Zeroing Method and System in a Wireless Communication Network

Abstract

The present disclosure relates to methods and systems for scheduling uplink data transmissions in a wireless communication network. In one embodiment, a method performed by a first wireless communication node includes: transmitting a first downlink control message to a wireless communication device; initiating a first channel access procedure for accessing a predetermined channel to receive scheduled UL data from the wireless communication device; determining whether the first channel access procedure is successfully completed before a predetermined event; and when the first channel access procedure is completed before the predetermined event, transmitting a notification message to the wireless communication device to notify the wireless communication device that the wireless communication node has successfully completed the first channel access procedure, wherein the notification message triggers the wireless communication device to transmit the scheduled UL data on the predetermined channel based on a specified time provided by the wireless communication node.

Description

Technical Field

[0001] The present disclosure generally relates to wireless communication, and more particularly, to methods and systems for scheduling uplink data transmissions in a wireless communication network. Background Art

[0002] With the advent of fifth-generation (5G) new radio (NR) networks, the number of new user data applications supported by NR networks will surge. With the rapid growth of user data, the demand for spectrum will increase dramatically. Previous solutions to existing and emerging user data services required increasing data rates by widening channels or increasing base station (BS) deployments. For example, the channel bandwidth has increased from 200 kHz in 2G Global System for Mobile Communications (GSM) to 5 MHz in 3G Wideband Code Division Multiple Access (WCDMA), and from 20 MHz in 4G Long Term Evolution (LTE) to 100 MHz in LTE-Advanced Pro. However, the conventional sub-6 GHz spectrum is almost fully allocated, and licensing is expensive for system operators. In addition, in millions of local jurisdictions, the cost and time required to obtain backhaul connections and siting permits limit further densification of the network.

[0003] Using unlicensed carrier frequencies (also known as unlicensed spectrum) to transmit data can improve the utilization of available transmission resources. One possible use of unlicensed spectrum is to support ultra-reliable low-latency communication (URLLC). However, according to the regulatory requirements for unlicensed operation, devices are required to be able to successfully perform an idle channel assessment (CCA) process (also known as listen before talk (LBT)), and have a successful result before data transmission. Therefore, when using unlicensed carriers, 5G NR systems need to address various issues. Additionally, in some countries and regions, there are regulatory policies for the use of unlicensed spectrum.

[0004] Currently, two types of CCA mechanisms have been standardized, and both types of CCA mechanisms must be successfully completed before a device can perform an uplink transmission. The first type is called "type-1 CCA", which implements a random backoff process and is configured for multiple access priority levels for different channels. The second type is called "type-2 CCA", which does not include a random backoff process and performs carrier sensing within a predefined duration. Generally, compared with type-1 CCA, type-2 CCA takes less time to complete, thus reducing the transmission delay time. In most cases, the data transmission of user equipment (UE), including transmissions scheduled by the base station and autonomous uplink transmissions (e.g., unlicensed transmissions or configured grant transmissions), requires a similar channel access process to be successfully completed before uplink transmission.

[0005] To improve the efficiency of data transmission, new channel access procedures and control signaling protocols need to be considered. When using unlicensed carriers to transmit URLLC uplink data, it would be beneficial for the communication system to support fast and reliable data transmission. For scheduled UL transmissions, according to existing methods and solutions, only the UE that is going to transmit data performs the CCA procedure. If the CCA cannot be successfully performed before the scheduled Physical Uplink Shared Channel (PUSCH) transmission time, the UE's uplink data is discarded and re-scheduled again, which adversely affects the URLLC performance and increases the data transmission delay. Therefore, the existing methods for scheduling UL transmissions are not entirely satisfactory. Summary of the Invention

[0006] Exemplary embodiments disclosed herein are directed to solving problems related to one or more problems existing in the prior art, and providing additional features that will become apparent when referring to the following detailed description in conjunction with the accompanying drawings. According to various embodiments, exemplary systems, methods, devices, and computer program products are disclosed herein. However, it should be understood that these embodiments are presented by way of example and not limitation, and it will be apparent to those of ordinary skill in the art who have read this disclosure that various modifications can be made to the disclosed embodiments while remaining within the scope of this disclosure.

[0007] In one embodiment, a method for scheduling uplink (UL) data transmission performed by a wireless communication node includes: transmitting a first downlink control message to a wireless communication device; initiating a first channel access procedure for accessing a predetermined channel to receive scheduled UL data from the wireless communication device; determining whether the first channel access procedure is successfully completed before a predetermined event; and when the first channel access procedure is completed before the predetermined event, transmitting a notification message to the wireless communication device to notify the wireless communication device that the wireless communication node has successfully completed the first channel access procedure, wherein the notification message triggers the wireless communication device to transmit the scheduled UL data on the predetermined channel based on a specified time provided by the wireless communication node.

[0008] In another embodiment, a method for scheduling uplink (UL) data transmission performed by a wireless communication device includes: receiving a first downlink control message from a wireless communication node; initiating a first channel access procedure for accessing a predetermined channel to transmit scheduled UL data; determining whether the first channel access procedure is successfully completed before a predetermined event; when the first channel access procedure is completed before the predetermined event, transmitting the scheduled UL data according to first timing information included in the first downlink control message; and when the first channel access procedure is not completed before the predetermined event, transmitting the scheduled UL data according to second timing information provided by the wireless communication node.

[0009] In another embodiment, a wireless communication node includes: a transceiver configured to transmit a first downlink control message to a wireless communication device; and at least one processor configured to: initiate a first channel access procedure for accessing a predetermined channel to receive scheduled UL data from the wireless communication device; and determine whether the first channel access procedure is successfully completed before a predetermined event, wherein when the first channel access procedure is completed before the predetermined event, the transceiver is further configured to transmit a notification message to the wireless communication device to notify the wireless communication device that the wireless communication node has successfully completed the first channel access procedure, and wherein the notification message triggers the wireless communication device to transmit the scheduled UL data on the predetermined channel based on a specified time provided by the wireless communication node.

[0010] In another embodiment, a wireless communication device includes: a transceiver configured to receive a first downlink control message from a wireless communication node; and at least one processor configured to: initiate a first channel access procedure for accessing a predetermined channel to transmit scheduled UL data; and determine whether the first channel access procedure is successfully completed before a predetermined event, wherein when the first channel access procedure is completed before the predetermined event, the transceiver is further configured to transmit the scheduled UL data according to first timing information included in the first downlink control message; and wherein when the first channel access procedure is not completed before the predetermined event, the transceiver is further configured to transmit the scheduled UL data according to second timing information provided by the wireless communication node.

[0011] In a further embodiment, the present invention provides a non-transitory computer-readable storage medium storing computer-executable instructions that, when executed, cause any of the methods disclosed herein to be performed.

[0012] In an even further embodiment, a wireless communication node includes: a memory storing computer-executable instructions that, when executed, perform any of the methods disclosed herein; and at least one processor coupled to the memory and configured to execute the computer-executable instructions. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Various exemplary embodiments of the present disclosure are described in detail below with reference to the accompanying drawings. The drawings are for illustrative purposes only and depict only the exemplary embodiments of the present disclosure to facilitate the reader's understanding of the present disclosure. Therefore, the drawings should not be considered as limiting the breadth, scope, or applicability of the present disclosure. It should be noted that, for clarity and convenience of illustration, these drawings are not necessarily drawn to scale.

[0014] Figure 1A block diagram of an exemplary communication network according to some embodiments of the present invention is shown, and the techniques and methods disclosed herein may be implemented in this exemplary communication network.

[0015] Figure 2 A flowchart showing an exemplary process for scheduling an uplink transmission according to some embodiments of the present invention.

[0016] Figure 3 A timing diagram showing an exemplary scenario for scheduling an uplink transmission according to some embodiments of the present invention, in which the UE successfully completes the CCA process before the BS successfully completes the CCA process.

[0017] Figure 4 A timing diagram showing an exemplary scenario for scheduling an uplink transmission according to some embodiments of the present invention, in which the BS successfully completes the CCA process before the UE successfully completes the CCA process.

[0018] Figure 5 A timing diagram showing an exemplary scenario for scheduling an uplink transmission according to some embodiments of the present invention, in which the BS successfully completes the CCA after the starting point indicated for the scheduled PUSCH transmission.

[0019] Figure 6 A timing diagram showing an exemplary scenario for a one-time trigger of an uplink transmission for multiple UL transmissions according to some embodiments of the present invention.

[0020] Figure 7 A block diagram of a wireless communication node configured to perform the methods disclosed herein according to various embodiments of the present invention. Detailed Description

[0021] The various exemplary embodiments of the present disclosure are described below with reference to the accompanying drawings so that those of ordinary skill in the art can make and use the present disclosure. It will be apparent to those of ordinary skill in the art that various changes or modifications can be made to the examples described herein after reading the present disclosure without departing from the scope of the present disclosure. Therefore, the present disclosure is not limited to the exemplary embodiments and applications described and illustrated herein. Additionally, the specific order and / or hierarchy of steps in the methods disclosed herein are merely exemplary methods. Based on design preferences, the specific order or hierarchy of steps of the disclosed methods or processes can be rearranged while remaining within the scope of the present disclosure. Therefore, those of ordinary skill in the art will understand that the methods and techniques disclosed herein present various steps or actions in an exemplary order, and the present disclosure is not limited to the specific order or hierarchy presented unless otherwise expressly stated.

[0022] As discussed herein, a "wireless communication node" may include or be implemented as a base station (BS), a next-generation node B (gNB), an E-UTRAN node B (eNB), a transmission and reception point (TRP), an access point (AP), a donor node (DN), a relay node, a core network (CN) node, a RAN node, a master node, a secondary node, a distributed unit (DU), a central unit (CU), etc., which is consistent with the customary understanding of these terms in the art. Additionally, as discussed herein, a "wireless communication device" may include or be implemented as a UE, a station (STA), a mobile terminal (MT), a mobile station (MS), etc., which is consistent with the customary understanding of these terms in the art. In the description of the following exemplary embodiments, the BS is described as an exemplary embodiment of a "wireless communication node", and the UE is described as an exemplary embodiment of a "wireless communication device". However, it should be understood that the scope of the present disclosure is not limited to these exemplary embodiments.

[0023] Figure 1 FIG. 100 shows an exemplary communication network 100 according to an embodiment of the present disclosure, in which the technologies disclosed herein may be implemented. As Figure 1 shown, the exemplary communication network 100 includes a first base station (BS1) 110 and a second base station (BS2) 120. BS1 110 supports communication in a first cell area 101, and a plurality of UEs (UE1 111 and UE2 112) are located in the first cell area 101, and wherein BS1 110 may communicate with these UEs according to various wireless communication protocols. Similarly, BS2 120 supports communication in a second cell area 102, and a plurality of UEs (UE2 112, UE3 123, and UE4 124) are located in the second cell area 102, and wherein BS2 120 may communicate with these UEs according to various wireless communication protocols. As Figure 1 shown, UE2 112 is simultaneously located within the cell coverage areas of both the first cell area 101 and the second cell area 102. Thus, according to various wireless communication protocols and / or wireless communication technologies, UE2 may be connected to both BS1 110 and BS2 120 simultaneously (i.e., dual connectivity (DC)) or only to one of BS1 110 and BS2 120.

[0024] Before a UE can initiate an uplink transmission to its associated BS, a channel access procedure must be successfully completed so that communication resources can be allocated to the UE prior to the uplink transmission. According to some embodiments, in order to increase the probability of completing the channel access procedure and improve the efficiency of the uplink data transmission protocol, one or more downlink control information (DCI) messages are transmitted to the UE.

[0025] In a first embodiment, after a base station (BS) sends an uplink (UL) grant including a first downlink control information (DCI1) message to a UE, both the BS and the UE will perform a channel access procedure (e.g., LBT) to access a channel for subsequent data communication between the BS and the UE. According to some embodiments, the first DCI includes two sets of time domain resource allocation (TDRA) fields. If the UE first successfully completes the channel access procedure, the first set of TDRA fields (TDRA1) is used to determine the time domain resources for data transmission. If the BS first successfully completes the channel access procedure before the UE, the second set of TDRA fields (TDRA2) is used to determine the time domain resources for data transmission. Thus, the UE can prepare UL data after receiving the first UL grant, and then determine which set of TDRA fields to use at the corresponding time to prepare and send a UL transmission (e.g., a physical uplink shared channel (PUSCH) transmission) according to whether the UE or the BS first successfully completes the channel access procedure.

[0026] Therefore, in some embodiments, if the UE first completes the channel access procedure, the UE determines the time domain position for PUSCH transmission based on the TDRA1 field included in the first DCI. In some embodiments, the TDRA1 field contains the same information as a conventional TDRA message. On the other hand, if the BS first completes the channel access procedure, the TDRA2 field or at least a part thereof is used to determine the channel resources for subsequent communication between the BS and the UE.

[0027] In some embodiments, the first DCI (DCI1) includes both the TDRA1 field and the TDRA2 field described above. In this case, when the UE wins the contention, the UE will transmit PUSCH data according to the information included in the TDRA1 field provided by the DCI1. On the other hand, when the BS wins the contention, the BS only notifies the UE that the BS has successfully completed the channel access through a conventional DCI 2_0 procedure or a predefined sequence, which can be detected by the UE when performing its CCA procedure. Thereafter, the UE can transmit data through PUSCH according to the information included in the TDRA2 field in the DCI1 without receiving further control information (e.g., a second DCI (DCI2)) from the BS.

[0028] In some embodiments, when DCI1 contains both the TDRA1 field and the TDRA2 field, the TDRA1 field will be the same as the regular TDRA information. In this case, the TDRA2 field includes two parts. In some embodiments, the first part includes two bits indicating a time period after which the first UL grant becomes invalid. In some embodiments, if within M milliseconds (ms) after the first UL grant, the UE does not receive the triggered DCI or a predefined sequence, the first UL grant becomes invalid. In some embodiments, the M value can indicate multiple symbols. In some embodiments, the second part includes two bits that indicate the timing or offset value relative to the triggering event (e.g., a predefined sequence or DCI2) for the UE to transmit the PUSCH. In some embodiments, this offset value can indicate the number of OFDM symbols after the transmission of the triggering DCI (e.g., 2, 4, 8, 12, 14 OFDM symbols).

[0029] In alternative embodiments, the first UL grant containing the first DCI is not modified and contains only the regular TDRA information, which is used for time-domain resource allocation when the UE successfully competes for resources. However, in this case, when the BS successfully completes the CCA before the UE, the BS sends a second UL grant containing a second DCI message (DCI2) to notify the UE of the time to transmit data via the PUSCH. In some embodiments, the DCI2 message contains only the second part described above, e.g., the offset value relative to the time when the second DCI is transmitted, which notifies the UE when to transmit the scheduled UL data on a predefined PUSCH.

[0030] Figure 2 A flowchart of a process 200 for scheduling UL transmissions according to some embodiments of the present invention is shown. In step 201, the BS (e.g., gNB) sends one or more DCI messages to the UE. In some embodiments, the BS sends only the first DCI message containing the regular DCI information, which is used when the UE successfully completes the channel access procedure before the BS. In this case, when the BS sends only the first DCI message and the BS wins the competition, the BS will subsequently send a second UL grant containing the second DCI message to the UE. In some embodiments, as discussed above, the second DCI message contains only the second part of the TDRA2 field.

[0031] In an alternative embodiment, at step 201, the BS transmits the TDRA1 and TDRA2 fields in the first DCI message of the first UL grant, where the first DCI message can be considered a "modified DCI message". If the UE wins the contention (e.g., the UE has successfully completed CCA before detecting any DMRS sequence or group common DCI that notifies the UE of the BS's successful completion of CCA), the TDRA1 field is used to allocate resources for subsequent communication between the US and the BS (e.g., PUSCH). On the other hand, if the BS wins the contention, the TDRA2 field is used to allocate resources for subsequent communication between the BS and the UE. Thus, in this embodiment, a second UL grant (e.g., PDCCH signal) containing a second DCI is not required before the UE can initiate a PUSCH transmission through the allocated resources. In some embodiments, when the first DCI contains a first set of TDRA fields and a second set of TDRA fields, as described above, if the BS successfully completes CCA earlier than the UE, the BS will only transmit a predefined sequence to the UE to notify the UE that the BS has successfully completed CCA. After receiving such a notification, the UE will transmit its PUSCH data according to the information contained in the TDRA2 field provided by the first DCI.

[0032] Next, at step 203, both the BS and the UE start performing the CCA process. At step 205, it is determined whether the UE has successfully completed the CCA process. If the UE successfully completes CCA before the BS, at step 207, the UE will transmit data according to the TDRA1 parameter contained in DCI1.

[0033] At step 209, it is determined whether the BS has successfully completed the CCA process. If the BS successfully completes CCA before the UE, at step 211, the BS transmits a second UL grant through PDCCH, or transmits a predefined sequence. In some embodiments, if at step 201, DCI1 only contains the TDRA1 field, at step 211, the BS transmits a second DCI (DCI2) containing the TDRA2 field or a part thereof. On the other hand, if at step 201, the first DCI contains both TDRA1 and TDRA2 fields, at step 211, the BS transmits a predefined sequence to notify the UE that the BS has successfully completed the CCA process. According to various embodiments, the predefined sequence may include a dedicated demodulation reference signal (DMRS), a synchronization signal block (SSB), a channel state information reference signal (CSI-RS), a pseudo-random number (PN), or a Zadoff-Chu (ZC) sequence.

[0034] In step 213, the UE transmits PUSCH data according to the TDRA2 field parameter included in the first DCI or the second DCI. In some embodiments, DCI2 only includes an offset value relative to the position or time when the DCI2 signal is transmitted. In this case, after the BS successfully completes CCA, the UE transmits PUSCH data according to the time slot position and start symbol indicated by the DCI2 parameter.

[0035] As discussed above, in some embodiments, both TDRA1 and TDRA2 can be included in the first DCI message (DCI1), in which case the BS does not need to send a second DCI message (DCI2) after successfully completing CCA. In this case, the BS only needs to send a predefined sequence to notify the UE that the BS has successfully completed CCA. On the other hand, in alternative embodiments, only TDRA1 is included in DCI1. In some embodiments, TDRA1 includes conventional TDRA information. In this case, if the BS successfully completes CCA before the UE successfully completes CCA, then at least a part of TDRA2 must subsequently be transmitted by the BS in the second DCI (DCI2). In some embodiments, DCI2 only includes the second part (e.g., the offset value) and does not include the first part (e.g., the expiration period of the first UL grant), because the first part may not be necessary in this case.

[0036] Also as discussed above, in various embodiments, with the help of the BS that performs CCA, the UL transmission probability can be increased, especially when the UE is configured to perform type-1 CCA. In some embodiments, for example, if the BS first successfully completes CCA, the UE is configured to perform type-2 CCA, which increases the CCA success probability of the UE, thereby improving the reliability and reducing the latency of the UE's URLLC transmission.

[0037] In some embodiments, when the UE successfully completes CCA for a scheduled uplink data transmission, for a single transmission time interval (TTI) or PUSCH scheduling, the DCI is in "Format 0_1". In this case, the UE first receives the DCI from the BS and then performs CCA. After a successful CCA procedure, the UE transmits data based on the indication in the DCI. In some embodiments, the DCI for scheduling PUSCH includes at least one of the following types of information: channel access type, channel access priority, time domain allocation information (including one or more start points and end points or lengths of the scheduled data transmission), carrier indication information, bandwidth part (BWP) index information, frequency domain resource allocation information, hybrid automatic repeat request (HARQ) process number information, new data indicator (NDI) information, redundancy version (RV) information, code block group transmission information (CBGTI), demodulation reference signal (DMRS) information, phase tracking reference signal (PTRS) information, channel state information (CSI) feedback request information, sounding reference signal (SRS) request information, modulation and coding scheme (MCS) information, number of scheduled TTIs or PUSCHs, etc.

[0038] Figure 3 A timing diagram showing an exemplary scenario according to some embodiments is presented, in which the UE successfully completes the CCA process before the BS completes the CCA process. At time t0, the BS starts transmitting the first DCI message. In some embodiments, the first DCI message includes timing information (e.g., K2 = 1), which indicates the number of time slots between the completion of the DCI transmission and the subsequent transmission of the PUSCH by the UE. In some embodiments, K2 = 1 means the number of time slots is 1. At time t1, the transmission of the first DCI is completed, and the BS starts performing the channel access procedure (e.g., CCA), but does not successfully complete the CCA before the UE completes its CCA, as Figure 3 shown. At time t2, after receiving the first DCI, the UE starts performing its specified channel access procedure. At time t3, the UE has successfully completed its channel access procedure and accessed the channel without detecting that the BS has successfully completed its channel access procedure (e.g., without detecting a PDCCH or other predefined sequence indicating that the channel for PUSCH transmission is occupied by the BS). Immediately after completing the CCA process, at time t3, the UE transmits data on the PUSCH according to the received first DCI.

[0039] Figure 4A timing diagram showing another exemplary scenario according to some embodiments, in which the BS successfully completes CCA earlier than the UE. In this case, at time t0, the BS transmits a first DCI containing timing information (e.g., K2 = 0100 (binary) or 4 (decimal)). In some embodiments, this first DCI contains both TDRA1 information and TDRA2 information. In alternative embodiments, the first DCI contains only TDRA1 information, and a subsequently transmitted second DCI contains at least a portion of the TDRA2 information, which is transmitted by the BS if the BS successfully completes CCA before the UE, as Figure 4 shown.

[0040] As discussed above, according to some embodiments, when DCI1 contains both TDRA1 and TDRA2 information, the TDRA2 information includes two parts. The first part includes two bits indicating the number of time slots after the DCI transmission after which the first UL grant becomes invalid. In some embodiments, if no valid trigger event (e.g., DCI or predefined sequence) is received within M ms after the initial grant, the initial UL grant becomes invalid, where M is a predefined positive integer. In other embodiments, the value of M may indicate the number of symbols after the DCI transmission after which the initial UL grant becomes invalid. The second part of the TDRA2 information includes two additional bits that indicate a timing or offset value after the BS transmits a second DCI (e.g., {2, 4, 8, 12, 14 OFDM symbols}) to transmit data via PUSCH. In some embodiments, in addition to the TDRA information, other information used by the UE to prepare data may be included in the first DCI. For example, such other information may include frequency domain resource allocation information, hybrid automatic repeat request (HARQ) process number information, new data indicator (NDI) information, redundancy version (RV) information, code block group transmission information (CBGTI), demodulation reference signal (DMRS) information, and modulation and coding scheme (MCS) information. In some embodiments, for example, CCA-related information of the UE (such as CCA type and channel access priority level) may also be included in the first DCI. On the other hand, as discussed above, when DCI1 contains only TDRA1 information, the second DCI (DCI2) will contain at least a portion of the TDRA2 information.

[0041] Referring again to Figure 4 , at time t1, after transmitting the first DCI, the BS starts to perform the CCA process. Next, at time t2, the UE also starts to perform the CCA process but does not succeed, as Figure 4As shown. At time t3, the BS successfully completes the CCA process, and if the BS successfully completes the CCA within the valid time period indicated in the first part of TDRA2 (e.g., within 4 time slots of the first DCI transmission), the BS transmits a second DCI or a predefined sequence via PDCCH to notify the UE that the BS has successfully completed the CCA. In some embodiments, the second DCI may be a group common DCI, such as DCI format 2_0 or other DCI.

[0042] Upon receiving the second DCI or the predefined sequence, the UE will know that the BS has successfully completed the CCA before the UE successfully completes the CCA. Thereafter, at time t4 (which may be different from the originally scheduled transmission time), the UE may transmit data via PUSCH according to the timing indicated in the first DCI (if the first DCI is modified to include both TDRA1 information and TDRA2 information), or the timing indicated in the second DCI (if the first DCI only includes TDRA1 information and the second DCI includes TDRA2 information). As discussed above, in some embodiments, the TDRA2 information includes at least two bits that indicate the timing or offset value relative to the time when the UE detects the predefined sequence (when the first DCI is modified) or the second DCI (when the first DCI is not modified) for transmitting PUSCH data. Therefore, through the mechanisms and schemes described above, the PUSCH transmission delay can be reduced because the UE does not need to prepare another PUSCH or continue to perform CCA after receiving the predefined sequence or the second DCI from the BS.

[0043] Figure 5 A timing diagram showing an exemplary scenario for scheduling uplink data transmission according to some embodiments is presented, in which the BS successfully completes the CCA after a starting point that indicates the UE has successfully completed the CCA and completed the PUSCH transmission. At time t0, the BS transmits a first DCI containing timing information (e.g., K2 = binary 0100 or decimal 4). At time t1, the UE starts to perform CCA but does not successfully complete it before the scheduled UL transmission at t2. At time t4, the BS successfully completes the CCA and transmits a PDCCH containing a predefined sequence (when DCI1 is modified) or a second DCI to the UE. Thereafter, at time t5, the UE will transmit PUSCH data according to the timing information contained in the first DCI or the second DCI, which can be earlier than waiting for the next scheduled PUSCH transmission by the conventional method. In this way, the PUSCH transmission delay can also be reduced because the UE does not need to prepare another PUSCH or continue to perform CCA after receiving the predefined sequence or the second DCI from the BS.

[0044] In some embodiments, the BS may assist the UE in performing CCA to reduce UL data transmission latency. For example, the BS may send a normal UL grant containing timer information for configuring the UE. For example, the timer may be set to 2 ms, and when the UE receives the first UL grant, the timer starts timing. After receiving the UL grant, the UE prepares the PUSCH according to the scheduling information contained in the UL grant. In some embodiments, if the UE receives a second UL grant (the second UL grant notifies the BS that CCA has been successfully completed) containing a second DCI or a predefined sequence, the UE will determine whether to perform CCA or which type of CCA should be performed according to the DL-UL gap duration. In some embodiments, for example, if the gap duration is less than 16 μs, the UE may directly transmit the PUSCH. In some embodiments, if the gap duration is between 16 μs and 25 μs, the UE may perform a 16-μs type of CCA, and if the CCA is successfully completed, the UE may transmit the PUSCH that has been prepared previously. Additionally, in some embodiments, if the gap duration is greater than 25 μs, the UE will perform a 25-μs type of CCA, and if the CCA is successfully completed, the UE will transmit the PUSCH that has been prepared previously.

[0045] In a further embodiment, as described in further detail below, the BS may trigger the UE to perform a "one-shot scheduling mode". In some embodiments, the DCI may be a UE-specific DCI scrambled by a specific radio network temporary identifier (RNTI). Alternatively, for example, the transmission mode may be triggered by 1 bit in the UL grant. In some embodiments, after detecting the DCI, the UE transmits all the data of the HARQ process that has not been successfully transmitted (including the data not sent due to the failure of the initially scheduled LBT and the data restricted by the maximum channel occupancy time (MCOT) (e.g., K2 = non-numeric)). In this case, the UE may send the data according to an order based on: the previously scheduled sequence, the minimum control channel element (CCE) index, the starting position in the frequency domain, or the HARQ process number.

[0046] In some embodiments, a single-shot scheduling DCI may trigger the transmission of multiple PUSCHs, because PUSCHs with previously failed CCAs or scheduled PUSCHs that have not yet been transmitted cannot be combined and transmitted via one PUSCH. Thus, for example, some methods are needed to send these multiple PUSCHs via different resources in different time domains and / or different frequency domains, etc. In some embodiments, different resources and their allocations may be indicated in a second DCI. For example, in some embodiments, the order of multiple PUSCH transmissions in a single-shot scheduling mode may be determined according to some predefined rules, such as based on the minimum CCE index, or the scheduling order of the first scheduling, or the starting point in the frequency domain, or the number of HARQ processes. In some embodiments, the BS may trigger a UE to perform a single-shot scheduling of multiple PUSCH transmissions via one DCI, as described below.

[0047] For example, a UE may be scheduled for one PUSCH transmission or multiple PUSCH transmissions, but before the start position of any PUSCH of one PUSCH transmission or the scheduled multiple PUSCHs, the UE cannot successfully perform a CCA. In this case, as described above, the BS may trigger the UE to retransmit the previously non-transmittable PUSCH according to a new timing relative to the transmission of a predefined sequence or a second DCI, and this new timing may be earlier than the second scheduling transmission time, that is, the second scheduling transmission time of one or more PUSCHs that cannot be transmitted at an earlier scheduling transmission time. Thus, the latency of UL transmissions is reduced.

[0048] As another example, a first DCI may schedule a PUSCH transmission by providing a timing value that is used to indicate to the UE to wait for the next DCI message (i.e., the second DCI) with a digital transmission timing indicator field to inform the UE when to transmit the PUSCH. In some embodiments, for one or more PUSCH transmissions, the second DCI may trigger the transmission of a stored PUSCH or a retransmitted PUSCH. In some embodiments, multiple outstanding PUSCHs of multiple HARQ process messages may be triggered and then transmitted in consecutive transmission time intervals (TTIs). In some embodiments, after the UE has prepared one or more PUSCHs according to the first DCI, the UE may store the PUSCH data for a period of time. After detecting a trigger event such as a second DCI or a predefined sequence indicating that the BS has successfully completed a CCA, the UE may then transmit the stored PUSCH data continuously.

[0049] In some embodiments, the DCI may be UE-specific DCI scrambled with a specific RNTI, or the transmission mode may be triggered by bits in the UL grant. For example, after detecting the triggering DCI, the UE may transmit UL data or multiple PUSCHs according to the bit fields in the triggering DCI or according to some predefined rules. For example, in a DCI indicating the one-shot scheduling mode, multiple TDRAs may be included, i.e., each PUSCH is associated with a corresponding TDRA. Alternatively, in some embodiments, each PUSCH is associated with a separate start and length indication value (SLIV) and mapping type. In some embodiments, the number of triggered PUSCHs may be signaled by the number of valid SLIVs included in the rows of the TDRA table included in the DCI.

[0050] With the above signaling design, one DCI can be configured to trigger multiple PUSCH transmissions, and each PUSCH can transmit different transport blocks (TBs). With this arrangement, the overhead of scheduling DCI is reduced, and the probability and latency of uplink transmission are increased. In some embodiments, the BS may trigger a UE to perform one-shot scheduling of multiple UL transmissions through one or more DCIs. For example, the UE may be scheduled for one PUSCH transmission or multiple PUSCH transmissions, but the UE cannot successfully perform CCA before the start position of one PUSCH transmission or any PUSCH of the multiple scheduled PUSCHs. In this case, as described above, the BS may trigger the UE to retransmit one or more PUSCHs according to the timing before the second scheduled transmission time of the UE.

[0051] As another example, the first DCI may schedule a PUSCH transmission by providing a timing value that indicates to the UE to wait for the next downlink control message with a digital transmission timing indicator field to inform the UE when to transmit one or more previously prepared and / or stored PUSCHs. Thus, a DL control message (e.g., DCI1 or DCI2) may trigger the transmission of one or more stored PUSCHs or retransmitted PUSCHs. In some embodiments, multiple pending PUSCHs of multiple HARQ process messages may be triggered and subsequently transmitted in consecutive TTIs. Thus, according to some embodiments, the UE may prepare one or more PUSCHs according to the first DCI and store the PUSCH data for a period of time. After detecting a triggering event (e.g., a second DCI or a predefined sequence), the UE then continuously transmits one or more PUSCHs according to the timing and / or resource allocation information included in the triggering DCI. In some embodiments, the DCI may be a UE-specific DCI scrambled with a specific RNTI, or the transmission mode may be triggered by bits in the UL grant. After the UE detects the DCI, the UE may transmit UL data on one or more PUSCHs according to the bit fields allocated in the UE-specific DCI or according to some predefined rules.

[0052] In some embodiments, in a one-shot scheduling DCI, multiple TDRAs may be included, each TDRA being separately assigned to one PUSCH among multiple PUSCHs. Alternatively, in some embodiments, each PUSCH has a separate SLIV and mapping type. In some embodiments, the number of triggered PUSCHs is indicated by the number of valid SLIVs indicated in the row of the TDRA table signaled in the DCI. With such a signaling design, one DCI can be configured to trigger multiple PUSCH transmissions, and each PUSCH can transmit a different TB. With this arrangement, the overhead of scheduling DCI is reduced, and the probability and latency of uplink transmission are increased.

[0053] Figure 6 A timing diagram showing an exemplary scenario of implementing a single-trigger transmission of multiple PUSCHs according to some embodiments is shown. As Figure 6As shown, at time t0, the BS sends one or more DCIs to the UE. In this example, three PUSCHs (PUSCH1, PUSCH2, and PUSCH3) can be scheduled by one DCI or three different DCIs, and these DCIs contain timing values (e.g., K2 values) associated with each PUSCH. Based on these timing values, PUSCH1 is scheduled for transmission at time t1, PUSCH2 is scheduled for transmission at time t2, and PUSCH3 is scheduled for transmission at time t3. However, in this example, due to CCA failure, the UE cannot access the channel before the time indicated by the DCI for each PUSCH transmission. Then, at time t4, the BS will transmit a new DCI after successfully completing CCA. The new DCI will contain the timing information for transmitting the data of PUSCH1, PUSCH2, and PUSCH3 that was previously prepared and stored by the UE. After the UE receives this new DCI / multiple DCIs, the UE can transmit the data of PUSCH1, PUSCH2, and PUSCH3 according to the timing indicated in the TDRA of the second DCI. In some embodiments, a single TDRA can indicate the timing value t5 for transmitting the first PUSCH1, and the remaining PUSCHs are subsequently transmitted continuously at times t6 and t7.

[0054] In some embodiments, the symbol duration L of PUSCH1, PUSCH2, and PUSCH3 is the same as the indication contained in the first DCI. In some embodiments, the starting symbol can be different. In some embodiments, the transmissions of PUSCH1, PUSCH2, and PUSCH3 are continuous. In further embodiments, the UE determines the time resources or transmission sequence for the transmissions of PUSCH1, PUSCH2, and PUSCH3 based on the indication contained in the first DCI. In some embodiments, PUSCH1, PUSCH2, and PUSCH3 are the last three PUSCHs that the BS did not successfully detect.

[0055] In some embodiments, there may be a time gap between the second DCI and the UL PUSCH transmission. According to some embodiments, if the gap is 16 us, the UE does not need to perform CCA and can directly transmit one or more PUSCHs. Through this scheme, the UL transmission delay can be reduced because the UE no longer needs to wait for multiple subsequent UL authorizations for triggering the retransmission of multiple PUSCHs, even when the UE fails to successfully complete CCA after the initial DCI. In some embodiments, for example, all the data of one or more HARQ processes that were not transmitted due to CCA failure and / or MCOT limitation are transmitted in an accelerated manner. In some embodiments, multiple PUSCHs are transmitted in the order corresponding to their previous scheduling and / or based on the CCE index value and / or the frequency domain starting position and / or the HARQ process number value.

[0056] Figure 7 FIG. 2 shows a block diagram of a network node (NN) 700 according to various embodiments of the present invention. The NN 700 is an example of a wireless communication node, which may be configured to implement various methods and processes described herein. In some embodiments, as described herein, the NN 700 may be a wireless communication node, such as a base station (BS). In other embodiments, as described herein, the NN 700 may be a wireless communication device, such as a user equipment (UE). As Figure 7 shown, the NN 700 includes a housing 740, which contains a system clock 702, a processor 704, a memory 706, a transceiver 710 including a transmitter 712 and a receiver 714, a power module 708, and a DCI module 720.

[0057] In this embodiment, the system clock 702 provides a timing signal to the processor 404 for controlling the timing of all operations of the NN 700. The processor 704 controls the general operation of the NN 700 and may include one or more processing circuits or modules, such as a central processing unit (CPU) and / or a general-purpose microprocessor, a microcontroller, a digital signal processor (DSP), a field programmable gate array (FPGA), a programmable logic device (PLD), a controller, a state machine, gated logic, discrete hardware components, any combination of a dedicated hardware finite state machine, or any other suitable circuit, device, and / or structure that can perform calculations or other data operations.

[0058] The memory 706, which may include a read-only memory (ROM) and a random access memory (RAM) simultaneously, may provide instructions and data to the processor 704. A portion of the memory 706 may also include a non-volatile random access memory (NVRAM). The processor 704 generally performs logical and arithmetic operations based on program instructions stored in the memory 706. The instructions (also referred to as software) stored in the memory 406 may be executed by the processor 704 to perform the methods described herein. The processor 404 and the memory 706 together form a processing system for storing and executing software. As used herein, "software" means any type of instruction, which may be referred to as software, firmware, middleware, microcode, etc., that can configure a machine or device to perform one or more desired functions or processes. The instructions may include code (e.g., source code format, binary code format, executable code format, or any other suitable code format). When executed by one or more processors, these instructions cause the processing system to perform various functions described herein.

[0059] A transceiver 710 including a transmitter 712 and a receiver 714 allows the NN 700 to transmit data to and receive data from an external network node (e.g., an STA or an AP). An antenna 750 is generally attached to the housing 740 and electrically coupled to the transceiver 710. In various embodiments, the NN 700 includes (not shown) multiple transmitters, multiple receivers, and multiple transceivers. In some embodiments, the antenna 750 includes a multi-antenna array that can form multiple beams according to MIMO beamforming techniques, each beam pointing in a different direction.

[0060] The DCI module 720 can be implemented as part of the processor 704 that is programmed to perform the functions herein, or the DCI module 720 can be a stand-alone module implemented in hardware, firmware, software, or a combination thereof. In some embodiments, the DCI module 720 is part of a BS and is configured to generate the first DCI message and / or the second DCI message as described herein. In some embodiments, the DCI module 720 is part of a UE and is configured to receive and process the first DCI message and / or the second DCI message as described herein. According to various embodiments, the DCI module 720 can be implemented as software (i.e., computer-executable instructions) stored in a non-transitory computer-readable medium that, when executed by the processor 704, transforms the processor 704 into a special-purpose computer to perform the nulling operations described herein.

[0061] The various components and modules within the housing 740 are coupled together by a bus system 730. For example, in addition to a data bus, the bus system 730 can also include a power bus, a control signal bus, and / or a status signal bus. It should be understood that the modules of the NN 700 can be operably coupled to each other using any suitable technology and medium. It should also be understood that additional modules (not shown) can be included in the NN 700 without departing from the scope of the present invention.

[0062] Although various embodiments of the present disclosure have been described above, it should be understood that these embodiments are presented by way of example only and not by way of limitation. Similarly, the various figures may depict example architectures or configurations that are provided to enable a person of ordinary skill in the art to understand the exemplary features and functions of the present disclosure. However, a person of ordinary skill in the art will understand that the present disclosure is not limited to the example architectures or configurations shown, but can be implemented using various alternative architectures and configurations. Additionally, as a person of ordinary skill in the art will understand, one or more features of one embodiment can be combined with one or more features of another embodiment described herein. Therefore, the breadth and scope of the present disclosure should not be limited by any of the exemplary embodiments described above.

[0063] It should also be understood that any reference in this document to elements using names such as "first", "second", etc. generally does not limit the number or order of these elements. Instead, these names are used in this document to conveniently distinguish between two or more elements or element instances. Thus, referring to a first element and a second element does not mean that only two elements can be used, or that the first element must come before the second element in some way.

[0064] Additionally, those of ordinary skill in the art will understand that information and signals can be represented using any of a variety of different techniques and technologies. For example, the data, instructions, commands, information, signals, bits, and symbols referred to in the above description can be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or optical particles, or any combination thereof.

[0065] Those skilled in the art will further understand that any of the various illustrative logical blocks, modules, processors, devices, circuits, methods, and functions described in connection with the aspects disclosed herein can be implemented by electronic hardware (e.g., digital implementations, analog implementations, or a combination of both), firmware, various forms of programs or design code incorporating instructions (which may be referred to herein for convenience as "software" or "software modules"), or any combination of these technologies.

[0066] To clearly illustrate this interchangeability of hardware, firmware, and software, the various illustrative components, blocks, modules, circuits, and steps have been generally described above in terms of their functionality. Whether this functionality is implemented as hardware, firmware, or software, or a combination of these technologies, depends on the particular application and the design constraints imposed on the overall system. Those skilled in the art can implement the described functionality in various ways for each particular application, but such implementation decisions do not result in departing from the scope of this disclosure. According to various embodiments, a processor, device, component, circuit, structure, machine, module, etc. can be configured to perform one or more of the functions described herein. The terms "configured to" or "configured for" as used herein with respect to a particular operation or function mean that a processor, device, component, circuit, structure, machine, module, signal, etc. is physically constructed, programmed, arranged, and / or formatted to perform the particular operation or function.

[0067] In addition, those of ordinary skill in the art will understand that the various illustrative logical blocks, modules, devices, components, and circuits described herein can be implemented within or performed by an integrated circuit (IC), which can include a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic device, or any combination thereof. The logical blocks, modules, and circuits can also include antennas and / or transceivers to communicate with various components within a network or device. A processor programmed to perform the functions herein will become a specifically programmed or dedicated processor and can be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other suitable configuration to perform the functions described herein.

[0068] If implemented in software, these functions can be stored as one or more instructions or code in a computer-readable medium. Accordingly, the steps of the methods or algorithms disclosed herein can be implemented as software stored in a computer-readable medium. A computer-readable medium includes both a computer storage medium and a communication medium including any medium that can transfer a computer program or code from one place to another. The storage medium can be any available medium that can be accessed by a computer. By way of example and not limitation, such computer-readable medium can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired program code in the form of instructions or data structures and that can be accessed by a computer.

[0069] As used herein, the term "module" refers to software, firmware, hardware, and any combination of these elements for performing the associated functions described herein. Additionally, for purposes of discussion, the various modules are described as discrete modules; however, it will be apparent to those of ordinary skill in the art that two or more modules can be combined to form a single module that performs the associated functions in accordance with embodiments of the present disclosure.

[0070] Various modifications to the embodiments described in this disclosure will be apparent to those skilled in the art, and the general principles defined herein can be applied to other embodiments without departing from the scope of the disclosure. Thus, the disclosure is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the novel features and principles disclosed herein, as recited in the claims.

Claims

1. A method for scheduling uplink (UL) data transmission performed by a wireless communication node, comprising: Transmit a first downlink control message to a wireless communication device; Initiate a first channel access procedure for accessing a predetermined channel to receive scheduled UL data from the wireless communication device; Determine whether the first channel access procedure is successfully completed before a predetermined event; And When the first channel access procedure is completed before the predetermined event, transmit a notification message to the wireless communication device to notify the wireless communication device that the wireless communication node has successfully completed the first channel access procedure, wherein the notification message triggers the wireless communication device to transmit the scheduled UL data on the predetermined channel based on a specified time corresponding to second timing information provided by the wireless communication node; wherein the predetermined event includes that the wireless communication device successfully completes a second channel access procedure for the predetermined channel and transmits the scheduled UL data to the wireless communication node based on first timing information provided by the wireless communication node.

2. The method according to claim 1, wherein, The predetermined event includes the expiration of a predetermined timer.

3. The method according to claim 2, wherein, The predetermined timer includes one of the following: a predefined value, a value configured by radio resource control (RRC) information, and a value included in the first downlink control message.

4. The method according to claim 1, wherein, The first downlink control message includes: First timing information, when the first channel access procedure is not successfully completed before the predetermined event, the wireless communication device uses the first timing information to transmit the scheduled UL data; and Second timing information, when the first channel access procedure is successfully completed before the predetermined event, the wireless communication device uses the second timing information to transmit the scheduled UL data.

5. The method according to claim 4, wherein, The second timing information includes: A first part, configured to indicate a time value, the time value indicating when the first downlink control message will no longer be valid, and after the time value, the wireless communication device should discard the UL data; and A second part, configured to indicate an offset value relative to the time when the notification message is transmitted, wherein the offset value notifies the wireless communication device when to transmit the scheduled UL data on the predetermined channel before the time value expires.

6. The method according to claim 1, further comprising: When the first channel access procedure is successfully completed before the predetermined event, transmit a second downlink control message to the wireless communication device, wherein the second downlink control message includes: An offset value relative to the time when the notification message is transmitted, wherein the offset value notifies the wireless communication device when to transmit the scheduled UL data on the predetermined channel, wherein the specified time includes the offset value, and wherein the first downlink control message includes timing information, when the wireless communication device successfully completes a second channel access procedure before the wireless communication node successfully completes the first channel access procedure, the wireless communication device uses the timing information to transmit the scheduled UL data.

7. The method according to claim 1, wherein, The notification message triggers the wireless communication device to transmit UL data on a plurality of UL channels including the predetermined UL channel respectively based on a plurality of timings including the specified time provided by the wireless communication node, wherein the UL data is previously stored by the wireless communication device for transmission on the plurality of UL channels.

8. The method according to claim 7, wherein, The plurality of timings corresponding to the plurality of UL channels are based on at least one of the following: the previously scheduled transmission order of each of the plurality of UL channels, the number of hybrid automatic repeat request (HARQ) processes, the minimum control channel element (CCE) index of each UL channel, and the starting position in the frequency domain.

9. A method for scheduling uplink (UL) data transmission performed by a wireless communication device, comprising: Receive a first downlink control message from a wireless communication node; Initiate a first channel access procedure for accessing a predetermined channel to transmit scheduled UL data; Determine whether the first channel access procedure is successfully completed before a predetermined event; When the first channel access procedure is completed before the predetermined event, transmit the scheduled UL data according to the first timing information included in the first downlink control message; And When the first channel access procedure is not completed before the predetermined event, transmit the scheduled UL data according to the second timing information provided by the wireless communication node; Wherein, the predetermined event includes: The wireless communication node successfully completes a second channel access procedure for the predetermined channel and transmits a notification message to the wireless communication device, the notification message notifying the wireless communication device that the wireless communication node has successfully completed the second channel access procedure, Wherein, the notification message triggers the wireless communication device to transmit the scheduled UL data on the predetermined channel based on the specified time corresponding to the second timing information provided by the wireless communication node.

10. The method according to claim 9, wherein, The predetermined event includes the expiration of a predetermined timer.

11. The method according to claim 10, wherein The predetermined timer includes one of the following: a predefined value, a value configured by radio resource control (RRC) information, and a value included in the first downlink control message.

12. The method according to claim 9, wherein The first downlink control message includes: First timing information, when the first channel access procedure is successfully completed before the predetermined event, the wireless communication device uses the first timing information to transmit the scheduled UL data; and Second timing information, when the first channel access procedure is not successfully completed before the predetermined event, the wireless communication device uses the second timing information to transmit the scheduled UL data.

13. The method according to claim 12, wherein The second timing information includes: A first part configured to indicate a time value, the time value indicating when the first downlink control message will no longer be valid, and after the time value, the wireless communication device should discard the scheduled UL data; and A second part is configured to indicate an offset value relative to the time when the notification message is transmitted from the wireless communication node to the wireless communication device, where the notification message notifies the wireless communication device that the wireless communication node has successfully completed a second channel access procedure, and where the offset value notifies the wireless communication device when to transmit the scheduled UL data on the predetermined channel before the expiration of the time value.

14. The method according to claim 9, further comprising: Receive a second downlink control message from the wireless communication node when the first channel access procedure is not successfully completed before the predetermined event; And When the first channel access procedure is successfully completed before the predetermined event, transmit the scheduled UL data based on the timing information included in the first downlink control message.

15. The method according to claim 14, wherein The second downlink control message includes: An offset value relative to the time when the second downlink control message is transmitted, where the offset value notifies the wireless communication device when to transmit the scheduled UL data on the predetermined channel.

16. The method according to claim 15, wherein The second downlink control message triggers the wireless communication device to transmit UL data on a plurality of UL channels including the predetermined channel respectively based on a plurality of timings including the specified time provided by the wireless communication node, where the UL data is previously stored by the wireless communication device for transmission on the plurality of UL channels.

17. The method according to claim 16, wherein The plurality of timings corresponding to the plurality of UL channels are based on at least one of the following: the previously scheduled transmission order of each of the plurality of UL channels, the number of hybrid automatic repeat request (HARQ) processes, the minimum control channel element (CCE) index of each UL channel, and the starting position in the frequency domain.

18. A non - transitory computer - readable storage medium, wherein The non-transitory computer-readable storage medium stores computer-executable instructions that, when executed, cause the method according to any one of claims 1 to 17 to be executed.

19. A wireless communication node, comprising: A transceiver configured to transmit a first downlink control message to a wireless communication device; And At least one processor configured to: Initiate a first channel access procedure for accessing a predetermined channel to receive scheduled UL data from the wireless communication device; And Determine whether the first channel access procedure is successfully completed before a predetermined event, where when the first channel access procedure is completed before the predetermined event, the transceiver is further configured to transmit a notification message to the wireless communication device to notify the wireless communication device that the wireless communication node has successfully completed the first channel access procedure, and where the notification message triggers the wireless communication device to transmit the scheduled UL data on the predetermined channel based on the specified time corresponding to the second timing information provided by the wireless communication node; where the predetermined event includes the wireless communication device successfully completing a second channel access procedure for the predetermined channel and transmitting the scheduled UL data to the wireless communication node based on the first timing information provided by the wireless communication node.

20. The wireless communication node according to claim 19, wherein The predetermined event includes the expiration of a predetermined timer.

21. The wireless communication node according to claim 20, wherein The predetermined timer includes one of the following: a predefined value, a value configured by radio resource control (RRC) information, and a value included in the first downlink control message.

22. The wireless communication node according to claim 19, wherein The first downlink control message includes first timing information and second timing information. When the first channel access procedure is not successfully completed before the predetermined event, the wireless communication device uses the first timing information to transmit the scheduled UL data. When the first channel access procedure is successfully completed before the predetermined event, the wireless communication device uses the second timing information to transmit the scheduled UL data, where the specified time includes the second timing information.

23. The wireless communication node according to claim 22, wherein The second timing information includes: A first part configured to indicate a time value that indicates when the first downlink control message will no longer be valid, and after the time value, the wireless communication device should discard the UL data; and A second part configured to indicate an offset value relative to the time when the notification message is transmitted, where the offset value notifies the wireless communication device when to transmit the scheduled UL data on the predetermined channel before the time value expires.

24. The wireless communication node according to claim 19, wherein: When the first channel access procedure is successfully completed before the predetermined event, the transceiver is further configured to transmit a second downlink control message to the wireless communication device, where the second downlink control message includes: An offset value relative to the time when the notification message is transmitted, where the offset value notifies the wireless communication device when to transmit the scheduled UL data on the predetermined channel, where the specified time includes the offset value, and where the first downlink control message includes timing information, and when the wireless communication device successfully completes a second channel access procedure before successfully completing the first channel access procedure at the wireless communication node, the wireless communication device uses the timing information to transmit the scheduled UL data.

25. The wireless communication node according to claim 19, wherein, The notification message triggers the wireless communication device to transmit UL data on a plurality of UL channels including the predetermined UL channel based on a plurality of timings including the specified time provided by the wireless communication node, where the UL data is previously stored by the wireless communication device for transmission on the plurality of UL channels.

26. The wireless communication node according to claim 25, wherein, The plurality of timings corresponding to the plurality of UL channels are based on at least one of the following: the previous scheduled transmission order of each of the plurality of UL channels, the number of hybrid automatic repeat request (HARQ) processes, the minimum control channel element (CCE) index of each UL channel, and the starting position in the frequency domain.

27. A wireless communication device, comprising: A transceiver configured to receive a first downlink control message from a wireless communication node; and At least one processor configured to: Initiate a first channel access procedure for accessing a predetermined channel to transmit scheduled UL data; and Determine whether the first channel access procedure is successfully completed before a predetermined event, Wherein, when the first channel access procedure is completed before the predetermined event, the transceiver is further configured to transmit the scheduled UL data according to the first timing information included in the first downlink control message; and Wherein, when the first channel access procedure is not completed before the predetermined event, the transceiver is further configured to transmit the scheduled UL data according to the second timing information provided by the wireless communication node; Wherein, the predetermined event includes: The wireless communication node successfully completes a second channel access procedure for the predetermined channel and transmits a notification message to the wireless communication device, the notification message notifying the wireless communication device that the wireless communication node has successfully completed the second channel access procedure, Wherein, the notification message triggers the wireless communication device to transmit the scheduled UL data on the predetermined channel based on a specified time corresponding to the second timing information provided by the wireless communication node.

28. The wireless communication device according to claim 27, wherein, The predetermined event includes the expiration of a predetermined timer.

29. The wireless communication device according to claim 28, wherein, The predetermined timer includes one of the following: a predefined value, a value configured by radio resource control (RRC) information, and a value included in the first downlink control message.

30. The wireless communication device according to claim 27, wherein, The first downlink control message includes: First timing information, when the first channel access procedure is successfully completed before the predetermined event, the wireless communication device uses the first timing information to transmit the scheduled UL data; and Second timing information, when the first channel access procedure is not successfully completed before the predetermined event, the wireless communication device uses the second timing information to transmit the scheduled UL data.

31. The wireless communication device according to claim 30, wherein, The second timing information includes: A first part, configured to indicate a time value, the time value indicating when the first downlink control message will no longer be valid, and after the time value, the wireless communication device should discard the scheduled UL data; and A second part, configured to indicate an offset value relative to the time when the notification message is transmitted from the wireless communication node to the wireless communication device, Wherein, the notification message notifies the wireless communication device that the wireless communication node has successfully completed the second channel access procedure, and wherein, the offset value notifies the wireless communication device when to transmit the scheduled UL data on the predetermined channel before the time value expires.

32. The wireless communication device according to claim 27, wherein: When the first channel access procedure is not successfully completed before the predetermined event, the transceiver is further configured to receive a second downlink control message from the wireless communication node; And When the first channel access procedure is successfully completed before the predetermined event, the transceiver is further configured to transmit the scheduled UL data based on the timing information included in the first downlink control message.

33. The wireless communication device according to claim 32, wherein, The second downlink control message includes: An offset value relative to the time when the second downlink control message is transmitted, wherein, the offset value notifies the wireless communication device when to transmit the scheduled UL data on the predetermined channel.

34. The wireless communication device according to claim 33, wherein, The second downlink control message triggers the wireless communication device to transmit UL data on a plurality of UL channels including the predetermined channel respectively based on a plurality of timings including the specified time provided by the wireless communication node, wherein the UL data is previously stored by the wireless communication device for transmission on the plurality of UL channels.

35. The wireless communication device according to claim 34, wherein, The plurality of timings corresponding to the plurality of UL channels are based on at least one of the following: the previously scheduled transmission order of each of the plurality of UL channels, the number of hybrid automatic repeat request (HARQ) processes, the minimum control channel element (CCE) index of each UL channel, and the starting position in the frequency domain.

36. The wireless communication device according to claim 27, wherein, The predetermined channel includes a physical uplink shared channel (PUSCH).

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