT initiating UE.

[0049] Therefore, for both alternatives, the condition that the initiating UE can share the COT with another or responding UE is that the responding UE is the target receiver mentioned. The initiating UE can provide the COT sharing information to the responding UE using the sidelink control information SCI. Since the SCI is transmitted in the PSCCH, all UEs within the range of the initiating UE will receive the COT sharing information. According to the above alternative 1, the main limitation is that only UEs that receive the SCI together with the data transmission can use the shared COT, while according to alternative 2, it is sufficient for the UE to only receive the SCI containing the COT sharing information, and is therefore called a target receiver. An additional condition applicable to the above two alternatives is that the COT initiating UE needs to be the target receiver of the transmission transmitted by the responding UE on the shared COT.

[0050] Therefore, there are essentially four options for operating the responding UE based on two factors, namely based on what the responding UE receives from the initiating UE and what the initiating UE receives when the responding UE uses COT.

[0051] - Option 1:

[0052] Assuming that the responding UE receives SCI and data simultaneously from the initiating UE, as shown in Alternative Solution 1, the initiating UE also receives SCI and data simultaneously from the responding UE using the shared COT.

[0053] - Option 2:

[0054] Assuming that the responding UE receives both SCI and data from the initiating UE, as shown in Alternative 1, the initiating UE may receive only SCI from the responding UE using the shared COT.

[0055] This is Figure 4 is shown in the figure, Figure 4 A COT initiating UE (UE1) and a responding UE (UE2) are shown. UE1 performs a channel access procedure for a specific frequency band or channel including resources from an unlicensed spectrum and occupies the channel for a certain COT duration after a successful CAP. As schematically illustrated at 310, UE1 performs transmission by sending an SCI and data associated with the SCI. In addition, the SCI includes COT sharing information.

[0056] According to option 2, UE2 uses COT sharing information to share the COT initiated by UE1 to perform transmission. As shown in 312, UE2 can use the shared COT to send data to a further UE (UE3), provided that UE1 also receives the SCI associated with the data sent by UE2 to UE3. Figure 4 314 is schematically illustrated.

[0057] - Option 3:

[0058] Assuming that the responding UE receives only the SCI from the initiating UE, as shown in Alternative 2, the initiating UE may receive both the SCI and data from the responding UE.

[0059] - Option 4:

[0060] Assuming that the responding UE receives only SCI from the UE, as shown in alternative 2, the initiating UE may also receive only SCI from the responding UE using the shared COT, as shown in alternative 2. Figure 5 Schematic diagram in the figure.

[0061] Figure 5 The figure shows a COT initiating UE (UE1), a responding UE (UE2) and a further UE (UE3), which can communicate with each other via sidelink resources in an unlicensed spectrum. After occupying the channel and establishing the COT, UE1 performs a transmission that is neither directed to UE2 nor UE3, however, the SCI associated with the transmission is received at both UE2 and UE3, as schematically shown in 310a and 310b. The SCI provided by UE1 contains COT sharing information to allow any one of UE2 and UE3 to perform a transmission using the shared COT.

[0062] exist Figure 5 In the example above, it is assumed that UE2 is Figure 4 The same manner as described is used to perform data transmission to UE3 using the shared COT, and it is assumed that the SCI associated with the transmission from UE2 to UE3 is also received at UE1, as schematically illustrated at 314.

[0063] When considering the above options, it can be seen that all options assume that UE2 and UE3 can share the COT in response to receiving SCI from UE1. While the relationship between UE1 and UE2 may be clear in options 1 and 2, since only UEs that receive both SCI and data transmission (i.e., UE2 in the above options) can share the COT initiated by UE1, at least options 3 and 4 allow any UE that receives SCI within range of UE1 (e.g., UE2 in the above options) to share the COT initiated by UE1. Figure 5As shown in 310a and 310b in the figure, i.e., UE2 or UE3) shares the COT. Therefore, there is either limited control (option 1 and option 2) which UEs can share the COT, or there may be no control at all which of the other UEs can actually share the COT (option 3 and option 4). This is disadvantageous because in a crowded scenario where there is no control over COT sharing as described above, too many UEs may compete to acquire the COT and transmit in many UEs trying to transmit in the unlicensed spectrum. This leads to a greater number of collisions and / or increased interference between UEs trying to decode control and / or data. On the other hand, if the control is limited, for example, in the case where a UE may only share the COT with another UE if it has data to send to this UE, this may be too restrictive because the responding UE may not benefit from the shared COT and needs to perform the CAP operation itself. Therefore, this wastes the precious COT, which can be easily allocated by the COT initiating UE even in the absence of data, and the COT sends the COT sharing information as control to the other UE. Furthermore, additional CAPs incur additional latency, so COT sharing without these constraints improves latency-constrained data transmission in unlicensed spectrum.

[0064] Embodiments of the present invention solve the above-mentioned problem by providing a method according to which an initiating UE (also referred to as a transmitting TX UE) determines one or more further network entities (e.g., further UEs, base stations BS, roadside units RSU or WiFi devices, etc.) to share the COT it initiated using the SCI previously received from one or more network entities in the vicinity of the initiating UE. Therefore, according to the method of the present invention, not only the fact that the initiating UE performs a transmission on an occupied channel is taken into account, but also the transmissions that may be scheduled by other network entities (so-called upcoming transmissions) are taken into account, which are evaluated using control messages associated with the upcoming transmissions (such as SCI). Therefore, an improved control of which one (one or more) of the network devices can share the COT initiated by the UE is achieved, which provides the following advantages:

[0065] -COT initiating UEs can share the COT, which increases the probability that other SL-U UEs can successfully transmit in the unlicensed spectrum using the COT.

[0066] -Another advantage is that the COT initiating UE can provide some further COT sharing information in order to limit the use of the shared COT to a specific group of SL-U UEs, such as a group with a specific group ID, or to limit the use of the shared COT to packet transmissions with packets of a specific priority, such as high priority packets based on 5G packet-per-packet priority (PPP).

[0067] - Yet another advantage is that it reduces the CAP burden on other UEs operating in the SL-U. These UEs can reduce their sensing work. Reduced sensing also means that these UEs can save power, for example, they can also perform discontinuous reception DRX instead of receiving and decoding data. This is also particularly beneficial for low-power UEs (such as pedestrian UEs, P-UEs) because their battery supply may be limited.

[0068] An embodiment of the present invention may be implemented in a wireless communication system as shown in FIG. 1 , FIG. 2( a ) or FIG. 2( b ), wherein the wireless communication system includes a base station and a user, such as a mobile terminal or an IoT device. Figure 3 3 is a schematic diagram of a wireless communication system including a transmitter 300 (such as a base station) and one or more receivers 302, 304 (such as user equipment UE). The transmitter 300 and the receivers 302, 304 can communicate via one or more wireless communication links or channels 306a, 306b, 308 (such as radio links). The transmitter 300 may include one or more antennas ANT coupled to each other. T Or an antenna array having a plurality of antenna elements, a signal processor 300a and a transceiver 300b. The receivers 302, 304 include one or more antennas ANT coupled to each other. UE Or an antenna array with multiple antennas, a signal processor 302a, 304a and a transceiver 302b, 304b. The base station 300 and the UE 302, 304 can communicate via corresponding first wireless communication links 306a and 306b (such as radio links using Uu interfaces), while the UE 302, 304 can communicate with each other via a second wireless communication link 308 (such as a radio link using PC5 or a side link SL interface). When the UEs are not served by the base station or are not connected to the base station, for example, they are not in an RRC connected state, or more generally, when the base station does not provide SL resource allocation configuration or assistance, the UEs can communicate with each other via the side link. Figure 3 systems or networks, Figure 3 One or more UEs 302, 304 and Figure 3 The base station 300 may operate according to the inventive teachings described herein.

[0069] UE initiates COT

[0070] The present invention provides a user equipment UE for a wireless communication network, wherein the wireless communication network is a third generation partnership project 3GPP network.

[0071] wherein the UE is configured to perform sidelink (SL) communication using a channel including resources from an unlicensed spectrum,

[0072] The UE is used to occupy the channel within the channel occupation time COT.

[0073] wherein the UE is configured to receive one or more control messages, wherein at least one of the control messages is associated with one or more upcoming SL transmissions by one or more network entities of the wireless communication network, and

[0074] The UE is configured to determine at least one network entity having an upcoming transmission using one or more control messages between one or more network entities, and share a COT with the at least one network entity.

[0075] According to an embodiment, the UE shares the COT with

[0076] - a network entity in case of frequency-continuous, non-interleaved transmissions by the UE and / or by the network entity, or

[0077] - more than one network entity in case of interleaved transmissions by the UE and / or by the network entity, up to the number of interleavings, or

[0078] - More than one network entity in case of feedback transmission, eg over the Physical Sidelink Feedback Channel PSFCH.

[0079] According to an embodiment, the UE is configured to perform a transmission during a first portion of the COT, and the network entity is configured to perform an upcoming transmission using all or one or more sub-portions of a second portion of the COT, wherein the second portion of the COT includes a duration of the COT that remains after the UE's transmission is completed.

[0080] According to an embodiment, the UE is used to share

[0081] - a first subdivision of the second part of the COT for feedback transmissions by a network entity receiving the UE's transmissions in the first part of the COT and / or by one or more other network entities, such as a PSFCH, and / or

[0082] - A second subdivision of the second part of the COT for further transmission by the network entity or another network entity only after completing the feedback transmission.

[0083] According to an embodiment, the UE is used to indicate COT sharing of a first sub-share and / or a second sub-share of a second part of the COT within a control message, wherein the control message is associated with a transmission performed by the UE in the first part of the COT, such as an SCI message, or the control message is associated with a transmission of an earlier sub-share within the second part of the COT, such as via an SCI message.

[0084] According to an embodiment, the UE is configured to share a second portion of the COT with a network entity that receives transmissions from the UE in the first portion of the COT to perform one or more of the following:

[0085] Feedback transmission PSFCH,

[0086] Data transmission PSSCH,

[0087] Control signaling PSCCH,

[0088] The transmission of demodulation reference symbols DMRS,

[0089] Automatic gain control AGC signal.

[0090] According to an embodiment, the UE is configured to indicate COT sharing of the second part of the COT within a control message associated with a transmission performed by the UE in the first part of the COT, such as an SCI message.

[0091] According to an embodiment, the SCI message contains information about the time slot structure to be used for transmission in the second part of the COT, for example, any combination of one or more of the following:

[0092] -Feedback only,

[0093] -Data only,

[0094] -DMRS only,

[0095] -Feedback and data,

[0096] -DMRS and feedback and data,

[0097] - Remaining COT duration,

[0098] - COT priority,

[0099] - Transmission range,

[0100] - type of transmission, e.g. type of propagation,

[0101] - No feedback transmission etc.

[0102] According to an embodiment, the feedback transmission PSFCH is performed by the network entity receiving the transmission performed by the UE in the first part of the COT, or by one or more further network entities.

[0103] According to an embodiment,

[0104] In a time interval following a transmission by the UE, some or all of the upcoming transmissions by the network entity are performed at different times, and

[0105] The UE is configured to share the COT with a network entity performing an upcoming transmission at a specific point in the time interval, wherein the specific point includes an earliest point in the time interval or any other later point.

[0106] According to an embodiment, the time interval is defined by a remaining COT timer or by a COT duration.

[0107] According to an embodiment, the UE is configured to receive one or more control messages before occupying a channel.

[0108] According to an embodiment, the UE is configured to respond to the following request for occupying a channel for COT:

[0109] - receiving a grant from one or more of the network entities indicating a channel, or interlace, or PSFCH index to be used by the UE, and / or

[0110] - determining the resources to be used within the channel based on a sensing process and a resource selection process, and / or

[0111] - A successful channel access procedure CAP performed by the UE on the channel.

[0112] According to an embodiment, the one or more control messages include one or more of the following:

[0113] - Sidelink Control Information SCI message,

[0114] - Downlink Control Information DCI message,

[0115] -Configuration approval CG configuration,

[0116] -MAC-CE,

[0117] -RRC configuration,

[0118] - Inter-UE coordination of IUC messages,

[0119] -Assistance Information Message AIM.

[0120] According to an embodiment, the control message is transmitted in one or more of the following:

[0121] - Stage I SCI,

[0122] - Stage II SCI,

[0123] -PDCCH,

[0124] -Media Access Control Layer Element, MAC CE,

[0125] -Radio Resource Control RRC messages, such as SL-RRC messages.

[0126] According to an embodiment, in the case of an SCI message, the UE is configured to determine whether an upcoming transmission by a network entity is to be performed during the COT using resource reservation or resource allocation information in the SCI message, such as a time resource indicator value TRIV and / or a frequency resource indicator value FRIV and / or an inter-UE coordination message IUC.

[0127] According to an embodiment, the resource allocation information includes future resource reservation information using a time resource indicator value TRIV and / or a frequency resource indicator value FRIV included in the SCI message and / or the inter-UE coordination message IUC.

[0128] According to an embodiment, in case the SCI message is for periodic transmission, the UE is configured to determine whether an upcoming transmission by the network entity is to be performed during the COT using the resource reservation periodicity and / or the resource reselection counter in the SCI message.

[0129] According to an embodiment, in case of a DCI message, the UE is configured to determine from the DCI at least one network entity with which the UE will share the COT.

[0130] According to an embodiment, in case of a CG configuration, the UE is used to determine from the CG configuration at least one network entity with which the UE will share the COT.

[0131] According to an embodiment,

[0132] The UE is configured to receive signaling indicating that COT sharing is enabled, or

[0133] The UE is configured to determine that COT sharing is enabled through system level configuration or pre-configuration, such as resource pool configuration.

[0134] According to an embodiment, the signaling includes one or more of the following:

[0135] - Downlink Control Information DCI message,

[0136] - Resource pool RP configuration,

[0137] -Configuration approval CG configuration,

[0138] - Sidelink Control Information SCI message,

[0139] - Downlink Control Information DCI message,

[0140] - Inter-UE coordination of IUC messages,

[0141] -Assistance Information Message AIM.

[0142] According to an embodiment, the signaling includes a flag indicating whether COT sharing is enabled for a channel or interlace to be used by the UE.

[0143] According to an embodiment, the signaling indicates a remaining COT time and / or a maximum COT time of the COT shared by the UEs.

[0144] According to an embodiment, the signaling indicates one or more of the following:

[0145] - Maximum COT time,

[0146] - Specific conditions when COT sharing is enabled, such as enabling COT sharing when one or more of the following occurs:

[0147] ο The remaining COT time exceeds a predefined threshold,

[0148] o an upcoming transmission to be performed by the network entity has a priority exceeding a predefined threshold,

[0149] o an upcoming transmission to be performed by a network entity has a specific identification ID,

[0150] o an upcoming transmission to be performed by the network entity belongs to a specific UE group,

[0151] o feedback has been enabled for upcoming transmissions to be performed by the network entity,

[0152] o the transmission to be performed by the UE or the upcoming transmission to be performed by the network entity has a predefined propagation type, o the communication range of the transmission to be performed by the UE or the communication range of the upcoming transmission by the network entity is below a predefined threshold,

[0153] o The network entity is located at a position less than a predefined threshold from the UE, for example within a minimum communication range MCR.

[0154] According to an embodiment, the UE is configured to determine one or more of the following information from an SCI previously received from a network entity or from signaling to determine characteristics of an upcoming transmission:

[0155] - the priority of the upcoming transmission,

[0156] - Network entity identification ID, such as UE ID,

[0157] - the group ID that the network entity is associated with or is a part of,

[0158] - whether feedback is enabled or disabled,

[0159] - the type of propagation transmitted,

[0160] -Minimum communication range.

[0161] According to an embodiment, the RP configuration indicates whether COT sharing is enabled for some or all of the resources or interlaces from an unlicensed SL resource pool SL-U RP, which SL-U RP includes multiple resources and / or interlaces from the unlicensed spectrum to be used for SL transmission.

[0162] According to an embodiment, in order to share the COT, the UE is configured to send a COT sharing control message to a network entity.

[0163] According to an embodiment, the COT sharing control message is transmitted in one or more of the following:

[0164] - Sidelink control information SCI message, such as first stage SCI and / or second stage SCI,

[0165] -Media Access Control Layer Element, MAC CE,

[0166] -Radio Resource Control RRC messages, such as SL-RRC messages.

[0167] According to an embodiment, the UE is configured to provide COT sharing information in one or more of the following:

[0168] - a first stage SCI and a MAC CE, wherein the first stage SCI indicates a physical side link shared channel PSSCH, wherein the physical side link shared channel PSSCH contains a MAC CE including COT sharing information,

[0169] - a second stage SCI and a MAC CE, wherein the second stage SCI indicates a physical side link shared channel PSSCH, wherein the physical side link shared channel PSSCH contains a MAC CE including COT sharing information,

[0170] - Stage 1 SCI only,

[0171] - Stage II SCI only,

[0172] - Stage I SCI and Stage II SCI,

[0173] - a first stage SCI and a second stage SCI and a MAC CE, wherein the first stage SCI and / or the second stage SCI indicates a physical sidelink shared channel PSSCH, wherein the physical sidelink shared channel PSSCH contains a MAC CE including COT sharing information,

[0174] -MAC CE only.

[0175] According to an embodiment, COT shared information includes

[0176] - the destination ID of the network entity, and / or

[0177] - Feedback indicators, such as PSFCH indicators,

[0178] - Remaining COT time, and / or

[0179] - Maximum COT time.

[0180] According to an embodiment, the COT sharing information is transmitted via unicast or multicast or broadcast.

[0181] According to an embodiment, the UE is configured to share the COT according to one or more conditions, for example, according to one or more of the following:

[0182] - The remaining COT time exceeds a predefined threshold,

[0183] - a transmission to be performed by the UE and / or an upcoming transmission to be performed by a network entity has a priority exceeding a predefined threshold,

[0184] - the upcoming transmission to be performed by the network entity has a specific identification ID or belongs to a specific UE group,

[0185] - a transmission to be performed by the UE and / or an upcoming transmission to be performed by a network entity has feedback enabled,

[0186] - a transmission to be performed by the UE and / or an upcoming transmission to be performed by a network entity has a predefined spreading type,

[0187] - a remaining packet delay budget PDB of a transmission to be performed by the UE and / or of an upcoming transmission to be performed by a network entity exceeds a predefined threshold,

[0188] - the communication range of a transmission to be performed by the UE and / or an upcoming transmission to be performed by a network entity is below a predefined threshold,

[0189] - the number of time slots for transmissions to be performed by the UE and / or for upcoming transmissions to be performed by a network entity exceeds a predefined threshold,

[0190] - the network entity is located at a distance from the UE that is less than a predefined threshold, such as within the minimum communication range MCR,

[0191] -The network entity is located within a specific area or geographic location.

[0192] UE Shared COT

[0193] The present invention provides a user equipment UE for a wireless communication network, wherein the wireless communication network is a third generation partnership project 3GPP network.

[0194] wherein the UE is configured to perform sidelink (SL) communication using a channel including resources from an unlicensed spectrum,

[0195] wherein the UE is configured to receive one or more control messages, wherein the control messages are associated with an upcoming SL transmission by one or more network entities of a wireless communication network, and

[0196] The UE is used to: determine at least one network entity of a wireless communication system using one or more control messages to occupy a channel for transmission within a channel occupation time COT, and use the complete remaining COT or only one or more parts of the remaining COT to perform transmission within a shared COT.

[0197] According to an embodiment, the UE is configured to request a network entity to share the COT with the UE for one or more upcoming transmissions.

[0198] The present invention provides a user equipment UE for a wireless communication network, wherein the wireless communication network is a third generation partnership project 3GPP network.

[0199] wherein the UE is configured to perform sidelink (SL) communication using a channel including resources from an unlicensed spectrum,

[0200] In response to sharing a channel occupation time COT signaled by a network entity of a wireless communication system, the UE is configured to perform transmission using a channel previously occupied by the network entity for transmission by the network entity.

[0201] According to an embodiment, the UE is configured to receive one or more control messages before determining one or more network entities occupying a channel.

[0202] According to the embodiment, the network entity includes a user equipment UE according to the embodiment of the present invention.

[0203] According to an embodiment, the network entity is configured to perform transmission during a first part of the COT, and the UE is configured to perform transmission using all or one or more sub-parts of a second part of the COT, the second part of the COT comprising a duration of the COT that remains after the network entity's transmission is completed.

[0204] According to an embodiment, the UE is used to share

[0205] - a first subdivision of the second part of the COT for transmitting a feedback transmission PSFCH for transmissions made by the network entity in the first part of the COT, and

[0206] - A second sub-part of the second part of the COT is used for further transmission by the UE only after completing the feedback transmission.

[0207] According to an embodiment, the UE is used to receive COT sharing signaling of a first sub-portion and / or a second sub-portion of the second part of the COT within a control message, which control message is associated with a transmission performed by a network entity in the first part of the COT, such as an SCI message, or the control message is associated with a transmission of an earlier sub-portion within the second part of the COT, such as via an SCI message.

[0208] According to an embodiment, the UE is configured to share the second part of the COT with a network entity, which transmits the transmission to the UE in the first part of the COT to perform one or more of the following:

[0209] - Feedback transmission PSFCH,

[0210] - Data transmission PSSCH,

[0211] - Control signaling PSCCH,

[0212] -Automatic gain control AGC signaling,

[0213] - Transmission of demodulation reference symbols DMRS.

[0214] According to an embodiment, the UE is configured to receive COT signaling of a second part of the COT within a control message associated with a transmission performed by a network entity in a first part of the COT, such as an SCI message.

[0215] According to an embodiment, the SCI message contains information about the time slot structure to be used for transmission in the second part of the COT, for example, any combination of one or more of the following:

[0216] -Feedback only,

[0217] -Data only,

[0218] -DMRS only,

[0219] -Feedback and data,

[0220] -DMRS and feedback and data,

[0221] -Automatic gain control AGC signaling,

[0222] - No feedback transmission etc.

[0223] According to an embodiment, the feedback transmission PSFCH is performed by the UE or by one or more further network entities.

[0224] According to an embodiment, the UE is configured to perform transmission within a COT initiated by a network entity according to one or more conditions, for example according to one or more of the following:

[0225] - The remaining COT time exceeds a predefined threshold,

[0226] - a transmission to be performed by the UE and / or by a network entity has a priority exceeding a predefined threshold,

[0227] - the transmissions to be performed by the UE and by the network entity have the same priority,

[0228] - transmissions performed by the UE and / or by a network entity have enabled feedback,

[0229] - the transmission performed by the UE and / or by the network entity has a predefined propagation type,

[0230] - the remaining packet delay budget PDB for the transmission to be performed by the UE exceeds a predefined threshold,

[0231] - The communication range of the transmission to be performed by the UE and / or by the network entity is below a predefined threshold.

[0232] According to an embodiment, the UE includes one or more of the following: a power-limited UE; or a handheld UE, such as a UE used by pedestrians and called a vulnerable road user VRU or a pedestrian UE P-UE; or a body-worn or handheld UE used by public safety personnel and emergency personnel and called a public safety UE PS-UE; or an IoT UE, such as a sensor, actuator, or UE provided in a campus network to perform repetitive tasks and requiring input from a gateway node at periodic intervals; or a mobile terminal; or a stationary terminal; or a cell IoT-UE; or a SL UE; or a vehicle UE; or a vehicle group leader UE GL-UE; or a dispatch UE S-UE; or an IoT or narrowband IoT NB-IoT device; or a ground-based vehicle; or an aircraft; or an unmanned aircraft; or a mobile base station; or a roadside unit RSU; or a building; or any other item or device with network connectivity that enables an item / device to communicate using a wireless communication network, such as a sensor or actuator; or any other item or device with network connectivity that enables an item / device to communicate using a side link of a wireless communication network, such as a sensor or actuator; or any network entity with side link capability.

[0233] According to an embodiment, the network entity includes one or more of the following: a further UE, such as a UE, or a SL UE, or a group leader UE GL-UE; or a base station, such as a macro cell base station or a small cell base station; or a central unit of a base station; or a distributed unit of a base station; or an integrated access and backhaul IAB node; or a road side unit RSU; or a relay device; or a remote radio head; or an AMF; or an SMF; or a core network entity; or a mobile edge computing MEC entity; or a network slice in the context of NR or 5G core; or any sending / receiving point TRP that enables an item or device to communicate using a wireless communication network; an item or device having network connectivity to communicate using a wireless communication network.

[0234] The network entity serving the UE initiates COT

[0235] The present invention provides a network entity for a wireless communication network, the wireless communication network being, for example, a 3rd Generation Partnership Project 3GPP network.

[0236] The network entity is used to provide services for multiple user equipments UE, and the multiple user equipments are used to communicate with each other through a side link SL using resources from an unlicensed spectrum,

[0237] The multiple UEs include a specific user equipment UE according to an embodiment of the present invention.

[0238] According to an embodiment, the network entity is configured to signal a DCI message to a specific UE, the DCI message indicating a UE with which the specific UE is to share a COT.

[0239] According to an embodiment, the DCI message may further include one or more of the following:

[0240] - a flag indicating whether COT sharing is enabled for the approval indicating the channels to be used by the UE,

[0241] - The remaining COT time or the maximum COT time of the COT shared by the UE.

[0242] According to an embodiment, the network entity is configured to signal the resource pool configuration to one or more specific UEs.

[0243] According to an embodiment, the RP configuration further includes one or more of the following:

[0244] - Flag indicating whether COT sharing is enabled,

[0245] - List of flags indicating whether COT sharing is enabled based on transmission priority,

[0246] - Maximum COT time,

[0247] - List of maximum COT times according to transport priority.

[0248] System / Network

[0249] The present invention provides a wireless communication system, such as a 3rd Generation Partnership Project 3GPP system, comprising one or more user equipments UE according to an embodiment of the present invention and / or one or more network entities according to an embodiment of the present invention.

[0250] According to an embodiment, the base station includes one or more of the following: a macro cell base station, or a small cell base station, or a central unit of a base station, or a distributed unit of a base station, or an integrated access and backhaul IAB node, or a road side unit RSU, or a UE, or a SLUE or a group leader UE GL-U, or a relay device, or a remote radio head, or an AMF, or an SMF, or a core network entity, or a mobile edge computing MEC entity, or a network slice in the context of NR or 5G core, or any sending / receiving point TRP that enables an item or device to communicate using a wireless communication network, an item or device having network connectivity to communicate using a wireless communication network.

[0251] method

[0252] The present invention provides a method for operating a user equipment UE for a wireless communication network, such as a 3rd Generation Partnership Project 3GPP network, wherein the UE is configured to perform a sidelink SL communication using a channel including resources from an unlicensed spectrum, and wherein the method comprises:

[0253] Occupy the channel within the channel occupation time COT,

[0254] receiving one or more control messages, wherein at least one of the control messages is related to one or more upcoming SL transmissions by one or more network entities of the wireless communication network,

[0255] determining at least one network entity having an upcoming transmission using one or more control messages between the one or more network entities, and

[0256] The COT is shared with at least one network entity.

[0257] The present invention provides a method for operating a user equipment UE for a wireless communication network, such as a 3rd Generation Partnership Project 3GPP network, wherein the UE is configured to perform a sidelink SL communication using a channel including resources from an unlicensed spectrum, and wherein the method comprises:

[0258] receiving one or more control messages, wherein the control messages are related to an upcoming SL transmission by one or more network entities of the wireless communication network,

[0259] at least one network entity of a wireless communication system that uses one or more control messages to determine an occupied channel for transmission within a channel occupation time COT, and

[0260] The transfer is performed within the shared COT using the entire remaining COT or using only one or more portions of the remaining COT.

[0261] The present invention provides a method for operating a user equipment UE for a wireless communication network, such as a 3rd Generation Partnership Project 3GPP network, wherein the UE is configured to perform a sidelink SL communication using a channel including resources from an unlicensed spectrum, and wherein the method comprises:

[0262] In response to sharing the channel occupation time COT signaled from a network entity of the wireless communication system, transmission is performed using a channel previously occupied by the network entity for transmission by the network entity.

[0263] Computer program product

[0264] An embodiment of a first aspect of the present invention provides a computer program product, the computer program product comprising instructions, which, when the program is executed by a computer, cause the computer to perform one or more methods according to the present invention.

[0265] It should be noted that in the description given herein, when the above-mentioned "sharing of channel occupancy" is mentioned, this is also referred to as UE sharing COT or using a shared COT. This means that the UE can successfully perform CAP, and then partially use or not use the COT, and share the remaining COT or the entire COT with another UE. From the perspective of a UE using a shared COT, the UE can use a channel initially occupied by another UE within or during at least a portion of the COT that begins in response to other UEs occupying the channel. In addition, UE occupation of a channel does not necessarily mean that the UE is transmitting data on the COT, but rather that a given UE has successfully performed a CAP operation for this COT and shared the COT, for example by transmitting control information about this COT to another UE or a set of UEs, the other UE or set of UEs may occupy this COT for control and / or data transmission.

[0266] Embodiments of aspects of the present invention are now described in more detail with reference to the accompanying drawings. It should be noted that the aspects or embodiments summarized and described subsequently may be combined so that some or all of the aspects / embodiments are implemented in one embodiment. In addition, it should be noted that in this specification, when referring to "resources", resources should be understood to include one or more of the following:

[0267] - one or more code elements,

[0268] - one or more time slots or subframes or frames,

[0269] - one or more frequencies or carriers or subchannels or groups of subchannels,

[0270] - one or more interlaces,

[0271] - one or more frequency bands, such as unlicensed sub-bands,

[0272] - one or more bandwidth portions,

[0273] - one or more resource pools,

[0274] - one or more LBT sub-bands,

[0275] - One or more spatial resources, for example using spatial multiplexing.

[0276] Furthermore, it should be noted that in this specification, when a "resource set" is mentioned, the resource set may include one or more resources, where the definition of a resource is as described above. Furthermore, it should be noted that in this specification, when a "channel" is mentioned, this may refer to a resource set as described above. Therefore, a "channel" may also refer to a subchannel, a subband, a resource pool, or an SL BWP.

[0277] Figure 6 FIG. 1 shows a wireless communication system, as shown in FIG. Figure 3A wireless communication system, such as a 3rd Generation Partnership Project 3GPP system or network. The wireless communication system includes user equipment 400, 402 and one or more base stations 404 operating according to an embodiment of the present invention. UE 400 (also referred to as a sidelink UE, SL-UE) includes one or more antennas 400a and a signal processor 400b for performing one or more operations, such as operations involving antenna 400a, such as sending / receiving data, such as payload data or control data, or inter-UE coordination (IUC) messages. UE 400 can communicate with other UEs (such as UE 402) using a sidelink or PC5 interface (such as 408 schematically illustrated). UE 402 (also referred to as a sidelink UE, SL-UE) includes one or more antennas 402a and a signal processor 402b for performing one or more operations, such as operations involving antenna 400a, such as sending / receiving data, such as payload data and / or control data, or inter-UE coordination (IUC) messages. In addition, UE 400 and / or UE 402 can be connected to a base station or gNB 404. The gNB 404 includes one or more antennas 404a for wireless communication with other network entities such as UE 400 and / or UE 402, and includes a signal processor 404b. When operating in Mode 1, UE 400 and UE 402 receive resources allocated by gNB 404 via Uu interface 412, which are to be used by the UE to communicate via side link 408. As described above, when operating in Mode 2, UE 400 and / or UE 402 may not have connectivity to gNB 404, nor sense-plus-access resource allocation or random access-based resource allocation performed prior to performing a transmission.

[0278] Figure 6 Spectrum 414 is further schematically illustrated, such as a radio spectrum including resources to be used for communication within a wireless communication system or network. Resources that can be used for SL communication may include one or more of the following: one or more symbols, one or more time slots or subframes or frames, one or more resource blocks (RBs) or frequencies, carriers or subchannels or subchannel groups, one or more frequency bands. As further schematically illustrated, spectrum 414 includes licensed spectrum 416 and unlicensed spectrum 418. Licensed spectrum 416 is a portion of the spectrum reserved for a wireless communication system (including UE 400 and UE 402 and base station 404). In other words, according to the definition of the regulatory agency and entity, the resources in the licensed spectrum are only used by this wireless system. Unlicensed spectrum 418 includes resources that can be used by multiple wireless communication systems, such as another wireless communication system operated by different operators according to the 3GPP standard or by a system using different wireless access technologies (such as WiFi or Bluetooth).

[0279] According to an embodiment, a resource pool 420 (also referred to as a side link resource pool SL-RP) may be provided for side link communications, and the UE 400 is configured or pre-configured with the resource pool 420. Although only a single resource pool is depicted in the figure, multiple such resource pools may be configured or pre-configured. The resource pool may include resources only from the unlicensed spectrum 418 or only from the licensed spectrum 416, or as Figure 6 As shown in the embodiment of FIG. 4 , resources from the licensed spectrum 416 and the unlicensed spectrum 420 may be included. According to further embodiments, carrier aggregation may be used to aggregate resources in the unlicensed spectrum.

[0280] According to an embodiment of the present invention, UE 400 is a SL-UE that communicates by using a SL from resources of an unlicensed spectrum. UE 400 determines at least one network entity with an upcoming transmission among one or more network entities based on a received control message about a transmission of one or more other network entities or devices (e.g., further SL-UE 402 or gNB 404 or any other device, such as RSU, WiFi device, etc.), and shares the COT with the at least one network entity.

[0281] For the following description of the embodiments of the present invention, it is assumed that UE 400 is the COT initiating UE or initiating UE mentioned above, and UE 402 is assumed to be a COT sharing UE or responding UE. The method of the present invention is not limited to such a scenario, but as mentioned above, UE 400 can share COT with one or more other network entities of the wireless communication network. In order to perform transmission via the side link 408 (for example, to one or more further UEs (such as UE 402)), as illustrated in 422, UE 400 occupies a channel, that is, a resource spanning a specific time in the time domain and a specific frequency in the frequency domain. Occupying the channel further starts or initiates a channel occupancy time COT. According to an embodiment, UE 400 occupies the channel in response to a successful channel access procedure CAP performed by UE 400 on the channel. According to other embodiments, UE 400 may receive assistance (for example, from gNB 404 or from any other network entity) so that CAP may not need to be performed on the channel. Instead, UE 400 may receive information about resources or channels to be used for transmission, e.g., gNB 404 may provide a grant indicating a channel (e.g., a resource in an unlicensed spectrum) to be used by UE 400 to perform transmission on the sidelink. In either case, as illustrated at 422, UE 400 occupies the channel for transmission, and COT begins.

[0282] Furthermore, as illustrated at 424, the UE 400 receives one or more control messages, such as one or more SCIs, from other network entities, such as further UEs (such as UE 402) and / or from a base station, such as gNB 404, related to respective upcoming sidelink transmissions by one or more further UEs, the one or more further UEs being located in the vicinity of the UE 400 and being able to communicate also via the sidelink 408. According to an embodiment, the UE 400 receives the SCI before occupying the channel. As illustrated at 426, the UE 400 uses the one or more received control messages, such as the one or more SCIs, in order to determine the one or more further UEs having upcoming transmissions to be performed during the COT. The upcoming transmissions may be one or more future reserved resources known to the given UE, such as in the case of a periodic reservation of resources when the UE knows that it needs to process future transmissions. Furthermore, these may also be future reservations for potential retransmissions, such as in the case of many UEs occupying the radio channel, the UE may have signaled advance reservations in order to increase the probability of a successful transmission. Alternatively, the upcoming transmission may be a feedback transmission (such as HARQ feedback) to be performed by the given UE. Finally, the UE may have scheduling capabilities, such as by helping other UEs perform successful transmissions, and may act as an agent for other UEs to pre-allocate resources for upcoming transmissions. In this way, other UEs may be aware of such future transmissions, and under certain conditions (e.g., with lower priority), may avoid performing CAP in unlicensed spectrum. In other words, UE 400 determines at 426 among further UEs one or more further UEs (e.g., UE 402) that have upcoming transmissions to be performed during the COT, and as illustrated at 428, UE 400 shares the COT with one or more further UEs (e.g., UE 402, also referred to as COT sharing UEs or responding UEs). As previously described, when a network entity (e.g., responding UE 402) is described as sharing a COT initiated by UE 400, this means that the responding UE may use a channel occupied by UE 400 within a portion of the COT, for example, for performing transmissions on the channel after the initiating UE completes its channel transmission. According to an embodiment, the upcoming transmission may be determined based on resource information derivable from respective SCIs received from a plurality of further UEs communicating via the sidelink and located in the vicinity of the UE 400 .

[0283] UE 400 may perform its transmission on the occupied channel during the first portion of the COT, and UE 402 may use all or one or more sub-portions of the second portion of the COT to perform its upcoming transmission. The second portion of the COT may be the duration of the COT that remains after UE 400 completes its transmission on the occupied channel.

[0284] According to an embodiment, similarly, UE 400 may perform its transmission during the first portion of the COT and share the portion of the COT not occupied by its transmission, i.e., the second portion of the COT, only for transmissions to the PSFCH by a transmission recipient of UE 400 (e.g., UE 402). Any remaining portion of the COT is not shared by UE 400. For example, UE 400 may indicate COT sharing of the second portion of the COT within a control message associated with a transmission performed by UE 400 in the first portion of the COT, such as an SCI message.

[0285] According to the embodiments described so far, UE 400 shares the COT with UE 402, i.e., among a plurality of network entities that signal an upcoming transmission, UE 400 selects UE 402 as the network entity with which to share the COT. Accordingly, UE 402 receives corresponding COT sharing information from UE 400 so as to use the channel occupied by UE 400 during at least a portion of the COT that still exists after UE 400 completes its transmission. For example, in the case where the transmission performed by UE 400 is a frequency-continuous, non-interleaved transmission, sharing the COT with only one other network entity may be performed by UE 400.

[0286] However, the present invention is not limited to sharing the COT with only one network entity. According to further embodiments, the UE 400 may determine more than one network entity with which to share the COT. Figure 6In addition to UE 402 in the figure, UE 400 may also determine another SL-UE (not shown) or any other network entity with which to share the COT. For example, in the case where the transmission performed by UE 400 is an interlaced transmission, sharing the COT with two or more other network entities may be performed by UE 400. In such a scenario, the number of network entities with which the COT is to be shared may be as many as the number of interlaces of the interlaced transmissions performed by UE 400. However, in the case of non-interlaced transmissions, UE 400 may also share the COT with two or more other network entities. In this case, if more than one UE obtains the shared COT, this may cause interference or conflict between these transmissions. However, in the case where more than one UE that obtains the COT is far away from each other so that they do not interfere, this does not need to happen. In another example, among the set of potential UEs eligible to use the shared COT, only one actually obtains the COT. This may happen if other UEs that used to use the COT lose interest in the transmission because they may have successfully transmitted their data; or, may have lost interest in the transmission because the COT does not provide enough transmission time for the data to be transmitted; or, if the maximum length of the COT is too short so that the UE cannot transmit its potential data within the COT; or, if the packet delay is too large if the UE uses the COT for its transmission. In the latter case, the UE may transmit its data in another part of the spectrum (e.g., on a licensed carrier).

[0287] According to an embodiment, UE 400 may perform its transmission during the first part of the COT and share the second part of the COT not occupied by its transmission, which is initially only used for the transmission of the PSFCH by the transmission recipient of UE 400 (e.g. UE 402). Only then, i.e. after sending the PSFCH, further parts of the second part of the COT can be used for further PSSCH / PSCCH transmissions (e.g. by the recipient and / or by further network entities such as further SL-UEs). In other words, UE 400 may share the second part of the COT not occupied by its transmission, which is initially only used for the transmission of the PSFCH by the transmission recipient of UE 400 (e.g. UE 402). Only then, i.e. after sending the PSFCH, further parts of the second part of the COT can be used for further PSSCH / PSCCH transmissions (e.g. by the recipient and / or by further network entities such as further SL-UEs).

[0288] - a first subdivision of the second part of the COT for feedback transmissions, such as PSFCH, by a network entity receiving the UE's transmissions in the first part of the COT, and

[0289] - A second subdivision of the second part of the COT for further transmission by the network entity or another network entity only after completing the feedback transmission.

[0290] For example, UE 400 may indicate COT sharing of a first subdivision and a second subdivision of a second portion of the COT within a control message associated with a transmission performed by UE 400 in the first portion of the COT, such as an SCI message.

[0291] With respect to the embodiment just described, it should be noted that the feedback transmission PSFCH may be performed by the UE 400 as the transmission recipient in the first part of the COT, and / or by one or more further network entities. The benefit of sending feedback from different devices is that the feedback may be only a very short message, and devices different from the UE 400 may not have to perform a long sensing process, or even have to perform a LBT-free transmission within the shared COT, and thus feedback information, such as HARQ ACK / NACK feedback, may be transmitted very quickly without waiting for a successful CAP to be performed. In this case, delay and jitter are reduced, and low-latency transmissions may even be performed in the unlicensed portion of the spectrum. Furthermore, this may make the transmission very robust, since more feedback may be transmitted, thereby increasing the probability that the past transmitting UE receives the corresponding feedback (e.g., HARQ feedback) in a timely manner.

[0292] Thus, the method of the invention at least mitigates or even avoids the disadvantages and problems encountered in the prior art due to the limited possibilities of which further network entities can actually share the COT under the control of the UE 400. According to the method of the invention, the UE 400 also takes into account whether other network entities are to perform transmissions during the COT and may offer to use a channel it has occupied for such upcoming transmissions within the COT, e.g. during a part of the COT that the UE 400 is not using to perform its transmissions, resulting in the advantages described above.

[0293] In the embodiments described so far, it has been assumed that the UE 400 that is to occupy a channel and thus start a COT evaluates control messages (such as SCI messages) it receives from further UEs or network entities that also communicate via the side link in order to determine which of the surrounding UEs has an upcoming transmission, and can therefore use the channel occupied by the UE 400 for a portion of the COT initiated by the UE 400. According to an embodiment, the UE 400 can use the identification ID of the further UE to identify the UE with which the COT is to be shared (also referred to as a COT sharing UE). For example, the COT sharing ID can be the complete ID of the further UE (such as UE 402) or another network entity, or a part of the ID, such as the last n bits, or a checksum or a pair of 2 nThe modulo value, for example 16. In this way, the number of bits used for the ID is reduced, and therefore the number of bits allocated within the SCI is small. In addition, the ID or partial bits of the ID can also be used as a group identifier, so that a specific portion of the ID is disguised as a specific group with group members, who may then be eligible to use the shared COT.

[0294] However, the present invention is not limited to such an embodiment, but a control message other than the SCI message may be used to determine which of the surrounding UEs communicating via the side link can share the COT initiated by the UE 400. For example, according to other embodiments, the UE 400 may operate in mode 1, i.e., may receive assistance from the gNB 404 for resource allocation to be used for transmission in the unlicensed spectrum. The gNB 404 may provide an approval to the UE 400 indicating the resources or channels that the UE 400 uses for transmission via the side link in the unlicensed spectrum. The approval may be provided using a control message (such as a downlink control information message, a DCI message), and in addition to the resource information, the gNB 404 may also include in the control message (such as the DCI) an identification of a specific UE with which the UE 400 is to share the COT. For example, the DCI may include Figure 6 402, thereby indicating to the COT sharing UE 400 that it wants to share the COT with UE 402.

[0295] According to an embodiment, the COT sharing method may utilize future resource reservation, which may be indicated in the SCI by future reservation information using a time resource indicator value TRIV and / or a frequency resource indicator value FRIV. By considering the future resource reservation, the UE 400 may already know the future resource reservation by decoding the SCI previously received from the further UE, and one of the further UEs may then share this information with the further UE based on the previously received decoded SCI, such as Figure 7 Schematically, Figure 7The figure shows an example of COT sharing for UEs with future reservations. As shown in this figure, UE-A may have two future reservations, future reservations 1 and 2, which it indicates in its SCI to the UEs around it. This may be the case where the UE has periodic data or data bursts to transmit and is aware of the need for future reservations. Therefore, in this case, by sharing its SCI, a potential UE in its vicinity (UE-B) may be aware of UE-A's future reservation 1 and may share its COT with UE-A so that UE-A does not have to perform a CAP or a potential LBT-free CAP for the data to be transmitted in its future reservation 1. In the case where UE-A only needs a portion of the shared COT of its transmission for future reservation 1, it may share the remaining portion of the COT with a third UE (such as UE-C), which may use the complete remaining COT of the shared COT or also use only a portion of the COT for its transmission. Also in this case, when it comes to the sensing process that UE-C has to perform, the CAP to be performed by UE-C may reduce the burden on UE-C, thereby reducing the delay of potential transmissions in UE-C.

[0296] According to a further embodiment, without considering future resource reservation, for example, when TRIV or FRIV is turned off, for example, by setting the parameter MaxNumPerReserve to 1, COT sharing can be operated as follows:

[0297] - In the case where SCI is used for periodic transmission, the COT initiating UE 400 may use the resource reservation period to determine which of the further UEs to share the COT with. In this case, the COT initiating UE may derive the potential time of future transmissions of the further UEs from the resource reservation period and share the COT with the UEs having a period that matches the time window of the COT.

[0298] - In this case, by default, only further UEs receiving unicast transmissions from UE 400 can share the COT initiated by UE 400 with UE 400, because future transmissions of other UEs with respect to the transmission period do not match the timeline of the COT to be shared.

[0299] According to other embodiments, UE 400 may be configured by gNB 404 with configuration approval. For such configuration approval, the configuration approval configuration may include information indicating the UEs with which UE 400 shares the COT. For example, the configuration approval configuration may include COT sharing information indicating the ID or group ID of the UE (such as UE 402) to which UE 400 is to transfer the COT, i.e., providing a COT sharing ID, which indicates the ID identification of the UE (such as UE 402), i.e., the COT sharing UE or responding UE with which UE 400 shares the COT.

[0300] According to other embodiments, UE 400 determines one or more network entities with which it wants to share the COT based on one or more control messages, which one or more control messages may also include or be transmitted via an inter-UE coordination IUC message or an auxiliary information message AIM.

[0301] According to other embodiments, the control message may be transmitted within one or more of the following: a first stage SCI, a second stage SCI, a medium access control layer control element MAC CE, a radio resource control RRC message, such as a SL-RRC message.

[0302] According to a further embodiment, COT sharing may be selectively enabled or disabled in a wireless communication system or a portion thereof (e.g., within a cell served by a gNB 404 in which a UE 400 or UE 402 is located). According to an embodiment, the UE 400 may receive signaling indicating the enabling of COT sharing. For example, the signaling may include a DCI message, a resource pool RP configuration, a configuration approval CG configuration, a side link control information SCI message, an inter-UE coordination IUC message, or an auxiliary information message AIM. Note that the AIM may also be sent by a base station or an RSU or another network entity of an auxiliary CAP.

[0303] The signaling for enabling / disabling COT sharing may be a flag indicating whether COT sharing is enabled, for example, for a specific resource or a channel or interlace to be used by the UE 400. For example, in the case of a DCI message, a flag may be included in the DCI message indicating whether COT sharing is enabled for approval of a channel to be used by the UE 400. For example, Figure 6 The gNB 404 in may provide approval to the UE 400 and include a flag set to a specific value in an associated DCI message to indicate whether COT sharing is enabled.

[0304] In addition, COT sharing may also be enabled / disabled only for a specific UE (eg, with a specific ID) or for a specific ID group (eg, with a specific group ID).

[0305] According to a further embodiment, the signaling for indicating whether COT sharing is enabled may include a resource pool RP configuration. For example, a side link resource pool configuration including information about resources to be used for side link communications may contain additional information indicating whether COT sharing is allowed, such as whether COT sharing is enabled for some or all of the resources from an unlicensed side link resource pool (which includes resources of an unlicensed spectrum to be used for side link transmissions). In this case, COT sharing may be allowed only for a subset of resources, such that a threshold for this quota is specified by signaling, configuration, or pre-configuration.

[0306] According to further embodiments, the configuration approval configuration described above may be used to signal the COT sharing enablement. For example, in addition to the aforementioned COT sharing ID, according to an embodiment, the configuration approval configuration may include a flag indicating whether COT sharing is allowed for the configuration approval associated with the configuration approval configuration. For example, according to the COT sharing flag, Figure 6 UE 400 in may determine that a configuration approval may be transmitted in an ongoing shared COT occupied by UE 400, and determine that the COT may also be shared and delivered to other UEs (eg, UE 402).

[0307] According to a further embodiment, in addition to a simple indication of whether COT sharing is enabled, the signaling may further include an indication of a maximum COT time of the COT shared by the UE 400. For example, a timer may be provided which indicates the maximum COT time in units of slots or minislots or OFDM symbols. According to other embodiments, the maximum COT time may also be indicated by a time indicated in milliseconds or as an absolute value pointing to the end time of the COT sharing duration. Indicating the maximum COT time is advantageous because a potential UE using a shared COT may avoid actual transmission within the COT if its required transmission time exceeds the COT. Alternatively, a potential UE using a shared COT may also decide which data to transmit within the COT based on the maximum COT time, for example, if the COT is too short, it only transmits control or feedback data within the COT, and does not transmit other data (e.g., PSSCH) within the COT.

[0308] According to an embodiment, the signaling may also indicate specific conditions when COT sharing is enabled. In other words, although the signaling indicates that COT sharing is basically enabled in the cell or system, the UE 400 may decide whether to actually adopt COT sharing when performing transmission based on one or more of the specific conditions. For example, COT sharing may be enabled in one or more of the following situations:

[0309] - The remaining COT time exceeds a predefined threshold.

[0310] For example, a timer may be provided that indicates the remaining COT time in units of slots or minislots or OFDM symbols. The remaining COT time may also be indicated by a time indicated in milliseconds or as an absolute value pointing to the end time of the COT sharing duration. Indicating the remaining COT time allows a COT sharing UE (such as UE 402) to determine whether its upcoming transmission can actually be transmitted on the channel occupied by UE 400 during the COT.

[0311] - An upcoming transmission to be performed by a network entity (such as UE 402) has a priority exceeding a predefined threshold.

[0312] For example, only packets transmitted at a certain priority level (eg, high priority) may use the shared COT, thereby increasing the likelihood that high priority transmissions benefit from COT sharing.

[0313] - An upcoming transmission to be performed by a network entity (such as UE 402) has a specific identification ID.

[0314] The UEs sharing the COT may be aware of a specific identified UE (e.g. with high priority) and therefore pick a specific UE or group of UEs from this set of UEs. The ID or list of IDs may also be configured or preconfigured by the gNB or by another network entity, so that different UEs have different sets of configured or preconfigured IDs. The advantage of this approach is that specific preferences can be configured and in this way, a specific set of UEs can access the radio channel faster. A further example where this can be applied is an on-board unit installed on a vehicle, which shares the COT with potential UEs in or around the vehicle, which in turn may be preferred users of the radio spectrum.

[0315] - An upcoming transmission to be performed by a network entity (such as UE 402) belongs to a specific UE group.

[0316] The advantages of this are described in the above points.

[0317] - Feedback has been enabled for upcoming transmissions to be performed by a network entity (eg, UE 402).

[0318] Since the feedback information is rather short, it may be transmitted in a shorter CAP, e.g. even using a non-LBTCAP, and may therefore be transmitted faster. This improves robustness, e.g. by reducing the number of retransmissions of the feedback data, and reduces the latency of the feedback traffic.

[0319] - The transmission to be performed by the UE or an upcoming transmission to be performed by a network entity (such as UE 402) has a predefined propagation type.

[0320] This is advantageous because it reduces the amount of signaling of the COT shared information, e.g., for unicast or broadcast, since more than one UE is addressed simultaneously, fewer bits need to be used for signaling.

[0321] - The communication range of a transmission to be performed by the UE or a communication range of an upcoming transmission to be performed by a network entity (such as UE 402) is below a predefined threshold.

[0322] This is advantageous because interference can be reduced because only a certain range of UEs can use the shared COT, thereby reducing interference to other UEs when transmitting in the shared COT.

[0323] - A network entity (eg, UE 402) is located at a distance from the UE that is less than a predefined threshold, such as within a minimum communication range MCR.

[0324] This is advantageous because transmission interference in the shared COT can be reduced. In addition, only UEs that are closer to a given UE can be configured to transmit using a smaller transmission power, which saves power for UEs transmitting in the shared COT. This is meaningful for energy-saving UEs (e.g., P-UEs).

[0325] As mentioned above Figure 6 As described, once the COT initiating UE 400 determines a further UE (such as UE 402) with which to share the COT, the UE 400 may signal a COT sharing control message to a specific further UE (such as the responding UE 402). According to an embodiment, the COT sharing control message may include a sidelink control information SCI message, such as a first-stage SCI and / or a second-stage SCI, or a media access control layer control element MAC CE, or a radio resource control RRC message, such as an SL-RRC message. The UE may provide the COT sharing information in one or more of the following:

[0326] - a first-stage SCI and a MAC CE, wherein the first-stage SCI indicates a physical sidelink shared channel PSSCH, and the physical sidelink shared channel PSSCH contains a MAC CE including COT sharing information,

[0327] - a second stage SCI and a MAC CE, wherein the second stage SCI indicates a physical side link shared channel PSSCH, and the physical side link shared channel PSSCH includes a MAC CE including COT sharing information,

[0328] - Stage I SCI,

[0329] - Stage II SCI,

[0330] - Stage I SCI and Stage II SCI,

[0331] - a first-stage SCI, a second-stage SCI and a MAC CE, wherein the first-stage SCI and / or the second-stage SCI indicates a physical sidelink shared channel PSSCH, and the physical sidelink shared channel PSSCH includes a MAC CE including COT sharing information,

[0332] -MAC CE.

[0333] According to a further embodiment, the COT sharing information may also indicate the remaining COT time, for example by providing a countdown of the remaining COT time. For example, the COT initiating UE 400 sets the countdown to a maximum value, and during each time slot belonging to the same COT, the countdown may be reduced accordingly. In addition, the COT timer may be indicated in the first phase SCI using a remaining bit (e.g., a spare bit) to minimize the number of bits used to signal this within the SCI. The timer may also be indicated in units of time slots or minimum time slots or OFDM symbols, or the remaining time may be indicated in milliseconds or as an absolute value pointing to the end time of the COT sharing duration. In addition, the COT sharing information may include a destination ID of a network entity (e.g., UE 402) and / or a maximum COT time. The COT sharing information may be transmitted via unicast, multicast, or broadcast.

[0334] According to a further embodiment, despite identifying one or more network entities with which to share the COT, the UE 400 may decide to actually share the COT only given one or more conditions. For example, the UE 400 may decide to share the COT based on one or more of the following conditions:

[0335] - The remaining COT time exceeds a predefined threshold.

[0336] In this case, if the remaining COT time is long enough to be used by another UE, the resources of the SL-U can be used effectively. If the COT time is too short, COT sharing may not be beneficial because the signaling of COT or COT-related information may cause unreasonable overhead.

[0337] - The transmission to be performed by the UE has a priority exceeding a predefined threshold.

[0338] This may be advantageous in situations where the UE is a potential recipient of data being transmitted in a shared COT, and it may be possible to select a particular UE for transmission so that it receives the data faster than if the potential UE performing the transmission in the shared COT and the independent CAP were to do so.

[0339] - Transmissions to be performed by the UE have feedback enabled.

[0340] Since the feedback information is rather short, it may be transmitted in a shorter CAP, e.g. even using a non-LBTCAP, and may therefore be transmitted faster. This improves robustness, e.g. by reducing the number of retransmissions of the feedback data, and reduces the latency of the feedback traffic.

[0341] - The transmission to be performed by the UE is of a predefined spreading type.

[0342] This is advantageous because it can reduce the signaling of COT shared information, e.g., for unicast or broadcast, since more than one UE is addressed simultaneously, fewer bits need to be used for signaling.

[0343] - The remaining packet delay budget PDB for the transmission to be performed by the UE exceeds a predefined threshold.

[0344] This is advantageous because if the COT is too short, a given data may not be transmitted within the COT, thereby wasting resources.

[0345] - The communication range of the transmission to be performed by the UE is below a predefined threshold.

[0346] This is advantageous because interference can be reduced because only a certain range of UEs can use the shared COT, thereby reducing interference to other UEs when transmitting in the shared COT.

[0347] - The number of time slots for transmission to be performed by the UE exceeds a predefined threshold.

[0348] This is advantageous because if the COT is too short, given data may not be transmitted within the COT, thereby wasting resources.

[0349] - The network entity is located at a distance from the UE that is less than a predefined threshold, such as within a minimum communication range MCR.

[0350] This is advantageous because transmission interference in the shared COT can be reduced. In addition, only UEs that are closer to a given UE can be configured to transmit using a smaller transmission power, which saves power for UEs transmitting in the shared COT. This is meaningful for energy-saving UEs (e.g., P-UEs).

[0351] -The network entity is located within a specific area or geographic location.

[0352] COT sharing may be limited to specific areas or regions to optimize resource usage in a specified area. This allows for reduced interference from COT sharing in a specific area, or increased resource usage in a specific area by allowing COT sharing. Limiting this feature to specific geographic locations or regions may be beneficial in the case of interference from other non-3GPP networks in a given area.

[0353] Further embodiments of the present invention relate to a COT sharing or responding network entity, such as UE 402. In response to an indication received from UE 400 that UE 400 shares the COT, UE 402 may share a channel occupied by UE 400 during a channel occupation time initiated by UE 400, such as Figure 6 As shown in 430.

[0354] Further embodiments of the present invention relate to COT sharing or responding to network entities, such as UE 402. As described above with reference to Figure 6 As described, UE 402 may also perform sidelink SL communication using a channel including resources from an unlicensed spectrum. UE 402 may receive one or more control messages related to an upcoming SL transmission by one or more network entities of a wireless communication network (such as UE 400), and UE 402 occupies the channel for transmission as described above. UE 402 may or may not be the actual recipient of the transmission by UE 400. In any case, UE 402 is aware that another UE has occupied the channel for transmission, so that COT also begins. UE 402 may attempt to gain access to the channel during the COT to perform its transmission, and may therefore request COT sharing from UE 400, such as Figure 6 430. In other words, using one or more control messages (such as SCI), UE 402 can determine at least one network entity (such as UE 400) of the wireless communication system that occupies the channel for transmission within the channel occupation time COT, request the network entity UE 400 to share the COT, and if the COT is shared, use the entire remaining COT or only one or more parts of the remaining COT to perform its transmission within the shared COT. For example, UE 402 can receive one or more control messages before determining whether UE 402 or other more network entities occupy the channel.

[0355] According to an embodiment, a network entity (such as UE 400) may perform a transmission on an occupied channel during a first portion of a COT, and UE 402 may perform its transmission using all or one or more portions of a second portion of the COT. The second portion of the COT is the duration of the COT that still exists after the completion of the UE 402's transmission on the occupied channel. For example, UE 402 may use a first subdivision of the second portion of the COT for a feedback transmission PSFCH for a transmission by the network entity in the first portion of the COT, and use a second subdivision of the second portion of the COT for further transmissions after the completion of the feedback transmission. UE 402 may receive COT sharing signaling of a first subdivision and a second subdivision of the second portion of the COT in a control message associated with a transmission performed by the network entity (UE 400) in the first portion of the COT, such as an SCI message. According to other embodiments, UE 402 shares or uses the second portion of the COT only for feedback transmission PSFCH for a transmission by the UE 400 entity in the first portion of the COT. It should be noted that UE 400 may or may not be a transmission recipient of UE 402. In the latter case, UE 402 can transmit feedback to the other SL-UE so that only the COT for the transmission is provided by the other UE (e.g., UE 400) and the COT is effectively utilized by the short feedback transmission. This enables UE 402 to transmit feedback to the other UE, which terminates the transmission and avoids further retransmissions of this data transmission. Effectively, this reduces the amount of communication in the unlicensed spectrum, thereby reducing the overall interference of the unlicensed band. In addition, this increases the data rate through better spectrum utilization.

[0356] According to an embodiment, further UE 402 may decide to accept COT sharing initiated by UE 400 or request COT sharing according to one or more conditions, for example according to one or more of the following:

[0357] - The remaining COT time exceeds a predefined threshold.

[0358] In this case, the UE may request COT sharing only if its data transmission fits in the COT. In other cases, the UE may decide to transmit its data in a different frequency band (eg, a licensed carrier or an unlicensed carrier).

[0359] - A transmission to be performed by the UE 402 and / or by a network entity such as the UE 400 has a priority exceeding a predefined threshold.

[0360] This is advantageous because a high priority UE may have a higher chance of receiving COT sharing information and therefore, there may be service differentiation for transmissions in the shared frequency band.

[0361] - Transmissions to be performed by the UE 402 and by a network entity (such as the UE 400) have the same priority.

[0362] This may be beneficial if the two UEs sharing the COT and the UEs transmitting within the COT are communicating with each other, and this constraint can be set to reduce the number of potential UEs transmitting within the COT.

[0363] - Transmissions performed by the UE 402 and / or by a network entity (such as the UE 400) have enabled feedback.

[0364] Since the feedback information is rather short, it may be transmitted in a shorter CAP, e.g. even using no LBTCAP, and may therefore be transmitted faster. This improves robustness, e.g. by reducing the number of retransmissions of the feedback data, and reduces the latency of the feedback traffic.

[0365] - The transmissions performed by the UE 402 and / or by a network entity (such as the UE 400) are of a predefined propagation type.

[0366] This reduces signaling, since also multicast and / or unicast can be addressed. Furthermore, COT sharing can be restricted to certain propagation types in order to reduce interference in the shared frequency band.

[0367] - The remaining packet delay budget PDB for transmissions to be performed by the UE 402 exceeds a predefined threshold.

[0368] This is advantageous because a potential UE that shares its COT may only do so if the UE using the shared COT effectively places its data into the COT, in order to efficiently use the shared resource.

[0369] - The communication range of a transmission to be performed by the UE 402 and / or by a network entity (such as the UE 400) is below a predefined threshold.

[0370] This is advantageous because interference may be reduced since only a certain range of UEs use the shared COT, thereby reducing interference to other UEs when transmitting in the shared COT.

[0371] A further embodiment of the present invention relates to a base station, such as Figure 6 404, which serves one or more user equipment (e.g., UE 400, UE 402), which communicate with each other via a side link using resources from an unlicensed spectrum 418. The gNB 404 serves one or more user equipments operating according to the above-described embodiments of the present invention. According to an embodiment, when serving a COT sharing UE 400, the gNB 404 may signal a DCI message to the UE 400, such as Figure 6As shown in 432, the DCI message indicates a further UE (such as UE 402) with which UE 400 shares the COT. As described above, the DCI message may further include a flag indicating whether COT sharing is enabled, such as a flag indicating whether COT sharing is enabled for an approval of a channel to be used by UE 400, and / or a remaining COT time or a maximum COT time of the COT shared by UE 400.

[0372] As described above, the embodiments of the present invention provide:

[0373] - A user equipment UE for a wireless communication network, such as a 3rd Generation Partnership Project 3GPP network.

[0374] o With respect to the 5G NR standard, the user equipment UE in the embodiment may correspond to the user equipment UE in the standard.

[0375] -The UE is configured to perform sidelink (SL) communication using a channel comprising resources from an unlicensed spectrum.

[0376] ο In the 5G NR standard, NR side link on unlicensed spectrum (SL-U) is specified for NR Rel-18.

[0377] -The UE is used to occupy the channel within the channel occupation time COT.

[0378] ο According to TS 38.212 (V17.5.0), 3.3 Abbreviation, channel occupation time is abbreviated as COT.

[0379] o According to TS 37.213 (V17.1.0), 4 Channel Access Procedure, 4.0 General, channel occupancy means the transmissions of the eNB / gNB / UE on the channel after the eNB / gNB / UE performs the corresponding channel access procedure described in this clause. Channel occupancy time means the total time that the eNB / gNB / UE and any eNB / gNB / UE that shares the channel perform transmissions on the channel after the eNB / gNB / UE performs the corresponding channel access procedure described in this clause. For the purpose of determining the channel occupancy time, if a transmission gap is less than or equal to , the gap duration is included in the channel occupancy time. The channel occupancy time may be shared for transmissions between the eNB / gNB and the corresponding UE.

[0380] Therefore, the channel occupancy time in an embodiment may correspond to the COT, as defined in NR-U.

[0381] -UE is used to receive one or more control messages.

[0382] According to TS 38.212 (V17.5.0), 8.3 Sidelink control information on PSCCH, 8.3.1 First stage SCI format, 8.3.1.1 SCI format 1-A, SCI format 1-A is used for scheduling of second stage SCI on PSSCH and PSSCH. The following information is transmitted in SCI format 1-A:

[0383] -

[0384]

[0385] when the value of the gher layer irameter sl-MaxNumPerReserve is configured to 3, as defined in clause 8.1.5of[6,TS 38.214].

[0386] Time resource assignment-5bits when the value of the higher layer parameter sl-MaxNumPerReserve is configured to 2; otherwise 9bits when the value of the higher layer parameter sl-MaxNumPerReserve is configured to 3, as defined in clause 8.1.5of[6,TS 38.214].

[0387] - at least one of the control messages is related to one or more upcoming SL transmissions by one or more network entities of the wireless communication network

[0388] o According to TS 38.331 (V17.3.0), 6.3.5 Sidelink Information Elements, sl-MaxNumPerReserve indicates the maximum number of reserved PSCCH / PSSCH resources that can be indicated by the SCI.

[0389] Therefore, the UE reads the control message from the other UE by decoding the first stage SCI, which indicates the future reservation in FRIV / TRIV.

[0390] - The UE is configured to determine at least one network entity having an upcoming transmission using one or more control messages between one or more network entities.

[0391] ο According to TS 38.212 (V17.5.0), 8.3.1.1 SCI format 1-A, the scheduling of the second stage SCI on PSSCH and PSSCH adopts SCI format 1-A. The following information is transmitted in SCI format 1-A: Second stage SCI format - 2 bits are defined in Table 8.3.1.11.

[0392] Thus, in an embodiment, a UE may detect an upcoming transmission by decoding the first stage SCI from the UE.See normative elements of claim element 4 above.

[0393] According to TS 38.212 (V17.5.0), 8.4.1.1 SCI format 2-A, the decoding of PSSCH adopts SCI format 2-A, and HARQ operation is performed when the HARQ-ACK information includes ACK or NACK, when the HARQ-ACK information includes only NACK, or when the HARQ-ACK information is not fed back. The following information is transmitted in SCI format 2-A:

[0394] -HARQ process number - bit.

[0395] - New Data Indicator - 1 bit.

[0396] - Redundancy version - 2 bits, as defined in Table 7.3.1.1.1-2.

[0397] - Source ID - 8 bits, as defined in clause 8.1 of [6, TS 38.214].

[0398] - Destination ID - 16 bits, as defined in clause 8.1 of [6, TS 38.214].

[0399] - HARQ feedback enable / disable indicator - 1 bit, as defined in clause 16.3 of [5, TS 38.213].

[0400] - Propagation type indicator - 2 bits, as defined in Table 8.4.1.1-1 and clause 8.1 of [6, TS 38.214].

[0401] - CSI request - 1 bit, as specified in clause 8.2.1 of [6, TS 38.214] and clause 8.1 of [6, TS 38.214]

[0402] As defined in the Terms.

[0403] Therefore, the network entity in the embodiment may correspond to the source ID detected in the second stage SCI2-A of the standard.

[0404] -The UE is configured to share the COT with at least one network entity.

[0405] o Support of UE-to-UE COT sharing in NR sidelink operation in shared channel (SL-U) according to RAN1#109e (09-20 May 2022).

[0406] o According to RAN1#112 (February 27 - March 3, 2023), PSSCH / PSCCH transmissions of acknowledging UEs within the set of RBs corresponding to the shared COT will be used for COT-initiated UEs in the following cases,

[0407] In the case of unicast from a responding UE, when the source ID and destination ID contained in the PSCCH / PSSCH of the responding UE match the destination ID of the unicast transmission from the COT initiator including the COT shared information

[0408] Matches the source ID, or an additional ID included in the COT share information (if supported)

[0409] In the case of a multicast or broadcast from a responding UE, when the destination ID contained in the PSCCH / PSSCH of the responding UE matches the destination ID of the multicast or broadcast transmission from the COT initiator that includes the COT shared information, or matches an additional ID included in the COT shared information (if supported)

[0410] Therefore, the UE in the embodiment may correspond to the COT initiator in the protocol, and the UE in the embodiment may be transmitted to one of the destination IDs according to the manner written in the protocol.

[0411] General

[0412] The embodiments of the present invention have been described in detail above, and the corresponding embodiments and aspects may be implemented separately or in combination of two or more embodiments or aspects.

[0413] It should be noted that the method of the present invention is not limited to CG or DG. According to other embodiments, the approval may be less than CG or DG, and it may also be just a broad resource coordination, such as which sub-band or sub-channel to use or avoid.

[0414] Depending on the embodiment, the wireless communication system may include a terrestrial network or a non-terrestrial network, or a network or network segment using an airborne vehicle or a space vehicle as a receiver, or a combination thereof.

[0415] According to an embodiment of the present invention, the user equipment includes one or more of the following: a power-limited UE; or a handheld UE, such as a UE used by pedestrians and referred to as a vulnerable road user VRU or a pedestrian UE P-UE; or a body-carried or handheld UE used by public safety personnel and emergency personnel and referred to as a public safety UE PS-UE; or an IoT UE, such as a sensor, actuator, or UE provided in a campus network to perform repetitive tasks and requiring input from a gateway node at periodic intervals; or a mobile terminal; or a stationary terminal; or a cell IoT-UE; or a vehicle UE; or a vehicle group leader (GL) UE; or a sidelink relay device; or an IoT or a narrowband IoT NB-IoT device; or wearable device, such as a smart watch, health tracker, or smart glasses; or ground-based vehicle; or aircraft; or drone; or mobile base station; or roadside unit (RSU); or building; or any other item or device with network connectivity that enables the item / device to communicate using a wireless communication network, such as a sensor or actuator; or any other item or device with network connectivity that enables the item / device to communicate using a side link of a wireless communication network, such as a sensor or actuator; or any network entity with side link capability.

[0416] According to an embodiment of the present invention, the network entity includes one or more of the following: a macro cell base station, or a small cell base station, or a central unit of a base station, or an integrated access and backhaul (IAB) node, or a distributed unit of a base station, or a road side unit RSU or a remote radio head, or AMF, or MME, or SMF, or a core network entity, or a mobile edge computing (MEC) entity, or a network slice in the context of NR or 5G core, or any sending / receiving point TRP that enables an item or device to communicate using the wireless communication network, an item or device having network connectivity to communicate using the wireless communication network.

[0417] Although some aspects of the concept have been described in the context of an apparatus, it is clear that these aspects also represent a description of a corresponding method, where a block or device corresponds to a method step or a feature of a method step. Similarly, various aspects described in the context of a method step also represent a description of an item or feature of a corresponding block or corresponding apparatus.

[0418] The various elements and functions of the present invention can be implemented in hardware using analog and / or digital circuits, can be implemented in software by executing instructions through one or more general or special processors, or can be implemented as a combination of hardware and software. For example, embodiments of the present invention can be implemented in the environment of a computer system or other processing system. Figure 8The figure shows an example of a computer system 600. The units or modules and the steps of the methods performed by these units can be executed on one or more computer systems 600. The computer system 600 includes one or more processors 602, such as a dedicated or general-purpose digital signal processor. The processor 602 is connected to a communication infrastructure 604, such as a bus or a network. The computer system 600 includes a main memory 606 (such as a random access memory RAM) and an auxiliary memory 608 (such as a hard drive and / or a removable storage drive). The auxiliary memory 608 can load computer programs or other instructions into the computer system 600. The computer system 600 can also include a communication interface 610 to allow software and data to be transmitted between the computer system 600 and external devices. Communication can be electronic, electromagnetic, optical or other signals that can be processed by a communication interface. Communication can use wires or cables, optical fibers, telephone lines, cellular phone links, RF links and other communication channels 612.

[0419] The terms "computer program medium" and "computer readable medium" are generally used to refer to tangible storage media, such as a removable storage unit or a hard disk installed in a hard drive. These computer program products are means for providing software to the computer system 600. The computer program, also known as computer control logic, is stored in the main memory 606 and / or the auxiliary memory 608. The computer program may also be received via the communication interface 610. The computer program, when executed, enables the computer system 600 to implement the present invention. In particular, the computer program, when executed, enables the processor 602 to implement the process of the present invention, such as any method described herein. Accordingly, such a computer program may represent a controller of the computer system 600. In the case of implementing the present disclosure using software, the software may be stored in a computer program product and loaded into the computer system 600 using a removable storage drive, an interface (such as the communication interface 610).

[0420] The implementation in hardware or software can be performed using digital storage media, such as cloud storage, floppy disk, DVD, Blu-ray, CD, ROM, PROM, EPROM, EEPROM or flash memory, which have electronically readable control signals stored thereon and can cooperate with or be able to cooperate with a programmable computer system to perform the corresponding method. Therefore, the digital storage medium can be computer readable.

[0421] Some embodiments according to the invention comprise a data carrier having electronically readable control signals, which are capable of cooperating with a programmable computer system, such that the system performs one of the methods described herein.

[0422] Generally, embodiments of the present invention can be implemented as a computer program product with a program code, when the computer program product runs on a computer, the program code can be operated to perform one of the methods.For example, the program code can be stored on a machine readable carrier.

[0423] Other embodiments comprise the computer program for performing one of the methods described herein, stored on a machine readable carrier. In other words, therefore, an embodiment of the inventive method is a computer program having a program code for performing one of the methods described herein, when the computer program runs on a computer.

[0424] Therefore, a further embodiment of the method of the present invention is a data carrier or a digital storage medium or a computer-readable medium, including a computer program for performing one of the methods described herein recorded therein. Therefore, a further embodiment of the method of the present invention is a data stream or a signal sequence representing a computer program for performing one of the methods described herein. For example, the data stream or signal sequence can be configured to be transmitted via a data communication connection (e.g., via the Internet). Further embodiments include a processing device, such as a computer or a programmable logic device, configured to or adapted to perform one of the methods described herein. Further embodiments include a computer having a computer program for performing one of the methods described herein installed thereon.

[0425] In some embodiments, a programmable logic device, such as a field programmable gate array, may be used to perform some or all of the functions of the methods described herein. In some embodiments, a field programmable gate array may be used in conjunction with a microprocessor to perform one of the methods described herein. Typically, the method is preferably performed by any hardware device.

[0426] The above embodiments are merely illustrative of the principles of the present invention. It is understood that modifications and variations of the arrangements and details described herein will be apparent to other persons skilled in the art. Therefore, it is intended that the present invention be limited only by the scope of the patent claims to be presented, and not by the specific details presented herein by way of description and explanation of the embodiments.

Claims

1. A user equipment UE for a wireless communication network, wherein the wireless communication network is a third generation partnership project 3GPP network, wherein the UE is configured to perform sidelink (SL) communication using a channel comprising resources from an unlicensed spectrum, The UE is used to occupy the channel within a channel occupation time COT, wherein the UE is configured to receive one or more control messages, wherein at least one of the control messages is associated with one or more upcoming SL transmissions by one or more network entities of the wireless communication network, and The UE is used - determining at least one network entity having an upcoming transmission using the one or more control messages between the one or more network entities, and - Sharing said COT with said at least one network entity.

2. The user equipment UE according to claim 1, wherein the UE shares the COT with - a network entity in case of frequency-continuous, non-interleaved transmissions by said UE and / or by said network entity, or - more than one network entity in case of interleaving transmissions by said UE and / or by said network entity, up to the number of interleavings, or - More than one network entity in case of feedback transmission, for example over the Physical Sidelink Feedback Channel PSFCH.

3. A user equipment (UE) as claimed in claim 1 or 2, wherein the UE is used to perform a transmission during a first part of the COT, and the network entity is used to use all or one or more sub-parts of a second part of the COT to perform the upcoming transmission, and the second part of the COT includes the duration of the COT that still exists after the transmission of the UE is completed.

4. The user equipment UE according to claim 3, wherein the UE is used to share - a first subdivision of the second part of the COT for feedback transmission by a network entity receiving the transmission of the UE in the first part of the COT and / or by one or more other network entities, such as a PSFCH, and / or - a second sub-portion of said second part of said COT for further transmission by said network entity or a further network entity only after completion of said feedback transmission.

5. A user equipment UE as claimed in claim 4, wherein the UE is used to indicate COT sharing of the first sub-share and / or the second sub-share of the second part of the COT within a control message, the control message being associated with the transmission performed by the UE in the first part of the COT, such as an SCI message, or the control message being associated with the transmission of an earlier sub-share within the second part of the COT, such as via an SCI message.

6. A user equipment (UE) according to any one of claims 3 to 5, wherein the UE is configured to share the second part of the COT with a network entity that receives the transmission from the UE in the first part of the COT to perform one or more of the following: - Feedback transmission PSFCH, - Data transmission PSSCH, - Control signaling PSCCH, - Transmission of demodulation reference symbols DMRS, - Automatic gain control AGC signal.

7. A user equipment (UE) as claimed in claim 6, wherein the UE is used to indicate COT sharing of the second part of the COT within a control message, the control message being associated with the transmission performed by the UE in the first part of the COT, such as an SCI message.

8. The user equipment (UE) according to claim 7, wherein the SCI message contains information about a time slot structure to be used for transmission in the second part of the COT, such as any combination of one or more of the following: -Feedback only, -Data only, -DMRS only, -Feedback and data, -DMRS and feedback and data, - Remaining COT duration, - COT priority, - Transmission range, - type of transmission, e.g. type of propagation, - No feedback transmission etc.

9. The user equipment UE according to any one of claims 6 to 8, wherein the feedback transmission PSFCH is performed by the network entity receiving the transmission performed by the UE in the first part of the COT, or Performed by one or more further network entities.

10. A user equipment (UE) as claimed in any one of the preceding claims, wherein some or all of the upcoming transmissions by the network entity are performed at different times within a time interval following the transmission by the UE, and The UE is configured to share the COT with a network entity performing the upcoming transmission at a specific point within the time interval, wherein the specific point includes an earliest point within the time interval or any other later point.

11. The user equipment (UE) according to claim 10, wherein the time interval is defined by a remaining COT timer or by the COT duration.

12. A User Equipment (UE) as claimed in any preceding claim, wherein the UE is configured to receive the one or more control messages before occupying the channel.

13. A user equipment (UE) as claimed in any one of the preceding claims, wherein the UE is configured to occupy the channel in response to the following: - receiving an approval from one or more of said network entities, said approval indicating said channel, or interlace or PSFCH index to be used by said UE, and / or - determining the resources to be used within the channel based on a sensing process and a resource selection process, and / or - A successful channel access procedure CAP performed by said UE on said channel.

14. A user equipment (UE) as claimed in any one of the preceding claims, wherein the one or more control messages include one or more of the following: - Sidelink Control Information SCI message, - Downlink Control Information DCI message, -Configuration approval CG configuration, -MAC-CE, -RRC configuration, - Inter-UE coordination of IUC messages, -Assistance Information Message AIM.

15. The user equipment (UE) according to claim 14, wherein the control message is transmitted in one or more of the following: - Stage I SCI, - Stage II SCI, -PDCCH, -Media Access Control Layer Element, MAC CE, -Radio Resource Control RRC messages, such as SL-RRC messages.

16. The user equipment UE according to claim 14 or 15, wherein: In the case of an SCI message, the UE is configured to determine whether an upcoming transmission by a network entity is to be performed during the COT using resource reservation or resource allocation information in the SCI message, such as a time resource indicator value TRIV and / or a frequency resource indicator value FRIV and / or an inter-UE coordination message IUC.

17. The user equipment UE according to claim 16, wherein the resource allocation information includes future resource reservation information using a time resource indicator value TRIV and / or a frequency resource indicator value FRIV included in the SCI message and / or an inter-UE coordination message IUC.

18. The user equipment UE according to claim 14 or 15, wherein: In case the SCI message is for periodic transmission, the UE is configured to determine whether an upcoming transmission by a network entity is to be performed during the COT using a resource reservation periodicity and / or a resource reselection counter in the SCI message.

19. The user equipment UE according to claim 14, wherein: In case of a DCI message, the UE is configured to determine from the DCI the at least one network entity with which the UE will share the COT.

20. The user equipment UE according to claim 14, wherein: In the case of a CG configuration, the UE is used to determine from the CG configuration the at least one network entity with which the UE will share the COT.

21. A user equipment (UE) as claimed in any one of the preceding claims, wherein The UE is configured to receive signaling indicating that COT sharing is enabled, or The UE is configured to determine that COT sharing is enabled through system level configuration or pre-configuration, such as resource pool configuration.

22. The user equipment (UE) according to claim 21, wherein the signaling comprises one or more of the following: - Downlink Control Information DCI message, - Resource pool RP configuration, -Configuration approval CG configuration, - Sidelink Control Information SCI message, - Downlink Control Information DCI message, - Inter-UE coordination of IUC messages, -Assistance Information Message AIM.

23. The user equipment (UE) according to claim 21 or 22, wherein the signaling comprises a flag indicating whether COT sharing is enabled for a channel or interlace to be used by the UE.

24. The user equipment (UE) according to any one of claims 21 to 23, wherein the signaling indicates a remaining COT time and / or a maximum COT time of the COT shared by the UE.

25. The user equipment (UE) according to any one of claims 21 to 24, wherein the signaling indicates one or more of the following: - Maximum COT time, - Specific conditions when COT sharing is enabled, such as enabling COT sharing when one or more of the following occurs: oThe remaining COT time exceeds a predefined threshold, o an upcoming transmission to be performed by the network entity has a priority exceeding a predefined threshold, o the upcoming transmission to be performed by the network entity has a specific identification ID, o an upcoming transmission to be performed by the network entity belongs to a specific UE group, o Feedback enabled for upcoming transmissions to be performed by the network entity, o a transmission to be performed by the UE or an upcoming transmission to be performed by a network entity has a predefined transmission type, o the communication range of a transmission to be performed by the UE or of an upcoming transmission by a network entity is below a predefined threshold, o The network entity is located at a distance from the UE that is less than a predefined threshold, for example, within a minimum communication range MCR.

26. A user equipment (UE) as claimed in any one of claims 21 to 25, wherein the UE is configured to determine one or more of the following information from an SCI previously received from the network entity or from the signalling to determine characteristics of an upcoming transmission: - the priority of the upcoming transmission, - the identification ID of the network entity, such as UE ID, - a group ID to which the network entity is associated or is a part of, - whether feedback is enabled or disabled, - the type of propagation of said transmission, -Minimum communication range.

27. A user equipment UE as described in any one of claims 21 to 26, wherein the RP configuration indicates whether COT sharing is enabled for some or all of the resources or interlaces from an unlicensed SL resource pool SL-U RP, and the SL-U RP includes multiple resources and / or interlaces from the unlicensed spectrum to be used for SL transmission.

28. A user equipment (UE) as claimed in any one of the preceding claims, wherein: In order to share the COT, the UE is configured to send a COT sharing control message to the network entity.

29. The user equipment (UE) according to claim 28, wherein the COT sharing control message is transmitted in one or more of the following: - Sidelink control information SCI message, such as first stage SCI and / or second stage SCI, -Media Access Control Layer Element, MAC CE, -Radio Resource Control RRC messages, such as SL-RRC messages.

30. The user equipment (UE) of claim 29, wherein the UE is configured to provide COT sharing information in one or more of the following: - a first-stage SCI and a MAC CE, wherein the first-stage SCI indicates a physical sidelink shared channel PSSCH, and the physical sidelink shared channel PSSCH contains the MAC CE including the COT sharing information, - a second-stage SCI and a MAC CE, wherein the second-stage SCI indicates a physical sidelink shared channel PSSCH, and the physical sidelink shared channel PSSCH includes the MAC CE including the COT sharing information, - Stage 1 SCI only, - Stage II SCI only, - Stage I SCI and Stage II SCI, - a first-stage SCI and a second-stage SCI and a MAC CE, wherein the first-stage SCI and / or the second-stage SCI indicates a physical sidelink shared channel PSSCH, and the physical sidelink shared channel PSSCH contains the MAC CE including the COT sharing information, -MAC CE only.

31. The user equipment (UE) according to any one of claims 28 to 30, wherein the COT shared information includes - the destination ID of the network entity, and / or - Feedback indicators, such as PSFCH indicators, - Remaining COT time, and / or - Maximum COT time.

32. The user equipment (UE) according to claim 31, wherein the COT sharing information is transmitted via unicast, multicast or broadcast.

33. A user equipment (UE) as claimed in any preceding claim, wherein the UE is configured to share the COT according to one or more conditions, such as according to one or more of the following: - The remaining COT time exceeds a predefined threshold, - a transmission to be performed by the UE and / or an upcoming transmission to be performed by a network entity has a priority exceeding a predefined threshold, - the upcoming transmission to be performed by the network entity has a specific identification ID or belongs to a specific UE group, - a transmission to be performed by the UE and / or an upcoming transmission to be performed by a network entity has feedback enabled, - a transmission to be performed by the UE and / or an upcoming transmission to be performed by a network entity has a predefined spreading type, - a remaining packet delay budget PDB of a transmission to be performed by the UE and / or of an upcoming transmission to be performed by a network entity exceeds a predefined threshold, - the communication range of a transmission to be performed by the UE and / or an upcoming transmission to be performed by a network entity is below a predefined threshold, - the number of time slots of transmissions to be performed by the UE and / or of upcoming transmissions to be performed by a network entity exceeds a predefined threshold, - the network entity is located at a distance from the UE that is less than a predefined threshold, such as within a minimum communication range MCR, - The network entity is located within a specific area or geographical location.

34. A user equipment UE for a wireless communication network, wherein the wireless communication network is a 3rd Generation Partnership Project 3GPP network. wherein the UE is configured to perform sidelink (SL) communication using a channel comprising resources from an unlicensed spectrum, wherein the UE is configured to receive one or more control messages, wherein the control messages are associated with an upcoming SL transmission by one or more network entities of the wireless communication network, and The UE is used - at least one network entity of the wireless communication system that uses the one or more control messages to determine an occupied channel for transmission within a channel occupation time COT, and - Performing the transmission within the shared COT using the complete remaining COT or using only one or more parts of said remaining COT.

35. The user equipment (UE) of claim 34, wherein the UE is configured to request the network entity to share the COT with the UE for one or more upcoming transmissions.

36. A user equipment UE for a wireless communication network, the wireless communication network being, for example, a 3rd Generation Partnership Project 3GPP network, wherein the UE is configured to perform sidelink (SL) communication using a channel comprising resources from an unlicensed spectrum, in, In response to sharing a signaled channel occupation time COT from a network entity of the wireless communication system, the UE is configured to perform transmission using a channel previously occupied by the network entity for transmission by the network entity.

37. The user equipment (UE) of claim 36, wherein the UE is configured to receive the one or more control messages before determining the one or more network entities occupying the channel.

38. The user equipment (UE) according to any one of claims 34 to 37, wherein the network entity comprises the user equipment (UE) according to any one of claims 1 to 33.

39. A user equipment (UE) as claimed in any one of claims 34 to 38, wherein the network entity is used to perform the transmission during a first part of the COT, and the UE is used to perform the transmission using all or one or more sub-parts of a second part of the COT, and the second part of the COT includes the duration of the COT that still exists after the transmission of the network entity is completed.

40. The user equipment UE according to claim 39, wherein the UE is used to share - a first subdivision of said second part of said COT for performing a feedback transmission PSFCH for said transmission performed by said network entity in said first part of said COT, and - a second sub-portion of the second part of the COT, for further transmission by the UE only after completing the feedback transmission.

41. A user equipment UE as claimed in claim 40, wherein the UE is used to receive COT sharing signaling of the first sub-portion and / or the second sub-portion of the second part of the COT within a control message, and the control message is associated with the transmission performed by the network entity in the first part of the COT, such as an SCI message, or the control message is associated with the transmission of an earlier sub-portion within the second part of the COT, such as via an SCI message.

42. A user equipment (UE) according to any one of claims 34 to 41, wherein the UE is configured to share the second portion of the COT with a network entity, the network entity transmitting the transmission to the UE in the first portion of the COT to perform one or more of the following: - Feedback transmission PSFCH, - Data transmission PSSCH, - Control signaling PSCCH, -Automatic gain control AGC signaling, - Transmission of demodulation reference symbols DMRS.

43. A user equipment (UE) as claimed in claim 42, wherein the UE is configured to receive COT signaling of the second part of the COT within a control message, the control message being associated with the transmission performed by the network entity in the first part of the COT, such as an SCI message.

44. The user equipment (UE) according to claim 43, wherein the SCI message contains information about a time slot structure to be used for transmission in the second part of the COT, such as any combination of one or more of the following: -Feedback only, -Data only, -DMRS only, -Feedback and data, -DMRS and feedback and data, -Automatic gain control AGC signaling, - No feedback transmission etc.

45. User Equipment (UE) according to any one of claims 40 to 44, wherein the feedback transmission (PSFCH) is performed by the UE or by one or more further network entities.

46. ​​A user equipment (UE) according to any one of claims 34 to 45, wherein the UE is configured to perform the transmission within the COT initiated by the network entity according to one or more conditions, such as according to one or more of the following: - The remaining COT time exceeds a predefined threshold, - a transmission to be performed by the UE and / or by the network entity has a priority exceeding a predefined threshold, - transmissions to be performed by the UE and by the network entity have the same priority, - a transmission performed by the UE and / or by the network entity has enabled feedback, - a transmission performed by said UE and / or by said network entity has a predefined propagation type, - a remaining packet delay budget PDB for the transmission to be performed by said UE exceeds a predefined threshold, - A communication range of a transmission to be performed by the UE and / or by the network entity is below a predefined threshold.

47. A User Equipment, UE, as claimed in any preceding claim, wherein the UE comprises one or more of: a power limited UE; or a handheld UE, such as a UE used by pedestrians and referred to as a vulnerable road user, VRU, or a pedestrian UE, P-UE; or body-worn or handheld UEs used by public safety personnel and emergency responders and are referred to as public safety UEPS-UEs; or IoT UE, such as a sensor, actuator or UE provided in a campus network to perform repetitive tasks and requiring input from a gateway node at periodic intervals; or a mobile terminal; or a stationary terminal; or a cell IoT-UE; or a SL UE; or a vehicle UE; or a vehicle group leader UE GL-UE; or dispatching UE S-UE; or IoT or narrowband IoT NB-IoT device; or ground-based vehicle; or aircraft; or an unmanned aerial vehicle; or a mobile base station; or a roadside unit RSU; or a building; or any other item or device with network connectivity that enables the item / equipment to communicate using the wireless communication network, such as a sensor or actuator; or any other item or device with network connectivity that enables the item / equipment to communicate using the side link of the wireless communication network, such as a sensor or actuator; or any network entity with side link capability.

48. A user equipment UE as described in any of the preceding claims, wherein the network entity includes one or more of the following: a further UE, such as a UE, or a SL UE, or a group leader UE GL-UE; or a base station, such as a macro cell base station or a small cell base station; or a central unit of a base station; or a distributed unit of a base station; or an integrated access and backhaul IAB node; or a road side unit RSU; or a relay device; or a remote radio head; or an AMF; or an SMF; or a core network entity; or a mobile edge computing MEC entity; or a network slice in the context of NR or 5G core; or any sending / receiving point TRP that enables an item or device to communicate using the wireless communication network; an item or device having network connectivity to communicate using the wireless communication network.

49. A network entity for a wireless communication network, such as a 3rd Generation Partnership Project 3GPP network, wherein the network entity is configured to provide services to a plurality of user equipments UE, the plurality of user equipments being configured to communicate with each other via a side link SL using resources from an unlicensed spectrum, The plurality of UEs include a specific user equipment UE as claimed in any one of claims 1 to 33.

50. The network entity of claim 49, wherein the network entity is configured to signal a DCI message to the specific UE, the DCI message indicating a UE with which the specific UE is to share the COT.

51. The network entity of claim 50, wherein the DCI message can further include one or more of the following: - a flag indicating whether COT sharing is enabled for the approval indicating the channels to be used by the UE, - The remaining COT time or the maximum COT time of the COT shared by the UE.

52. The network entity of claim 48, wherein the network entity is configured to signal a resource pool configuration to one or more specific UEs.

53. The network entity of claim 52, wherein the RP configuration further comprises one or more of the following: - Flag indicating whether COT sharing is enabled, - List of flags indicating whether COT sharing is enabled based on transmission priority, - Maximum COT time, - A list of maximum COT times according to the transmission priorities.

54. A wireless communication system, such as a 3rd Generation Partnership Project 3GPP system, comprising one or more user equipments UE according to any one of claims 1 to 47 and / or one or more network entities according to any one of claims 48 to 50.

55. A wireless communication system as described in claim 54, wherein the base station includes one or more of the following: a macro cell base station, or a small cell base station, or a central unit of a base station, or a distributed unit of a base station, or an integrated access and backhaul IAB node, or a road side unit RSU, or UE, or SL UE or group leader UE GL-U, or a relay device, or a remote radio head, or AMF, or SMF, or a core network entity, or a mobile edge computing MEC entity, or a network slice in the context of NR or 5G core, or any sending / receiving point TRP that enables an item or device to communicate using a wireless communication network, an item or device with network connectivity to communicate using a wireless communication network.

56. A method for operating a user equipment (UE) for a wireless communication network, such as a 3rd Generation Partnership Project (3GPP) network, wherein the UE is configured to perform sidelink (SL) communication using a channel comprising resources from an unlicensed spectrum, and wherein the method comprises: occupying the channel for a channel occupation time COT, receiving one or more control messages, wherein at least one of the control messages is related to one or more upcoming SL transmissions by the one or more network entities of the wireless communication network, determining at least one network entity having an upcoming transmission using the one or more control messages between the one or more network entities, and The COT is shared with the at least one network entity.

57. A method for operating a user equipment (UE) for a wireless communication network, such as a 3rd Generation Partnership Project (3GPP) network, wherein the UE is configured to perform sidelink (SL) communication using a channel comprising resources from an unlicensed spectrum, and wherein the method comprises: receiving one or more control messages, wherein the control messages are related to an upcoming SL transmission by one or more network entities of the wireless communication network, at least one network entity of the wireless communication system using the one or more control messages to determine an occupied channel for transmission within a channel occupation time COT, and The transmission is performed within the shared COT using the entire remaining COT or using only one or more portions of the remaining COT.

58. A method for operating a user equipment (UE) for a wireless communication network, such as a 3rd Generation Partnership Project (3GPP) network, wherein the UE is configured to perform sidelink (SL) communication using a channel comprising resources from an unlicensed spectrum, and wherein the method comprises: In response to sharing a signaled channel occupation time COT from a network entity of the wireless communication system, transmission is performed using a channel previously occupied by the network entity for transmission by the network entity.

59. A non-transitory computer program product comprising a computer readable medium storing instructions which, when executed on a computer, perform the method of any one of claims 56 to 58.

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