System and method for scheduling uplink transmission allocations

Abstract

A user equipment (UE) that schedules uplink transmission allocations via a shared carrier utilizing a base station that communicates with the user equipment receives from the base station a configuration indicating (i) a first channel access procedure to be performed by the user equipment before sending an uplink transmission and (ii) at least one timing (1602) at which the user equipment is to send an uplink transmission; receives from the base station via the shared carrier a signal indicating that the shared carrier is available for at least a portion of a transmission time period of the base station (1604); and performs the first channel access procedure or the second channel access procedure (1606) before sending an uplink transmission based at least in part on whether the timing is within the transmission time period.

Description

Technical Field

[0001] The present disclosure relates to wireless communications and, more particularly, to scheduling the transmission of control channel information in an unlicensed or otherwise shared spectrum. Background Art

[0002] This background description is intended to generally present the context of the present disclosure. The work of the inventors currently mentioned within the scope of the description in this background section, as well as the aspects of the description that do not qualify as prior art at the time of filing the application, are neither explicitly nor implicitly admitted as prior art against the present disclosure.

[0003] Some wireless communication networks allow compatible devices to share unlicensed carriers with other radio access technologies. In such cases, in order to avoid unfair use of the shared medium, devices operating in the unlicensed carrier typically need to perform a channel access procedure before transmitting a message. Specifically, the device may need to listen to other communications (i.e., detect energy) on the unlicensed carrier before transmitting information using the unlicensed carrier, thereby reducing or eliminating interference with communications of other networks / devices.

[0004] The Third Generation Partnership Project (3GPP) specifications for fifth generation (5G) radio access (“NR”) networks, and specifically 3GPP TS 38.899 v16.0.0 (addressing the use of unlicensed carriers by 5G NR devices in a study item commonly referred to as “NR-U”), attempt to maintain compatibility with other radio access technologies (e.g., (IEEE 802.11)). This restriction on the use of unlicensed carriers can be problematic for communications that would otherwise be synchronized or tightly scheduled. For example, in NR-U, a base station (e.g., a gNB) must perform a successful LBT procedure to establish a channel occupancy time (COT) before using an unlicensed carrier. If the UE determines that a timing configured by the base station is within the COT established by the base station, the UE must also perform a successful LBT procedure to send an uplink transmission to the base station using resources at that timing. Unless the UE is aware of the COT, the UE is not authorized to transmit by using resources at that timing while the COT is in progress.

[0005] However, the 3GPP specification does not address the scenario where the base station provides a COT indication to a UE in a connected state while the UE is still performing an LBT procedure or before the UE has initiated the LBT procedure. If the UE detects energy on an unlicensed carrier while performing the LBT procedure, the UE may not be able to successfully complete the LBT procedure. Therefore, even if the UE receives an indication of COT, the UE is not authorized to send uplink transmissions at that time while the COT is in progress. Alternatively, if the UE continues to perform the LBT procedure after the COT, the UE is not authorized to successfully complete the LBT procedure. Therefore, even if the UE receives an indication of COT, the UE is not authorized to send uplink transmissions at a time after the COT.

[0006] In addition, if the UE is in an idle state (e.g., RRC_IDLE) or an inactive state (e.g., RRC_INACTIVE), the 3GPP specification does not specify any way in which the base station can indicate COT to the UE. The UE must successfully complete the LBT procedure on the unlicensed carrier before performing a random access procedure with the base station, but if the UE continues to detect energy on the unlicensed carrier while performing the LBT procedure or before the UE has initiated the LBT procedure, the UE may not be able to successfully complete the LBT procedure before this opportunity. Therefore, the UE cannot send a preamble at this opportunity to perform a random access procedure. Summary of the invention

[0007] The base station (e.g., gNB) of the present disclosure communicates with a UE and accesses a shared carrier using a channel access procedure (e.g., LBT). The base station configures the UE to monitor a control channel. Specifically, the base station provides a configuration to the UE in a downlink transmission, the configuration including (i) at least a first channel access procedure (e.g., Class 4 LBT) to be performed by the UE before sending an uplink transmission to the base station and (ii) a timing for the UE to send an uplink transmission. Each "timing" may represent a time or time window at which the base station is able (i.e., according to the specification of the wireless communication network) but does not necessarily send control channel information to the UE. The configuration may include a time distribution of one timing or timings that are repeated once per time unit, where the time unit is fixed and may have any suitable length or duration (e.g., a time slot, a group of N consecutive or non-consecutive time slots, a subframe, etc.), depending on the implementation.

[0008] As described above, the base station performs a channel access procedure to gain access to the shared carrier. When the channel access procedure is successful, the base station obtains or establishes a transmission time period (e.g., COT) during which the shared carrier is available for use by the base station, and thereby obtains authorization for the channel. The base station then provides a signal indicating at least a portion of the COT to the UE via the shared carrier, regardless of the UE's radio resource control (RRC) state (e.g., RRC_CONNECTED, RRC_INACTIVE, RRC_IDLE). In various embodiments, the base station may send a signal to the UE indicating that the COT has begun, or a signal indicating the structure of the COT (e.g., COT length or duration) to notify the UE of the COT.

[0009] In some embodiments, the base station configures the UE (e.g., via one or more radio resource control (RRC) messages, one or more medium access control (MAC) control elements, one or more downlink control information (DCI), etc.) to perform a first channel access procedure or a different channel access procedure (i.e., a second channel access procedure) based at least in part on whether the opportunity is within the COT. Prior to receiving a signal indicating at least a portion of the COT from the base station, the UE performs the first channel access procedure before the start of the COT. Upon receiving a signal indicating at least a portion of the COT from the base station, if the UE determines that the opportunity is not within the COT, the UE selectively performs the first channel access procedure.

[0010] If the UE determines that the timing is within the COT, the UE selectively performs a second channel access procedure (e.g., Class 2 LBT) that requires the UE to monitor the unlicensed carrier for a shorter duration than the duration required to perform the first channel access procedure. Due to the shorter duration, the UE can increase the likelihood that it will successfully complete the second channel access procedure before the timing. Alternatively, in some embodiments, the UE may selectively perform the first channel access procedure in consideration of fair coexistence of other compatible devices sharing the unlicensed carrier configured to perform the corresponding first channel access procedure. Otherwise, if the UE is configured to perform the second channel access procedure more frequently, other compatible devices may unfairly detect energy from the UE and fail to complete their respective first channel access procedures.

[0011] An example embodiment of these techniques is a method for scheduling uplink transmission allocations through a shared carrier using a base station in communication with a user equipment. The method can be implemented in a user equipment using processing hardware and includes: receiving a configuration from the base station indicating (i) a first channel access procedure to be performed by the user equipment before sending an uplink transmission and (ii) at least one opportunity for the user equipment to send an uplink transmission; receiving a signal from the base station through the shared carrier indicating at least a portion of a transmission time period that the shared carrier can be used for the base station when the user equipment is in a connected state, an idle state, or an inactive state of a protocol for controlling radio resources; and performing the first channel access procedure or the second channel access procedure before sending the uplink transmission based at least in part on whether the opportunity is within the transmission time period.

[0012] Another example embodiment of the techniques is a user device including processing hardware and configured to perform the above methods.

[0013] Another example embodiment of these techniques is a method for providing control channel information to a user equipment communicating with a base station via a shared carrier. The method can be implemented in a base station using processing hardware and includes: sending to the user equipment an indication of (i) a first channel access procedure that the user equipment performs before sending an uplink transmission and (ii) at least one opportunity for the user equipment to send an uplink transmission; using the channel access procedure to determine that the shared carrier is available to the base station within a transmission time period; and sending to the user equipment a signal indicating at least a portion of the transmission time period that the shared carrier is available to the base station, so that the user equipment performs the first channel access procedure or the second channel access procedure before sending the uplink transmission based at least in part on whether the opportunity is within the transmission time period.

[0014] Another example embodiment of the techniques is a base station comprising processing hardware and configured to perform the above method. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a block diagram of an example wireless communication network that implements the scheduling and channel monitoring techniques of the present disclosure;

[0016] Figure 2A is an example message flow diagram of a UE performing a second channel access procedure when the base station (i) establishes a COT when the UE has initiated a first channel access procedure and (ii) provides the UE with an opportunity within the COT when the UE can send uplink transmissions to the base station.

[0017] Figure 2Bis an example message flow diagram of a UE completing a first channel access procedure when the base station (i) establishes a COT when the UE has initiated the first channel access procedure and (ii) provides the UE with an opportunity within the COT when the UE can send uplink transmissions to the base station.

[0018] Figure 3 is an example message flow diagram in which the UE performs a second channel access procedure or completes a first channel access procedure based at least in part on an uplink transmission type when the base station (i) establishes a COT when the UE has initiated a first channel access procedure and (ii) provides the UE with an opportunity within the COT when the UE can send an uplink transmission to the base station.

[0019] Figure 4 is an example message flow diagram of a UE performing a first channel access procedure and a second channel access procedure in parallel when the base station (i) establishes a COT when the UE has initiated a first channel access procedure and (ii) provides the UE with an opportunity within the COT when the UE can send an uplink transmission to the base station.

[0020] Figure 5A is an example message flow diagram of a UE performing a second channel access procedure when the base station (i) establishes a COT before the UE initiates the second channel access procedure and (ii) provides the UE with opportunities within the COT when the UE can send uplink transmissions to the base station.

[0021] Figure 5B is an example message flow diagram of a UE performing a first channel access procedure when a base station (i) establishes a COT before the UE initiates the first channel access procedure and (ii) provides the UE with opportunities within the COT when the UE can send uplink transmissions to the base station.

[0022] Figure 6 is an example message flow diagram of a UE performing a first channel access procedure or a second channel access procedure based at least in part on an uplink transmission type when the base station (i) establishes a COT before the UE initiates a channel access procedure and (ii) provides the UE with an opportunity within the COT when the UE can send an uplink transmission to the base station.

[0023] Fig. 7A is an example message flow diagram of a UE performing a second channel access procedure when the base station (i) establishes a COT when the UE has initiated a RACH procedure and a first channel access procedure and (ii) provides the UE with an opportunity within the COT when the UE can send an uplink transmission to the base station.

[0024] Figure 7Bis an example message flow diagram of a UE completing a first channel access procedure when the base station (i) establishes a COT when the UE has initiated a RACH procedure and a first channel access procedure and (ii) provides the UE with an opportunity within the COT when the UE can send an uplink transmission to the base station.

[0025] Figure 8 is an example message flow diagram of a UE performing a second channel access procedure or completing a first channel access procedure based at least in part on the purpose of initiating a RACH procedure when the base station (i) establishes a COT when the UE has initiated a RACH procedure and a first channel access procedure and (ii) provides the UE with an opportunity within the COT when the UE can send an uplink transmission to the base station.

[0026] Fig. 9 is an example message flow diagram of a UE performing a first channel access procedure and a second channel access procedure in parallel when the base station (i) establishes a COT when the UE has initiated a RACH procedure and a first channel access procedure and (ii) provides the UE with an opportunity within the COT when the UE can send an uplink transmission to the base station.

[0027] Fig. 10A is an example message flow diagram of a UE performing a second channel access procedure when the base station (i) establishes a COT before the UE initiates the second channel access procedure but after the UE initiates a RACH procedure and (ii) provides the UE with an opportunity within the COT when the UE can send an uplink transmission to the base station.

[0028] Fig. 10B is an example message flow diagram of a UE performing a first channel access procedure when the base station (i) establishes a COT before the UE initiates the first channel access procedure but after the UE initiates a RACH procedure and (ii) provides the UE with an opportunity within the COT when the UE can send an uplink transmission to the base station.

[0029] Fig.11 An example message flow diagram of a UE performing a first channel access procedure or a second channel access procedure based at least in part on the purpose of initiating a RACH procedure when the base station (i) establishes a COT before the UE initiates a channel access procedure but after the UE initiates a RACH procedure and (ii) provides the UE with an opportunity within the COT at which the UE can send an uplink transmission to the base station.

[0030] Fig.12 is an example message flow diagram of a UE performing a first channel access procedure when the base station (i) establishes a COT when the UE has initiated the first channel access procedure and (ii) provides the UE with an opportunity outside the COT when the UE can send uplink transmissions to the base station.

[0031] Fig.13is an example message flow diagram of a UE performing a first channel access procedure when the base station (i) establishes a COT when the UE has initiated a RACH procedure and a first channel access procedure and (ii) provides the UE with an opportunity outside the COT when the UE can send an uplink transmission to the base station.

[0032] Fig.14 is an example message flow diagram of a UE performing a first channel access procedure when the base station (i) establishes a COT before the UE initiates the first channel access procedure and (ii) provides the UE with an opportunity outside the COT when the UE can send uplink transmissions to the base station.

[0033] Fig.15 is an example message flow diagram of a UE performing a first channel access procedure when the base station (i) establishes a COT before the UE initiates the first channel access procedure but after the UE initiates a RACH procedure and (ii) provides the UE with an opportunity outside the COT when the UE can send uplink transmissions to the base station.

[0034] Fig.16 is a flow chart of an example method for scheduling uplink transmission allocations, which may be performed in Figure 1 implemented in a user device; and

[0035] Fig.17 is a flow chart of an example method for providing control channel information to a user equipment, which method may be Figure 1 is implemented in the base station. DETAILED DESCRIPTION

[0036] Using the techniques of the present disclosure, a communication device such as a UE monitors a control channel on a shared carrier in a manner to ensure that a channel access process is completed before starting transmission (e.g., requiring the base station to configure the UE's uplink transmission via a control channel) upon receiving a COT indication from a base station. As the term is used herein, a "carrier" can be any type of spectrum or frequency band that corresponds to at least one channel in a given radio access network. In addition, as used herein, a "shared" carrier can be an unlicensed carrier shared by different radio access networks and / or technologies, or a carrier shared in some other manner and / or for some other reason (e.g., a carrier shared only between multiple devices of a single radio access network).

[0037] These techniques are discussed below primarily with reference to 5G NR technology, and more specifically, with reference to the operation of a 5G NR network on an unlicensed carrier (i.e., NR-U operation). However, the techniques of the present disclosure may be applied to other radio access technologies and / or other types of shared carriers (e.g., licensed bands shared by devices of a single radio access network). In the case of licensed bands, the following types of channel access procedures may or may not be performed.

[0038] First reference Figure 1 , the wireless communication network 100 includes a UE 102, where the UE 102 can be any suitable device capable of wireless communication (as further discussed below). The wireless communication network 100 also includes a base station 104 associated with an NR-U cell 106 and connected (directly or indirectly) to a 5G core network (5GC) 110. For example, the base station 104 can operate as a 5G Node B (gNB), a distributed unit gNB (gNB-DU), or an integrated access backhaul (IAB) node. Although Figure 1 Base station 104 is depicted as serving only cell 106, but it is understood that base station 104 may also cover Figure 1 In general, wireless communication network 100 may include any number of base stations, and each base station may cover one, two, three, or any other suitable number of cells.

[0039] 5G NR UEs (including UE 102) operating in cell 106 can utilize unlicensed carriers and portions of the radio spectrum that are exclusively allocated to the service provider operating base station 104 and 5GC 110. When exchanging data using the 5G NR air interface, UE 102 and base station 104 can share the unlicensed carrier with other devices of other radio access networks. For example, other UEs ( Figure 1 The UE (not shown) may be a subscriber of a service provider operating the base station 104 and the 5GC 110 and may be able to communicate with the base station 104 via an unlicensed carrier. Additionally or alternatively, other UEs utilizing an unlicensed carrier may communicate with base stations or network nodes other than the base station 104 using different radio access technologies. Figure 1 An example of such a scenario is depicted in which UE 102 and base station 104 coexist with access point (AP) 112. When operating in a wireless local area network (WLAN) in accordance with one of the IEEE 802.11 standards, AP 112 can utilize spectrum that includes or is contained in at least a portion of an unlicensed carrier. For example, AP 112 can be configured to communicate with one or more unlicensed carriers. Figure 1102 and base station 104. In some other embodiments and / or scenarios, UE 102 and base station 104 also or alternatively coexist with devices operating according to other radio access technologies. In yet another embodiment and / or scenario, base station 104 is not connected to 5GC 110 and can operate as an AP (e.g., similar to AP 112). Thus, for example, wireless communication network 100 can omit 5GC 110, or use 5GC 110 only in certain scenarios.

[0040] UE 102 is equipped with processing hardware 120, wherein the processing hardware 120 may include one or more general-purpose processors (e.g., CPUs) and non-transitory computer-readable memory storing instructions that the one or more general-purpose processors can execute. Additionally or alternatively, for example, the processing hardware 120 may include a dedicated processing unit, such as a wireless communication chipset. The processing hardware 120 includes a channel access module 122, a control channel monitoring module 124, and the memory of the processing hardware 120 stores a monitoring configuration 126. The channel access module 122 and the control channel monitoring module 124 may be implemented using any suitable combination of hardware, software, and / or firmware. Typically, the channel access module 122 may be configured to perform one or more types of channel access procedures (e.g., Class 1 LBT, Class 2 LBT, Class 3 LBT, Class 4 LBT), and the control channel monitoring module 124 may be configured to monitor the timing of the UE 102 to send an uplink transmission on the control channel. In one example implementation, the channel access module 122 and / or the control channel monitoring module 124 include a set of instructions defining the corresponding components of the operating system of the UE 102, and one or more CPUs of the processing hardware 120 execute these instructions to perform the channel access process and the channel monitoring functions. In another implementation, the channel access module 122 and / or the control channel monitoring module 124 are implemented using firmware as part of a wireless communication chipset.

[0041] In operation, the control channel monitoring module 124 monitors the control channel according to the monitoring configuration 126 provided by the gNB 104 to the UE 102. In some embodiments and / or scenarios, the control channel monitoring module 124 monitors the PDCCH. However, in other embodiments and / or scenarios, the control channel monitoring module 124 monitors the group common PDCCH (GC-PDCCH). The monitoring configuration 126 may indicate a channel access procedure (e.g., an LBT procedure) that the channel access module 122 may perform before sending an uplink transmission to the base station 104, and at least one resource (i.e., a time-frequency resource) at an opportunity when the UE 102 is to send an uplink transmission. Each "opportunity" may represent a time or time window at which the gNB 104 may (i.e., according to the specifications of the wireless communication network) but does not necessarily send control channel information to the UE 102. The base station 104 can configure the UE 102 with a time distribution of opportunities that repeat once per time unit, where the time unit is fixed and can have any suitable length or duration (e.g., one time slot, a group of N consecutive or non-consecutive time slots, one subframe, etc.), depending on the implementation. The base station 104 is equipped with processing hardware 130, where the processing hardware 130 can include one or more general-purpose processors (e.g., CPUs) and non-transitory computer-readable memory storing instructions that the one or more general-purpose processors can execute. Additionally or alternatively, the processing hardware 130 can include a dedicated processing unit, such as, for example, a wireless communication chipset. Figure 1 The processing hardware 130 in the example implementation of includes a channel access module 132 , a resource allocation unit 134 , and a COT signal controller 136 .

[0042] The channel access module 132 performs a channel access procedure, such as an LBT procedure, to access the shared carrier in the NR-U cell 106. When the channel access procedure is successful, the channel access module 132 determines that the gNB 104 has obtained or established a COT, and therefore can transmit various signals during the COT. The resource allocation unit 134 allocates at least one resource at the above-mentioned timing to the UE 102, and provides an indication of a channel access procedure (e.g., an LBT procedure) that the UE 102 can perform before sending an uplink transmission to the base station 104. The COT signal controller 136 determines when the gNB 104 sends an indication to the UE 102 that the gNB 104 has obtained a COT. In some embodiments, the COT signal controller 136 also determines which format the gNB 104 should use for the indication. The example functions of components 132, 134, and 136 are discussed in more detail below with reference to various example scenarios and monitoring modes. As further discussed below, based at least in part on whether the timing is within the COT, UE 102 may selectively perform a channel access procedure indicated by gNB 104, or another channel access procedure known to access module 122 of UE 102.

[0043] For simplicity, Figure 1 Various components of the UE 102 and the base station 104 are not depicted. In addition to the above components, for example, the UE 102 and the base station 104 include respective transceivers, which include various hardware, firmware and / or software components configured to send and receive wireless signals. The processing hardware 120 and the processing hardware 130 can send commands and exchange information with the respective transceivers as needed to perform various connection establishment procedures, perform various RRC or mobility management (MM), or communicate with other network elements, etc.

[0044] Figures 2A to 15Several example configurations are illustrated according to which the gNB 104 may provide a COT indication to the UE 102, in response to which the UE 102 may successfully perform a channel access procedure prior to sending an uplink transmission to the gNB 104. In general, the UE 102 monitors opportunities for at least two respective time intervals: before the gNB 104 is able to access a shared carrier and after the UE 102 receives an indication that the gNB 104 has been able to access the shared carrier. The UE 102 also selectively performs one of at least two types of channel access procedures to enable sending an uplink transmission to the gNB 104 in anticipation of the gNB 104 being able to access the shared carrier and providing the UE 102 with an indication that the gNB 104 has been able to access the shared carrier (e.g., a COT indication). Typically, the UE 102 requires less time to complete one of the two channel access procedures (e.g., Type 2 LBT) than the other (e.g., Type 4 LBT). In some embodiments, if UE 102 receives a COT indication that gNB 104 has been able to access the shared carrier, and the timing of the time interval is within the COT, then instead of the channel access procedure indicated by gNB 104 (i.e., the first channel access procedure), UE 102 may selectively perform a different channel access procedure (i.e., the second channel access procedure) that requires less time to complete than the first channel access procedure. In other embodiments, UE 102 may selectively perform the first channel access procedure in consideration of fair coexistence with other compatible devices sharing a carrier configured to perform the first channel access procedure.

[0045] Now turn to Figure 2A , Figure 2B , Figure 3 and Figure 4 , which generally illustrate example message flow diagrams of a UE performing a channel access procedure when a base station (i) establishes a COT when the UE has initiated the same or a different channel access procedure and (ii) provides the UE with an opportunity within the COT when the UE can send an uplink transmission to the base station.

[0046] First reference Figure 2AIn example scenario 200, UE 102 is in a connected state (e.g., NR-RRC CONNECTED) with gNB 104 for a RAT protocol for controlling radio resources, and gNB 104 typically configures UE 102 to monitor a control channel (e.g., PDCCH), such as via a configuration in a downlink transmission (e.g., physical downlink control channel (PDCCH), physical downlink shared channel (PDSCH), channel state information reference signal (CSI-RS), synchronization signal block (SSB)), an RRC message on PDSCH (e.g., RRCReconfiguration message), or a first DCI on PDCCH. Specifically, the gNB 104 determines 202 to configure an uplink grant for the UE 102, the uplink grant indicating that the UE 102 may send an uplink transmission on a specific physical uplink shared channel (PUSCH) using resources at a specific timing (e.g., a PDCCH timing), where the timing may occur at a time slot, a group of N consecutive or non-consecutive time slots, a subframe, etc. The gNB 104 also determines 202 a specific channel access procedure (e.g., a first channel access procedure) that the UE 102 should use before sending an uplink transmission at the timing. The gNB 104 indicates 204 the channel access procedure and timing to the UE 102, such as by sending one or more configuration messages with implicit or explicit indicators identifying the channel access procedure to the UE 102 via a shared carrier, or by sending a DCI at the timing, wherein the DCI may include an uplink grant indicating that the UE 102 may send an uplink transmission on the specific physical uplink shared channel (PUSCH).

[0047] Continue to refer Figure 2A, upon receiving (e.g., using the control channel monitoring module 124) a configuration message (e.g., monitoring configuration 126), the UE 102 initiates 206 a first channel access procedure (e.g., using the channel access module 122). When the UE 102 performs the first channel access procedure, the gNB 104 is able to access the shared carrier to establish 208 a COT. After the gNB 104 establishes the COT (e.g., using the channel access module 132), the gNB 104 indicates to the UE 102 that the COT has begun (e.g., using the resource allocation unit 134). To indicate to the UE 102 that the COT has begun, the gNB 104 may send 212 a signal (e.g., any suitable signal generated by the COT signal controller 136) that generally indicates that the COT has begun (i.e., a COT indication). The COT indication may include a structure of the COT (e.g., a duration or length 210 of the COT). The gNB 104 may not include in the COT indication the first channel access procedure that the UE 102 should perform. In some embodiments, the gNB 104 indicates 212 the COT duration in a broadcast message. In yet other embodiments, the base station 104 includes the signal in a second DCI having a CRC scrambled by a radio network temporary identifier (RNTI) (e.g., a slot formation indicator RNTI (SFI-RNTI) or a COT-RNTI). The UE 102 may receive the RNTI in an RRCReconfiguration message from the gNB 104. In one embodiment, the UE 102 may descramble the CRC with the RNTI to obtain the second DCI, and then decode the second DCI to obtain the COT indication. In another embodiment, the UE 102 may calculate the CRC from the second DCI, scramble the UE-calculated CRC with the RNTI to obtain the second DCI, and then decode the second DCI to obtain the COT indication. The RRCReconfiguration message and / or the COT indication may include a slot format configuration.

[0048] In some embodiments, in response to such a COT indication, if the UE 102 determines that the opportunity is within the COT (e.g., length 210), the UE 102 terminates 214 the first channel access procedure and initiates 216 a second channel access procedure having a different type than the first channel access procedure on the unlicensed carrier frequency (e.g., using the channel access module 122). Due to the shorter duration required to perform the second channel access procedure, the UE 102 advantageously increases the likelihood that it will successfully complete the second channel access procedure before the opportunity. In this way, the UE 102 is likely to complete 218 the second channel access procedure and subsequently send 222 an uplink transmission to the gNB 104 at the opportunity (e.g., indicated by the gNB 104 in a configuration message). If the UE 102 performs the first channel access procedure as indicated by the gNB 104, the UE 102 may fail to complete the first channel access procedure before the opportunity, in which case the UE 102 will not be authorized to send an uplink transmission at the opportunity.

[0049] In other embodiments, the UE 102 may continue to perform and complete the first channel access procedure in response to the COT indication, in consideration of fair coexistence of other compatible devices sharing the unlicensed carrier configured to perform the corresponding first channel access procedure, such as Figure 2B As shown in event 220 of , and then sending 222 an uplink transmission to gNB 104 at this opportunity. That is, even if UE 102 determines that the opportunity is within the COT, UE 102 continues to perform the first type channel access process.

[0050] In some embodiments, the uplink transmission is a PUSCH transmission. UE 102 may send a medium access control (MAC) protocol data unit (PDU), a hybrid automatic repeat request (HARQ) acknowledgement (ACK), a HARQ negative acknowledgement (NACK), and / or channel state information (CSI) in a PUSCH transmission on the resources of the opportunity. In other embodiments, the uplink transmission is a physical uplink control channel (PUCCH) transmission. UE 102 may send a HARQ ACK, a HARQ NACK, and / or CSI in a PUCCH transmission on the resources of the opportunity. In a further embodiment, the uplink transmission includes a sounding reference signal (SRS), a random access (RA) preamble, or a message A (MsgA) (i.e., a RA preamble and a PUSCH transmission).

[0051] Reference now Figure 3 At the beginning of scenario 300, UE 102 is in a connected state with gNB 104. UE 102 and gNB 104 proceed to events 302, 304, 306, 308, and 312, similar to events 202, 204, 206, 208, and 212.

[0052] In response to receiving the COT indication, UE 102 performs a first channel access procedure or a second channel access procedure by determining 313 the type of the uplink transmission. If the uplink transmission is of the first type, UE 102 may terminate 314 the first channel access procedure, initiate 316 the second channel access procedure, and complete 318 the second channel access procedure, similar to events 214, 216, and 218. Otherwise, if the uplink transmission is of the second type, UE 102 may continue to perform and complete 320 the first channel access procedure, similar to event 220. In some embodiments, the first type may be PUSCH and the second type may be SRS, or vice versa. In other embodiments, the first type may be PUSCH and the second type may be PUCCH, or vice versa. In yet another embodiment, the first type may be PUCCH and the second type may be SRS, or vice versa.

[0053] In response to completing 318 the second channel access process or completing 320 the first channel access process, UE 102 sends 322 an uplink transmission to gNB 104 at this time, similar to event 222.

[0054] Reference now Figure 4 At the beginning of scenario 400, UE 102 is in a connected state with gNB 104. UE 102 and gNB 104 proceed to events 402, 404, 406, 408, and 412, similar to events 202, 204, 206, 208, and 212.

[0055] In response to receiving the COT indication, the UE 102 initiates 416 a second channel access procedure. Thus, the UE 102 performs the first channel access procedure and the second channel access procedure in parallel. In some embodiments, if the UE 102 completes the second channel access procedure while performing the first type of channel access procedure, the UE 102 may terminate the first channel access procedure. In other embodiments, if the UE 102 completes the second type of channel access procedure while performing the first type of channel access procedure, the UE 102 may continue to perform the first type of channel access procedure. In still other embodiments, if the UE 102 completes the first channel access procedure while performing the second channel access procedure, the UE 102 may terminate the second channel access procedure. In still other embodiments, if the UE 102 completes the first type of channel access procedure while performing the second channel access procedure, the UE 102 may continue to perform the second channel access procedure. Thus, the UE 102 completes 419 the first channel access procedure and / or the second channel access procedure.

[0056] In response to completing the first channel access process and / or the second channel access process, UE 102 sends 422 an uplink transmission to gNB 104 at this opportunity, similar to event 222.

[0057] Now turn to Figure 5A , Figure 5B and Figure 6 , which generally illustrate example message flow diagrams for a UE to perform a channel access procedure when a base station (i) establishes a COT before the UE initiates a channel access procedure and (ii) provides the UE with opportunities within the COT when the UE can send uplink transmissions to the base station.

[0058] Reference now Figure 5A , at the start of scenario 500, UE 102 is in a connected state with gNB 104. UE 102 and gNB 104 proceed to events 502 and 504, similar to events 202 and 204. In contrast to scenario 200, in which UE 102 initiates a first channel access procedure while gNB 104 establishes COT, and subsequently receives a COT indication from gNB 104 after initiating the first channel access procedure, after gNB 104 establishes 508 COT and after receiving 512 COT indication, similar to event 212, UE 102 of scenario 500 initiates 516 a second channel access procedure instead of the first channel access procedure, similar to event 216. Therefore, despite receiving 504 configuration indicating that UE 102 performs the first channel access procedure, UE 102 does not initiate the first channel access procedure at all.

[0059] Thus, it is possible for UE 102 to complete 518 the second channel access process and subsequently send 522 an uplink transmission to gNB 104 at that opportunity, similar to events 218 and 212.

[0060] In other embodiments, under fair coexistence considerations for other compatible devices sharing an unlicensed carrier configured to perform a corresponding first channel access procedure, UE 102 may initiate 507 a first channel access procedure after receiving 512 a COT indication, similar to event 212, and complete the first channel access procedure in response to the COT indication, such as Figure 5B As shown in event 520 of , and then sends 522 an uplink transmission to gNB 104 at this opportunity, similar to event 222. That is, even if UE 102 determines that the opportunity is within the COT, UE 102 continues to perform the first type channel access process.

[0061] In some other embodiments, Figure 5BAlternatively or in addition to determining that UE 102 has the configuration as shown in event 502, gNB 104 may determine 503 to configure a second uplink grant for UE 102, the second uplink grant indicating that UE 102 may send a second uplink transmission on a specific physical uplink shared channel (PUSCH) using second resources at a second opportunity (e.g., a second PDCCH opportunity), where the second opportunity may occur at a time slot, a group of N consecutive or non-consecutive time slots, a subframe, etc. gNB 104 also determines 503 another channel access procedure (e.g., a second channel access procedure) that UE 102 should use before sending the second uplink transmission at the second opportunity. The gNB 104 indicates 505 the second channel access procedure and the second timing to the UE 102, for example, by sending one or more second configuration messages to the UE 102 via the shared carrier, wherein the second configuration message carries an implicit or explicit indicator identifying the second channel access procedure, or by sending a second DCI at the second timing, wherein the second DCI may include an uplink grant indicating that the UE 102 may send a second uplink transmission on the second PUSCH, or by sending at the first timing. Other ways of indicating 504, 505 the configuration and the second configuration are contemplated, such as by a first RRC message and a second RRC message, respectively.

[0062] In response to receiving 512 the COT indication, if UE 102 determines that the second opportunity is within the COT, UE 102 initiates 509 a second channel access procedure having a different type from the first channel access procedure on the unlicensed carrier frequency, and completes 521 the second channel access procedure before sending 523 a second uplink transmission to gNB 104.

[0063] Reference now Figure 6 At the beginning of scenario 600, UE 102 is in a connected state with gNB 104. UE 102 and gNB 104 proceed to events 602, 604, 608, and 612, similar to events 502, 504, 508, and 512.

[0064] In response to receiving the COT indication, UE 102 performs a first channel access procedure or a second channel access procedure by determining 613 the type of the uplink transmission, similar to event 313. If the uplink transmission is of the first type, UE 102 may initiate 616 a second channel access procedure and complete 618 the second channel access procedure, similar to events 316 and 318. Otherwise, if the uplink transmission is of the second type, UE 102 initiates 607 a first channel access procedure and completes 620 the first channel access procedure, similar to event 320. In some embodiments, the first type may be PUSCH and the second type may be SRS, or vice versa. In other embodiments, the first type may be PUSCH and the second type may be PUCCH, or vice versa. In yet another embodiment, the first type may be PUCCH and the second type may be SRS, or vice versa.

[0065] In response to completing 618 the second channel access process or completing 620 the first channel access process, UE 102 sends 622 an uplink transmission to gNB 104 at this time, similar to event 322.

[0066] Now turn to Fig. 7A , Figure 7B , Figure 8 and Fig. 9 , these figures generally illustrate example message flow diagrams for a UE to perform a channel access procedure when a base station (i) establishes a COT when the UE has initiated a RACH procedure and the same or different channel access procedure and (ii) provides the UE with an opportunity within the COT when the UE can send an uplink transmission to the base station.

[0067] Reference now Fig. 7AAt the start of scenario 700, UE 102 is in an idle or inactive state (e.g., NR-RRC IDLE, NR-RRC INACTIVE) (i.e., disengaged state) with gNB 104, and gNB 104 typically determines 702 to configure UE 102 to initiate a random access channel (RACH) procedure, such as by broadcasting 704 information associated with the RACH procedure in system information (e.g., physical RACH (PRACH) timing and RA preamble) to UE 102 on a shared carrier. In some embodiments, the system information includes a first SIB and a second SIB, which respectively include RACH procedure related information and an RNTI. In other embodiments, the system information includes a SIB, wherein the SIB includes both the RACH procedure related information and the RNTI. In yet other embodiments, the system information includes a SIB, wherein the SIB includes an energy detection threshold for UE 102 to perform the first channel access procedure and / or the second channel access procedure. The gNB 104 also broadcasts 702 a specific channel access procedure (e.g., a first channel access procedure) that the UE 102 should use before sending the RA preamble at the PRACH opportunity. Thus, the gNB 104 indicates 704 the channel access procedure, the RA preamble, and the PRACH opportunity to the UE 102 by broadcasting system information.

[0068] Continue to refer Fig. 7A , in response to receiving the broadcasted system information, UE 102 selects a PRACH opportunity and a RA preamble to initiate 705 a RACH procedure. To ultimately send the RA preamble to gNB 104 at the PRACH opportunity, UE 102 initiates 706 a RACH procedure as a first channel access procedure, similar to event 206. When UE 102 performs the first channel access procedure, gNB 104 is able to access the shared carrier to establish 708 a COT, similar to event 208. After gNB 104 establishes the COT (e.g., using channel access module 132), gNB 104 indicates to UE 102 that the COT has begun. To indicate to UE 102 that the COT has begun, gNB 104 may send 712 a COT indication, similar to event 212. The COT indication may include a structure of the COT (e.g., a duration or length 210 of the COT).

[0069] In some embodiments, in response to such a COT indication, if the UE 102 determines that the PRACH opportunity is within the COT (e.g., length 210), the UE 102 terminates 714 the first channel access procedure and initiates 716 a second channel access procedure of a different type than the first channel access procedure on the unlicensed carrier frequency, similar to events 214 and 216. Due to the shorter duration required to perform the second channel access procedure, the UE 102 advantageously increases its likelihood of successfully completing the second channel access procedure before the PRACH opportunity. In this way, the UE 102 is likely to complete 718 the second channel access procedure, similar to event 218, and subsequently send 722 an RA preamble to the gNB 104 at a PRACH opportunity (e.g., indicated by the gNB 104 in broadcasted system information). If the UE 102 performs the first channel access procedure as indicated by the gNB 104, the UE 102 may fail to complete the first channel access procedure before the PRACH opportunity, in which case the UE 102 will not be authorized to send an RA preamble at the PRACH opportunity.

[0070] In other embodiments, the UE 102 may continue to perform and complete the first channel access procedure in response to the COT indication, under fair coexistence considerations for other compatible devices sharing the unlicensed carrier configured to perform the corresponding first channel access procedure, such as Figure 7B As shown in event 720 of , and then sending 722 a RA preamble code to gNB 104 at the PRACH opportunity. That is, even if UE 102 determines that the PRACH opportunity is within the COT, UE 102 continues to perform the first type channel access process.

[0071] Reference now Figure 8 At the beginning of scenario 800, UE 102 is in a detached state from gNB 104. UE 102 and gNB 104 proceed to events 802, 804, 805, 806, 808, and 812, similar to events 702, 704, 705, 706, 708, and 712.

[0072] In response to receiving the COT indication, the UE 102 performs a first channel access procedure or a second channel access procedure by determining 813 the purpose of the UE 102 initiating the RACH procedure. If the purpose is of the first type, the UE 102 may terminate 814 the first channel access procedure, initiate 816 the second channel access procedure, and complete 818 the second channel access procedure, similar to events 314, 316, and 318. Otherwise, if the purpose is of the second type, the UE 102 may continue to perform and complete 820 the first channel access procedure, similar to event 320. In some embodiments, the purpose of the first type may be to perform a 2-step RACH (i.e., the UE 102 sends a message A including a preamble and a PUSCH transmission), and the purpose of the second type may be to perform a 4-step RACH, or vice versa. In other embodiments, the first type may be to initiate an RRC connection establishment procedure (if the UE 102 is in an idle state) or an RRC connection recovery procedure (if the UE 102 is in an inactive state), and the purpose of the second type may be a request for on-demand system information, or vice versa. In yet another embodiment, the first type of purpose may be associated with a first RRC connection establishment cause (e.g., when making an emergency call or answering a mobile terminated call), and the second type of purpose may be associated with a second RRC connection establishment cause (e.g., sending mobile originated data), or vice versa. In some embodiments, the PUSCH radio resources used for PUSCH transmissions may be indicated by the gNB 104 in broadcasted system information. For example, the broadcasted system information may include a PUSCH configuration that configures the PUSCH radio resources. The PUSCH radio resources may consist of contiguous subcarriers and / or non-contiguous subcarriers. The gNB 104 may also indicate one or more PUSCH opportunities for PUSCH transmissions in the broadcasted system information. The UE 102 may send a PUSCH transmission on the PUSCH radio resources at the one or more PUSCH opportunities.

[0073] In response to completing 818 the second channel access process or completing 820 the first channel access process, UE 102 sends 822 a RA preamble code to gNB 104 at a RACH timing, similar to event 722.

[0074] Reference now Fig. 9 At the beginning of scenario 900, UE 102 is in a connected state or a disconnected state with gNB 104. UE 102 and gNB 104 proceed to events 902, 904, 905, 906, 908, and 912, similar to events 702, 704, 705, 706, 708, and 712.

[0075] In response to receiving the COT indication, UE 102 initiates 916 a second channel access procedure, similar to event 416. Therefore, UE 102 performs the first channel access procedure and the second channel access procedure in parallel. In some embodiments, if UE 102 completes the second channel access procedure while performing the first type of channel access procedure, UE 102 may terminate the first channel access procedure. In other embodiments, if UE 102 completes the second type of channel access procedure while performing the first type of channel access procedure, UE 102 may continue to perform the first type of channel access procedure. In still other embodiments, if UE 102 completes the first channel access procedure while performing the second channel access procedure, UE 102 may terminate the second channel access procedure. In still other embodiments, if UE 102 completes the first type of channel access procedure while performing the second channel access procedure, UE 102 may continue to perform the second channel access procedure. Therefore, UE 102 completes 919 the first channel access procedure and / or the second channel access procedure, similar to event 419.

[0076] In response to completing the first channel access procedure and / or the second channel access procedure, UE 102 sends 922 a RA preamble to gNB 104 at the opportunity, similar to event 722. If UE 102 completes the first channel access procedure and / or the second channel access procedure before the PRACH opportunity, and the RACH procedure is a 2-step RACH procedure, UE 102 may send a RA preamble and a PUSCH transmission associated with the RA preamble at the PRACH opportunity. In some embodiments, the PUSCH radio resources for PUSCH transmission may be indicated by gNB 104 in the broadcast system information. For example, the broadcast system information may include a PUSCH configuration that configures the PUSCH radio resources. The PUSCH radio resources may consist of continuous subcarriers and / or non-continuous subcarriers. gNB 104 may also indicate one or more PUSCH opportunities for PUSCH transmission in the broadcast system information. UE 102 may send a PUSCH transmission on the PUSCH radio resources at the one or more PUSCH opportunities.

[0077] Now turn to Fig. 10A , Fig. 10B and Fig.11 , which generally illustrate example message flow diagrams for a UE to perform a channel access procedure when a base station (i) establishes a COT before the UE initiates a channel access procedure but after the UE initiates a RACH procedure and (ii) provides the UE with an opportunity within the COT when the UE can send an uplink transmission to the base station.

[0078] Reference now Fig. 10A, at the beginning of scenario 1000, UE 102 is in a detached state from gNB 104. UE 102 and gNB 104 proceed to events 1002, 1004, and 1005, similar to events 702, 704, and 705. In contrast to scenario 700, in which UE 102 initiates a first channel access procedure while gNB 104 establishes a COT, and then receives a COT indication from gNB 104 after initiating the first channel access procedure, after receiving 1012 the COT indication, similar to event 512, UE 102 of scenario 1000 initiates 1016 a second channel access procedure instead of the first channel access procedure, similar to event 516. Therefore, despite receiving 1004 the system information instructing UE 102 to perform the first channel access procedure, UE 102 does not initiate the first channel access procedure at all.

[0079] Therefore, it is possible for UE 102 to complete 1018 the second channel access process and subsequently send 1022 the RA preamble code to gNB 104 at the PRACH opportunity, similar to events 518 and 722.

[0080] In other embodiments, under fair coexistence considerations for other compatible devices sharing an unlicensed carrier configured to perform a corresponding first channel access procedure, UE 102 may initiate 1007 a first channel access procedure after receiving 1012 a COT indication (similar to event 512), and similar to event 507, complete the first channel access procedure in response to the COT indication, such as Fig. 10B As shown in event 1020 of , and then sends 1022 a RA preamble code to gNB 104 at the PRACH opportunity, similar to event 722. That is, even if UE 102 determines that the PRACH opportunity is within the COT, UE 102 continues to perform the first type channel access process.

[0081] In some other embodiments, Fig. 10B Alternatively or in addition to determining that UE 102 has the configuration as shown in event 1002, gNB 104 may determine 1003 to configure a second uplink grant for UE 102, the second uplink grant indicating that UE 102 may use second resources to send a second RA preamble at a second opportunity (e.g., a second PRACH opportunity). gNB 104 also determines 1003 another channel access procedure (e.g., a second channel access procedure) that UE 102 should use before sending the second RA preamble at the second opportunity. gNB 104 indicates 1005 the second channel access procedure and the second opportunity to UE 102 by broadcasting 1004 system information.

[0082] In response to receiving 1012 the COT indication, if UE 102 determines that the second opportunity is within the COT, UE 102 initiates 1009 a second channel access procedure of a different type from the first channel access procedure on the unlicensed carrier frequency, and completes 1021 the second channel access procedure before sending 1023 a second RA preamble code to gNB 104.

[0083] Reference now Fig.11 At the beginning of scenario 1100, UE 102 is in a detached state from gNB 104. UE 102 and gNB 104 proceed to events 1102, 1104, 1105, 1108, and 1112, similar to events 702, 704, 705, 608, and 612.

[0084] In response to receiving the COT indication, UE 102 performs the first channel access procedure or the second channel access procedure by determining 1113 the purpose for which UE 102 initiated the RACH procedure, similar to event 813. If the purpose is of the first type, UE 102 may initiate 1116 the second channel access procedure and complete 1118 the second channel access procedure, similar to events 616 and 618. Otherwise, if the destination transmission is of the second type, UE 102 initiates 1107 the first channel access procedure and completes 1120 the first channel access procedure, similar to events 607 and 620.

[0085] In response to completing 1118 the second channel access procedure or completing 1120 the first channel access procedure, UE 102 sends 1122 a RA preamble code to gNB 104 at a PRACH timing, similar to event 722.

[0086] Now turn to Figures 12 to 15 , which generally illustrate example message flow diagrams of a UE performing a channel access procedure when a base station (i) establishes a COT and (ii) provides the UE with opportunities when UEs outside the COT can send uplink transmissions to the base station.

[0087] Reference now Fig.12In example scenario 1200, UE 102 is in a connected state with gNB 104, and gNB 104 determines 1202 to configure an uplink grant for UE 102, which indicates that UE 102 may send an uplink transmission on a specific physical uplink shared channel (PUSCH) using resources at a specific timing (e.g., a PDCCH timing), and a specific channel access procedure (e.g., a first channel access procedure) that UE 102 should use before sending an uplink transmission at the timing, similar to events 202, 302, and 402. gNB 104 indicates 1204 the channel access procedure and timing to UE 102, similar to events 204, 304, and 404.

[0088] Continue to refer Fig.12 , in response to the configuration message, UE 102 initiates 1206 a first channel access procedure, similar to events 206, 306, and 406. When UE 102 performs the first channel access procedure, gNB 104 is able to access the shared carrier to establish 1208 a COT, similar to events 208, 308, and 408. After gNB 104 establishes the COT, gNB 104 indicates to UE 102 that the COT has begun. To indicate to UE 102 that the COT has begun, gNB 104 may send 1212 a COT indication, similar to events 212, 312, and 412.

[0089] In response to such a COT indication, if the UE 102 determines that the opportunity is outside the COT, the UE 102 continues 1220 to perform the first channel access procedure.

[0090] Reference now Fig.13 , at the beginning of scenario 1300, UE 102 is in a detached state from gNB 104, and gNB 104 typically determines 1302 to configure UE 102 to initiate a random access channel (RACH) procedure, for example by broadcasting 1304 information associated with the RACH procedure to UE 102 in system information on a shared carrier, including a specific channel access procedure (e.g., a first channel access procedure) that UE 102 should use before sending a RA preamble code at a PRACH opportunity, similar to events 702, 802, and 902.

[0091] Continue to refer Fig.13, in response to receiving the broadcasted system information, UE 102 selects a PRACH opportunity and a RA preamble to initiate 1305 a RACH procedure, similar to events 705, 805, and 905. To ultimately send the RA preamble to gNB 104 at the PRACH opportunity, UE 102 initiates 1306 a first channel access procedure, similar to events 706, 806, and 906. When UE 102 performs the first channel access procedure, gNB 104 is able to access the shared carrier to establish 1308 a COT, similar to events 708, 808, and 908. After gNB 104 establishes the COT, gNB 104 indicates to UE 102 that the COT has begun. To indicate to UE 102 that the COT has begun, gNB 104 may send 1312 a COT indication, similar to events 712, 812, and 912.

[0092] In response to such a COT indication, if the UE 102 determines that the PRACH opportunity is outside the COT, the UE 102 proceeds 1320 to perform a first channel access procedure.

[0093] Reference now Fig.14 In example scenario 1400, UE 102 is in a connected state with gNB 104, and gNB 104 determines 1402 to configure an uplink grant for UE 102, which indicates that UE 102 may send an uplink transmission on a specific physical uplink shared channel (PUSCH) using resources at a specific timing (e.g., a PDCCH timing), and a specific channel access procedure (e.g., a first channel access procedure) that UE 102 should use before sending an uplink transmission at the timing, similar to events 502 and 602. gNB 104 indicates 1404 the channel access procedure and timing to UE 102, similar to events 504 and 604.

[0094] Continue to refer Fig.14 , in response to the configuration message, after gNB 104 establishes 1408 the COT, similar to events 508 and 608, and after receiving 1412 a COT indication, similar to events 512 and 612, UE 102 initiates 1407 a first channel access procedure, similar to event 507. If UE 102 determines that the opportunity is outside the COT, UE 102 continues 1420 to perform the first channel access procedure.

[0095] In some other embodiments, Fig.14Alternatively or in addition to determining that UE 102 has the configuration as shown in event 1402, gNB 104 may determine 1403 to configure a second uplink grant for UE 102, the second uplink grant indicating that UE 102 may send a second uplink transmission on a specific physical uplink shared channel (PUSCH) using a second resource at a second timing (e.g., a second PDCCH timing), similar to event 503. gNB 104 also determines 1403 another channel access procedure (e.g., a second channel access procedure) that UE 102 should use before sending the second uplink transmission at the second timing. gNB 104 indicates 1405 the second channel access procedure and the second timing (i.e., the second configuration) to UE 102, similar to event 505.

[0096] In response to the second configuration, after gNB 104 establishes 1408 the COT and after receiving 1412 the COT indication, UE 102 initiates 1409 a second channel access procedure, similar to event 509. If UE 102 determines that the opportunity is outside the COT, UE 102 continues 1421 to perform the second channel access procedure.

[0097] Reference now Fig.15 At the beginning of scenario 1500, UE 102 is in a connected state with gNB 104. UE 102 and gNB 104 proceed to events 1502, 1504, 1505, 1508, 1512, and 1507, similar to events 1002, 1102, 1004, 1104, 1005, 1105, 1008, 1108, 1012, 1112, and 1007.

[0098] If the UE 102 determines that the PRACH opportunity is outside the COT, the UE 102 continues 1520 to perform a first channel access procedure.

[0099] In some other embodiments, Fig.15 Alternatively or in addition to determining that UE 102 has the configuration as shown in event 1502, gNB 104 may determine 1503 to configure a second uplink grant for UE 102, the second uplink grant indicating that UE 102 may use a second resource at a second opportunity (e.g., a second PRACH opportunity) to send a second RA preamble, similar to event 1003. gNB 104 also determines 1503 another channel access procedure (e.g., a second channel access procedure) that UE 102 should use before sending the second RA preamble at the second opportunity. gNB 104 indicates 1505 the second channel access procedure and the second opportunity (i.e., the second configuration) to UE 102, similar to event 1004.

[0100] In response to the second configuration, after gNB 104 establishes 1508 the COT and after receiving 1512 the COT indication, UE 102 initiates 1509 a second channel access procedure, similar to event 1009. If UE 102 determines that the opportunity is outside the COT, UE 102 continues 1521 to perform the second channel access procedure.

[0101] Fig.16 An example method 1600 is depicted, which may be implemented by UE 102, for scheduling uplink transmission allocations over a shared carrier with a base station in communication with a user equipment.

[0102] Method 1600 begins at block 1602, where the UE receives from a base station a configuration (i) a first channel access procedure to be performed by the user equipment before sending an uplink transmission and (ii) at least one occasion when the user equipment is to send an uplink transmission. Figures 2A to 15 In addition, at block 1604, the UE receives a signal ( Figures 2A to 15 In response to the signal, at block 1606, the UE performs a first channel access procedure or a second channel access procedure ( Figures 2A to 15 events 206, 216, 306, 316, 406, 416, 516, 507, 616, 607, 706, 716, 806, 816, 906, 916, 1016, 1007, 1116, 1107, 1206, 1306, 1407, and 1507).

[0103] Fig.17 An example method 1700 is depicted, which may be implemented by base station 104, for providing control channel information to user equipment communicating with a base station over a shared carrier.

[0104] Method 1700 begins at block 1702, where a base station sends a configuration (i) to a UE indicating a first channel access procedure to be performed by the user equipment before sending an uplink transmission and (ii) at least one opportunity for the user equipment to send an uplink transmission. Figures 2A to 15In addition, at block 1704, the base station determines that a shared carrier is available to the base station during a transmission time period using a channel access procedure. Figures 2A to 15 In response to the determination, at block 1706, the base station sends a signal to the UE indicating that the shared carrier is available for at least a portion of the transmission time period of the base station, so that the UE performs a first channel access procedure or a second channel access procedure (based at least in part on whether the opportunity is within the transmission time period) before sending an uplink transmission. Figures 2A to 15 events 212, 312, 412, 512, 612, 712, 812, 912, 1012, 1112, 1212, 1312, 1412, and 1512).

[0105] The following additional considerations apply to the foregoing discussion.

[0106] The user equipment (e.g., UE 102) in which the technology of the present disclosure can be implemented can be any suitable device capable of wireless communication, such as a smart phone, a tablet computer, a laptop computer, a mobile game console, a point-of-sale (POS) terminal, a health monitoring device, a drone, a camera, a media-streaming dongle or other personal media device, a wearable device such as a smart watch, a wireless hotspot, a femtocell or a broadband router. In addition, the user equipment in some cases can be embedded in an electronic system, such as a head unit or an advanced driver assistance system (ADAS) of a vehicle. In addition, the user equipment can be operated as an Internet of Things (IoT) device or a mobile Internet device (MID). Depending on the type, the user equipment may include one or more general-purpose processors, a computer-readable memory, a user interface, one or more network interfaces, one or more sensors, etc.

[0107] In the present disclosure, specific embodiments are described as including logic or multiple components or modules. A module can be a software module (e.g., a code or machine-readable instruction stored on a non-transitory machine-readable medium) or a hardware module. A hardware module is a tangible unit that is capable of performing a specific operation and can be configured or arranged in a specific manner. A hardware module can include a dedicated circuit or logic that is permanently configured (e.g., permanently configured as a dedicated processor, such as a field programmable gate array (FPGA) or an application-specific integrated circuit (ASIC), a digital signal processor (DSP)) to perform a specific operation. A hardware module can also include programmable logic or circuits that are temporarily configured by software to perform a specific operation (e.g., including the programmable logic or circuit in a general-purpose processor or other programmable processor). The decision to implement a hardware module in a dedicated and permanently configured circuit or in a temporarily configured circuit (e.g., configured by software) can be driven by cost and time considerations.

[0108] When implemented in software, the techniques may be provided as part of an operating system, a library used by multiple applications, a specific software application, etc. The software may be executed by one or more general-purpose processors or one or more special-purpose processors.

[0109] After reading this disclosure, those skilled in the art will appreciate that there are additional or alternative structural and functional designs for scheduling uplink transmission allocations through the principles disclosed in this disclosure. Therefore, although specific embodiments and applications have been shown and described, it should be understood that the disclosed embodiments are not limited to the precise construction and components disclosed herein. Various modifications, changes and variations may be made in the arrangement, operation and details of the methods and apparatus disclosed herein without departing from the spirit and scope defined in the appended claims, and these modifications, changes and variations will be obvious to those of ordinary skill in the art.

[0110] Aspect 1. A method for scheduling uplink transmission allocation in a user equipment via a shared carrier using a base station communicating with the user equipment, the method comprising: receiving a configuration by processing hardware of the user equipment and from the base station, the configuration indicating (i) a first channel access process to be performed by the user equipment before sending an uplink transmission and (ii) at least one timing for the user equipment to send the uplink transmission; receiving a signal from the base station via the shared carrier by the processing hardware, the signal indicating that the shared carrier can be used for at least a part of the transmission time period of the base station; and performing the first channel access process or the second channel access process before sending the uplink transmission by the processing hardware at least in part based on whether the timing is within the transmission time period.

[0111] Aspect 2. The method according to aspect 1, wherein the execution includes: in response to determining that the opportunity is within the transmission time period, performing the first channel access procedure.

[0112] Aspect 3. A method according to aspect 2, wherein the execution includes: if the user equipment initiates the first channel access process before receiving the signal, completing the first channel access process before sending the uplink transmission.

[0113] Aspect 4. A method according to Aspect 2, wherein the execution includes: if the user equipment has not initiated the first channel access process before receiving the signal, then initiating and completing the first channel access process after receiving the signal.

[0114] Aspect 5. A method according to Aspect 1, wherein the execution includes: in response to the processing hardware determining that the possibility of completing the first channel access process during the transmission time period is less than the possibility of completing the second channel access process within the transmission time period, executing the second channel access process.

[0115] Aspect 6. A method according to Aspect 5, wherein the execution includes: if the user equipment initiates the first channel access process before receiving the signal when the user equipment is in a connected state, then terminating the first channel access process before initiating the second channel access process.

[0116] Aspect 7. A method according to Aspect 5, wherein the execution includes: if the user equipment has not initiated the first channel access process before receiving the signal when the user equipment is in a connected state, then initiating and completing the second channel access process after receiving the signal.

[0117] Aspect 8. A method according to Aspect 5, wherein the execution includes: if the user equipment initiates the first channel access process before receiving the signal when the user equipment is in a connected state: initiating the second channel access process, and completing the first channel access process or the second channel access process before sending the uplink transmission.

[0118] Aspect 9. A method according to Aspect 5, wherein the execution includes: if the user equipment initiates the first channel access process before receiving the signal when the user equipment is in a connected state: determining the type of the uplink transmission; and performing at least one of the following: if the type is the first type, terminating the first channel access process before initiating and completing the second channel access process, or, if the type is the second type, completing the first channel access process before sending the uplink transmission.

[0119] Aspect 10. A method according to Aspect 5, wherein the execution includes: if the user equipment has not initiated the first channel access process before receiving the signal when the user equipment is in a connected state: determining the type of the uplink transmission; and performing at least one of the following: if the type is the first type, then after receiving the signal, initiating and completing the second channel access process; or, if the type is the second type, then initiating and completing the first channel access process after receiving the signal.

[0120] Aspect 11. The method according to Aspect 9 or 10 includes one of the following: the first type is a physical uplink control channel (PUSCH) and the second type is a sounding reference signal (SRS), the first type is the SRS and the second type is the PUSCH; the first type is the PUSCH and the second type is a physical uplink control channel (PUCCH); the first type is the PUCCH and the second type is the PUSCH; the first type is the SRS and the second type is the PUCCH; the first type is the PUCCH and the second type is the SRS; the first type is the PUSCH and the second type is a random access (RA) preamble; the first type is the RA preamble and the second type is the PUSCH; the first type is the PUSCH and the second type is message A of a random access channel (RACH) process; or, the first type is the message A and the second type is the PUSCH.

[0121] Aspect 12. A method according to Aspect 5, wherein the execution includes: if the user equipment has initiated the first channel access process before receiving the signal, performing at least one of the following: if the user equipment has performed a RACH process at least in part based on a first purpose, terminating the first channel access process before initiating and completing the second channel access process; or, if the user equipment has performed a RACH process at least in part based on a second purpose, completing the first channel access process before sending the uplink transmission.

[0122] Aspect 13. A method according to Aspect 5, wherein the execution includes: if the user equipment has not initiated the first channel access process before receiving the signal, then executing at least one of the following: if the user equipment has performed a RACH process at least in part based on a first purpose, then initiating and completing the second channel access process after receiving the signal and before sending the uplink transmission; or, if the user equipment has performed a RACH process at least in part based on a second purpose, then initiating and completing the first channel access process after receiving the signal and before sending the uplink transmission.

[0123] Aspect 14. The method according to Aspect 12 or 13 includes one of the following: the first purpose is a 2-step RACH process, and the second purpose is a 4-step RACH process; the first purpose is the 4-step RACH process, and the second purpose is the 2-step RACH process; the first purpose is the RRC connection recovery process in the idle state of the user equipment, and the second purpose is a request for on-demand system information; or, the first purpose is the RRC connection recovery process in the inactive state of the user equipment, and the second purpose is a request for the on-demand system information.

[0124] Aspect 15. The method according to aspect 1, wherein the performing comprises: performing the first channel access procedure in response to determining that the opportunity is outside the transmission time period.

[0125] Aspect 16. The method according to aspect 15, wherein the execution includes: if the user equipment initiates the first channel access procedure before receiving the signal, completing the first channel access procedure before sending the uplink transmission.

[0126] Aspect 17. The method according to aspect 15, wherein the execution comprises: if the user equipment has not initiated the first channel access procedure before receiving the signal, completing the first channel access procedure after receiving the signal.

[0127] Aspect 18. A method according to aspects 3, 4, 6, 7, 8, 12 to 14 or 16 to 17, wherein the receiving includes receiving the configuration, the configuration indicating (i) a random access channel (RACH) process as the first channel access process and (ii) a physical RACH (PRACH) opportunity and a random access (RA) preamble as the opportunity, and the method further includes: when the user equipment is in the idle state or the inactive state, selecting the PRACH opportunity and the RA preamble according to the configuration to perform the RACH process; wherein sending the uplink transmission includes sending the RA preamble.

[0128] Aspect 19. The method according to Aspect 4 or 17 further includes: receiving a second configuration from the base station, the second configuration indicating (i) a second channel access process to be performed by the user equipment before sending a second uplink transmission and (ii) a second timing for the user equipment to send the second uplink transmission; and performing the second channel access process before sending the second uplink transmission, regardless of whether the second timing is within the transmission time period.

[0129] Aspect 20. A method according to any one of the preceding aspects, wherein the configuration or the second configuration is provided in a downlink control information (DCI) message or a radio resource control (RRC) reconfiguration message sent by the base station to the user equipment.

[0130] Aspect 21. The method according to any of the preceding aspects, wherein receiving the signal indicating the transmission time period comprises receiving a signal indicating the duration of the transmission time period.

[0131] Aspect 22. A method according to any one of the preceding aspects, wherein the uplink transmission and the second uplink transmission are each at least one of a PUSCH transmission, a PUCCH transmission or a sounding reference signal (SRS), and the configuration and the second configuration configure the PUSCH transmission, the PUCCH transmission or the SRS, respectively.

[0132] Aspect 23. A method according to any one of the preceding aspects, wherein the first channel access process is a Class 4 listen-before-talk (LBT) process, and the second channel access process is at least one of a Class 3 LBT process, a Class 2 LBT process, or a Class 1 LBT process.

[0133] Aspect 24. A user equipment comprising processing hardware and configured to implement the method according to any one of aspects 1 to 23.

[0134] Aspect 25. A method for providing control channel information to a user equipment communicating with the base station via a shared carrier in a base station, the method comprising: sending a configuration by the processing hardware of the base station to the user equipment, the configuration indicating (i) a first channel access process to be performed by the user equipment before sending an uplink transmission and (ii) at least one timing for the user equipment to send the uplink transmission; determining by the processing hardware of the base station that the shared carrier is available to the base station within a transmission time period using the channel access process; and sending a signal to the user equipment indicating that the shared carrier is available to at least a part of the transmission time period of the base station, so that the user equipment performs the first channel access process or the second channel access process before sending the uplink transmission at least in part based on whether the timing is within the transmission time period.

[0135] Aspect 26. The method according to Aspect 25 further includes: sending a second configuration by the processing hardware of the base station to the user equipment, the second configuration indicating (i) the second channel access process to be performed by the user equipment before sending the second uplink transmission and (ii) the second timing for the user equipment to send the second uplink transmission, wherein the sending of the signal further causes the user equipment to perform the second channel access process before sending the second uplink transmission, regardless of whether the second timing is within the transmission time period.

[0136] Aspect 27. A method according to aspect 25 or 26, wherein the configuration or the second configuration is provided in a downlink control information (DCI) message or a radio resource control (RRC) reconfiguration message sent by the base station to the user equipment.

[0137] Aspect 28. A method according to Aspect 25 or 26, wherein the configuration or the second configuration is sent in a downlink transmission, and the downlink transmission includes at least one of a physical downlink control channel (PDCCH), a physical downlink shared channel (PDSCH), a channel state information reference signal (CSI-RS) or a synchronization signal block (SSB).

[0138] Aspect 29. A method according to aspect 25 or 26, wherein the configuration is included in a first RRC reconfiguration message and sent on a first PDSCH, or is included in a first DCI and sent on the first PDCCH.

[0139] Aspect 30. A method according to Aspect 29, wherein the second configuration is included in the first RRC reconfiguration message and sent on the first PDSCH, is included in a second RRC reconfiguration message and sent on a second PDSCH, or is included in a second DCI and sent on the second PDCCH.

[0140] Aspect 31. A base station comprising processing hardware configured to perform the method according to any one of aspects 25 to 30.

Claims

1. A method for scheduling uplink transmission in a user equipment by using a base station communicating with the user equipment through a shared carrier, the method comprising: receiving, by the user equipment, a configuration from the base station, the configuration indicating (i) a first channel access procedure to be performed by the user equipment before sending the uplink transmission and (ii) at least one time-frequency resource of a timing at which the user equipment is to send the uplink transmission; The user equipment initiates the first channel access process; Receiving, by the user equipment, a signal from the base station via the shared carrier, the signal indicating that the shared carrier is available for at least a portion of a channel occupation time COT of the base station; as well as When the opportunity is within the COT, a second channel access procedure is performed by the user equipment before sending the uplink transmission.

2. The method according to claim 1, wherein: The execution includes: In response to determining by the user equipment that the likelihood of completing the first channel access procedure during the COT is less than the likelihood of completing the second channel access procedure during the COT, performing the second channel access procedure.

3. The method according to claim 1, wherein: The execution includes: The first channel access procedure is terminated in response to receiving the signal and before initiating the second channel access procedure.

4. The method according to claim 1, wherein: The execution includes: If the user equipment initiates the first channel access procedure before receiving the signal when the user equipment is in a connected state: Initiating the second channel access process, and The first channel access procedure or the second channel access procedure is completed before sending the uplink transmission.

5. The method according to claim 1, wherein: The execution includes: If the user equipment initiates the first channel access process before receiving the signal, performing at least one of the following: If the user equipment performs a random access channel (RACH) procedure based at least in part on the first purpose, terminating the first channel access procedure before initiating and completing the second channel access procedure; or If the user equipment performed a RACH procedure based at least in part on a second purpose, then completing the first channel access procedure prior to sending the uplink transmission.

6. The method according to claim 1, wherein: The execution includes: If the user equipment has not initiated the first channel access procedure before receiving the signal, performing at least one of the following: If the user equipment has performed a random access channel (RACH) procedure based at least in part on the first purpose, initiating and completing the second channel access procedure after receiving the signal and before sending the uplink transmission; or If the user equipment performed a RACH procedure based at least in part on a second purpose, the first channel access procedure is initiated and completed after receiving the signal and before sending the uplink transmission.

7. The method according to claim 5 or 6, comprising one of the following: The first purpose is a 2-step RACH procedure, and the second purpose is a 4-step RACH procedure; The first purpose is a 4-step RACH procedure, and the second purpose is a 2-step RACH procedure; The first purpose is a radio resource control RRC connection resumption procedure in an idle state of the user equipment, and the second purpose is a request for on-demand system information; or The first purpose is an RRC connection resumption procedure in an inactive state of the user equipment, and the second purpose is a request for on-demand system information.

8. The method according to any one of claims 1 to 6, wherein: The opportunity is a physical uplink shared channel PUSCH opportunity.

9. The method according to any one of claims 1 to 6, wherein: The receiving configuration includes receiving a configuration indicating (i) a random access channel RACH procedure as the first channel access procedure and (ii) a physical RACH PRACH opportunity and a random access RA preamble as the opportunity, and the method further includes: When the user equipment is in an idle state or an inactive state, selecting the PRACH opportunity and the RA preamble according to the configuration to perform the RACH procedure, wherein sending the uplink transmission includes sending the RA preamble; and A second configuration is received from the base station, the second configuration indicating (i) a second channel access procedure to be performed by the user equipment before sending a second uplink transmission and (ii) a second timing at which the user equipment is to send the second uplink transmission.

10. The method according to claim 9, wherein: The configuration or the second configuration is provided in a downlink control information DCI message or a radio resource control RRC reconfiguration message sent by the base station to the user equipment.

11. The method according to claim 9, wherein: The uplink transmission and the second uplink transmission are each at least one of a physical uplink shared channel PUSCH transmission, a physical uplink control channel PUCCH transmission or a sounding reference signal SRS, and the configuration and the second configuration configure the PUSCH transmission, the PUCCH transmission or the SRS, respectively.

12. The method of any one of claims 1-6, wherein receiving the signal indicative of at least a portion of the COT comprises receiving a signal indicative of a duration of the COT.

13. The method according to any one of claims 1 to 6, wherein: The first channel access process is a Class 4 listen-before-talk (LBT) process, and the second channel access process is at least one of a Class 3 LBT process, a Class 2 LBT process, or a Class 1 LBT process.

14. The method according to any one of claims 1 to 6, wherein: Receiving the signal includes receiving a downlink control information (DCI) message.

15. A user equipment, configured to schedule uplink transmission using a base station communicating with the user equipment via a shared carrier, the user equipment being configured to: receiving a configuration from the base station, the configuration indicating (i) a first channel access procedure to be performed by the user equipment before sending the uplink transmission and (ii) at least one time-frequency resource of a timing at which the user equipment is to send the uplink transmission; Initiating the first channel access process; receiving a signal from the base station via the shared carrier, the signal indicating that the shared carrier is available for at least a portion of a channel occupancy time COT of the base station; as well as When the opportunity is within the COT, a second channel access procedure is performed before sending the uplink transmission.

16. The user equipment according to claim 15, wherein: The opportunity is a physical uplink shared channel PUSCH opportunity.

17. A method for providing control channel information to a user equipment communicating with the base station in a base station through a shared carrier, the method comprising: Sending, by the base station, a configuration to the user equipment, the configuration indicating (i) a first channel access procedure to be performed by the user equipment before sending an uplink transmission and (ii) at least one time-frequency resource of a timing at which the user equipment is to send the uplink transmission; The base station determines, using a channel access procedure, that the shared carrier is available to the base station within a channel occupation time COT; as well as A signal is sent by the base station to the user equipment indicating that the shared carrier is available for at least a portion of the COT of the base station, so that the user equipment performs the first channel access procedure or the second channel access procedure before sending the uplink transmission based at least in part on whether the opportunity is within the COT.

18. The method according to claim 17, wherein: The opportunity is a physical uplink shared channel PUSCH opportunity.

19. The method according to any one of claims 17-18, further comprising: sending, by the base station, to the user equipment, a second configuration, the second configuration indicating (i) a second channel access procedure to be performed by the user equipment before sending a second uplink transmission and (ii) a second timing at which the user equipment is to send the second uplink transmission, Wherein, sending the signal further causes the user equipment to perform the second channel access procedure before sending the second uplink transmission, regardless of whether the second timing is within the COT.

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