SL unlicensed frame structure

Abstract

An apparatus configured to communicate in a mobile wireless communication network, the apparatus comprising a wireless interface for transceiving wireless signals in the mobile wireless communication network, the apparatus being configured to communicate in a mobile wireless communication system via a sidelink (SL), the sidelink providing a plurality of time slots, each time slot having a time slot duration. The apparatus is configured to use at least a first time interval of a time slot duration to perform a listen before talk (LBT) process to determine availability of a time slot; and using a second time interval of the time slot duration for the wireless transmission based on the determined availability; and / or to use at least the first time slot duration to perform a listen before talk (LBT) procedure to determine availability of a subsequent second time slot, and to use the second time slot for wireless transmission based on the determined availability.

Description

[0001] manual

[0002] The present application relates to the field of wireless communication systems or networks, and more particularly, to the enhancement of communication between network entities of a communication network when performing communication using multiple frequency bands (part or all of which may include frequency bands in unlicensed spectrum). Embodiments of the present invention relate to improvements in feedback mechanisms for reporting successful / unsuccessful data transmission, or data that does not require redundancy, or data that requires some redundancy, or data that requires a certain amount of additional redundancy in multi-band operation, such as improvements to hybrid automatic repeat request HARQ feedback.

[0003] 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 includes a core network 102 and one or more radio access networks RAN1, RAN2, ...RAN N Figure 1(b) is a wireless access point network RAN n The example schematic diagram of the network may include one or more base stations gNB1 to gNB5, each base station serving a specific area around the base station, as represented by corresponding cells 1061 to 1065. The base station provides services to users within the cell. One or more base stations may provide services to users within licensed and / or unlicensed frequency bands. The term base station (BS) refers to a gNB in ​​a 5G network, an eNB in ​​UMTS / LTE / LTE-A / LTE-A Pro, or a BS in other mobile communication standards. Users may be fixed devices or mobile devices. Mobile or fixed IoT devices connected to a base station or user may also access the wireless communication system. Mobile devices or IoT devices may include physical devices, ground 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 objects or devices embedded with electronic components, software, sensors, actuators or similar devices and network connections, enabling these devices to collect and exchange data through existing network infrastructure. Figure 1(b) shows an example view of five cells, however, RAN n More or fewer such cells may be included, and the RAN nOnly one base station may also be included. FIG1(b) shows two users UE1 and UE2 (also referred to as user equipment UE) located in cell 1062 and served by base station gNB2. Another user UE3 is shown in cell 1064 served by base station gNB4. Arrows 1081, 1082 and 1083 schematically represent uplink / downlink connections for transmitting data from users UE1, UE2 and UE3 to base stations gNB2, gNB4, or from base stations gNB2, gNB4 to users UE1, UE2, UE3. This can be achieved in a licensed band or an unlicensed band. In addition, FIG1(b) shows two IoT devices 1101 and 1102 in cell 1064, which may be fixed devices or mobile devices. IoT device 1101 accesses the wireless communication system via base station gNB4 to receive and send data, as schematically represented by arrow 1121. IoT device 1102 accesses the wireless communication system via user UE3, as schematically represented by arrow 1122. Each base station gNB1 to gNB5 can be connected to the core network 102 via a respective backhaul link 1141 to 1145, for example, via an S1 interface, and these backhaul links are schematically represented by arrows pointing to "core" in Figure 1(b). The core network 102 can be connected to one or more external networks. In addition, some or all of the base stations gNB1 to gNB5 can be connected to each other via respective backhaul links 1161 to 1165 through the S1 or X2 interface or XN interface in the NR, for example, schematically represented by arrows pointing to "gNB" in Figure 1(b).

[0004] For data transmission, a physical resource grid can 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, physical channels may include physical downlink, uplink and sidelink shared channels (PDSCH, PUSCH, PSSCH) carrying user-specific data, also known as downlink, uplink and sidelink load data, physical broadcast channels (PBCH) carrying, for example, master information blocks (MIB) and system information blocks (SIB), physical downlink, uplink and sidelink control channels (PDCCH, PUCCH, PSSCH) carrying, for example, downlink control information (DCI), uplink control information (UCI) and sidelink control information (SCI). For the uplink, the physical channel may also include a physical random access channel (PRACH or RACH), which the UE uses to access the network once it is synchronized and acquires the MIB and SIB. Physical signals may include reference signals or symbols (RS), synchronization signals, etc. The resource grid may include frames or radio frames with a certain duration in the time domain and a given bandwidth in the frequency domain. A frame may have a certain number of subframes of a predefined length, such as 1 ms. Depending on the cyclic prefix (CP) length, each subframe may include one or more time slots of 12 or 14 OFDM symbols. A frame may also consist of a smaller number of OFDM symbols, for example, when using a shortened transmission time interval (sTTI) or a mini-slot / non-slot based frame structure consisting of only a few OFDM symbols.

[0005] The wireless communication system can be a single tone or multi-carrier system using frequency division multiplexing technology, such as an orthogonal frequency division multiplexing (OFDM) system, an orthogonal frequency division multiple access (OFDMA) system, or any other IFFT-based signal with or without CP, such as DFT-s-OFDM. Other waveforms, such as non-orthogonal waveforms for multiple access, such as filter bank multicarrier (FBMC), generalized frequency division multiplexing (GFDM) or universal filtered multicarrier (UFMC) can also be used. The wireless communication system can operate, for example, according to the principles of LTE-Advanced pro or 5G or NR (New Radio) or NR-U New Radio Unlicensed.

[0006] The wireless network or communication system depicted in Figure 1 can be a heterogeneous network with different overlapping networks, such as a macrocellular network and a small cell base station network (not shown in Figure 1), each macrocell includes a macro base station (such as base stations gNB1 to gNB5), and a small cell base station such as a femto base station or a pico base station.

[0007] In addition to the above-mentioned terrestrial wireless networks, there are also non-terrestrial wireless communication networks (also called NTNs), including space transceivers such as satellites and / or airborne transceivers such as unmanned aerial systems. Non-terrestrial wireless communication networks or systems operate in a similar manner to the terrestrial systems described in Figure 1 above, for example in accordance with LTE-Advanced Pro or 5G or NR New Radio principles.

[0008] It should be noted that the information in the above section is only used to deepen the understanding of the background of the invention and therefore may contain some information that does not constitute the prior art known to a person of ordinary skill in the art.

[0009] Based on the above-mentioned prior art, it may be necessary to improve the feedback mechanism used in wireless communication between wireless communication network entities using multiple frequency bands.

[0010] Now, embodiments of the present invention are described in further detail with reference to the accompanying drawings:

[0011] FIG1 shows a schematic representation of an example of a wireless communication system;

[0012] Figure 2a A schematic diagram showing interleaving in NR-U is shown;

[0013] Figure 2b -c is a schematic diagram showing an exemplary time slot configuration in TR37.985;

[0014] Figure 3a - b is a schematic diagram showing an example of LBT-based transmission in unlicensed spectrum via mini-slots;

[0015] Figure 4 shows a schematic timeline describing the channel access timeline according to the 3GPP time slot definition;

[0016] FIG5 shows an example table of the time slot format of the normal cyclic prefix defined in Table 11.1.1-1 of Section 11.1.1 of TS38.213;

[0017] Figure 6 A schematic diagram showing a process of combining LBT with transmission symbols according to an embodiment;

[0018] Figure 7a - b shows different mini-slot configurations according to embodiments;

[0019] Figure 8 shows a schematic diagram illustrating the configuration of aggregated time slots according to an embodiment;

[0020] Figure 9a - b shows a schematic diagram illustrating the configuration of aggregated time slots using common control information according to an embodiment;

[0021] Fig.10a shows a schematic representation of a symbol configuration according to an embodiment that utilizes existing mini-slot constraints for slot aggregation;

[0022] Fig.10b shows a schematic diagram of a symbol configuration according to an embodiment, the symbol configuration being aligned in time with a reference of a time slot;

[0023] Fig.11 A schematic diagram of an existing Rel-16 time slot structure 224 is shown, which is transmitted after the inventive advantageous LBT;

[0024] Fig.12 shows a block diagram of a mobile wireless communication network according to an embodiment;

[0025] Fig.13 is a schematic representation of a wireless communication system, comprising a transmitter (such as a base station) and one or more receivers (such as user equipment UE); and

[0026] Fig.14 An example of a computer system is shown, on which the units or modules described according to the method of the present invention and the steps of the method can be executed.

[0027] Embodiments of the present invention will now be described in more detail with reference to the accompanying drawings, in which the same or similar elements have the same reference characters.

[0028] In a mobile communication system or network, as described above with reference to Figure 1, for example in an LTE or 5G / NR network, each entity may use one or more frequency bands for communication. 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, a bandwidth portion BWP, a subband, or a subchannel, etc. In addition, only certain frequencies in a frequency interleaving or frequency comb structure may be used to exploit frequency domain diversity, which means that frequencies belonging to the same transmission do not have to be located at adjacent frequencies, but may be propagated within a channel or subchannel, subband, carrier, or bandwidth portion according to the configured interleaving structure.

[0029] NR-U is designed to coexist with other RATs (such as IEEE802.11), especially in the frequency band below 6 GHz. Therefore, based on regulatory requirements, NR-U only supports bandwidths of integer multiples of 20 MHz, where each 20 MHz channel is designated as a subband. NR-U supports two resource allocation schemes: continuous and interleaved. For the interleaved resource allocation scheme, the basic unit of resource allocation is called interlace, which consists of multiple equally spaced resource blocks within a 20 MHz subband. Figure 2a Interleaving in NR-U is described by a schematic diagram of a bandwidth part BWP190, which includes a set of physical resource blocks (PRBs) grouped into interleavings 1921, ..., 192 n ,1941,…,194 n ,1961,…,196 n , where the number of interleaved PRBs and the number of interleavings within a PRB can be freely chosen.

[0030] Therefore, the UE is configured with a parameter M, indicating the number of interleavings, and defines an interleaving of multiple resource blocks, where each interleaving consists of common resource blocks determined by {m, M+m, 2M+m, 3M+m, …}. The UE is then expected to perform an interleaving operation with the resource blocks of the configured BWP. The number of interleavings is limited to a maximum of 10.

[0031] 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 a 20 MHz frequency band.

[0032] When two or more frequency bands are used, the communication may be referred to as multi-band operation or broadband operation or carrier aggregation operation. These 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 may be part or all of the frequency bands separated in the frequency domain.

[0033] 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.

[0034] Carrier aggregation (CA) is an example of using two or more frequency bands in licensed spectrum and / or unlicensed spectrum.

[0035] 5G New Radio (NR) can support operation in unlicensed spectrum so that multi-band operation can include bands in unlicensed spectrum. This may be referred to as NR-based unlicensed spectrum access (NR-U), and the bands may be referred to as sub-bands. Unlicensed spectrum may include bands that may coexist with IEEE802.11, such as 5GHz and 6GHz bands. For example, due to regulatory requirements, NR-U may support bandwidths that are integer multiples of 10 or 20MHz. The purpose of splitting into sub-bands is to minimize interference to coexisting systems (such as IEEE802.11 systems), which may use the same nominal bandwidth channels in one or more of the same frequency bands, such as 10MHz or 20MHz channels. Other examples of coexistence systems may use sub-bands with sub-band sizes and nominal frequencies different from those of the above-mentioned IEEE802.11 systems. For example, unlicensed spectrum may include 5GHz bands, 6GHz bands, 24GHz bands, and 60GHz bands. Examples of such 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.

[0036] During operation using unlicensed subbands, channel access procedures such as Listen-before-talk (LBT) or request to send / clear to send (RTS / CTS) are performed separately for each subband. This may cause one or more subbands to be busy or occupied due to interference, such as interference from other communication systems co-existing in the same band, such as other public land mobile networks (PLMNs) or systems operating according to the IEEE 802.11 specification. In this case, the transmitter, whether a transmitting gNB or a transmitting UE, can only transmit on subbands that are detected to be not busy (also called idle or unoccupied subbands), as determined by the LBT algorithm. For example, when transmitting in the 5 GHz unlicensed operating band spanning more than 20 MHz, the transmitter (such as a gNB or UE) performs Listen-Before-Talk (LBT) on each subband separately. Once the LBT results for each subband are obtained, the device (e.g., gNB for downlink (DL) or UE for uplink (UL)) can transmit on subbands determined to be idle or unoccupied, i.e., on winning subbands. Transmission is not allowed on occupied, busy, or non-winning subbands.

[0037] For example, 5G New Radio (NR) technology supports operation in unlicensed bands through a technology called NR-based unlicensed spectrum access (NR-U). Unlicensed spectrum may include bands that may coexist with IEEE802.11, such as 5GHz and 6GHz bands. For example, due to regulatory requirements, NR-U can support bandwidths of integer multiples of 10 or 20MHz. Each of the 10MHz or 20MHz bandwidth channels is designed as a subband, and the purpose of dividing into these subbands is to minimize interference to coexisting systems (such as IEE 802.11 systems), which can operate in one or more of the same bandwidth channels (such as 10MHz or 20MHz channels). Other examples of coexistence systems may use subbands with subband sizes and nominal frequencies different from those of the above-mentioned IEEE802.11 systems. For example, unlicensed subbands such as 24GHz and 60GHz may be used. Examples of such unlicensed sub-bands include Industrial, Scientific and Medical (ISM), which are bands reserved internationally for use of radio frequency energy for industrial, scientific and medical purposes other than telecommunications.

[0038] Generally speaking, during wideband operation using unlicensed subbands, such as transmissions spanning more than 20 MHz in the 5 GHz unlicensed band, the transmitter (such as a gNB or UE) performs LBT for each subband separately, and once the LBT results for each subband are available, the device (such as a gNB in ​​the downlink (DL) or a UE in the uplink (UL)) is allowed to transmit only on subbands that are determined to be idle or unoccupied, that is, on the winning subbands. For example, in the 5 GHz unlicensed band, the number of 20 MHz subbands used for wideband operation may be four, so the total bandwidth is 80 MHz, but the actual number of subbands used may be different.

[0039] For example, when considering NR unlicensed (NR-U) operation, i.e., multi-band communication using bands or subbands in the unlicensed spectrum, the UE or gNB can perform LBT to acquire the channel to obtain the channel occupancy time (COT). The COT can also be shared with other devices, for example, the UE can share the COT initiated by the gNB, and the UE can use the COT initiated by the gNB after the so-called handover gap. If the gap exceeds a certain duration (e.g. 16μs), other devices can perform LBT (CAT-2 or CAT-4), depending on the duration of the gap. In wideband operation, the UE or gNB should perform LBT for each subband, and the total number of subbands can include the complete bandwidth part (BWP).

[0040] When transmitting in multi-band or wideband operation, a transport block (TB) is sent by the transmitter. For example, in communications between a base station and a user equipment, the transmission may be a downlink transmission from a gNB to a UE or an uplink transmission from a UE to a gNB. In the case of sidelink communications, the transmitter may be a UE that sends a transport block to a receiving UE via a sidelink. The receiver (UE or gNB) receives the TB and decodes the data. The feedback mechanism is similar to the HARQ mechanism. The feedback mechanism may indicate or signal to the transmitter that the data transmission was successful or unsuccessful, for example, by sending an ACK or NACK message. The feedback mechanism may indicate or signal to the transmitter that the data does not require redundancy or that the data requires some redundancy. The feedback may also indicate or signal the amount of additional redundancy required for the data. Based on the feedback, the transmitter may perform a retransmission in the event of a NACK. For example, the retransmission may contain the same information, such as the same data and the same parity bits, to allow tracking combining at the receiver. Retransmissions may also include incremental redundancy.

[0041] The TB can be divided into multiple code block groups (CBGs), and the retransmission mechanism is used to indicate ACK / NACK and retransmit data in units of CBGs. A CBG may include one or more code blocks (CBs). Therefore, when a TB is divided into multiple CBGs, HARQ based on multiple code block groups can be used. When multi-band operation is considered, the CBGs are confined to their respective bands or subbands, and one or more CBGs can share the TB duration or time slot duration in a time division multiplexed (TDMed) manner.

[0042] Although UE is referred to herein as a device or apparatus according to an embodiment, the embodiment is not limited to UE. The embodiment can be implemented without limitation by other devices capable of communicating in a mobile wireless communication network, such as a mobile terminal, or a fixed terminal, or a cell IoT-UE, or a vehicle-mounted UE, or a vehicle-mounted group leader (GL) UE, or an IoT, or a narrowband IoT (NB-IoT) device, or a WiFi non-access point STAtion, a non-AP STA (e.g., 802.11ax or 802.11be), or a ground-based vehicle, or a control aircraft, or a drone, or a mobile base station, or a road side unit (RSU), or a building, or any other item or device with network connectivity, enabling the item / device to communicate using a wireless communication network (e.g., a sensor or actuator). Alternatively or additionally, such a device or apparatus may include a base station (BS), wherein the BS may be used as a mobile or non-mobile base station and includes a macrocell base station, or a small cell base station, or a central unit of a base station, or a distributed base station unit, or a roadside unit, or a UE, or a group leader (GL), or a relay, or a remote wireless head, or an AMF, or an SMF, or a core network entity, or a mobile edge computing entity, or a network slice in the context of NR or 5G core, or a WiFi AP STA (e.g., 802.11ax or 802.11be), or one or more of any transmission / reception points (TRP), the TRP enabling an item or device to communicate using a wireless communication network, and the item or device being provided with network connectivity to communicate using the wireless communication network.

[0043] 3GPP LTE Release 14 was the first LTE version to include vehicle-to-everything (V2X) technology. The scheduling and allocation of resources were modified to meet V2X requirements and were designed using the original LTE device-to-device (D2D) communication mechanism as a basis. 3GPPs LTE Release 15 (also known as enhanced V2X or eV2X) was completed in June 2018, and Release 16, the first release of 5G NR V2X, was completed in March 2020. 3GPPs NR Release 17 focuses on sidelink enhancements, emphasizing energy saving, enhanced reliability and reduced latency, meeting not only vehicular communications but also public safety and commercial use cases.

[0044] Current discussions on NR Release 18, such as RP-220300 (available at https: / / www.3GPP.org / ftp / TSG_RAN / TSG_RAN / TSGR_95e / Docs / ?sortby=size), focus primarily on implementing sidelink in unlicensed spectrum (SL-U). This present report deals with the frame structure to be used by SL-U, taking into account the resource pool structure of NR-U for NR V2X and Rel-16.

[0045] To understand the complexity behind the NR-U and NR V2X systems, this section will delve into the working principles of NR-U Listen-Before-Talk (LBT) and NR V2X frame structure.

[0046] NR V2X slot format

[0047] The NR V2X UE is configured with an activated sidelink bandwidth part (SL BWP) for transmission and reception. The SLB WP also contains a resource pool for transmission and reception of specific sidelink channels. The frame structure of the time slots using the synchronization channel is different from the frame structure for transmission / reception, and the time slots for transmission / reception are related to the present invention report.

[0048] These time slots contain the Physical Sidelink Control Channel (PSCCH) for control, the Physical Sidelink Shared Channel (PSSCH) for control / data, and the Physical Sidelink Feedback Channel (PSFCH) for hybrid automatic repeat request (HARQ) feedback, automatic gain control (AGC), symbols, and protection symbols. The second SL symbol (containing the first PSCCH or PSCCH / PSSCH symbol) is repeated with the first SL symbol for AGC. [Source: 5G NR V2X Communication Tutorial - Mate Boban et al.] In the time slot that can be used for PSSCH transmission, 7 to 14 symbols can be reserved for sidelink operation, of which PSSCH can be transmitted in 5 to 12 symbols. The remaining sidelink symbols transmit part or all of PSCCH, PSFCH, DMRS, AGC, and protection symbols. Figure 2b and Figure 2c The timeslot configurations 2001 and 2002 shown (from TR 37.985) are examples of timeslots with and without PSFCH configured.

[0049] In a timeslot configuration 2001 without PSFCH, Figure 2b As shown, symbol 2021 to symbol 202 14 It includes symbols related to AGC, PSSCH, PSCCH, DMRS and protection. In the time slot configuration 2002 with PSFCH, Figure 2c As shown, symbol 202 13 The PSFCH is included in the symbol, which can be copied and used as symbol 202 12 AGC in.

[0050] All transmission and reception is done on a slot-by-slot basis. This means that a given Protocol Data Unit (PDU) is packaged for transmission in a single slot, containing control information in the form of Sidelink Control Information (SCI) format 2A (located in the PSCCH), followed by the second stage SCI format 2B or 2C and data (both located in the PSSCH). Depending on the configuration of the resource pool, some slots may be configured with PSFCH and some may not. The UE uses the (pre-)configured slots between the next possible and configured PSFCH slot and the time when the transmission is received to determine the slot in which to transmit feedback for a given transmission.

[0051] NR-U frame structure

[0052] The NR frame structure supports time division duplex (TDD) and frequency division duplex (FDD) transmission, and can operate in both licensed and unlicensed spectrum. The frame structure follows three key design principles to enhance forward compatibility and reduce interactions between different features.

[0053] The first principle is that the transmission is self-contained. The data in a slot and / or beam can be decoded independently without relying on other slots and / or beams.

[0054] ●The second principle is that transmission is well confined in both time and frequency. The NR frame structure avoids mapping of control channels over the entire system bandwidth.

[0055] - The third principle is to avoid static and / or strict timing relationships across time slots and across different transmission directions.

[0056] A slot in NR consists of 7 or 14 OFDM symbols for digital structures with frequencies ≤ 60kHz and 14 OFDM symbols for digital structures with frequencies ≥ 120khz. Since the OFDM symbol duration is inversely proportional to its subcarrier spacing (SCS), the slot duration is also proportional to the selected digital structure. Slots can be supplemented by mini-slots to support transmissions with flexible starting positions and shorter duration than regular slots. Mini-slots can be as short as an OFDM symbol and can start at any time. Mini-slots are useful in various scenarios, especially when transmitting in unlicensed spectrum, as LBT needs to be used at the beginning of the slot. When transmitting in unlicensed spectrum, it is beneficial to start transmission immediately after the end of LBT, as transmission needs to start immediately without waiting for the start of the slot boundary to avoid interference with other users or other technologies. Figure 3a and Figure 3b An example of LBT-based transmission in unlicensed spectrum via mini-slots is provided. [Source: https: / / www.ericsson.com / en / reports-and-papers / ericsson-technology-review / articles / designing-for-the-future-the-5g-nr-physical-layer]

[0057] 3GPP introduced a new frame structure type 3 for operation in unlicensed communication channels. Similar to LTE TDD, uplink and downlink operations using frame structure type 3 are located on the same frequency channel but separated in time. However, unlike LTE TDD, subframes are not configured as downlink subframes or uplink subframes and can be used by base stations or wireless devices. [Source: https: / / ofinno.com / technologies / new-radio-unlicensed-band / ]

[0058] Listen before you speak - LBT

[0059] In NR-U, both downlink and uplink channel access rely on listen-before-talk (LBT) functionality. A wireless device or base station must first "sense" the communication channel to determine that there is no communication before any transmission. When the communication channel is a wideband unlicensed carrier (such as hundreds of MHz), the "channel sensing" process relies on detecting the energy levels of multiple sub-bands of the communication channel.

[0060] After competing for k idle time slots on the channel, the device can use the channel for a period of time, which is called the channel occupancy time (COT). The system's definition of time slots is different. In NR, a time slot consists of 14 (normal cyclic prefix) or 12 (extended cyclic prefix) OFDM symbols. Using the standard digital structure of 15khz subcarrier spacing (SCS), the OFDM symbol length is typically 71.4μs, and using the standard digital structure of 30khz subcarrier spacing, the OFDM symbol length is 35.7μs. In addition, NR also defines a concept called mini-slots, which can occupy 2, 4, or 7 OFDM symbols, thereby enabling non-slot-based scheduling. "Non-slots" typically combine multiple OFDM symbols together, and the combined length is less than the defined and commonly used slot length. In the system, the time reference is called "slot time", and the latest In the specification (such as IEEE802.11g / n / ac), the slot time is defined as 9μs.

[0061] LBT parameters (such as type / duration, clear channel assessment parameters, etc.) are configured in the wireless device by the base station. [Source: https: / / ofinno.com / technologies / new-radio-unlicensed-band / ]

[0062] ● Type 2 LBT can only be performed in an activated COT. Therefore, for COT activation, the UE must always perform Type 1 LBT. [Source: TS37.213 Section 4.2.1]

[0063] ○The minimum duration of Type 1 LBT is 34μs

[0064] ○ Type 2 LBT can only be performed if the UE initiating the COT indicates that it wants to share its COT with another UE

[0065] ○Type 2A: 25μs

[0066] ○Type 2B: 16μs

[0067] ○ Type 2C without LBT (transmission duration up to 584μs, gap up to 16μs)

[0068] ○ Maximum contention window (CW) for priority 4 ranges from 15 to 1023 sensing slots, or 135 to 9207 μs, or 4 to 256 slots (30kHz SCS)

[0069] ● Wideband LBT: UE performs Type 1 LBT on one band and Type 2 LBT on other bands

[0070] ○ If the cell guard band is configured, the transmission is carried out on the idle frequency band

[0071] The channel access process is described in the following sections. Figure 4 The timeline shown illustrates a channel access timeline description according to the 3GPP time slot definition.

[0072] NR-U channel access process

[0073] The channel access process is a sensing-based process used to evaluate whether the channel is available for transmission. The basic unit of sensing is a duration of T. si=9μs sensing time slot. If the eNB / gNB or UE senses the channel during the sensing time slot duration and determines that the detected power for at least 4μs during the sensing time slot duration is less than the energy detection threshold X Thresh , then the perception time slot duration is considered to be T si is idle. Otherwise, the sensing time slot T si Considered busy.

[0074] Channel occupancy refers to the transmission performed by the eNB / gNB / UE on the channel after performing the corresponding channel access procedure in this clause.

[0075] Channel occupancy time (COT) is the total time that the eNB / gNB / UE and any eNB / gNB / UE sharing the channel occupancy perform transmissions on the channel after the eNB / gNB / UE performs the corresponding channel access procedures described above. For the purpose of determining the channel occupancy time, if a transmission gap is less than or equal to 25 μs, the gap duration is counted towards the channel occupancy time. The channel occupancy time may be shared between transmissions of the eNB / gNB and the corresponding UE.

[0076] Type 1 Uplink (UL) channel access procedure

[0077] In step 4, the UE d After the channel is first sensed to be idle during a time slot of N, and after the counter N is zero, a transmission may be sent using a Type 1 channel access procedure. The counter N is adjusted by sensing the additional time slot duration of the channel according to the steps described below.

[0078] Step 1) Set N = N init , where N init is between 0 and CW p A random number uniformly distributed between , and then go to step 4;

[0079] Step 2) If N>0 and the eNB / gNB chooses to decrement the counter, set N=N-1;

[0080] Step 3) sensing the duration of the additional sensing time slot of the channel, if the duration of the additional sensing time slot is idle, go to step 4; otherwise, go to step 5;

[0081] Step 4) If N=0, stop; otherwise, go to step 2.

[0082] Step 5) Sense the channel until the additional delay time T d The busy sensing time slot is detected within 1 second, or an additional delay time T d All sensing time slots of are detected as idle;

[0083] Step 6) If the additional delay time T d If the channel is sensed to be idle during the duration of all sensing time slots, go to step 4; otherwise, go to step 5;

[0084] If the UE does not send an UL transmission on the channel on which the UL transmission was performed after step 4 above, then if the UE is ready to send a transmission at least within the perceived time slot duration T sl The channel is sensed to be idle within 1 second, and if a delay of duration T is applied before transmission d If the UE senses that the channel is idle during all time slot durations of T, then it can send a transmission on the channel. sl The channel is not sensed to be idle in , or if a delay of slot duration T precedes the expected transmission d If the UE does not sense that the channel is idle during any sensing time slot duration, the UE will delay the time slot duration T. d Continue with step 1 after sensing that the channel is idle during the time slot duration.

[0085] Delay duration T d Including duration T f =16μs followed by m p The duration of each time slot is T sl =9μs, and T f Included in T f The duration of the idle time slot at the beginning is T sl .

[0086] Type 2A UL channel access procedure

[0087] If the UE is instructed to perform a Type 2A UL channel access procedure, the UE uses the Type 2A UL channel access procedure for UL transmission. short_ul = 25 μs after being idle, the UE can immediately send a transmission. short_ul Including duration T f = 16μs followed by a sensing time slot, and T f Included in T f The sensing time slot starts. If T short_ul If both sensing time slots of T are idle, then it is considered that short_ul , the channel is idle.

[0088] Type 2B UL channel access procedure

[0089] If the UE is instructed to perform a Type 2B UL channel access procedure, the UE uses the Type 2B UL channel access procedure for UL transmission. f =16μs duration, the UE can immediately send a transmission. f Including the occurrence of T f If the channel is idle for a total of at least 5 μs, of which at least 4 μs of the sensing occurs in the sensing slot, then the channel is idle for duration T. f is considered idle.

[0090] 2C UL channel access process

[0091] If the UE is instructed to perform a Type 2C UL channel access procedure for UL transmission, the UE does not perform channel sensing before transmission. The corresponding UL transmission duration is at most 584 μs.

[0092] Timeslot format for NR-U

[0093] FIG. 5 shows an example table of a time slot format of a normal cyclic prefix defined in Table 11.1.1-1 of Section 11.1.1 of TS38.213.

[0094] The inventors have identified three main issues with implementing the unlicensed procedure on the sidelink, primarily dealing with the fact that LBT in NR-U occurs on a per-symbol basis, while NR V2X operates on a per-slot basis:

[0095] Question 1: Since NR V2X uses slot-by-slot transmission, if LBT determines that a few symbols at the beginning of a slot are available, the UE cannot start transmission in the same slot due to the limitations of slot-by-slot transmission. It can only transmit in the next slot, but the LBT check does not contain any information about the availability of the next slot, only the current symbol in the slot.

[0096] Question 2: If LBT can be used in SL-U, the criteria and actions that the UE must take when handling LBT failures must be based on NR V2X.

[0097] In order to solve the technical problems related to LBT in NR, especially the technical problems related to V2X, the inventors proposed a series of solutions.

[0098] Proposed technical solutions

[0099] The inventors propose to combine LBT and data transmission within one time slot, regardless of whether the device (eg, UE or base station) operates on a time slot basis or a symbol basis.

[0100] The solution described herein can be applied to systems containing only 3GPP devices or UEs (e.g. LTE UEs and NR UEs) as well as systems containing 3GPP devices / UEs and non-3GPP devices (e.g. NR UEs and WiFi or Bluetooth devices). In addition, the gNB or another UE may inform one or more other UEs about the presence or absence of such devices, for example using the absenceOfAnyOtherTechnology flag in the ServingCellConfig information element, see example from TS 38.331 (3GPP TS 38.331 Version 16.7.0 Version 16):

[0101] absenceOfAnyOtherTechnology

[0102] The presence of this field indicates that there are no other technologies sharing the carrier in the long term (e.g., at regulatory levels); the absence of this field indicates that there may be any other technologies sharing the carrier, as specified in clauses 4.2.1 and 4.2.3 of TS 37.213

[48] .

[0103] In addition, flags such as absenceOfNon3GPPTechnology and presenceOfWiFiTechnology can be used to signal the UE to indicate the presence or absence of a certain RAT or a non-3GPP RAT.

[0104] Depending on the presence or absence of these fields, different solutions described in the present invention may be triggered, enabled or disabled, for example, in a system without non-3GPP devices, mini-slots with slot aggregation may be used.

[0105] Concept 1: Flexible transmission slot structure

[0106] Question 1: Since NR V2X uses slot-by-slot transmission, if LBT determines that a few symbols at the beginning of a slot are available, the UE cannot start transmission in the same slot due to the limitations of slot-by-slot transmission. It can only transmit in the next slot, but the LBT check does not contain any information about the availability of the next slot, only the current symbol in the slot.

[0107] Solution 1: Use a (pre)configured or (pre)defined mini-slot structure

[0108] Solution 1-1 for Concept 1

[0109] Solution 1-1 is to introduce a (pre)configured or (pre)defined mini-slot structure. The slot structure allowed for NR-U is listed in Section 11.1.1 of TS38.213.

[0110] The UE will sense the initial resource selection and perform a combination of sensing and re-evaluation of the reserved resources based on the initial transmission, similar to Release 16. Before transmitting in the selected resources, the embodiment provides that the device (such as the UE) will perform LBT on the first symbol of the time slot. In other words, the UE will follow the Release 16 or Release 17 time slot boundary for the LBT process.

[0111] Once the UE completes LBT and determines that the subchannel is available, it will have occupied at least 1-2 symbols. But the current slot structure does not allow the UE to transmit between slots. Therefore, this article proposes to use new mini-slots with different symbol lengths so that after LBT, the remaining symbols in the slot can be used (each remaining symbol is used for TX). Each mini-slot can contain a small number of symbols, such as 2-3 symbols for PSCCH, and the remaining multiple symbols are used for data and / or feedback and / or pilot symbols, such as DMRS.

[0112] Considering the slot structure of NR-U in TS38.213, we propose to replace the DL and UL symbols within the slot with TX and RX symbols. This will define the symbols within the slot that the UE can receive / sense / perform LBT, and once it determines that the channel is available, the UE can use the remaining symbols for transmission. In addition, the new slot structure can be used alone or in combination with one or more other structures, as follows:

[0113] ■ In each slot structure, there can be at least 1 symbol used for LBT and a maximum of 14 symbols of a slot used for LBT. This means that the LBT symbol is represented by the received R.

[0114] ■The symbols that the UE will use to transmit PSCCH, PSSCH, AGC and DMRS are represented by T, while some time slots are allowed to be used flexibly, represented by F.

[0115] ■ Each slot may have LBT (R) symbols at the beginning, followed by transmission symbols (T). If the slot supports receiving PSFCH, a small number of symbols at the end of the slot should also be represented by R.

[0116] ■ The table shown in Figure 5 can be expanded since only 55 values ​​are defined out of a possible 254. As mentioned above, reserved format indices (e.g. 56-254) can be used to define the SL non-grant slot structure.

[0117] Therefore, if the UE has performed LBT on the first 3 symbols, the UE can use the remaining symbols to transmit control and data on the subchannel, using a mini-slot structure including PSCCH, PSSCH and demodulation reference symbols (DRMS). A mini-slot can also start with an AGC symbol and end with a guard symbol.

[0118] Figure 6 The process of combining LBT with sending a symbol shape in a time slot is shown. After the side link or channel may be sensed during the sensing window 212 and the selection of further resources has been performed, the device can transmit during the selection window 214, more specifically during the time slot 2001. The device is configured to perform LBT during the first time interval 216 of the time slot 2001. By way of non-limiting example, the time interval 216 may include or correspond to the duration of symbols 2021 and 2022. The time interval 216 may last for at least one symbol. The upper limit of the first time interval may be within the time slot 2001, wherein the embodiment also includes the implementation of the LBT process extending the time slot boundary. For example, according to ETSI BRAN, LBT can be performed in up to 256 time slots, for example using a 30kHz SCS, which technically means that according to the embodiment, a full time slot, more than one time slot, or multiple time slots can be used for LBT.

[0119] After determining the availability of time slots 2001 or time slots or symbols after the first time interval 216, the device may start its transmission in the second time interval 218. According to one embodiment, the device may use the remainder of time slot 2001 and / or at least a portion of the subsequent time slot 2002 for transmission.

[0120] According to an embodiment, a device configured to communicate in a mobile wireless communication network includes a wireless interface for transmitting and receiving wireless signals in the mobile wireless communication network; and is configured to:

[0121] In a mobile wireless communication system, communication is performed via a side link (SL), the side link providing a plurality of time slots, each time slot having a time slot duration.

[0122] wherein the apparatus is configured to use at least a first time interval of the time slot duration to perform a listen-before-talk (LBT) procedure to determine availability of the time slot; and based on the determined availability, use a second time interval of the time slot duration for wireless transmission; and / or

[0123] Therein, the device is configured to use at least a first time slot duration to perform a listen-before-talk (LBT) process to determine the availability of at least a portion of a subsequent second time slot (e.g., a time slot, a mini-time slot, or a mini-frame), and / or to use at least a portion of the subsequent second time slot for wireless transmission based on the determined availability.

[0124] According to an embodiment, the apparatus is configured to communicate in a mobile wireless communication network based on one or more of the following:

[0125] - slot-based, where each slot consists of a number of symbols across time,

[0126] - on a symbol basis, where each symbol is associated with a symbol duration defined according to the subcarrier spacing used for the resource pool,

[0127] -Based on a configuration or preconfigured symbol set.

[0128] According to an embodiment, the apparatus is configured to use the second time interval at least as a remainder of the time slot duration after the first time interval, ie the second time interval may end at, be shorter than or exceed a time slot boundary.

[0129] According to an embodiment, the device is configured to transmit a mini-frame in a second time interval, the mini-frame comprising a reduced number of symbols compared to the time slot capacity of the mobile wireless communication network. In NR, a frame may consist of a plurality of time slots, depending on the SCS. For a 30khz SCS, a frame may have 10 subframes, each subframe may include 2 time slots (for 15khz, only 1 time slot), and each time slot may include 14 symbols. A mini-slot may be understood as a time slot of less than 14 symbols, and 3GPP defines their sizes for mini-slots as 2, 4 and 7 symbols. Thus, a frame may include one or more time slots or mini-slots, and a mini-frame may be one or more mini-slots.

[0130] According to an embodiment, the capacity of a time slot corresponds to a frame comprising one or more time slots; wherein a time slot comprises one or more symbols; wherein a mini-frame comprises one or more mini-time slots; wherein a mini-time slot or a mini-frame consists of one or more symbols; wherein the number of symbols is less than the number of symbols in a time slot.

[0131] According to an embodiment, the mini-frame includes one or more of the following:

[0132] ●OFDM symbols less than the slot capacity,

[0133] ● any number of OFDM symbols in the set {1..13},

[0134] ● Other mini-frames where the total number of OFDM symbols does not exceed the time slot boundary,

[0135] ●Combination of multiple mini-frames to form new, longer mini-frames.

[0136] According to an embodiment, the apparatus is configured to time align an end of the second time interval with an end of a time slot of the mobile wireless communication network.

[0137] According to an embodiment, the apparatus is configured or preconfigured to transmit across frequency in one or more channels or sub-channels during the second time interval.

[0138] According to an embodiment, a subchannel includes one or more resource blocks across frequency, and / or

[0139] Wherein, the channel or sub-channel is defined in one or more resource pools, and / or

[0140] wherein the subbands are defined within the bandwidth portion;

[0141] Each channel, sub-channel or sub-band includes one or more continuous or non-continuous resource blocks.

[0142] According to an embodiment, frequency resources are interleaved according to a configured or preconfigured scheme.

[0143] According to an embodiment, according to the configuration of the mobile wireless communication network, the time slot duration includes multiple symbol durations; wherein the device is configured to perform LBT during a first subset of the symbol durations; and for transmitting multiple symbols for wireless transmission during a second subset of the symbol durations.

[0144] According to an embodiment, the apparatus is configured to perform sensing prior to performing LBT to determine resources for transmission and / or initial transmission and / or to determine one or more future reserved resources to be re-evaluated for retransmission.

[0145] Therein, the apparatus is configured to perform LBT to determine availability of resources for transmission and / or initial transmission and / or one or more future reservations prior to wireless transmission.

[0146] According to an embodiment, the device is configured to transmit a symbol of the wireless transmission using a first symbol duration in time after a first time interval based on the availability of the determined time slot. As the first symbol in time, it can be understood as the first symbol after the last symbol used for LBT.

[0147] According to an embodiment, the apparatus is configured to use a predetermined number of symbols (eg 2 or 3 symbols) of the second time interval for transmitting control information, eg control information associated with a Physical Sidelink Control Channel (PSCCH).

[0148] like Figure 7a and Figure 7b As mentioned above, the second time interval 218 may be used to transmit different symbols 202 according to different configurations.

[0149] According to an embodiment, the apparatus is configured to use the remaining symbols of the second time interval 218 to transmit one or more of the following in at least one or more symbols:

[0150] ● control channels, e.g. via PSCCH,

[0151] ● data channels, e.g. via PSSCH,

[0152] ● Broadcast channels, e.g. via PSBCH,

[0153] ● Feedback channels, such as PSFCH,

[0154] ● Pilot symbols, e.g. via DMRS,

[0155] ● duplicated symbols (copies of the previous symbol), e.g. for AGC adjustments,

[0156] ●Protection symbol.

[0157] According to an embodiment, the apparatus is configured to transmit an AGC symbol at the beginning of the second time interval and / or to transmit a guard symbol at the end of the second time interval.

[0158] According to an embodiment, the apparatus is configured to transmit the control information at a predetermined position in the second time interval, for example during the first 2 or 3 symbols after the AGC symbol.

[0159] According to an embodiment, the apparatus is configured to use at least one symbol duration for LBT and a maximum of 14 symbol durations for LBT in the first time interval of a time slot. However, other configurations are possible.

[0160] According to an embodiment, the apparatus is configured to use the symbol durations of at least two different time slots for LBT. For example, before transmission, more than one time slot may be occupied or reserved.

[0161] According to an embodiment, the apparatus is configured to select the duration of the first time interval based on a random value between a minimum time duration and a maximum time duration.

[0162] According to an embodiment, the minimum duration and / or the maximum duration is based on a priority of the radio transmission.

[0163] Alternatively or additionally, according to an embodiment, the minimum duration and / or the maximum duration is based on one or more of the following aspects of the wireless transmission:

[0164] ● Type of communication,

[0165] ● Remaining PDB,

[0166] ●Whether to enable / disable HARQ feedback during transmission;

[0167] ●The distance between the sending device and the receiving device.

[0168] A device (such as a UE or other device) may also use a slot structure that allows it to include PSFCH symbols and required guard symbols at the end of a slot in order to receive feedback for previous transmissions, so that transmissions requiring feedback (unicast / multicast) can use a mini-slot with PSFCH enabled, while broadcast transmissions can use a mini-slot structure with PSFCH disabled. Guard symbols are actually null symbols used to switch between transmission and reception and vice versa.

[0169] Problems with this solution:

[0170] ■Depending on the different CW lengths, more SL slot structures need to be defined, which will be different from the slot structure used in Release 16 / Release 17. This will also result in a smaller amount of data transmitted in a slot, due to the smaller number of PSSCH symbols contained in the slot.

[0171] ■Another problem is that the sensing process in Release 16 / Release 17 relies on the first 2-3 symbols of the time slot where the PSCCH is located after the AGC. If multiple such time slot structures are introduced, the UE needs to search for the PSCCH in all symbols of the time slot, which increases the power consumption of the UE for sensing.

[0172] Solution 1-2 for Concept 1

[0173] Solution 1-2 involves using solution 1-1 in conjunction with slot aggregation to address the first issue, which is an insufficient number of symbols for transmission. This can include "equalizing" the start or end of a transmission so that it terminates or starts at a slot boundary so that subsequent transmissions can start at the slot boundary, thereby efficiently using all resources. The second aggregated slot can contain the same PSCCH content as the first mini-slot, which is actually transmitted after LBT.

[0174] like Figure 8 As shown, the second time interval 218 may extend from the first time slot 2001 in which at least a portion of the first time interval 216 is scheduled and thus used for LBT to at least another aggregated time slot 2002. Figure 8 As shown, the number of aggregated time slots may be 2, but may also be a larger number, such as 2, 3, 4, 5 or more, such as 254.

[0175] The symbols 2021 to 202 included in the second time interval 218 24 The configuration or use of can be dynamic, static, preconfigured or configured. Figure 8As shown, PSCCH 2221 and 2222 may be transmitted during each aggregated time slot 2001 and 2002. However, based on the variable length of time interval 216, the position of PSCCH 2221 may vary, which may make it difficult for the receiver to decode the PSCCH. To address this issue, one possible solution is to remove PSCCH 2221 of time slot 2001 and insert the required information in PSCCH 2222, which may be located at a position known to the receiver.

[0176] This could mean that the PSCCH from the second slot could inform the aware UE of the regular reservation information, although it is not the intended receiving UE of the transmission. This would solve the second problem of the PSCCH being located in the first 2-3 symbols, although not of the first mini-slot, but at least of the second aggregated slot. The control information could include that the previous slot was also used for the transmission mini-slot, to make the aware UE aware of the unavailability of resources.

[0177] Another variation of this time slot aggregation solution is to remove the control and / or feedback channels from the time slots with reduced number of symbols, e.g. Figure 9a or Figure 9b Here, PSCCH and / or PSFCH are only carried in slot 2. In addition, the PSCCH in slot 2 can have a backward reference indicating the type of mini-slot frame structure used in slot 1. The type defines how many symbols and which symbols carry one or more of AGC, DMRS, PSFCH, PSSCH, PSCCH and / or guard symbols.

[0178] This new indication can indirectly indicate that the two time slots belong together, so that a UE decoding the second time slot will also extract the data in the first time slot from its receive buffer and decode it independently or together with the data in the second time slot. In this way, the shortened time slot can be effectively combined with the existing time slot structure.

[0179] Note: This non-slot-based or shortened frame structure also allows for a different frame structure to be included in the first slot, such as PSCCH or a new type of PSCCH and / or PSFCH. In addition, the non-slot-based portion of the first slot may also be limited to occupy only 2, 4 or 7 OFDM symbols, for example, consistent with the existing mini-slot frame structure defined in NR. These mini-slot structures may include one or more of PSCCH, PSSCH, PSFCH, DMRS, AGC and / or guard symbols.

[0180] like Figure 9a As shown, when using aggregated time slots, the device may use a mini-time slot structure in the first time slot carrying the second time interval 218 transmission, for example, without using PSCCH, or as an alternative, such as Figure 8 As shown, PSCCH is used. Therefore, subsequent symbols can be aligned in time with the slot structure. However, alignment itself, especially alignment of the first slot, is a possible solution.

[0181] like Figure 9b As shown, whether or not PSCCH is inserted, the second time interval 218 can start with a symbol according to a regular time slot, for example, including 14 symbols. Before the end of the transmission, a mini-time slot is optionally used to align with the time slot boundary in time. For example, the position of such a mini-time slot can be the second, third, ... or last time slot for transmission.

[0182] The SCI may be transmitted in the mini-slot portion of the frame within the PSSCH, similar to the Phase 2 SCI, immediately after the LBT. This SCI may be a further Phase 2 SCI or a Phase 3 SCI, or may be a conventional Phase 2 SCI propagated before the Phase 1 SCI. This enables the receiving / perceiving UE to be aware of the presence of the aggregated slot containing the PSCCH. Additionally, this may implicitly configure the UE to not flush the buffer containing the mini-slot. The corresponding Phase 1 SCI will be in the 2nd slot of the PSCCH.

[0183] Fig.10a A schematic diagram showing the symbol configuration of slot aggregation using existing mini-slot constraints is shown. OS represents OFDM symbol. Here, LBT is done on 4 OSs, and the transmission uses the remaining 2+7=9 OSs 2021 to 2029.

[0184] According to the solution described, the apparatus may be configured to aggregate the first time slot and at least one second time slot into an aggregated set of time slots, and to use the second time slot in combination with the second time interval of the first time slot for transmission.

[0185] According to an embodiment, the apparatus is configured to normally perform LBT for an aggregated set of time slots within a first time interval of a first time slot.

[0186] According to an embodiment, the apparatus is configured to align in time the end of the transmission symbol with the end of a time slot according to a time slot basis of the mobile wireless communication network.

[0187] According to an embodiment, the apparatus is configured to transmit a plurality of time slots or frames during a second time interval and to temporally align the end of the last frame in time with a time slot basis of the mobile wireless communication network by forming an earlier frame (e.g. the first frame) of the plurality of frames into a mini-frame.

[0188] According to an embodiment, the apparatus is configured to transmit a plurality of frames during the second time interval and to temporally align an end of the temporally last frame with a time slot basis of the mobile wireless communication network by forming a last frame of the plurality of frames as a mini-frame.

[0189] According to an embodiment, at least one frame of the plurality of frames exceeds or does not reach a time slot boundary.

[0190] According to an embodiment, the apparatus is configured to transmit a plurality of frames during a second time interval, wherein the apparatus is configured to include in the second frame one or more information identical to an earlier first frame, for example:

[0191] ● control information, for example as the Physical Sidelink Control Channel (PSCCH),

[0192] ● data, for example as a Physical Sidelink Shared Channel (PSSCH),

[0193] Feedback information, for example as a Physical Sidelink Feedback Channel (PSFCH),

[0194] ● broadcast signals, such as the Physical Sidelink Broadcast Channel (PSBCH),

[0195] ● Reference signals, such as Demodulation Reference Signal (DMRS),

[0196] ● Automatic Gain Control (AGC) symbol, and

[0197] ●Protection symbol.

[0198] According to an embodiment, the apparatus is configured to transmit a plurality of frames during a second time interval, wherein the apparatus is configured to include one or more of the following in a subsequent second frame:

[0199] - Physical Sidelink Control Channel (PSCCH),

[0200] - Control within a data channel (such as PSSCH), for example contained in a further stage SCI (such as stage 2 or stage 3 SCI), MAC-CE, RRC or PC5-RRC or any other higher level signaling, which contains control information related to an earlier first frame.

[0201] According to an embodiment, the device is configured to generate control information to include information for notifying a sensing device receiving the control information about generally reserved information; and / or for notifying the sensing device about time slot aggregation; and / or time slot format; and / or time slot offset; and / or information about the location of further control information.

[0202] According to an embodiment, the apparatus is configured to generate the control information in the second time interval to contain a backward reference to a symbol transmitted in the first frame.

[0203] According to an embodiment, the device is configured to generate control information to indicate the type of mini-frame structure used in the second time interval, for example, the type defines how many symbols and which symbols carry one or more of AGC, DMRS, PSFCH, PSSCH, PSCCH, PSBCH and protection symbols.

[0204] According to an embodiment, the device is suitable for forming at least one mini frame, the mini frame having a smaller number of symbols compared to a frame occupying a complete time slot of a mobile wireless communication network, and the formed mini frame does not contain information associated with a control channel (e.g. PSCCH) and / or with a feedback channel (e.g. PSFCH), and / or does not contain information of a higher layer control channel using MAC-CE or PC5-RRC or RRC or higher layer control signaling or similar signaling transmitted on PSSCH.

[0205] The inventors have also identified further possibilities for achieving additional advantages. A remaining problem with the described solution may be that, at the time of UE perception, there is no guarantee that the following time slots are also available for data transmission and time slot aggregation is used.

[0206] Solutions 1-3 for Concept 1

[0207] Solution 1-3: To solve the problem that the UE is not aware of the availability of subsequent time slots, one approach is to let the UE sense and check the availability of at least 2 or more consecutive time slots. The PSCCH in the first mini-time slot will contain information about the existence of slot aggregation transmission, which will implicitly inform the receiving UE that the transmission is performed after LBT.

[0208] According to an embodiment, before using the first time slot, the apparatus is configured to sense the channel to check the availability of at least two or more consecutive time slots, for example, by evaluating a received Physical Sidelink Control Channel (PSCCH).

[0209] According to an embodiment, the apparatus is configured to identify information indicating the presence of slot aggregation transmission in a received wireless signal, for example, thereby identifying that the transmission of the wireless signal is performed after performing LBT.

[0210] Solution 2: Use existing SL slot structure with transmission offset

[0211] Solution 2-1 for Concept 1

[0212] Solution 2-1 is to use the existing slot structure, such as a 14-symbol SL slot, but transmit after a (pre-)configured offset value, or depend on how long LBT takes for the UE to decide whether a subchannel is available.

[0213] o In this case, the UE may do LBT and may transmit after a (pre-)configured number of symbols (or symbol offset), e.g. depending on when the UE finds the channel / subband unoccupied / available.

[0214] ○ Once the UE finds that the time slot is available after LBT, the UE can use the existing time slot structure and send a regular frame, such as 14 symbols. This ensures that the existing time slot structure with DMRS symbols and PSFCH can be reused.

[0215] ○ In another variation, the UE may find that it only needs to use a short offset to be able to transmit aligned slots or half-slots. In this embodiment, the UE transmits after performing an intended LBT transmission, such as by extending the LBT duration and / or extending the AGC, so that if the medium remains idle, subsequent transmissions can be performed in a slot or half-slot aligned manner. In this way, resource waste is minimized by still utilizing the specified frame structure while having minimal impact on existing UEs.

[0216] o The control information transmitted in the PSCCH will indicate the symbol offset used by the UE so that it can transmit after the LBT. The UE may also use the new mini-slot to occupy the remainder of the subsequent slot to maintain the slot boundaries and have enough symbols to transmit data.

[0217] ■ The new mini-slot may or may not contain a copy of the PSCCH previously transmitted in the full slot.

[0218] Fig.10bA schematic representation of a slot configuration according to increasing the LBT time to align with a predefined reference 232 of a slot 2001 or 2002 is shown. For example, the predefined reference may be half of a slot or a slot boundary or any other reference, such as the beginning or end of a symbol, etc. According to an example, such alignment may be achieved in any case to align with the next predefined reference 232 in time. According to another example, such alignment may be achieved only if the remaining time 234 before reaching the predefined reference 232 is at most a predefined threshold (e.g., 2 or 3 symbols or similar short offsets). If the time is longer, alignment may be skipped to avoid unnecessary waste of resources, while within the predefined threshold, the gain obtained by alignment may compensate for the limited loss of throughput. For example, alignment to the start of the expected transmission may be achieved by extending the first time interval 216 to an extended time interval 216' using additional symbols 2021 to 2023. Alternatively or additionally, the start of transmission may be delayed by using one or more symbols for AGC in addition to symbol 2024. This may be understood as reducing the second time interval 218 to a reduced time interval 218 ′ in order to align the start and / or end of the transmission in time, for example to the time intervals 218 , 218 ′, respectively.

[0219] According to an embodiment, the apparatus is configured to align the start or end of the second time interval (218) in time with a predefined reference (232) in the time slot.

[0220] According to an embodiment, the calibration comprises extending the first time interval and / or using at least an additional AGC symbol directly after the first time interval.

[0221] According to an embodiment, the apparatus is adapted to determine that the end of the first time interval is within a predefined threshold before a predetermined reference and align with the predetermined reference; and / or not align with the predefined reference if the end of the first time interval is earlier than the predefined threshold.

[0222] According to an embodiment, the predefined reference is the end of a half slot or a slot or a predefined number of symbols within a slot, eg based on the supported mini-frame or mini-slot sizes.

[0223] Fig.11 A schematic diagram of an existing Rel-16 slot structure 224 is shown, which is transmitted after the proposed advantageous LBT, followed by a new mini-slot 226 with a reduced number of symbols, such as 10 symbols.

[0224] While this may not strictly follow slot boundaries, slots can still be defined using existing boundaries and the same NR V2X slot structure will be used.

[0225] Depending on the network configuration, there may be only a limited number of offsets (pre-)configured to enable an RX UE to receive signals from multiple TX UEs and to be able to find a 14 symbol or mini-slot duration slot for its own transmission.

[0226] In this solution, solutions 1-3 can be used in addition to enable the UE to sense the continuous time slots to check their availability.

[0227] According to an embodiment, the apparatus is configured to transmit a symbol frame after performing the LBT procedure, the frame having a time duration according to a time slot duration, wherein a time end of the frame is later than a time end of the time slot.

[0228] According to an embodiment, the frame includes a frame structure corresponding to LBT-free transmission.

[0229] Depending on the embodiment, the frame structure includes exactly 7 or 14 or any number of time symbols between 1 and 14 symbols, which are suitable for carrying one or more of AGC, DMRS, PSFCH, PSSCH, PSCCH, PSBCH and protection symbols.

[0230] According to an embodiment, the first time interval comprises a time offset of the frame relative to the no LBT transmission.

[0231] According to an embodiment, the apparatus is configured to include control information in a wireless transmission, for example in a symbol frame, for example as a Physical Sidelink Control Channel (PSCCH), to indicate the time offset.

[0232] According to an embodiment, the apparatus is configured to occupy the remainder of a subsequent time slot using a mini-frame structure so as to be aligned in time with a time slot boundary of the subsequent time slot.

[0233] According to an embodiment, the apparatus is configured to select the time offset as value from a set of predefined values.

[0234] According to an embodiment, the device is configured to sense the channel before using the first time slot to check the availability of at least two or more consecutive time slots, for example, by decoding the received physical sidelink control channel (PSCCH) and / or by measuring the energy received on the time slot using RSRP or RSSI to evaluate the presence of other transmissions.

[0235] The problem with this solution is that the perceiving UE may check the PSCCH at the beginning of the slot, but since the TX UE transmits the PSCCH only after the LBT, the PSCCH will not be present at the beginning of the slot. This may mislead the perceiving UE into assuming that resources are available. The inventors have found further possibilities to solve this problem.

[0236] Solution 2-2 for Concept 1

[0237] To solve the problem of solution 2-1, solution 2-2 can be implemented, which suggests that the desired sensing UE checks the availability of PSCCH transmission based on the (pre)configured offset. In other words, the UE must sense the subchannel within 2-3 PSCCH symbols after the (pre)configured offset. Reducing the sensing of subchannels can greatly reduce power consumption because the UE only needs to monitor much fewer frequencies or bandwidths. Note that monitoring a large bandwidth accounts for a large proportion of the battery power used by the UE.

[0238] The offset is (pre)configured per resource pool. This will allow a sensing UE to know where to check for PSCCH transmissions, if any.

[0239] According to an embodiment, the apparatus is configured to perform a LBT procedure by performing sensing to check the availability of time slots, and / or based on a configured or preconfigured time offset (e.g., per resource pool).

[0240] According to an embodiment, the apparatus is configured to check the availability of one or more of the following:

[0241] ● Each symbol in a time slot,

[0242] ● Each symbol after time shift,

[0243] ● after a time offset or based on a configured or preconfigured slot / frame definition, only a configured or preconfigured number of symbols,

[0244] Therein, the apparatus is configured to check availability by decoding a received Physical Sidelink Control Channel (PSCCH) and / or evaluating the presence of other transmissions by measuring the energy received on a time slot using RSRP or RSSI measurements.

[0245] Solution 3: Recalibrate perception and resource allocation from slot to symbol

[0246] Solution 3 is to recalibrate time slots into symbols, so that UE can transmit on a symbol basis without being restricted by time slots. That is, UE can operate on a symbol basis instead of a time slot basis.

[0247] This means that the UE may transmit at the end of LBT, for example, requiring the PSCCH to be transmitted within the first 2-3 symbols after the start of transmission.

[0248] The UE does not need to wait to perform LBT at the beginning of the time slot boundary, but can start LBT after there is data in the buffer and has sensed to select available resources.

[0249] The control information will inform the RX UE about the length of the scheduled transmission by using the existing or new slot structure. The existing slot structure is limited to 14 symbols in length, while the new slot structure can span multiple symbols depending on the size of the data transmission.

[0250] Due to the flexibility of the transmission, an aware UE can check for PSCCH transmissions at predefined, configured or preconfigured locations or even in every symbol of a slot.

[0251] According to an embodiment, the device is configured to communicate in a mobile wireless communication network, the basis of the communication being that each symbol is associated with a defined symbol duration according to a subcarrier spacing used for a resource pool, wherein the device is configured to transmit a plurality of symbols, e.g. 2 or 3 symbols, during a second time interval and at a predetermined position after the start of the transmission, for transmitting control information, e.g. as a physical sidelink control channel (PSCCH).

[0252] According to an embodiment, the apparatus is configured to transmit a plurality of symbols in a second time interval after transmitting control information of data, feedback, broadcast and / or reference signals, wherein the number of symbols used for each symbol as well as their position and transmission length are based on a configured or preconfigured time slot / frame / mini-frame structure.

[0253] According to an embodiment, the apparatus is configured to generate control information to indicate the length of the transmission, for example by indicating the used frame or mini-frame structure.

[0254] According to an embodiment, the apparatus is configured to generate control information to indicate that the frame structure comprises 14 symbols or a number of symbols different from 7 and / or 14.

[0255] Idea 2: LBT Failure Option

[0256] Question 2 : In the case of LBT, if a channel is detected to cause LBT failure, it may cause the UE to be unable to transmit on the selected resources and subchannels. LBT failure occurs when the UE attempts to determine whether a subchannel is available for longer than the maximum contention window size. Another problem is that when the UE performs LBT on a subchannel, any subsequent LBT on the same channel will result in LBT. This means that the UE is constantly being locked out of the subchannel.

[0257] Solution 1-1 for Concept 2

[0258] Solution 1-1 is to switch to another subband or resource pool or SL BWP. This is especially feasible in Mode 2 operation because the UE will not get any help from the gNB. In this case, although the sensing process indicates the availability of resources, the LBT does not, and we recommend that the UE switch to another band or subchannel to check its availability.

[0259] The UE may wait for a (pre)configured timer before switching to another subchannel / subband / resource pool / SL BWP. The timer may be a global setting or may be configured per resource pool or per transmission as indicated by the new SCI.

[0260] As an alternative or in addition, the UE may also use a (pre-)configured counter so that only a (pre-)configured number of LBT attempts are allowed, after which the UE will perform a handover.

[0261] In addition, the user can change its operating mode based on an LBT failure or a set of LBT failures. This change can be a predefined, preconfigured, configured or any other default mode. That is, the device can fall back to a predefined, preconfigured, configured or default configuration based on an LBT failure or a set of LBT failures, for example, when one or both of the timer and / or counter thresholds associated with the LBT failure are reached. In this case, the default configuration can be configured or preconfigured in a given UE, or changed by the base station in mode 1, or by another UE (if operating in mode 2), for example via an inter-UE coordination information message (IUC) or AIM.

[0262] According to an embodiment, the apparatus is configured to detect the unavailability of a time slot associated with a frequency band for transmission, for example, based on an LBT procedure, by experiencing an LBT failure (or a set of LBT failures defined by a (pre)configured threshold) to detect the unavailability of the time slot for transmission; and in case the channel is found to be unavailable, perform one or more of the following operations:

[0263] - a subsequent LBT process on a second, different frequency band to determine availability of the second frequency band for wireless transmission;

[0264] ● Switching of the operating mode from Mode 2 to Mode 1, e.g. using assistance from a base station,

[0265] ● Switching from Mode 1 to Mode 2, for example when moving out of base station coverage,

[0266] ● Switching from sidelink (e.g. PC5 interface) to legacy (e.g. Uu) interface, using base station to assist and route transmission,

[0267] ● triggering an inter-UE coordination information request from another UE to obtain assistance in finding another suitable transmission resource,

[0268] ● notifying another UE about an LBT failure or a persistent LBT failure, or an LBT failure for a future reserved transmission (e.g. at T5 or T10) via an IuC message, e.g. using an IuC Collision Indicator (CI),

[0269] ● Switching to a non-NR-U band, e.g. when a failure threshold is reached,

[0270] ● Send a notification about the number of LBT failures to the base station, UE or RSU at the next successful transmission;

[0271] ●Interruption of transmission.

[0272] According to an embodiment, the apparatus is configured to operate in Mode 2.

[0273] According to an embodiment, the device is configured to perform one or more LBT procedures in the channel during a configuration or preconfiguration of the LBT timer before performing one or more operations.

[0274] According to an embodiment, the LBT timer is configured according to a network global setting (e.g., configured or pre-configured using SIB), configured according to a resource pool (e.g., configured or pre-configured using RRC signaling), or configured according to a transmission configuration (e.g., as shown in the sidelink control information SCI or if in mode 1 via downlink control information).

[0275] According to an embodiment, the apparatus is configured to perform an LBT procedure in a channel a configured or preconfigured number of LBT times before performing one or more operations.

[0276] According to an embodiment, the LBT times are based on network global settings (e.g. configured or pre-configured using SIB), resource pool configuration (e.g. configured or pre-configured using RRC signaling), or transmission configuration (e.g. as described in the sidelink control information SCI and / or if in mode 1 via downlink control information).

[0277] Fig.12 A schematic block diagram of a mobile wireless communication network according to an embodiment is shown, wherein the mobile wireless communication network involves different or mobility driven network configuration of similar networks.

[0278] The network 1200 includes, for example, means 8021, 8022, and 8023, which may be according to an embodiment and may be according to devices of the network 100. For example, in order to handle an LBT failure, such as a persistent LBT failure, particularly when operating in mode 2, the devices may use an LBT failure indication. Alternatively or additionally, if possible, the devices may switch to mode 1 and / or Uu, for example, see means 8021. Alternatively or additionally, a message requesting assistance (AIM) may be sent to other devices and / or base stations.

[0279] In addition, similar procedures may also be applied if LBT fails to reserve a time slot in the future, for example, in the case where multiple resources are reserved for future transmissions. This may occur if the UE has successfully transmitted data at time instance T0 and intends to reserve resources for future transmissions at time instances T5 and / or T10. If LBT fails before T5 and / or T10, the UE may perform a similar procedure and attempt to transmit the intended transmission for T5 and / or T10 in another time and / or frequency resource. For example, transmission may be performed in another subchannel or subband or even BWP if resources are available.

[0280] In addition, the operation of the transmitting UE also depends on the interference source that caused the LBT failure. If the interference is caused by a non-3GPP device (e.g., a WiFi device), the above process may be different. For example, the UE may perform one or more expected future transmissions in a frequency band that only allows transmissions from 3GPP devices, such as at T5 and / or T10, or any other future transmissions. That is, the device may attempt to switch to a non-WiFi frequency band for future transmissions.

[0281] Alternatively or additionally, for transmission, a frequency band may be used in which it is currently determined that there are no other non-3GPP devices, for example based on other available sensing results or based on information received by the base station or one or more other UEs.

[0282] Solution 1-2 for Concept 2

[0283] Solution 1-2 is that if the UE is within the coverage of the gNB and the gNB can assist the UE for sidelink transmission, the UE can switch the operation mode. Another option for the UE is to continue to use NR-U for transmission on Uu, where the gNB can provide resource allocation assistance for another UE's UL transmission.

[0284] Solutions 1-3 for Concept 2

[0285] Solution 1-3 is that the UE requests resource assistance through inter-UE coordination. When the UE senses resource availability but still detects LBT failure, the UE can also use the LBT failure as a trigger to send a resource allocation assistance request to another UE-A via IUC.

[0286] According to solutions 1-2 and 1-3 of Concept 2, the embodiments involve one or more of the following:

[0287] The device is configured to request assistance information from at least one different device (e.g., UE and / or base station) based on the LBT failure or multiple LBT failures.

[0288] According to an embodiment, the assistance information relates to resource allocation assistance information, indicating whether the functional resources are used for LBT and / or one or more future transmissions.

[0289] According to an embodiment, resources are defined as bitmaps, vectors in the time domain and / or frequency domain.

[0290] Question 3 : In this case, the UE has already sensed a given transmission and selected resources for the initial transmission and also reserved resources for later retransmissions. If the initial transmission attempt results in LBT, how does the UE handle the remaining reserved resources? The remaining reserved resources are also in the same subband / resource pool as the initial transmission.

[0291] Solution 2-1 for Concept 2

[0292] Solution 2-1 is that the UE attempts to retransmit on the reserved resources. In the case that the UE has reached the maximum number of LBT attempts or the LBT timer has passed, the UE can release these resources and select new resources in another subchannel / subband / channel / resource pool / SL BWP for retransmission.

[0293] If the UE decides to use another subchannel / subband / channel / resource pool / SL BWP, the UE preferably releases the remaining reserved resources so that another UE that may find these resources beneficial for its use can use them. However, since the UE has noted the reservation of these resources in the SCI attached to the failed initial transmission, the UE may use these resources when sending IUC to another UE.

[0294] According to an embodiment, the device is configured to reserve multiple resources for multiple transmissions within a time slot, which time slots may also be related to a resource set, a time slot, or the like on a channel, and perform LBT for a first resource associated with a first in time among the multiple transmissions, and experience an LBT failure indicating unavailability; wherein the device is configured to release resources associated with one or more subsequent transmissions.

[0295] According to an embodiment, the apparatus is configured to transmit information for notifying different devices about releasing resources using resources in the reserved resources by using inter-UE coordination messages, or, for example, notifying the base station or RSU via uplink control information in mode 1.

[0296] According to an embodiment, the other device is one or more of the following:

[0297] - Base stations, such as gNB in ​​NR or eNB in ​​LTE,

[0298] - Road Side Unit (RSU),

[0299] - Another UE (e.g., P-UE, V2X-UE, normal UE, etc.).

[0300] According to an embodiment, the other device is a UE, and the information is sent via one or more of the following:

[0301] - Sidelink, such as PC5,

[0302] - As relay information via base station or RSU via Uu.

[0303] According to an embodiment, the information is sent via an inter-UE coordination (IuC) information message, for example included in a stage 1 and / or stage 2 SCI or a new stage 2 or stage 3 SCI, or via a PC5-RRC, RRC, MAC-CE or higher layer control message.

[0304] Further solutions to be applied together with other solutions or individually

[0305] New Phase 2 SCI Format Parameters

[0306] Based on the solutions discussed in the previous sections, the embodiments involve introducing a new second-stage SCI format 2_D for transmission in unlicensed bands. In addition to the specified data transmission parameters, the possible parameters in the SCI are as follows:

[0307] ● Indication of the use of slot aggregation, explicitly or implicitly instructing the RX UE to continue receiving in the subsequent slot. This can be achieved by declaring that the mini-slot format was used in the previous slot (Problem 1 Solution 1-2).

[0308] ● Backward reference indicator: The PSCCH in slot 2 may have a backward reference indicating the type of mini-slot frame structure used in slot 1. The type may refer to the (pre-)configured mini-slot structure, and the parameter indicates the index.

[0309] • An indication of the number of symbols used for offset transmission (Problem 1 Solution 2-1). The indication may also be an index into a list of (pre-)configured offsets that are allowed to be used in a given resource pool.

[0310] • Transmission length (Problem 1 Solution 3). This indication will inform the RX UE about how long the current transmission will last so that it can implicitly identify the symbols containing DMRS, PSFCH, etc.

[0311] ●Indication of the slot structure to be used (Solution 3 to Problem 1). In the case where the UE uses both mini-slots and full slots, and the positions of PSCCH, PSSCH, PSFCH (if present) and DMRS are different, this parameter may indicate an index into a list of (pre-)configured slot structures that are allowed to be used in a given resource pool.

[0312] ●LBT timer (e.g., description related to Viewpoint 2 Solution 1-1 for solving Problem 2).

[0313] ●LBT counter (e.g., description related to Viewpoint 2 Solution 1-1 for solving Problem 2).

[0314] According to an embodiment, such a device may be a device configured to transmit control information (SCI), the SCI indicating at least one of the following:

[0315] ● indication of the use of explicit or implicit slot aggregation;

[0316] ● A backward reference indicator; wherein the PSCCH in a later frame of the aggregation includes a backward reference, e.g., indicating the type of mini-frame structure used in an earlier frame;

[0317] An indication of the number of symbols used to offset the transmission relative to the time slot structure (e.g., time slot boundaries) of the mobile wireless communication network;

[0318] ● Information indicating the length of the transmission, for example, informing the receiving device how long the current transmission may be so that it can implicitly identify symbols containing demodulation reference signals (DMRS), physical sidelink feedback channels (PSFCH), etc.;

[0319] ● information indicating one or more future transmissions, such as a pre-reservation,

[0320] ●Information indicating that non-3GPP technologies exist on this channel or adjacent channels,

[0321] ● Information indicating that a 3GPP RAT (such as another NR or LTE system) is operating in this channel or an adjacent sub-channel,

[0322] = an indication of the slot structure or slot format or frame format to be used;

[0323] ●Information indicating the LBT timer;

[0324] ●Information indicating the LBT counter.

[0325] According to an embodiment, the control information is in the form of stage 1, stage 2 or stage n control information. Parameters may be included in one or more of these stages, and / or the control information may be transmitted on PSCCH and / or PSSCH, and / or the control information may be sent via the physical layer via a sidelink or Uu, PC5-RRC, RRC, MAC-CE or higher layer control message.

[0326] While at least some of the details provided herein relate to advantageous modifications applied to a transmitting device, the present invention also provides advantageous modifications related to a receiving device. For example, based on LBT, the symbols received by the device occupy only a portion of the time slot, which may deviate from the known mini-time slot. That is, the receiving device can take into account the behavior of the transmitting device, especially taking into account the use of the missing portion for LBT and / or for the use of time slot aggregation.

[0327] Alternatively or additionally, such a receiving device may wish to sense in all symbols of a slot, for example because it does not know where the PSCCH is transmitted.

[0328] Such an apparatus may be configured to sense control information in all symbols of a receive time slot, for example control information contained in a physical sidelink control channel and / or control information contained in a physical sidelink shared channel.

[0329] Alternatively or additionally, if a set of (pre-)configured mini-slots and mini-slot formats are defined (system-wide or per resource pool), such a receiving device may sense PSCCH transmissions at symbols where PSCCH transmissions are expected according to these mini-slot formats.

[0330] Such a device may be configured to sense for transmission of a PSCCH on a symbol on which the PSCCH is expected to be transmitted according to a preconfigured or configured mini-slot format for communications.

[0331] If a set of (pre)configured offsets is defined (either system-wide or per resource pool), a device may sense a PSCCH transmission on symbol 2, 3 or 4. This is because using offsets means using the existing slot format, where the first symbol is used for AGC and the PSCCH is located within the next 2-3 symbols.

[0332] Such an apparatus may be configured to sense a PSCCH transmission according to a (pre-)configured set of offsets defined for offsets of transmission slots, e.g. for the entire system or per resource pool.

[0333] If slot aggregation is enabled either system-wide or per resource pool, if the device detects a transmission by measuring the energy in the first slot, but is unable to decode the PSCCH, the device should retain the reception in its buffer. This is to take into account the case where a mini-slot (whether containing a PSCCH or not) is transmitted in the first slot and subsequent slots contain a 14-symbol slot structure, the UE can decode the PSCCH pointing to the data transmitted in the first mini-slot.

[0334] Such an apparatus may be configured to measure the energy in a first slot of the aggregated slots and retain the received information in its buffer and use control information of a subsequent slot for decoding.

[0335] If the device is sensing and looking for resources to transmit, the UE should look for consecutive available time slots to incorporate the time slot aggregation aspects, similar to Solution 1-3 of Concept 1.

[0336] Such a device may be configured to sense and seek resources to transmit, and to include contiguous available time slots into the process for transmission using time slot aggregation.

[0337] The present invention provides improvements and enhancements in wireless communication systems that solve the above problems. A wireless communication system may use one or more subbands, also referred to as channels or subbands or frequency bands of an NR carrier, where the frequency band includes a start frequency, an end frequency, and all intermediate frequencies between the start frequency and the end frequency. A subband may have a predefined bandwidth, such as 10 or 20 MHz. When multiple subbands are used, the operation is also referred to as wideband operation.

[0338] The embodiment of the present invention may be implemented in a wireless communication system as shown in FIG. 1 , which includes a base station and a user, such as a mobile terminal or an IoT device. Fig.13 is a schematic diagram of a wireless communication system comprising a transmitter 300 like a base station and one or more receivers 3021 to 302 like user equipment UE n The transmitter 300 and the receiver 302 may communicate via one or more wireless communication links or channels 304a, 304b, 304c (eg, radio links). The transmitter 300 may include one or more antennas ANT T Or an antenna array having multiple antenna elements, a signal processor 300a and a transceiver 300b are coupled to each other. The receiver 302 includes one or more antennas ANT R or an antenna array having multiple antennas, a signal processor 302a1, 302a n and transceivers 302b1, 302b n, coupled to each other. The base station 300 and the UE 302 can communicate via corresponding first wireless communication links 304a and 304b (such as radio links using Uu interfaces), and the UE 302 can communicate with each other via a second wireless communication link 304c (such as a radio link using a PC5 interface). When the UE does not obtain base station service, is not connected to the base station (for example, is not in an RRC connected state), or more generally, when the base station does not provide SL resource allocation configuration or assistance, the UE can communicate with each other via a side link. The system, one or more UEs 302 and the base station 300 can operate according to the teachings of the invention described herein.

[0339] The present invention provides a computer program product comprising instructions which, when executed by a computer, cause the computer to perform one or more methods according to the present invention.

[0340] With respect to the above-described embodiments of various aspects of the present invention, it should be noted that these embodiments are described in the context of communication between a transmitter (e.g., a gNB or UE) and a receiver (e.g., a UE and a gNB). However, the present invention is not limited to the above-described communications, but rather the above-described principles are equally applicable to device-to-device communications, such as D2D, V2V, and V2X communications. In this scenario, the communication is performed via a sidelink between the respective devices. The transmitter is a first UE and the receiver is a second UE that communicates using sidelink resources.

[0341] 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 or a combination thereof as a receiver.

[0342] According to an embodiment, the device may be or may include a user equipment (UE), such as a mobile terminal, or a fixed terminal, or a cell IoT-UE, or a vehicle UE, or a vehicle group leader (GL) UE, or an IoT, or a narrowband IoT (NB-IoT) device, or a WiFi non-access point station (non-AP STA) such as 802.11ax or 802.11be, or a ground vehicle, or an aircraft, or an unmanned aircraft, or a mobile base station, or a roadside unit, or a building or any other item / device with network connectivity that enables the item / device to communicate using a wireless communication network such as one or more of a sensor or an actuator, and / or a base station (BS), which may be implemented as a mobile base station or a fixed base station, and includes a macro cell base station, or a small cell base station, or a central unit of a base station, or a distributed base station unit, or a roadside unit, or a UE, or a group leader (GL), or a relay, or a remote radio head, or an AMF or an SMF, or a core network entity, or a mobile edge computing entity, or a network slice in the context of an NR or 5G core, or a WiFi AP STAs such as 802.11ax or 802.11be, or one or more of any transmit / receive points (TRPs) that enable an item or device to communicate using a wireless communication network, and the item or device is provided with network connectivity to communicate using a wireless communication network.

[0343] Although some aspects of the described concepts are described in the context of devices, it is clear that these aspects also represent a description of a corresponding method, where a module or device corresponds to a method step or a feature of a method step. Similarly, the various aspects described in the method steps are also descriptions of corresponding modules or items or features of the corresponding device. The various elements and features 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. Fig.14An example of a computer system 500 is shown. The units or modules and the method steps performed by these units can be executed on one or more computer systems 500. The computer system 500 includes one or more processors 502, such as a dedicated or general-purpose digital signal processor. The processor 502 is connected to a communication infrastructure 504, such as a bus or a network. The computer system 500 includes a main memory 506 (such as a random access memory (RAM)) and an auxiliary memory 508 (such as a hard drive and / or a removable storage drive). The auxiliary memory 508 can load computer programs or other instructions into the computer system 500. The computer system 500 can also include a communication interface 510 to allow software and data to be transmitted between the computer system 500 and external devices. The communication can be electronic, electromagnetic, optical or other signals that can be processed by the communication interface. The communication can use wires or cables, optical fibers, telephone lines, cellular phone links, RF links and other communication channels 512.

[0344] 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 devices that provide software to the computer system 500. Computer programs, also known as computer control logic, are stored in the main memory 506 and / or the secondary memory 508. The computer program can also be received via the communication interface 510. When the computer program is executed, it enables the computer system 500 to implement the present invention. In particular, when the computer program is executed, it enables the processor 502 to implement the process of the present invention, such as any method described in the present invention. Therefore, such a computer program can represent a controller of the computer system 500. When using software to implement the present invention, the software can be stored in a computer program product and loaded into the computer system 500 through a removable storage drive, an interface (such as the communication interface 510).

[0345] The hardware or software implementation can be performed using a digital storage medium (e.g., cloud storage, floppy disk, DVD, Blu-ray, CD, ROM, PROM, EPROM, EEPROM, or flash memory), on which electronically readable control signals are stored, which can cooperate (or be able to cooperate) with a programmable computer system to perform the corresponding method. Therefore, the digital storage medium can be computer-readable.

[0346] 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.

[0347] Generally, the 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.

[0348] Other embodiments comprise a 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.

[0349] 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) on which there is a computer program for performing one of the methods described herein. 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 the signal sequence can be configured to be transmitted via a data communication connection (for example via the Internet). A further embodiment comprises a processing device, such as a computer or a programmable logic device configured to or adapted to perform one of the methods described herein. A further embodiment comprises a computer on which a computer program for performing one of the methods described herein is installed.

[0350] In some embodiments, a programmable logic device (e.g., 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.

[0351] The above embodiments are merely illustrative of the principles of the present invention. It goes without saying that modifications and variations of the arrangements and details of the present invention will be apparent to other persons skilled in the art. Therefore, the present invention is intended to be limited only by the scope of the patent claims to be filed, and not by the specific details set forth herein through the description and explanation of the embodiments.

Claims

1. A device configured to communicate in a mobile wireless communication network, the device comprising a wireless interface for transmitting and receiving wireless signals in the mobile wireless communication network; wherein, The device is configured as: In a mobile wireless communication system, communication is performed via a side link (SL), the side link providing a plurality of time slots, each time slot having a time slot duration, wherein the apparatus is configured to use at least a first time interval of the time slot duration to perform a listen-before-talk (LBT) procedure to determine availability of the time slot; and / or based on the determined availability, use a second time interval of the time slot duration for wireless transmission; and / or Therein, the device is configured to use at least a first time slot duration to perform a listen-before-talk (LBT) process to determine the availability of at least a portion of a subsequent second time slot, such as a full time slot, a mini time slot, or a mini frame, and / or based on the determined availability, use at least a portion of the subsequent second time slot for wireless transmission.

2. The apparatus of claim 1, wherein the apparatus is configured to communicate in a mobile wireless communication network based on one or more of: - slot-based, where each slot consists of a number of symbols across time, - symbol-based, where each symbol is associated with a symbol duration defined according to the subcarrier spacing used for the resource pool, - Based on configuration or preconfigured symbol sets.

3. An apparatus as claimed in any one of claims 1 or 2, wherein the apparatus is configured to use the second time interval at least as a remainder of the time slot duration after the first time interval.

4. An apparatus as claimed in any preceding claim, wherein the apparatus is configured to transmit a mini-frame in the second time interval, the mini-frame comprising a smaller number of symbols than the capacity of a time slot of the mobile wireless communication network.

5. An apparatus as claimed in claim 4, wherein the capacity of a time slot corresponds to a frame comprising one or more time slots; wherein a time slot comprises one or more symbols; wherein a mini-frame comprises one or more mini-time slots; wherein a mini-time slot or a mini-frame comprises one or more symbols; wherein the number of symbols is less than the number of symbols in a time slot.

6. The apparatus of claim 4 or 5, wherein the mini-frame comprises one or more of the following: OFDM symbols that are less than the capacity of a time slot, any number of OFDM symbols in the set {1..13}, Other mini-frames, where the total number of OFDM symbols does not exceed the slot boundary, The combination of multiple mini-frames to form a new, longer mini-frame.

7. A device as claimed in any one of the preceding claims, wherein: The apparatus is configured to align in time the end of the second time interval with the end of a time slot of the mobile wireless communication network.

8. A device as claimed in any one of the preceding claims, wherein: The apparatus is configured to align the beginning or end of the second time interval (218) in time with a predefined reference (232) in the time slot.

9. The apparatus of claim 8, wherein the aligning comprises extending the first time interval and / or using at least an additional AGC symbol directly after the first time interval.

10. The device according to any one of claims 8 or 9, wherein The apparatus is adapted to determine that the end of the first time interval is within a predefined threshold before a predefined reference and aligned with the predefined reference; and / or not aligned with the predefined reference if the end of the first time interval is earlier than the predefined threshold.

11. The apparatus of any of claims 8 to 10, wherein the predefined reference is the end of a half slot or a slot or a predefined number of symbols within a slot, for example based on the size of supported mini-frames or mini-slots.

12. An apparatus as claimed in any preceding claim, wherein the apparatus is configured or preconfigured to transmit across frequency in one or more channels or sub-channels in the second time interval.

13. The apparatus of claim 12, wherein a subchannel comprises one or more cross-frequency resource blocks, and / or in, Channels or sub-channels are defined within one or more resource pools, and / or wherein the subbands are defined within the bandwidth portion; Each channel, sub-channel or sub-band includes one or more continuous or non-continuous resource blocks.

14. The apparatus of claim 13, wherein frequency resources are interleaved according to a configuration or preconfiguration scheme.

15. A device as claimed in any preceding claim, wherein: The time slot duration comprises a plurality of symbol durations according to the configuration of the mobile wireless communication network; The apparatus is configured to perform LBT during a first subset of the symbol durations; and transmit a plurality of symbols of the wireless transmission during a second subset of the symbol durations.

16. The apparatus of any of the preceding claims, wherein the apparatus is configured to sense before performing LBT to determine resources for transmission and / or for initial transmission, and / or to determine one or more future reserved resources to be re-evaluated for retransmission, in, The apparatus is configured to perform LBT to determine availability of resources for a transmission and / or an initial transmission and / or one or more future reserved resources prior to a wireless transmission.

17. An apparatus as claimed in any preceding claim, wherein the apparatus is configured to use a first symbol duration at a time after the first time interval for transmitting a symbol for a wireless transmission based on the determined availability of time slots.

18. An apparatus as claimed in any preceding claim, wherein the apparatus is configured to use a predefined number of symbols, e.g. 2 symbols or 3 symbols, of the second time interval for transmitting control information, e.g. control information associated with a Physical Sidelink Control Channel (PSCCH).

19. The apparatus of any preceding claim, wherein the apparatus is configured to use the remaining symbols of the second time interval to transmit, in at least one or more symbols, one or more of the following: · control channels such as via PSCCH, Data channels such as via PSSCH, For example, via the broadcast channel of PSBCH, Feedback channels, such as PSFCH, Pilot symbols, e.g. via DMRS, Duplicate symbol (copy of the previous symbol), e.g. for AGC adjustment, Protection symbol.

20. The apparatus of claim 19, wherein the apparatus is configured to transmit an AGC symbol at the beginning of the second time interval and / or to transmit a guard symbol at the end of the second time interval.

21. The apparatus of any one of claims 19 or 20, wherein the apparatus is configured to transmit the control information at a predetermined position in the second time interval, for example during the first 2 symbols or 3 symbols after the AGC symbol.

22. An apparatus as claimed in any preceding claim, wherein the apparatus is configured to use at least one symbol duration and at most 14 symbol durations for LBT in a first time interval of a time slot.

23. An apparatus as claimed in any preceding claim, wherein the apparatus is configured to use symbol durations of at least two different time slots for LBT.

24. An apparatus as claimed in any preceding claim, wherein the apparatus is configured to select the duration of the first time interval based on a random value between a minimum time duration and a maximum time duration.

25. The apparatus of claim 24, wherein the minimum time duration and / or the maximum time duration is based on a priority of the wireless transmission.

26. The apparatus of claim 24, wherein the minimum time duration and / or the maximum time duration is based on one or more of the following aspects of the wireless transmission: Type of communication, Remaining PDB, Whether to enable / disable HARQ feedback for transmission; The distance between the transmitting device and the receiving device. ---------------------------------------------------------------- Concept 1; Solutions 1-2 --------------------------------------------------------------- 27. An apparatus as claimed in any preceding claim, wherein the apparatus is configured to aggregate a first time slot and at least one second time slot into a time slot aggregation set and to use the second time slot in combination with a second time interval of the first time slot for transmission.

28. The apparatus of claim 27, wherein the apparatus is configured to perform LBT for the aggregated set of time slots, typically within a first time interval of a first time slot.

29. An apparatus as claimed in any one of claims 26 or 27, wherein the apparatus is configured to align the end of the transmitted symbol in time with the end of a time slot according to a time slot basis of the mobile wireless communication network.

30. An apparatus as claimed in any one of claims 26 to 29, wherein the apparatus is configured to transmit a plurality of frames during a second time interval, and to align the end of a last frame in time with a time slot basis of the mobile wireless communication network by forming an earlier frame of the plurality of frames, such as a first frame, into a mini-frame.

31. An apparatus as claimed in any one of claims 26 to 30, wherein the apparatus is configured to transmit a plurality of frames during a second time interval, and to align the end of the last frame in time with a time slot basis of the mobile wireless communication network by forming the last frame of the plurality of frames as a mini frame.

32. The apparatus of claim 30 or 31, wherein at least one frame of the plurality of frames exceeds a time slot boundary or does not reach a time slot boundary.

33. An apparatus as claimed in any one of claims 27 to 32, wherein the apparatus is configured to transmit a plurality of frames during a second time interval, wherein the apparatus is configured to include in a second frame the same one or more information as in an earlier first frame, such as: control information, such as the Physical Sidelink Control Channel (PSCCH), Data, for example as a Physical Sidelink Shared Channel (PSSCH), Feedback information, for example as a Physical Sidelink Feedback Channel (PSFCH), Broadcast signals, such as the Physical Sidelink Broadcast Channel (PSBCH), Reference signals, such as Demodulation Reference Signal (DMRS), Automatic Gain Control (AGC) symbol, Protection symbol.

34. The apparatus of any one of claims 27 to 33, wherein the apparatus is configured to transmit a plurality of frames during a second time interval, wherein the apparatus is configured to include one or more of the following in a subsequent second frame: - Physical Sidelink Control Channel (PSCCH), - Control within a data channel such as PSSCH, for example contained in further stage SCI such as stage 2 or stage 3 SCI, MAC-CE, or RRC or PC5-RRC or any other higher layer signaling, the control containing control information related to an earlier first frame.

35. An apparatus as claimed in claim 34, wherein the apparatus is configured to generate control information to include: notifying a sensing device receiving the control information of information about generally reserved information; and / or notifying the sensing device of information about time slot aggregation, and / or time slot format, and / or time slot offset, and / or the location of further control information.

36. An apparatus as claimed in any one of claims 34 or 35, wherein the apparatus is configured to generate the control information in the second time interval to contain a backward reference to the symbols transmitted in the first frame.

37. An apparatus as claimed in claim 36, wherein the apparatus is configured to generate control information to indicate the type of mini-frame structure used in the second time interval, for example, the type defines how many symbols and which symbols carry one or more of AGC, DMRS, PSFCH, PSSCH, PSCCH, PSBCH and protection symbols.

38. An apparatus as described in any one of claims 27 to 37, wherein the apparatus is adapted to form at least one mini-frame having a smaller number of symbols than a frame occupying a complete time slot of a mobile wireless communication network, and is adapted to form a higher layer control channel using MAC-CE or PC5-RRC or RRC or higher layer control signaling transmitted on PSSCH without information related to control channels such as PSCCH and / or information related to feedback channels such as PSFCH and / or without higher layer control channels using MAC-CE or PC5-RRC or RRC or higher layer control signaling transmitted on PSSCH. ---------------------------------------------------------------- Idea 1; Solutions 1-3 ---------------------------------------------------------------- 39. An apparatus as described in any one of claims 27 to 38, wherein the apparatus is configured to sense the channel before using the first time slot to check the availability of at least two or more consecutive time slots, for example by evaluating a received physical sidelink control channel (PSCCH).

40. The apparatus of claim 39, wherein the apparatus is configured to identify information indicating the presence of slot aggregation transmission in a received wireless signal, for example, to identify that the transmission of the wireless signal is performed after performing LBT. ----------------------------------------------------------- Concept 1; Solution 2-1 ----------------------------------------------------------- 41. An apparatus as claimed in any preceding claim, wherein the apparatus is configured to transmit a symbol frame after performing the LBT process, the frame having a time duration according to a time slot duration, wherein a time end of the frame is later than a time end of the time slot.

42. The apparatus of any one of claims 41, wherein the frame comprises a frame structure corresponding to a non-LBT transmission.

43. An apparatus as claimed in claim 42, wherein the frame structure includes exactly 7 or 14 time symbols or any number of symbols between 1 and 14 symbols, and the symbols are suitable for carrying one or more of AGC, DMRS, PSFCH, PSSCH, PSCCH, PSBCH and protection symbols.

44. The apparatus of any one of claims 41 to 43, wherein the first time interval comprises a time offset relative to a frame without LBT transmission.

45. An apparatus as claimed in claim 44, wherein the apparatus is configured to include control information, for example as a Physical Sidelink Control Channel (PSCCH), into the wireless transmission, for example into a symbol frame, to indicate the time offset.

46. ​​The apparatus of claim 45, wherein the apparatus is configured to use a mini-frame structure to occupy a remainder of a subsequent time slot to align in time with a time slot boundary of the subsequent time slot.

47. An apparatus as claimed in any one of claims 45 or 46, wherein the apparatus is configured to select the time offset as a value from a set of predefined values.

48. An apparatus as described in any of claims 41 to 47, wherein the apparatus is configured to sense the channel before using a first time slot to check the availability of at least two or more consecutive time slots, for example by decoding a received physical sidelink control channel (PSCCH) and / or by evaluating the presence of other transmissions by measuring the energy received on the time slot using RSRP or RSSI. --------------------------------------------------------------- Concept 1; Solution 2-2 -------------------------------------------------------------- 49. An apparatus as claimed in any one of claims 41 to 48, wherein the apparatus is configured to perform an LBT process by sensing the availability of a time slot and / or based on a time offset of a received transmission, for example configured by a resource pool or preconfigured.

50. The apparatus of claim 49, wherein the apparatus is configured to check for availability of one or more of: Each symbol in a time slot, Each symbol after time shift, Only a configured or preconfigured number of symbols after a time offset or based on a configured or preconfigured slot / frame definition, in, The apparatus is configured to check availability by decoding a received Physical Sidelink Control Channel (PSCCH) and / or by measuring the energy received on a timeslot using RSRP or RSSI measurements to assess the presence of other transmissions. ---------------------------------------------------------------- Idea 1; Solution 3 ---------------------------------------------------------------- 51. An apparatus as claimed in any of the preceding claims, wherein the apparatus is configured to communicate on the basis of symbols in a mobile wireless communication network, wherein each symbol is associated with a symbol duration defined according to a subcarrier spacing used for a resource pool, and wherein the apparatus is configured to transmit a plurality of symbols, e.g. 2 or 3 symbols, at a predetermined position after the start of transmission during a second time interval for transmitting control information, e.g. as a physical sidelink control channel (PSCCH).

52. An apparatus as claimed in claim 51, wherein the apparatus is configured to transmit a plurality of symbols for transmitting data, feedback, broadcast and / or reference signals during a second time interval, after transmitting the control information, wherein the number of symbols used for each of them and their position and transmission length are based on a configured or preconfigured time slot / frame / mini-frame structure.

53. An apparatus as claimed in claim 51 or 52, wherein the apparatus is configured to generate control information to indicate the length of the transmission, for example by indicating the frame or mini-frame structure used.

54. The apparatus of any one of claims 51 to 53, wherein the apparatus is configured to generate control information to indicate that the frame structure comprises 14 symbols or a number of symbols different from 7 and / or 14. ------------------------------------------------------------------- Concept 2; Solution 1-1 – Compatible with Concept 1 based on LBT ------------------------------------------------------------------- 55. An apparatus as claimed in any preceding claim, wherein the apparatus is configured to detect unavailability of a time slot associated with a frequency band for transmission based on an LBT procedure, e.g. by experiencing an LBT failure or a set of LBT failures, e.g. defined by a (pre-)configured threshold; and Used to perform one or more of the following actions if the channel is found to be unavailable: a subsequent LBT process on a second, different frequency band to determine availability of the second frequency band for wireless transmission; Switching between operating modes, such as from Mode 2 to Mode 1 with assistance from a base station, Switching between operating modes, such as from Mode 1 to Mode 2 when moving out of base station coverage, · Switching from a sidelink such as the PC5 interface to a legacy interface such as the Uu interface using a base station to assist and route transmission, triggering a request for inter-UE coordination information from another UE to obtain assistance in finding another suitable resource for transmission, notifying another UE about a LBT failure or a persistent LBT failure or a LBT failure for a future reserved transmission, e.g. at T5 or T10, e.g. using an IuC Collision Indicator (CI), e.g. via an IuC message, For example, switching to a non-NR-U band if a failure threshold is met, Send a notification about the number of LBT failures to the base station, UE or RSU at the next successful transmission, Interruption of transmission.

56. The apparatus of claim 55, configured to operate in Mode 2.

57. An apparatus as described in any one of claims 55 or 56, wherein the apparatus is configured to perform one or more LBT processes in a channel during a configured or preconfigured LBT timer before performing one or more operations.

58. An apparatus as claimed in claim 57, wherein the LBT timer is configured or pre-configured according to a network global setting, for example using an SIB; the LBT timer is configured per resource pool, for example using an RC signaling configuration or pre-configuration, or the LBT timer is configured per transmission, for example as indicated in a sidelink control information (SCI) or if in mode 1 via downlink control information.

59. The apparatus of any one of claims 55 to 58, wherein the apparatus is configured to perform an LBT process in a channel a configured or preconfigured number of LBT times before performing one or more operations.

60. An apparatus as claimed in claim 59, wherein the number of LBT times is configured or pre-configured according to a network global setting, for example, using SIB; the number of LBT times is configured by resource pool, for example, using RRC signaling configuration or pre-configuration, or the number of LBT times is configured by transmission, for example, as indicated in sidelink control information (SCI) or if in mode 1 via downlink control information. ----------------------------------------------------------------- Idea 2; Solutions 1-2 and 1-3 ----------------------------------------------------------------- 61. An apparatus as claimed in any one of claims 55 to 60, wherein the apparatus is configured to request assistance information from at least one different apparatus, such as a UE and / or a base station, based on an LBT failure or multiple LBT failures.

62. The apparatus of claim 61, wherein the assistance information relates to resource allocation assistance information indicating resources used or not used for LBT and / or one or more future transmissions.

63. The apparatus of claim 62, wherein resources are defined as bitmaps or vectors in the time domain and / or frequency domain.

64. An apparatus as described in any one of claims 55 to 63, wherein the apparatus is configured to fall back to a predefined, preconfigured, configured or default configuration based on an LBT failure or a set of LBT failures, for example when one or both of a timer threshold and / or a counter threshold related to the LBT failure is reached.

65. An apparatus as claimed in any one of claims 55 to 64, wherein the apparatus is configured to select an operation to react to an LBT fault or a set of LBT faults based on a source of interference causing the LBT fault.

66. An apparatus as described in claim 65, wherein the apparatus is used to determine interference caused by non-3GPP devices, such as WiFi devices, and perform one or more expected future transmissions, such as at T5 and / or T10, or any other future transmissions, within a frequency band specifically related to 3GPP device transmissions; and / or perform transmissions in a frequency band that is identified as being free of any other non-3GPP devices, such as based on other available perception results or based on information received by the base station or one or more other UEs. -------------------------------------------------------------- Concept 2; Solution 2-1 --------------------------------------------------------------- 67. An apparatus as described in any of the preceding claims, wherein the apparatus is configured to reserve multiple resources for multiple transmissions within a time slot on a channel, and to perform LBT for a first resource associated with a first transmission in time among the multiple transmissions, and to experience an LBT failure indicating unavailability; wherein the apparatus is configured to release resources associated with one or more subsequent transmissions.

68. The apparatus of claim 67, wherein the apparatus is configured to use resources in the reserved resources to transmit information for notifying different devices about releasing resources by using an inter-UE coordination message or by notifying a base station or RSU via uplink control information, such as in mode 1.

69. The apparatus of claim 68, wherein the other apparatus is one or more of: - Base stations, such as gNB in ​​NR or eNB in ​​LTE, - Road Side Unit (RSU), - Another UE (e.g., P-UE, V2X-UE, normal UE, etc.).

70. The apparatus of any one of claims 68 or 69, wherein the other device is a UE, and the information is sent via one or more of the following: - Sidelink, such as PC5, - Relay information via Uu via base station or RSU.

71. An apparatus as described in any of claims 68 to 70, wherein the information is sent via an Inter-UE Cooperation (IuC) information message, for example included in a Stage 1 and / or Stage 2 SCI or a new Stage 2 or Stage 3 SCI, or via a PC5-RRC, RRC, MAC-CE or higher layer control message. ----------------------------------------------------------------- Solution-3.3 New SCI format parameters ----------------------------------------------------------------- 72. The device according to any one of the preceding claims, in, The apparatus is configured to transmit control information (SCI) indicating at least one of the following: Explicit or implicit indication of the use of time slot aggregation; · A backward reference indicator; wherein the PSCCH in a later frame of the aggregation includes a backward reference, for example indicating the type of mini-frame structure used in an earlier frame; An indication of the number of symbols to be transmitted offset relative to a time slot structure (eg, a time slot boundary) of the mobile wireless communication network; Information indicating the length of the transmission, for example, to inform the receiving device about how long the current transmission is so that the receiving device can implicitly identify symbols containing a demodulation reference signal (DMRS), a physical sidelink feedback channel (PSFCH), etc.; Information indicating one or more future transmissions, such as a pre-reservation, Information indicating the presence of non-3GPP technologies in the channel or adjacent channels, Information indicating that a 3GPP RAT (such as another NR or LTE system) is operating on the channel or in an adjacent sub-channel, An indication of the time slot structure or time slot format or frame format to be used; Information indicating the LBT timer; Information indicating the LBT counter.

73. The apparatus of claim 72, wherein the control information is in the form of first-stage control information, second-stage control information, or n-stage control information, in, One or more of these phases include parameters, and / or Wherein, the control information is transmitted on PSCCH and / or PSSCH, and / or Among them, the control information is sent via the physical layer through the side link or Uu, PC5-RRC, RRC, MAC-CE or higher layer control messages.

74. A device configured to communicate in a mobile wireless communication network, the device comprising a wireless interface for transmitting and receiving wireless signals in the mobile wireless communication network; wherein, The device is configured as: In a mobile wireless communication network, communication with an apparatus as claimed in any one of the preceding claims is carried out via a sidelink (SL).

75. The apparatus of claim 74, wherein the apparatus is configured to sense in the following symbols of a control information reception slot: All symbols, or All symbols after time offset, or a configured or preconfigured number of symbols after a time offset or based on a configured or preconfigured timeslot / frame definition, The control information is contained in, for example, a physical sidelink control channel or in a physical sidelink shared channel.

76. An apparatus as described in claim 74 or 75, wherein the apparatus is configured to sense PSCCH transmissions at symbols where PSCCH is expected to be transmitted based on a preconfigured or configured mini-time slot or mini-frame format for wireless communication.

77. An apparatus as claimed in any one of claims 74 to 76, wherein the apparatus is configured to sense PSCCH transmissions based on a configuration or preconfigured set of offsets for transmission time slots, such as system-wide or per-resource pool definition.

78. An apparatus as claimed in any one of claims 74 to 77, wherein the apparatus is configured to measure the energy in a first slot of aggregated slots and retain the received information in its buffer and decode using control information of subsequent slots.

79. An apparatus as claimed in any one of claims 74 to 78, wherein the apparatus is configured to sense and seek resources for transmission and include consecutively available time slots into the process for transmission using time slot aggregation.

80. An apparatus as described in any of the preceding claims, comprising a user equipment (UE), wherein the UE comprises a mobile terminal, or a fixed terminal, or a cell IoT-UE, or a vehicle UE, or a vehicle group leader (GL) UE, or an IoT, or a narrowband IoT (NB-IoT) device, or a WiFi non-access point station, a non-AP STA such as 802.11ax or 802.11be, or a ground vehicle, or an aircraft, or a drone, or a mobile base station, or a roadside unit, or a building, or any other item / device having network connectivity that enables the item / device to communicate using a wireless communication network, such as one or more of a sensor or an actuator, and / or It includes a base station (BS), wherein the BS is implemented as a mobile base station or a non-mobile base station and includes a macro cell base station, or a small cell base station, or a central unit of a base station, or a distributed base station unit, or a road side unit, or a UE, or a group leader (GL), or a relay, or a remote radio head, or an AMF or an SMF, or a core network entity, or a mobile edge computing entity, or a network slice in the context of NR or 5G core, or a WiFi AP STA such as 802.11ax or 802.11be, or one or more of any transmit / receive points (TRPs) that enable an item or device provided with network connectivity to communicate using a wireless communication network to communicate using a wireless communication network.

81. A mobile wireless communication system, comprising: At least one device according to any one of claims 1 to 73; as well as At least one device according to any one of claims 74 to 80.

82. A method for operating a device to communicate in a mobile wireless communication network, the device comprising a wireless interface for transmitting and receiving wireless signals in the mobile wireless communication network; the method comprising: In a mobile wireless communication system, communication is performed via a side link (SL), the side link providing a plurality of time slots, each time slot having a time slot duration. Using at least a first time interval of the time slot duration to perform a listen-before-talk (LBT) procedure to determine availability of the time slot; and / or based on the determined availability, using a second time interval of the time slot duration for wireless transmission; and / or Using at least the first time slot duration to perform a listen-before-talk (LBT) process to determine the availability of at least a portion of a subsequent second time slot, such as a full time slot, a mini time slot, or a mini frame, and / or based on the determined availability, using at least a portion of the subsequent second time slot for wireless transmission.

83. A method for operating a device to communicate in a mobile wireless communication network, the device comprising a wireless interface for transmitting and receiving wireless signals in the mobile wireless communication network; the method comprising: receiving a wireless transmission of the method of claim 82; as well as Run accordingly.

84. A 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 claim 82 or 83.

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