Base station operations during UE-initiated channel access procedure

Abstract

The present invention provides a base station (BS), which configures parameters for a channel access operation on a shared channel for a user equipment (UE). The BS transmits a first configuration (BS-FFP) to the UE for a fixed frame period (FFP) (BS-FFP) initiated by the BS, and transmits a second configuration to the UE for a FFP (UE-FFP) initiated by the UE, wherein the BS-FFP overlaps with the UE-FFP; during the UE-FFP, an uplink (UL) transmission is scheduled; and when there is no downlink (DL) transmission in the BS-FFP, during the BS-FFP, the UL transmission is received from the UE.

Description

Background Art

[0001] A user equipment (UE) may be configured to establish a connection with a network. In one example, the UE may be connected to a 5G New Radio (NR) network. When connected to a 5G NR network, the UE may utilize capabilities associated with the network. In the 5G NR standard, NR-U involves the management of unlicensed (shared) spectrum. Similar to Licensed Assisted Access (LAA) in the LTE standard, NR-U provides modifications to the carrier aggregation (CA) functionality that allow unlicensed bandwidth to be used for secondary component carriers (SCCs). NR-U may also be utilized in a standalone configuration, where a single NR cell provides unlicensed bandwidth for data transmission.

[0002] NR-U is designed to maintain fair coexistence with other incumbent technologies (such as WiFi) that use shared spectrum, and in order to do so, some regulatory restrictions may apply depending on the specific frequency band in which it may operate. For example, if operating in the 5GHz band, a listen-before-talk (LBT) process may be required to acquire the medium before a transmission occurs. LBT, such as a clear channel assessment (CCA), may be performed by the next generation Node B (gNB) on the downlink (DL) channel before a DL transmission occurs. Currently, a UE is only allowed to perform (UL) transmissions when a DL signal or channel is first detected. This requirement can increase UL latency, especially for the physical resource access channel (PRACH) and some latency-sensitive service types, such as ultra-reliable low latency communications (URLLC). Summary of the invention

[0003] Some exemplary aspects relate to a base station having a transceiver and one or more processors. The transceiver is configured to connect to a user equipment (UE) via a shared channel subject to a channel access operation. One or more processors are communicatively coupled to the transceiver and configured to perform operations. These operations include: transmitting a first configuration to a UE for a fixed frame period (FFP) (BS-FFP) initiated by a BS, and transmitting a second configuration to the UE for a FFP (UE-FFP) initiated by the UE, wherein the BS-FFP overlaps with the UE-FFP; scheduling uplink (UL) transmissions during the UE-FFP; and receiving UL transmissions from the UE during the BS-FFP when there is no downlink (DL) transmission in the BS-FFP.

[0004] Other exemplary aspects relate to a baseband processor that performs operations including: transmitting a first configuration to a user equipment (UE) for a fixed frame period (BS-FFP) initiated by a base station (BS), and transmitting a second configuration to the UE for a FFP (UE-FFP) initiated by the UE, wherein the BS-FFP overlaps with the UE-FFP; scheduling an uplink (UL) transmission during the UE-FFP; and receiving a downlink (DL) transmission from the UE during the BS-FFP when the BS-FFP has no downlink (DL) transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] Figure 1 Exemplary network arrangements according to various exemplary aspects are shown.

[0006] Figure 2 An exemplary UE according to various exemplary aspects is shown.

[0007] Figure 3 Example network cells according to various example aspects are shown.

[0008] Figure 4 An operational diagram of the channel access procedure for an NR-U unlicensed channel is shown, where only the gNB is allowed to initiate frame-based equipment (FBE) listen-before-talk (LBT) operations such as clear channel assessment (CCA).

[0009] Figure 5 An information element (IE) for transmitting semi-static channel access configuration information (SemiStaticChannelAccessConfig) to a UE in a system information block (SIB) is shown.

[0010] Figure 6 A diagram of FBE operations for UE-initiated FFP according to an exemplary aspect is shown.

[0011] Figure 7 Methods of FBE operation for UE-initiated FFP according to various exemplary aspects are shown.

[0012] Figure 8 A diagram of UE-initiated conditional CCA operations is shown according to an exemplary aspect. DETAILED DESCRIPTION

[0013] The exemplary aspects may be further understood with reference to the following description and associated drawings, wherein similar elements have the same reference numerals. The exemplary aspects describe configurations of a user equipment (UE) wherein the UE may, under certain conditions, initiate a channel access procedure for determining a channel state for a scheduled uplink (UL) transmission. In some aspects, the exemplary UE may be configured with two fixed frame periods (FFPs), one corresponding to a channel access procedure initiated by a new generation Node B (gNB) and the other corresponding to a channel access procedure initiated by the UE. The gNB-initiated channel access procedure may include a frame-based equipment (FBE) listen-before-talk (LBT) operation followed by a gNB-FFP, during which the UE may detect a downlink (DL) transmission after the FBE succeeds at the gNB. In some aspects, when no DL transmission is detected and certain conditions for a scheduled UL transmission are met, the UE may initiate its own channel access procedure, including a FBE, which upon success allows the UE to perform a scheduled UL transmission. In other aspects, when the UL transmission is within a particular symbol of the gNB-FFP, the UE may perform some UL transmissions instead of configuring the UE-FFP.

[0014] Although these exemplary aspects will be described with reference to 5G NR networks, those skilled in the art will appreciate that these exemplary aspects may be modified and / or may be used with any network that supports the following functionality: utilizing additional bandwidth outside of a designated or licensed spectrum that may be shared between radio access technologies (RATs). For example, legacy networks such as LTE support CA functionality where SCCs may be established for unlicensed bands, and certain of these exemplary aspects may be used with such networks, such as when a licensed assisted access (LAA) functionality is configured. In addition, NR-U may be used as a standalone feature for connecting to unlicensed bandwidth, independent of any CA operation. Therefore, the exemplary aspects described below may be used in a CA configuration or in the absence of a CA configuration.

[0015] Network / Equipment

[0016] Figure 1 An exemplary network arrangement 100 according to various exemplary aspects is shown. The exemplary network arrangement 100 includes a plurality of UEs 110, 112. Those skilled in the art will appreciate that a UE may be any type of electronic component configured to communicate via a network, such as a component of a connected car, a mobile phone, a tablet computer, a smart phone, a tablet phone, an embedded device, a wearable device, an Internet of Things (IoT) device, etc. It should also be appreciated that an actual network arrangement may include any number of UEs used by any number of users. Therefore, an example with two UEs 110, 112 is provided for illustration purposes only. In some exemplary aspects described below, a UE group may be employed to perform corresponding channel measurements.

[0017] UE 110, 112 can communicate directly with one or more networks. In the example of network configuration 100, the networks with which UE 110, 112 can wirelessly communicate are 5G NR radio access network (5G NR-RAN) 120, LTE radio access network (LTE-RAN) 122, and wireless local area network (WLAN) 124. Therefore, UE 110, 112 may include a 5G NR chipset that communicates with 5G NR-RAN 120, an LTE chipset that communicates with LTE-RAN 122, and an ISM chipset that communicates with WLAN 124. However, UE 110, 112 may also communicate with other types of networks (e.g., traditional cellular networks), and UE 110 may also communicate with the network via a wired connection. Referring to the exemplary aspects, UE 110, 112 may establish a connection with 5G NR-RAN 122 and / or LTE-RAN 120.

[0018] 5G NR-RAN 120 and LTE-RAN 122 may be part of cellular networks that may be deployed by cellular providers (e.g., Verizon, AT&T, Sprint, T-Mobile, etc.). These networks 120, 122 may include, for example, cells or base stations (NodeB, eNodeB, HeNB, eNBS, gNB, gNodeB, macrocell base stations, microcell base stations, small cell base stations, femtocell base stations, etc.) configured to send and receive traffic from UEs equipped with appropriate cellular chipsets. WLAN 124 may include any type of wireless local area network (WiFi, hotspot, IEEE 802.11x network, etc.).

[0019] UE 110, 112 may be connected to 5G NR-RAN via at least one of the next generation Node B (gNB) 120A and / or gNB 120B. gNB 120A, 120B may be configured with necessary hardware (e.g., antenna array), software and / or firmware to perform massive multiple input multiple output (MIMO) functions. Massive MIMO may refer to a base station configured to generate multiple beams for multiple UEs. Reference to two gNBs 120A, 120B is for illustrative purposes only. The exemplary aspects may be applied to any appropriate number of gNBs. Specifically, UE 110, 112 may be simultaneously connected to multiple gNBs 120A, 120B in a multi-cell CA configuration and exchange data with them. UE 110, 112 may also be connected to LTE-RAN 122 via either or both of eNBs 122A, 122B, or to any other type of RAN, as described above. In network arrangement 100, UE 110 is shown as having a connection to gNB 120A, while UE 112 is shown as having a connection to gNB 120B. The connection of UE 110 to gNB 120A may be, for example, an NR-U connection that utilizes an unlicensed portion of the RF spectrum.

[0020] In addition to networks 120, 122, and 124, network arrangement 100 also includes a cellular core network 130, the Internet 140, an IP multimedia subsystem (IMS) 150, and a network service backbone 160. Cellular core network 130 (e.g., 5GC of NR) can be considered as an interconnected collection of components that manage the operation and traffic of a cellular network. Cellular core network 130 also manages traffic flowing between the cellular network and the Internet 140.

[0021] The IMS 150 may be generally described as an architecture for delivering multimedia services to the UE 110 using the IP protocol. The IMS 150 may communicate with the cellular core network 130 and the Internet 140 to provide multimedia services to the UE 110. The network service backbone 160 communicates directly or indirectly with the Internet 140 and the cellular core network 130. The network service backbone 160 may be generally described as a set of components (e.g., servers, network storage arrangements, etc.) that implement a set of services that may be used to extend the functionality of the UE 110 to communicate with various networks.

[0022] Figure 2 An exemplary UE 110 is shown according to various exemplary aspects. Figure 1100 is used to describe the UE 110. The UE 110 may represent any electronic device and may include a processor 205, a memory arrangement 210, a display device 215, an input / output (I / O) device 220, a transceiver 225, and other components 230. The other components 230 may include, for example, an audio input device, an audio output device, a battery providing a limited power source, a data acquisition device, a port for electrically connecting the UE 110 to other electronic devices, a sensor for detecting the status of the UE 110, and the like. Figure 2 The UE 110 shown may also represent UE 112 .

[0023] The processor 205 may be configured to execute a plurality of engines of the UE 110. For example, the engines may include a channel access engine 235 for performing operations including, at the UE, initiating a channel access procedure. The channel access procedure may include a FBE followed by a UE fixed frame period (FFP), the FFP including a channel occupancy time (COT), during which the UE may perform an UL transmission, as will be described in detail below. In other aspects, the channel access engine 235 may cause the processor to perform operations including, during a gNB-FFP, initiating a FBE, and performing an UL transmission when the UL transmission is within a particular symbol of the gNB-FFP, as will be described in detail below.

[0024] The above-described engine as an application (e.g., program) executed by the processor 205 is merely exemplary. The functionality associated with the engine may also be represented as an independently integrated component of the UE 110, or may be a modular component coupled to the UE 110, such as an integrated circuit with or without firmware. For example, an integrated circuit may include an input circuit for receiving a signal and a processing circuit for processing the signal and other information. The engine may also be embodied as an application or multiple separate applications. In addition, in some UEs, the functionality described for the processor 205 is shared between two or more processors such as a baseband processor and an application processor. The exemplary aspects may be implemented in any of these or other configurations of the UE.

[0025] The memory 210 may be a hardware component configured to store data related to operations performed by the UE 110. The display device 215 may be a hardware component configured to display data to a user, and the I / O device 220 may be a hardware component that enables a user to perform input. The display device 215 and the I / O device 220 may be separate components or may be integrated together (such as a touch screen). The transceiver 225 may be a hardware component configured to establish a connection with the 5G-NR RAN 120, the LTE RAN 122, etc. Thus, the transceiver 225 may operate on a variety of different frequencies or channels (e.g., a continuous frequency group). For example, when, for example, NR-U is configured, the transceiver 225 may operate on an unlicensed spectrum.

[0026] Figure 3 An exemplary network cell, in this case a gNB 120A, is shown according to various exemplary aspects. As described above with reference to the UE 110, the gNB 120A may represent a cell that provides service as a PCell or SCell or is independently configured with respect to the UE 110. The gNB 120A may represent any access node of the 5G NR network through which the UEs 110, 112 may establish connections and manage network operations. Figure 3 The gNB 120A shown may also represent gNB 120B.

[0027] The gNB 120A may include a processor 305, a memory arrangement 310, an input / output (I / O) device 320, a transceiver 325, and other components 330. The other components 330 may include, for example, an audio input device, an audio output device, a battery, a data acquisition device, a port for electrically connecting the gNB 120A to other electronic devices, and the like.

[0028] The processor 305 may be configured to execute multiple engines of the gNB 120A. For example, the engines may include a channel access engine 235 for performing operations including configuring a UE-FFP for a UE during which the UE may send an UL transmission, as described in detail below.

[0029] The engines described above are each represented as an application (e.g., a program) executed by the processor 305 and are merely exemplary. The functionality associated with the engines may also be represented as independently integrated components of the gNB 120A, or may be modular components coupled to the gNB 120A, such as integrated circuits with or without firmware. For example, an integrated circuit may include input circuitry for receiving signals and processing circuitry for processing signals and other information. In addition, in some gNBs, the functionality described for the processor 305 is split between multiple processors (e.g., a baseband processor, an application processor, etc.). The exemplary aspects may be implemented in any of these or other configurations of the gNB.

[0030] The memory 310 may be a hardware component configured to store data related to operations performed by the UE 110, 112. The I / O device 320 may be a hardware component or port that enables a user to interact with the gNB 120A. The transceiver 325 may be a hardware component configured to exchange data with the UE 110, 112 and any other UE in the system 100. The transceiver 325 may operate on a variety of different frequencies or channels (e.g., a set of continuous frequencies). For example, when the NR-U function is configured, the transceiver 325 may operate on an unlicensed bandwidth. Thus, the transceiver 325 may include one or more components (e.g., a radio component) to enable data exchange with various networks and UEs.

[0031] Channel access process on a shared channel

[0032] NR-U is designed to maintain fair coexistence with other incumbent technologies (such as WiFi) that use shared spectrum, and in order to do so, some regulatory restrictions may apply depending on the specific frequency band in which it may operate. For example, if operating in the 5GHz band, a listen-before-talk (LBT) process may be used to acquire the medium before a transmission occurs. For example, a clear channel assessment (CCA) may be performed by the next generation Node B (gNB) on a downlink (DL) channel before a DL transmission to a user equipment (UE) occurs. However, Rel-16 NR-U currently only supports the gNB as the initiator of CCA. Therefore, a UE is allowed to perform (UL) transmission only if a DL signal or channel, such as a physical downlink control channel (PDCCH), a synchronization signal block (SSB), a system information block (SIB) (e.g., RMSI), or a packet common (GC) PDCCH, is first detected within a fixed frame period (FFP).

[0033] The FFP is a time resource available to the UE for sending / receiving transmissions. The FFP length and starting position (timing offset) are parameters provided by the network in, for example, SIB1 information. Each frame period consists of a channel occupation time (COT) and an idle period at the end of the FFP, after which the FFP is repeated. During the idle period before the next FFP, the gNB may perform LBT, such as a frame-based equipment (FBE) operation, such as a single-shot CCA, and if the CCA is successful, at the start of the FFP, perform DL signaling or data transmission. If a DL transmission is detected at the UE, the UE is allowed to perform UL transmission within the FFP. The size of the COT may be determined according to the rules defined for the FBE. For example, the idle period may not be shorter than 5% of the FFP, and the COT may not be longer than 95% of the FFP.

[0034] Figure 4A channel access procedure operation diagram 400 for an NR-U unlicensed channel is shown, wherein only the gNB is allowed to initiate frame-based equipment (FBE) listen-before-talk (LBT) operations, such as clear channel assessment (CCA). The example diagram 400 includes a first FFP 402 followed by a second FFP 404. The first CCA 406 is performed by the gNB before the first FFP 402, which has a first scheduled UL transmission 410 within its COT 408. In this example operation, the first CCA 406 may be considered to fail at the gNB. Therefore, during the first COT 408, the gNB does not transmit on the DL. Because the UE did not detect any DL transmissions before the first scheduled UL transmission 410, the UL transmission 410 is discarded. At the end of the first FFP 402 and before the COT 416 of the second FFP 404, the second CCA 414 is performed by the gNB within the idle period 412. In this exemplary operation, the second CCA 414 may be considered successful at the gNB. Therefore, during the COT 416, the gNB transmits on the DL 418, and the UE detects the DL transmission 418 before the second scheduled UL transmission 420 within the COT 416. Because the UE detects the DL transmission 418 before the second scheduled UL transmission 420, the UE performs the second scheduled UL transmission 420.

[0035] As shown in the example diagram 400, given that the UE needs to wait until the second COT 416 to perform UL transmission 420, before transmitting on the UL, the UE needs to first detect the DL transmission / signal, which increases the UL delay. This delay increase may have a particular impact on the physical resource access channel (PRACH) and some delay-sensitive service types such as ultra-reliable low-delay communication (URLLC). For example, such requirements may make it impossible for URLLC services to operate in unlicensed bands.

[0036] UE-initiated COT for FBE operation

[0037] According to some exemplary aspects, the UE is configured to initiate FBE and establish a second fixed frame period (FFP) / channel occupancy time (COT) when the FBE initiated by the gNB is unsuccessful, and transmit UL data, such as high priority data, such as URLLC communication, during the second fixed frame period / channel occupancy time. For example, the UE can be configured with: a first FFP and a corresponding offset configuration (hereinafter referred to as "gNB-FFP") with the gNB as the FBE initiator; and a second FFP and a corresponding offset configuration (hereinafter referred to as "UE-FFP") with the UE as the FBE initiator. The UE-FFP can be configured to be shorter than the gNB-FFP so that one or more UE-FFPs can fall within the gNB-FFP. For example, the UE-FFP can be configured as, for example, a percentage of the gNB-FFP relative to the gNB-FFP. For example, in the 3GPP standard, for a UE, a candidate percentage value X of the UE-FFP period may be fixed to values ​​such as 0%, 15%, 30%, 45%, 60% and 95% of the gNB-FFP period, where when the value is configured to 0, this indicates that the UE is not allowed to be a FBE initiating device. UE-FFP may be configured via a system information block (SIB), such as in SIB1 (a common SIB for all UEs in the same serving cell), or via dedicated RRC signaling.

[0038] Figure 5 An information element (IE) 500 of semi-static channel access configuration information (SemiStaticChannelAccessConfig) for transmission to a UE in a system information block (SIB) is shown. IE 500 may be an ASN.1 message that is prepared for separate FBE configuration parameters to enable a UE to act as an FBE initiating device. In this example, IE 500 includes a first row (Period) 502 for configuring gNB-FFP and offset and a second row (Period 2) for configuring UE-FFP and offset. In IE 500, the second row includes parameters corresponding to each of the parameters included in the first row. However, as described above, in some aspects, the UE-FFP configuration may be indicated as a percentage "X" of the period in the first row. For example, the value of X may be a fraction or an integer. In one aspect, the candidate X values ​​may be fixed in the specification, such as X = <0, 15, 30, 45, 60, 95>%, where a value of "0" indicates that the UE is not allowed to initiate COT.

[0039] When configured to initiate FFP, the UE may perform LBT operations, such as CCA, during a single observation period, e.g., Tsl = 9 microseconds, immediately before starting transmission at the start of UE-FFP. The UE may perform LBT operations and initiate COT if the following two conditions are met. First, within the gNB-FFP before the start of UE-FFP, at a predetermined time interval, the UE does not detect any DL transmission burst from the gNB. As described above, the gNB-FFP overlaps with at least a portion of one or more UE-FFPs, but when a DL transmission burst is expected, UE CCA may not be initiated during a predefined time of the gNB-FFP (during the observation period immediately before the UE-FFP). In some aspects, the predefined time interval includes at least the code elements configured for PDCCH, SSB, and periodic CSI-RS monitoring.

[0040] Regarding the second condition, before initiating UE CCA, within UE-FFP, the UE should have at least one PUSCH (DG-PUSCH) dynamically granted by DCI format or configured granted (CG) PUSCH transmission (CG-PUSCH). In other words, although the actual CG-PUSCH or DG-PUSCH transmission is subject to the result of CCA, DG-PUSCH or CG-PUSCH should be scheduled during UE-FFP. Alternatively, some other "predefined" UL transmission scheduled during UE-FFP can trigger UE CCA to initiate COT.

[0041] In some aspects, for the second condition, the above-mentioned DG-PUSCH and CG-PUSCH can be associated with a predefined channel access priority category (CAPC) 'p'. For example, only high priority data, such as data with priority category "1" or "2", can trigger the UE to initiate UE-FFP. In this case, the CAPC threshold Tp will be 2, where p≤Tp (e.g., higher priority packets) allows the occurrence of UE CCA and associated UE-COT to be triggered. For DG-PUSCH transmissions, the CAPC value 'p' can be indicated in the scheduling DCI corresponding to the UL transmission. For CG-PUSCH, the CAPC value 'p' can be determined based on the 5G QoS identifier (5QI) values ​​of all quality of service (QoS) flows multiplexed by the CG-PUSCH.

[0042] In other aspects, for the second condition, the above-mentioned CG-PUSCH corresponding to the configuration grant may have a priority value set to 1 in the ConfiguredGrantConfig IE, thereby indicating that the CG-PUSCH is a high priority. DG-PUSCH is a PUSCH scheduled by PDCCH and may be indicated as a higher priority by using the priority indicator field in the scheduling DCI. In other aspects, the above-mentioned so-called "predefined" UL transmissions in the second condition include, for example, UL transmissions related to RACH processes (e.g., PRACH transmissions) and higher priority uplink control information (UCI) transmissions (e.g., HARQ-ACK and SR transmissions via PUCCH or PUSCH). On the other hand, SRS transmissions may also be included in the "predefined" UL transmissions.

[0043] Figure 6 FIG600 shows FBE operation for UE-initiated FFP according to an exemplary aspect. FBE in this exemplary aspect is described as Type 2A CCA for gNB-initiated FFP and UE-initiated FFP (gNB-FFP and UE-FFP). However, in other aspects, other LBT categories may be used, such as Type 1 CCA. Figure 7 The method 700 is shown to describe the diagram 600 .

[0044] Figure 7 A method 700 of FBE operation for UE-initiated FFP according to various exemplary aspects is shown. As described above, at 705, the gNB configures gNB-FFP and UE-FFP for the UE. Figure 6 In the example of , subject to the first condition discussed above, the gNB-FFP 602 overlaps with multiple UE-FFPs 604, wherein the UE does not perform CCA (before the UE-FFP) during a predefined time interval in which the UE can detect a DL transmission burst from the gNB. Two UL grants are configured for the UE, specifically: a first UL grant 606, which is, in this aspect, a DG-PUSCH scheduled by the scheduling DCI with a CAPC value of p=4; and a second UL grant 808, which is, in this aspect, a CG-PUSCH determined to have a CAPC value of p=1 based on the 5QI value of the corresponding data stream. In this aspect, the value of the threshold p value Tp is 2. Therefore, when p≤2, UE-FFP is allowed to occur. During the UE-FFP 604a, the first UL grant 606 is scheduled, and during the UE-FFP 604b, the second UL grant 608 is scheduled.

[0045] In 710, the gNB performs Type 2A CAA prior to the configured gNB-FFP. Figure 6In the example of , a gNB initiated CAA 610 is performed before the gNB-FFP 602. In this example, the CAA 610 fails at the gNB, thereby preventing the gNB from transmitting a DL transmission burst within the gNB-FFP 602. Therefore, during the above-mentioned predefined time interval, the UE does not detect any DL transmission burst.

[0046] In 715, based on the fact that no DL transmission burst is detected during the predefined time, the UE determines whether to schedule a DG-PUSCH or a CG-PUSCH that meets the configuration conditions for the subsequent UE-FFP. Figure 6 In the example of , after gNB CCA, DG-PUSCH 606 ​​is scheduled in UE-FFP 604a. However, the priority p=4 of DG-PUSCH 606 ​​is greater than the threshold Tp=2. Therefore, these conditions are not met.

[0047] In 720, when the UE determines not to schedule any DG-PUSCH or CG-PUSCH that meets these conditions for the subsequent UE-FFP, the UE does not perform UL transmission during the UE-FFP. Figure 6 In the example of , the UE discards the scheduled DG-PUSCH transmission 606. If an additional UE-FFP is established before the gNB-FFP ends, the method returns to 720 and the UE performs the same determination process for the additional UE-FFP. Figure 6 In the example of , the UE determines that within the UE-FFP 604b, the CG-PUSCH 608 is scheduled. The CG-PUSCH 608 has a priority p=1 that is less than or equal to a threshold Tp=2. Therefore, the conditions for the scheduled UL transmission 608 are met.

[0048] In 725, when the UE determines to schedule a DG-PUSCH or CG-PUSCH that meets these conditions for a subsequent UE-FFP, the UE performs Type 2A CCA before the subsequent UE-FFP. Figure 6 In the example of , before UE-FFP 604b, UE-initiated CAA 612 is performed. In this example, CAA 612 succeeds at the UE, thereby allowing the UE to access the channel for UL.

[0049] At 730, after the CCA is successful, the UE performs the UL transmission scheduled for the subsequent UE-FFP. Figure 6 In the example of , based on successful CAA 612 (which is only allowed to occur when the UL transmission conditions for UE-FFP are met), the UE performs CG-PUSCH transmission 608.

[0050] According to some exemplary aspects, for UE-FFP, the UE may perform a Type 1 channel access procedure instead of a Type 2A channel access procedure. If Type 1 operation is configured and the above two conditions are met, the UE may perform Type 1 FBE operation. Those skilled in the art will appreciate that the general characteristics of the Type 2A channel access procedure are that once the channel is sensed to be idle, the device (e.g., UE) will transmit. On the other hand, the Type 1 channel access procedure may enable the UE to sense that multiple time slots are idle. Therefore, in exemplary aspects related to Type 1 CCA, the UE may maintain a contention window value CWp and make adjustments for transmissions corresponding to each channel access priority category (CAPC) 'p', for example, the number of idle time slots to be sensed may depend on the CAPC.

[0051] According to other exemplary aspects, the energy detection threshold XThreshUE used by the UE for CCA can be configured separately by the upper layer. Those skilled in the art will understand that the energy detection threshold is the minimum energy required to declare the channel busy during the CCA process. Based on associated PUSCH transmission parameters, such as priority category and / or 5QI value (delay requirement), the UE can autonomously select one of a set of energy detection thresholds. For example, for higher priority categories, the UE can set the energy detection threshold to a higher value to attempt to transmit even if the channel may be occupied. In some aspects, the set of energy detection thresholds can be derived based on a basic threshold and the number of offset values ​​relative to the basic threshold. The offset value can be determined based at least on the corresponding CAPC value.

[0052] In other exemplary aspects, the UE may share a UE-initiated COT with the gNB. In this way, if the gNB knows when (if ever) the UE will initiate an UL transmission, the gNB can reserve resources. The UE may implicitly or explicitly inform the gNB of the sharing. In a first option, detection of a PUSCH transmission (e.g., DG-PUSCH or CG-PUSCH) for the UE is used as an implicit indicator that the corresponding UE-FFP is shared with the gNB. In a second option, 1 bit may be encoded into the uplink control information (UCI) to indicate whether the UE-FFP may be shared with the gNB. This provides the following flexibility: as described above, different energy thresholds are selected for CCA operation; then, the UE-FFP sharing is indicated accordingly. In a third option, the UE provides a row index of a table configured by higher layers, such as RRC signaling, in which the following items are jointly encoded: the number of time slots for sharing, the offset value indicating the start of the UL transmission, and the CAPC for the UL transmission. A row may indicate that the COT is not shared with the gNB.

[0053] Conditional CCA for PUSCH transmission in FBE operation

[0054] In some exemplary aspects, the UE may additionally perform CCA for a given UL transmission (e.g., DG-PUSCH or CG-PUSCH) if the UL transmission is aligned with a gNB-FFP boundary or if the gap between the start of the gNB-FFP and the start of the PUSCH symbol is less than N2 symbols. If these conditions are met, the UE may transmit the PUSCH immediately after sensing that the channel is idle for at least the sensing slot duration Tsi = 9 microseconds. This configuration is based on a minimum scheduling delay of N2 symbols between PDCCH and PUSCH, making it impossible to schedule PUSCH transmissions via PDCCH within the same gNB-FFP.

[0055] Figure 8 A diagram 800 of conditional CCA operation initiated by a UE according to an exemplary aspect is shown. As described above, the conditional CCA operation depends on the presence or absence of a CG-PUSCH or DG-PUSCH having at least one symbol within a timing window, which starts at the beginning of a gNB-FFP and has a duration of N2 symbols. Figure 8 , gNB-FFP 802 includes PDCCH transmission 806, and gNB-FFP 804 includes PUSCH transmission 810. When the first codeword of PUSCH 604 falls within the N2 codeword window starting at the beginning of gNB-FFP 804, the UE performs Type 2A CCA operation 808 to sense the availability of the channel immediately before PUSCH transmission 810.

[0056] In other exemplary aspects, if within the gNB-FFP, the UE does not detect any DL signal / channel that ends N1 codewords before the start of the UL transmission, the UE does not perform CCA on the UL transmission, where N1 is the PDSCH for the UE's HARQ-ACK timeline capability.

[0057] Those skilled in the art will appreciate that the exemplary aspects described above may be implemented in any suitable software configuration or hardware configuration or combination thereof. Exemplary hardware platforms for implementing the exemplary aspects may include, for example, Intel x86-based platforms with compatible operating systems, Windows OS, Mac platforms and MAC OS, mobile devices with operating systems such as iOS, Android, etc. In other examples, the exemplary aspects of the above methods may be embodied as a program including lines of code stored on a non-transitory computer-readable storage medium, which, when compiled, may be executed on a processor or microprocessor.

[0058] Although this patent application describes various combinations of various aspects, each with different features, those skilled in the art will understand that any feature of one aspect may be combined with features of other aspects or features that are not functionally or logically inconsistent with the operation or function of the device of the aspects disclosed in the present invention in any manner not publicly denied.

[0059] It is understood that the use of personally identifiable information should be subject to privacy policies and practices that are generally recognized to meet or exceed industry or government requirements for maintaining user privacy. Specifically, personally identifiable information data should be managed and processed to minimize the risk of unintentional or unauthorized access or use, and the nature of the authorized use should be clearly stated to users.

[0060] It will be apparent to those skilled in the art that various modifications may be made to the present disclosure without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure is intended to cover modifications and variations of the present disclosure, provided that these modifications and variations are within the scope of the appended claims and their equivalents.

Claims

1. A base station (BS), comprising: a transceiver configured to connect to a user equipment (UE) via a shared channel subject to a channel access operation; and One or more processors communicatively coupled to the transceiver and configured to perform operations including: transmitting a first configuration to the UE for a BS-initiated fixed frame period (FFP) (BS-FFP), and transmitting a second configuration to the UE for a UE-initiated FFP (UE-FFP), wherein the BS-FFP overlaps with the UE-FFP; During the UE-FFP, scheduling uplink (UL) transmissions; and The UL transmission is received from the UE during the BS-FFP when there is no downlink (DL) transmission in the BS-FFP.

2. The BS of claim 1, wherein the operations further comprise: A channel access operation is performed during an idle period of a BS-FFP immediately preceding the BS-FFP, wherein the channel access operation fails.

3. The BS of claim 2, wherein the BS channel access operation comprises a frame-based equipment (FBE) listen-before-talk (LBT) operation (BS FBE).

4. The BS of claim 1, wherein the operations further comprise: During the BS-FFP, one of a physical downlink control channel (PDCCH), a synchronization signal block (SSB), or a periodic channel state indicator reference signal (CSI-RS) is scheduled for the UE.

5. The BS of claim 1, wherein the operations further comprise: A priority value threshold is configured for UL transmission, wherein the UE performs UL transmission based at least on the priority value threshold.

6. The BS of claim 5, wherein the UL transmission comprises a physical uplink shared channel (PUSCH) (DG-PUSCH) granted by a downlink control information (DCI), and wherein the operations further comprise: The priority of the UL transmission is indicated via DCI.

7. The BS of claim 5, wherein the UL transmission comprises a Configuration Grant (CG) Physical Uplink Shared Channel (CG-PUSCH), and wherein the operations further comprise: The priority of the UL transmission is indicated via the CG.

8. The BS of claim 7, wherein the priority is based at least on a quality of service (QoS) of a flow multiplexed in the UL transmission.

9. The BS of claim 1, wherein the operations further comprise: Based at least on receiving the UL transmission, a determination is made whether the UE-FFP is to be shared with the BS.

10. The BS of claim 1, wherein the operations further comprise: Uplink control information (UCI) is received from the UE, the UCI including an indication of whether the UE-FFP is to be shared with the BS.

11. The BS of claim 1 , wherein the operations further comprise: A row index of a table is received from the UE, wherein the BS includes the table, and the row index of the table indicates a number of time slots for sharing, an offset indicating a start of the UL transmission, and a priority of the UL transmission.

12. A baseband processor, the baseband processor being configured to perform operations comprising: Transmitting a first configuration to a user equipment (UE) for a fixed frame period (FFP) (BS-FFP) initiated by a base station (BS), and transmitting a second configuration to the UE for a UE-initiated FFP (UE-FFP), wherein the BS-FFP overlaps with the UE-FFP; During the UE-FFP, scheduling uplink (UL) transmissions; and The UL transmission is received from the UE during the BS-FFP when there is no downlink (DL) transmission in the BS-FFP.

13. The baseband processor of claim 12, wherein the operations further comprise: A channel access operation is performed during an idle period of a BS-FFP immediately preceding the BS-FFP, wherein the channel access operation fails.

14. The baseband processor of claim 12, wherein the operations further comprise: During the BS-FFP, one of a physical downlink control channel (PDCCH), a synchronization signal block (SSB), or a periodic channel state indicator reference signal (CSI-RS) is scheduled for the UE.

15. The baseband processor of claim 12, wherein the operations further comprise: A priority value threshold is configured for UL transmission, wherein the UE performs UL transmission based at least on the priority value threshold.

16. The baseband processor of claim 15, wherein the UL transmission comprises a physical uplink shared channel (PUSCH) (DG-PUSCH) granted by a downlink control information (DCI), wherein the operations further comprise: The priority of the UL transmission is indicated via DCI.

17. The baseband processor of claim 15, wherein the UL transmission comprises a Configuration Grant (CG) Physical Uplink Shared Channel (CG-PUSCH), and wherein the operations further comprise: The priority of the UL transmission is indicated via the CG, wherein the priority is based at least on a quality of service (QoS) of a stream multiplexed in the UL transmission.

18. The baseband processor of claim 12, wherein the operations further comprise: Based at least on receiving the UL transmission, a determination is made whether the UE-FFP is to be shared with the BS.

19. The baseband processor of claim 12, wherein the operations further comprise: Uplink control information (UCI) is received from the UE, the UCI including an indication of whether the UE-FFP is to be shared with the BS.

20. The baseband processor of claim 12, wherein the operations further comprise: A row index of a table is received from the UE, wherein the BS includes the table, and the row index of the table indicates a number of time slots for sharing, an offset indicating a start of the UL transmission, and a priority of the UL transmission.

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