Channel Congestion Measurement

Abstract

The present disclosure provides systems, methods, and apparatus for channel congestion measurement and recovery triggering based on listen-before-talk (LBT) failures. In one aspect, a user equipment (UE) may determine an LBT metric based on the results of an attempt to perform uplink transmissions for an LBT procedure. For example, the UE may determine an absolute amount of LBT failures, a ratio of failed uplink transmissions to total uplink transmission attempts, an absolute amount of LBT successes, or another type of LBT metric. The UE may trigger a recovery action, such as a radio link failure (RLF) recovery action or a bandwidth part switch, based on a determination that the LBT metric meets a threshold.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This patent application claims priority to commonly assigned Indian Patent Application No. 201941017594 entitled "CHANNEL CONGESTION MEASUREMENT" filed on May 2, 2019, and U.S. Non-Provisional Patent Application No. 16 / 793,853 entitled "CHANNEL CONGESTION MEASUREMENT" filed on February 18, 2020, the disclosures of which are hereby incorporated by reference into this patent application, the disclosures of which are deemed to be part of this patent application.

[0002] Aspects of the present disclosure relate generally to wireless communications, and more particularly, to techniques for channel congestion measurements. [Background technology]

[0003] Wireless communication systems have been widely deployed to provide various telecommunication services, such as telephony, video, data, messaging, and broadcast. A typical wireless communication system may employ multiple access technologies capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, etc.). Examples of such multiple access technologies include Code Division Multiple Access (CDMA) systems, Time Division Multiple Access (TDMA) systems, Frequency Division Multiple Access (FDMA) systems, Orthogonal Frequency Division Multiple Access (OFDMA) systems, Single Carrier Frequency Division Multiple Access (SC-FDMA) systems, Time Division Synchronous Code Division Multiple Access (TD-SCDMA) systems, and Long Term Evolution (LTE). LTE / LTE-Advanced is a set of extensions to the Universal Mobile Telecommunications System (UMTS) mobile standard promulgated by the 3rd Generation Partnership Project (3GPP).

[0004] A wireless communication network may include several base stations (BSs) that can support communication for several user equipments (UEs). The user equipments (UEs) may communicate with the base stations (BSs) via a downlink (DL) and an uplink (UL). The DL (or forward link) refers to the communication link from the BS to the UE, and the UL (or reverse link) refers to the communication link from the UE to the BS. As described in more detail herein, a BS may be referred to as a Node B, an LTE evolved Node B (eNB), a gNB, an access point (AP), a radio head, a transmit / receive point (TRP), a New Radio (NR) BS, or a 5G Node B.

[0005] The above multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that allows different UEs to communicate on a city, national, regional, or even global scale. NR, sometimes referred to as 5G, is a set of enhancements to the LTE mobile standard promulgated by the 3rd Generation Partnership Project (3GPP). NR is designed to better support mobile broadband Internet access by improving spectral efficiency, lowering costs, improving services, utilizing new spectrum, using OFDM with cyclic prefix (CP) (CP-OFDM) on the DL and CP-OFDM or SC-FDM (also known as Discrete Fourier Transform Spread OFDM (DFT-s-OFDM) (or a combination thereof) on the UL, as well as better integrating with other open standards that support beamforming, multiple-input multiple-output (MIMO) antenna technology, and carrier aggregation. Summary of the Invention [Means for solving the problem]

[0006] The systems, methods, and devices of the present disclosure each have several inventive aspects, no one of which is solely responsible for the desirable attributes disclosed herein.

[0007] One inventive aspect of the subject matter described in this disclosure may be implemented in a method of wireless communications performed by a user equipment (UE) device. The method may include performing a set of Listen Before Talk (LBT) procedures to access an unlicensed spectrum, determining an LBT metric associated with results of the set of LBT procedures, and selectively triggering a recovery procedure based on the LBT metric satisfying an LBT metric threshold.

[0008] In some aspects, selectively triggering a recovery procedure includes at least one of triggering one or more Radio Link Failure (RLF) related procedures, performing a recovery action, or reporting an LBT metric to a base station (BS). In some aspects, the LBT metric is an LBT failure metric. In some aspects, determining the LBT metric includes determining that an LBT failure has occurred for an LBT procedure of the set of LBT procedures based on a failure to transmit on an uplink transmission instance. In some aspects, the uplink transmission instance is at least one of a Physical Uplink Shared Channel (PUSCH) transmission, a Physical Uplink Control Channel (PUCCH) transmission, or a Physical Random Access Channel (PRACH) transmission, or a Sounding Reference Signal (SRS) transmission.

[0009] In some aspects, the LBT metric is incremented for each failure to transmit on an uplink transmission instance. In some aspects, the LBT metric is incremented based on whether at least one failure to transmit on an uplink transmission instance occurred during a threshold time period. In some aspects, the LBT metric is incremented based on a ratio of uplink transmission failures to uplink attempts during a threshold time period. In some aspects, the LBT metric is incremented based on a threshold amount of uplink transmission failures occurring during the threshold time period. In some aspects, a threshold time period associated with identifying an LBT failure associated with the LBT metric expires and an LBT failure is not determined based on a threshold amount of successful uplink transmissions occurring during the threshold time period.

[0010] In some aspects, the LBT metric is incremented based on whether at least one uplink transmission failure occurs during an evaluation period that includes an uplink transmission. In some aspects, the LBT metric is incremented based on an amount of uplink transmission failures during the evaluation period. In some aspects, the LBT metric is incremented based on whether an amount of uplink transmission failures during the evaluation period meets an uplink transmission failure threshold. In some aspects, an LBT failure associated with the LBT metric is not determined when an amount of successful uplink transmissions meets an uplink transmission threshold during the evaluation period. In some aspects, the LBT metric is incremented based on the occurrence of a scheduled uplink transmission.

[0011] In some aspects, the scheduled uplink transmission includes at least one uplink transmission instance, and is at least one of an uplink grant, a PUCCH, or an uplink channel. In some aspects, the LBT metric is incremented based on an uplink transmission failure occurring for every uplink transmission instance of the scheduled uplink transmission. In some aspects, the LBT metric is incremented based on whether the uplink transmission failure occurs in an uplink burst or a channel occupancy time. In some aspects, the LBT metric is incremented based on an uplink transmission failure occurring for every uplink transmission instance of an uplink burst or a channel occupancy time.

[0012] In some aspects, the LBT metric is at least one of an absolute metric representing at least one LBT failure in the measurement interval, a ratio metric representing a ratio of LBT failures to opportunities that an LBT failure may occur in the measurement interval, an absolute metric representing a threshold amount of LBT failures occurring in the measurement interval, or an absolute metric representing an amount of LBT failures occurring in the measurement interval. In some aspects, the measurement interval is at least one of a set of slots, a set of minislots, a set of opportunities in a single slot, or a set of uplink grants in a channel occupancy time or uplink burst. In some aspects, the LBT metric is per LBT type. In some aspects, the LBT metric includes a first LBT metric for a Category 4 LBT and a second LBT metric for a Category 2 LBT.

[0013] In some aspects, the first LBT metric and the second LBT metric are weighted equally to determine whether the LBT metric meets an LBT metric threshold. In some aspects, selectively triggering the recovery procedure includes triggering the recovery procedure based on the first LBT metric meeting a first threshold or the second LBT metric meeting a second threshold. In some aspects, the first weight is applied to the first LBT metric and the second weight is applied to the second LBT metric to determine whether the LBT metric meets an LBT metric threshold. In some aspects, at least one of the first weight or the second weight is determined based on at least one of a ratio of busy slots of the corresponding channel to a total amount of slots of the corresponding channel, an initial LBT counter value, a congestion window size, or a channel access priority class. In some aspects, the LBT metric includes a first LBT metric for an outer acquired channel occupation time (COT) LBT and a second LBT metric for an inner acquired COT LBT.

[0014] In some aspects, the LBT metric is subband specific or common to multiple subbands. In some aspects, the LBT metric is determined based on at least one of an LBT failure on one or more subbands, an LBT success on one or more subbands, or an LBT failure on a single subband. In some aspects, the LBT metric is related to a secondary cell, and selectively triggering the recovery procedure includes transmitting a report indicating that the LBT metric meets an LBT metric threshold for the secondary cell. In some aspects, the report includes information identifying at least one of the LBT metric, a measurement report for the secondary cell, a COT metric, or a received signal strength indicator (RSSI) for the secondary cell. In some aspects, the LBT metric is at least one of a metric related to an amount of LBT failures, a metric related to a channel busy condition as a result of the LBT failures, or a metric related to an amount of lost data as a result of the LBT failures.

[0015] In some aspects, the LBT metric is related to the first bandwidth part. In some aspects, selectively triggering the recovery procedure includes performing a bandwidth part switch from the first bandwidth part to the second bandwidth part. In some aspects, the second bandwidth part is different from the initial access bandwidth part or the default bandwidth part. In some aspects, the method may include transmitting a report message to a serving cell indicating triggering of the bandwidth part switch. In some aspects, the report message is at least one of a Radio Resource Control (RRC) message, a Medium Access Control (MAC) message, or a physical layer message. In some aspects, the report message includes information identifying at least one of a bandwidth part switch triggering event, or an amount of LBT failures. In some aspects, the method may include transmitting a report message to a serving cell after the bandwidth part switch, the report message may be a Random Access Channel (RACH) message.

[0016] Another inventive aspect of the subject matter described in this disclosure may be implemented in a UE for wireless communication. The UE may include a memory and one or more processors operably coupled to the memory. The memory and the one or more processors may be configured to perform a set of LBT procedures to access an unlicensed spectrum, determine an LBT metric associated with results of the set of LBT procedures, and selectively trigger a recovery procedure based on the LBT metric satisfying an LBT metric threshold.

[0017] Another inventive aspect of the subject matter described in this disclosure may be implemented in a non-transitory computer-readable medium. The non-transitory computer-readable medium may store one or more instructions for wireless communication. The one or more instructions, when executed by one or more processors of a UE, may cause the one or more processors to perform a set of LBT procedures to access an unlicensed spectrum, determine an LBT metric associated with results of the set of LBT procedures, and selectively trigger a recovery procedure based on the LBT metric satisfying an LBT metric threshold.

[0018] Another inventive aspect of the subject matter described in this disclosure may be implemented in an apparatus for wireless communications that may include means for performing a set of LBT procedures to access an unlicensed spectrum, means for determining an LBT metric associated with results of the set of LBT procedures, and means for selectively triggering a recovery procedure based on the LBT metric satisfying an LBT metric threshold.

[0019] Another inventive aspect of the subject matter described in this disclosure may be implemented in a method of wireless communication performed by an apparatus of a BS. The method may include: configuring, for a UE on a first bandwidth part, a second bandwidth part to enable bandwidth part switching for the UE and with respect to an LBT metric, the second bandwidth part being different from an initial access bandwidth part or a default bandwidth part; and receiving a report message indicating triggering of bandwidth part switching by the UE after the LBT metric meets a threshold.

[0020] Another inventive aspect of the subject matter described in this disclosure may be implemented in a BS for wireless communication. The BS may include a memory and one or more processors operably coupled to the memory. The memory and the one or more processors may be configured to configure, for a UE on a first bandwidth part, a second bandwidth part to enable bandwidth part switching for the UE and with respect to an LBT metric, where the second bandwidth part is different from an initial access bandwidth part or a default bandwidth part, and to receive a report message indicating triggering of a bandwidth part switching by the UE after the LBT metric meets a threshold.

[0021] In some aspects, the reporting message is at least one of an RRC message, a MAC message, or a physical layer message. In some aspects, the reporting message includes information identifying at least one of a bandwidth part switching triggering event or an amount of LBT failure. In some aspects, the method may include receiving a RACH message after the bandwidth part switching.

[0022] Another inventive aspect of the subject matter described in this disclosure may be implemented in a non-transitory computer-readable medium. The non-transitory computer-readable medium may store one or more instructions for wireless communication. The one or more instructions, when executed by one or more processors of a BS, may cause the one or more processors to configure, for a UE on a first bandwidth part, a second bandwidth part to enable bandwidth part switching for the UE and with respect to an LBT metric, where the second bandwidth part is different from an initial access bandwidth part or a default bandwidth part, and to receive a report message indicating a trigger of a bandwidth part switching by the UE after the LBT metric meets a threshold.

[0023] Another inventive aspect of the subject matter described in this disclosure may be implemented in an apparatus for wireless communication. The apparatus may include means for configuring, for a UE on a first bandwidth part, a second bandwidth part to enable bandwidth part switching for the UE and with respect to an LBT metric, where the second bandwidth part is different from an initial access bandwidth part or a default bandwidth part, and means for receiving a report message indicating triggering of a bandwidth part switching by the UE after the LBT metric meets a threshold.

[0024] Aspects generally include methods, apparatus, systems, computer program products, non-transitory computer-readable media, user equipment, base stations, wireless communication devices, and processing systems, as fully described herein with reference to and as illustrated by the accompanying drawings and this specification.

[0025] The foregoing has outlined rather broadly the features and technical advantages of examples according to the present disclosure in order that the detailed description that follows may be better understood. Additional features and advantages are described below. The concepts and examples disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure. Such equivalent constructions do not depart from the scope of the appended claims. The nature of the concepts disclosed herein, both their organization and method of operation, together with associated advantages, will be better understood from the following description when considered in conjunction with the accompanying figures. Each of the figures is provided for the purpose of illustration and description, and not as a definition of the limits of the claims. [Brief description of the drawings]

[0026] [Figure 1] FIG. 1 is a block diagram conceptually illustrating an example of a wireless network. [Diagram 2] FIG. 1 is a block diagram conceptually illustrating an example of a base station (BS) in communication with user equipment (UE) in a wireless network. [Figure 3A] FIG. 2 illustrates an example of channel congestion management. [Figure 3B] FIG. 2 illustrates an example of channel congestion management. [Figure 3C] FIG. 2 illustrates an example of channel congestion management. [Figure 3D] FIG. 2 illustrates an example of channel congestion management. [Figure 3E] FIG. 2 illustrates an example of channel congestion management. [Figure 4] FIG. 1 illustrates an example process performed, for example, by a UE. [Diagram 5] FIG. 1 illustrates an exemplary process performed, for example, by a BS. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] Like reference numbers and designations in the various drawings indicate like elements.

[0028] The following description is directed to several implementations for the purpose of describing the inventive aspects of the present disclosure. However, those skilled in the art will readily recognize that the teachings herein can be applied in many different ways. Some of the examples in this disclosure are based on wireless and wired local area network (LAN) communication according to the Institute of Electrical and Electronics Engineers (IEEE) 802.11 wireless standard, the IEEE 802.3 Ethernet standard, and the IEEE 1901 Power Line Communication (PLC) standard. However, the described implementations may be based on any of the IEEE 802.11 standards, the Bluetooth standard, code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), Global System for Mobile Communications (GSM), GSM / General Packet Radio Service (GPRS), Enhanced Data GSM Environment (EDGE), Terrestrial Based Radio (TETRA), Wideband CDMA (W-CDMA), Evolution Data Optimized (EV-DO), 1xEV-DO, EV-DO Rev A, EV-DO Rev B. It may be implemented in any device, system or network capable of transmitting and receiving radio frequency signals according to any of the wireless communications standards including High Speed ​​Packet Access (HSPA), High Speed ​​Downlink Packet Access (HSDPA), High Speed ​​Uplink Packet Access (HSUPA), Evolved High Speed ​​Packet Access (HSPA+), Long Term Evolution (LTE), AMPS, or other known signals used to communicate within a wireless, cellular or Internet of Things (IOT) network, such as a system utilizing 3G, 4G or 5G technologies, or further implementations thereof.

[0029] Some wireless communication frequency ranges may be reserved for unlicensed spectrum. In some unlicensed spectrum deployment implementations, different operators or technologies may use different portions of the unlicensed spectrum simultaneously. Multiple operators may deploy NR, Wi-Fi, or LTE networks at a single location, for example, using the unlicensed spectrum for communication. In such cases, each operator or technology may operate at a common location and use a common set of frequency bands, but remain isolated from other operators or other technologies. For example, a first BS operated by a first operator may not cooperate with a second BS operated by a second operator. In some other unlicensed spectrum deployment implementations, a single operator may deploy multiple ad-hoc cells without a central entity for coordinating the multiple ad-hoc cells. For example, a first BS operated by an operator and a second BS operated by the same operator may not have central coordination via a central entity.

[0030] To gain access to communication resources using unlicensed spectrum, the UE may perform a contention-based access procedure. For example, the UE may perform a listen-before-talk or listen-before-transmit (LBT) procedure to gain access to the communication resources. The LBT procedure may be a category type 2 LBT procedure (Cat-2 LBT) for fixed duration detection or a category 4 LBT procedure (Cat-4 LBT) with variable duration detection, where the variable duration is based on a priority class and a backoff period when the UE detects interference. In some cases, the UE may experience an LBT failure when the UE fails to transmit an uplink transmission during an uplink transmission instance. For example, when an interfering node, such as another UE, attempts to access the same communication resources as the UE, the interfering node may transmit a transmission that interferes with the UE's uplink transmission. When attempting to acquire resources, the UE may perform multiple successive LBT procedures.

[0031] Some aspects described herein provide channel congestion measurements based on LBT failures. For example, the UE may determine an LBT metric based on LBT failures, such as an absolute amount of LBT failures, an amount of LBT failures within a particular measurement period, whether a particular measurement period includes a threshold amount of LBT failures, a ratio of uplink transmission failures to successful uplink transmissions for an LBT procedure, and other possible types of LBT metrics. In this case, when an LBT metric threshold is met, the UE may trigger a recovery action, such as triggering a radio link failure (RLF)-related action, reporting an LBT metric to a BS, or switching bandwidth parts.

[0032] Particular implementations of the subject matter described in this disclosure may be implemented to achieve one or more of the following potential advantages: For example, the UE may avoid preemptively triggering recovery actions when an interfering node causes a relatively large amount of LBT failures within a relatively short period of time. In this manner, the UE may reduce network signaling for performing recovery actions in situations where recovery actions are unnecessary because the consequences of LBT failures are temporary and localized to a relatively short period of time. Furthermore, by triggering a bandwidth part switch after a threshold LBT metric is met for a particular bandwidth part, the UE may enable switching to another bandwidth part with reduced interference, thereby improving network and UE performance.

[0033] FIG. 1 is a block diagram conceptually illustrating an example of a wireless network 100. The wireless network 100 may be an LTE network or some other wireless network, such as a 5G or NR network. The wireless network 100 may include several BSs 110 (depicted as BS 110a, BS 110b, BS 110c, and BS 110d) and other network entities. A BS is an entity that communicates with user equipment (UE) and may also be referred to as a base station, NR BS, Node B, gNB, 5G Node B (NB), access point, or transmit / receive point (TRP). Each BS may provide communication coverage for a particular geographic area. In 3GPP, the term "cell" can refer to a coverage area of ​​a BS, a BS subsystem serving this coverage area, or a combination thereof, depending on the context in which the term is used.

[0034] A BS may provide communication coverage for a macro cell, a pico cell, a femto cell, another type of cell, or a combination thereof. A macro cell may cover a relatively large geographic area (e.g., a few kilometers in radius) and may allow unrestricted access by UEs with a service subscription. A pico cell may cover a relatively small geographic area and may allow unrestricted access by UEs with a service subscription. A femto cell may cover a relatively small geographic area (e.g., a home) and may allow restricted access by UEs with an association with the femto cell (e.g., UEs in a Closed Subscriber Group (CSG)). A BS for a macro cell may be referred to as a macro BS. A BS for a pico cell may be referred to as a pico BS. A BS for a femto cell may be referred to as a femto BS or a home BS. In the example shown in FIG. 1, BS 110a may be a macro BS for macro cell 102a, BS 110b may be a pico BS for pico cell 102b, and BS 110c may be a femto BS for femto cell 102c. A BS may support one or multiple (e.g., three) cells. The terms "eNB," "base station," "NR BS," "gNB," "TRP," "AP," "Node B," "5G NB," and "cell" may be used interchangeably herein.

[0035] In some examples, the cells may not necessarily be fixed and the geographic area of ​​the cells may move according to the location of the mobile BS. In some examples, the BSs may be interconnected to each other and to one or more other BSs or network nodes (not shown) in the wireless network 100 through various types of backhaul interfaces, such as direct physical connections, virtual networks, or combinations thereof, using any suitable transport network.

[0036] The wireless network 100 may also include relay stations. A relay station is an entity that can receive a transmission of data from an upstream station (e.g., a BS or a UE) and send a transmission of data to a downstream station (e.g., a UE or a BS). A relay station may also be a UE that can relay a transmission for another UE. In the example shown in FIG. 1, a relay station 110d may communicate with a macro BS 110a and a UE 120d to facilitate communication between the BS 110a and the UE 120d. A relay station may also be referred to as a relay BS, a relay base station, a relay, etc.

[0037] The wireless network 100 may be a heterogeneous network including different types of BSs, e.g., macro BSs, pico BSs, femto BSs, relay BSs, etc. These different types of BSs may have different transmit power levels, different coverage areas, and different impacts on interference in the wireless network 100. For example, a macro BS may have a high transmit power level (e.g., 5-40 watts), while a pico BS, femto BS, and relay BS may have a lower transmit power level (e.g., 0.1-2 watts).

[0038] A network controller 130 may couple to a set of BSs and provide coordination and control for these BSs. The network controller 130 may communicate with the BSs via a backhaul. The BSs may also communicate with each other directly or indirectly, e.g., via wireless or wireline backhaul.

[0039] The UEs 120 (e.g., 120a, 120b, 120c) may be distributed throughout the wireless network 100, and each UE may be fixed or mobile. A UE may also be referred to as an access terminal, terminal, mobile station, subscriber unit, station, etc. A UE may be a cellular phone (e.g., a smartphone), a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL) station, a tablet, a camera, a gaming device, a netbook, a smartbook, an ultrabook, a medical device or equipment, a biometric sensor / device, a wearable device (smart watch, smart clothing, smart glasses, smart wristband, smart jewelry (e.g., smart ring, smart bracelet)), an entertainment device (e.g., a music or video device, or satellite radio), a vehicle component or sensor, a smart meter / sensor, industrial manufacturing equipment, a global positioning system device, or any other suitable device configured to communicate over a wireless or wired medium.

[0040] Some UEs may be considered as machine type communication (MTC) UEs or evolved or extended machine type communication (eMTC) UEs. MTC UEs and eMTC UEs include, for example, a robot, a drone, a remote device, a sensor, a meter, a monitor, a location tag, etc. that may communicate with a base station, another device (e.g., a remote device), or some other entity. A wireless node may provide, for example, connectivity for or to a network (e.g., a wide area network such as the Internet or a cellular network) via a wired or wireless communication link. Some UEs may be considered as Internet of Things (IoT) devices or may be implemented as NB-IoT (Narrowband Internet of Things) devices. Some UEs may be considered as customer premises equipment (CPE). The UE 120 may be included within a housing that houses components of the UE 120, such as a processor component, a memory component, similar components, or a combination thereof.

[0041] In general, any number of wireless networks may be deployed in a given geographic area. Each wireless network may support a particular RAT and may operate on one or more frequencies. The RAT may also be referred to as a radio technology, an air interface, etc. The frequencies may also be referred to as a carrier, a frequency channel, etc. Each frequency may support a single RAT in a given geographic area to avoid interference between wireless networks of different RATs. In some cases, NR or 5G RAT networks may be deployed.

[0042] In some examples, access to the air interface may be scheduled, and a scheduling entity (e.g., a base station) allocates resources for communication among some or all devices and equipment within the scheduling entity's coverage area or cell. Within this disclosure, as described further below, the scheduling entity may be responsible for scheduling, allocating, reconfiguring, and releasing resources for one or more subordinate entities. That is, for scheduled communication, the subordinate entities utilize resources allocated by the scheduling entity.

[0043] A base station is not the only entity that may function as a scheduling entity. That is, in some examples, a UE may function as a scheduling entity that schedules resources for one or more subordinate entities (e.g., one or more other UEs). In this example, the UE is functioning as a scheduling entity, and the other UEs utilize the resources scheduled by the UE for wireless communication. A UE may function as a scheduling entity in a peer-to-peer (P2P) network, in a mesh network, or in another type of network. In the mesh network example, the UEs may optionally communicate directly with each other in addition to communicating with the scheduling entity.

[0044] Thus, in wireless communication networks with scheduled access to time-frequency resources and having cellular, P2P and mesh configurations, a scheduling entity and one or more subordinate entities may communicate utilizing the scheduled resources.

[0045] In some aspects, two or more UEs 120 (e.g., shown as UE 120a and UE 120e) may communicate directly (e.g., without using the base station 110 as an intermediary to communicate with each other) using one or more sidelink channels. For example, the UEs 120 may communicate using peer-to-peer (P2P) communication, device-to-device (D2D) communication, a vehicle-to-everything (V2X) protocol (which may include a vehicle-to-vehicle (V2V) protocol, a vehicle-to-infrastructure (V2I) protocol, or a similar protocol), a mesh network, or a similar network, or a combination thereof. In this case, the UEs 120 may perform scheduling operations, resource selection operations, as well as other operations described elsewhere herein as being performed by the base station 110.

[0046] 2 is a block diagram conceptually illustrating an example base station 200 in communication with a UE 120. In some aspects, the base station 110 and the UE 120 may be one of the base stations and one of the UEs, respectively, in the wireless network 100 of FIG 1. The base station 110 may be equipped with T antennas 234a through 234t, and the UE 120 may be equipped with R antennas 252a through 252r, where in general T≧1 and R≧1.

[0047] At the base station 110, the transmit processor 220 may receive data for one or more UEs from a data source 212, select one or more modulation and coding schemes (MCS) for each UE based on a channel quality indicator (CQI) received from the UE, process (e.g., encode and modulate) the data for each UE based on the MCS selected for the UE, and provide data symbols to all UEs. The transmit processor 220 may also process system information (e.g., for semi-static resource partitioning information (SRPI), etc.) and control information (e.g., CQI requests, grants, higher layer signaling, etc.) and provide overhead symbols and control symbols. The transmit processor 220 may also generate reference symbols for reference signals (e.g., cell-specific reference signals (CRS)) and synchronization signals (e.g., primary synchronization signals (PSS) and secondary synchronization signals (SSS)). A transmit (TX) multiple-input multiple-output (MIMO) processor 230 may perform spatial processing (e.g., precoding) on ​​the data symbols, control symbols, overhead symbols, or reference symbols, if applicable, and may provide T output symbol streams to T modulators (MODs) 232a through 232t. Each modulator 232 may process a respective output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator 232 may further process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal. The T downlink signals from modulators 232a through 232t may be transmitted via T antennas 234a through 234t, respectively. According to various aspects described in more detail below, synchronization signals may be generated using location coding to convey additional information.

[0048] At the UE 120, antennas 252a-252r may receive downlink signals from the base station 110 or other base stations and may provide received signals to demodulators (DEMODs) 254a-254r, respectively. Each demodulator 254 may condition (e.g., filter, amplify, downconvert, and digitize) the received signal to obtain input samples. Each demodulator 254 may further process the input samples (e.g., for OFDM, etc.) to obtain received symbols. A MIMO detector 256 may obtain received symbols from all R demodulators 254a-254r, perform MIMO detection on the received symbols, if applicable, and provide detected symbols. A receive processor 258 may process (e.g., demodulate and decode) the detected symbols and provide decoded data for the UE 120 to a data sink 260 and provide decoded control and system information to a controller or processor (controller / processor) 280. The channel processor may determine a reference signal received power (RSRP), a received signal strength indicator (RSSI), a reference signal received quality (RSRQ), a channel quality indicator (CQI), etc. In some aspects, one or more components of the UE 120 may be included in a housing.

[0049] On the uplink, at the UE 120, the transmit processor 264 may receive and process data from the data source 262 and control information (e.g., for reports including RSRP, RSSI, RSRQ, CQI, etc.) from the controller / processor 280. The transmit processor 264 may also generate reference symbols for one or more reference signals. The symbols from the transmit processor 264 may be precoded by a TX MIMO processor 266, further processed by modulators 254a-254r (e.g., for DFT-s-OFDM, CP-OFDM, etc.), if applicable, and transmitted to the base station 110. At the base station 110, uplink signals from the UE 120 and other UEs may be received by the antennas 234, processed by the demodulator 232, detected by a MIMO detector 236, if applicable, and further processed by the receive processor 238 to obtain decoded data and control information sent by the UE 120. The receive processor 238 may provide the decoded data to a data sink 239 and provide the decoded control information to a controller or processor (i.e., controller / processor) 240. The base station 110 may include a communication unit 244 and communicate with the network controller 130 via the communication unit 244. The network controller 130 may include a communication unit 294, a controller or processor (i.e., controller / processor) 290, and a memory 292.

[0050] The controller / processor 240 of the base station 110, the controller / processor 280 of the UE 120, or any other component of FIG. 2 may perform one or more techniques associated with channel congestion measurement, as described in more detail elsewhere herein. For example, the controller / processor 240 of the base station 110, the controller / processor 280 of the UE 120, or any other component (or combination of components) of FIG. 2 may perform or direct the operation of, for example, process 400 of FIG. 4, process 500 of FIG. 5, or other processes as described herein. The memories 242 and 282 may store data and program codes for the base station 110 and the UE 120, respectively. The scheduler 246 may schedule UEs for data transmission on the downlink, uplink, or a combination thereof.

[0051] In some aspects, the UE 120 may include means for performing a set of Listen-Before-Talk (LBT) procedures to access the unlicensed spectrum, means for determining an LBT metric associated with a result of the set of LBT procedures, means for selectively triggering a recovery procedure based on the LBT metric satisfying an LBT metric threshold, or a combination thereof. In some aspects, such means may include one or more components of the UE 120 described with respect to FIG.

[0052] In some aspects, the base station 110 may include means for configuring a second bandwidth part to enable bandwidth part switching for a user equipment (UE) and with respect to a listen-before-talk (LBT) metric, where the second bandwidth part is different from the initial access bandwidth part or the default bandwidth part, means for receiving a report message indicating triggering of a bandwidth part switching by the UE after the LBT metric meets a threshold, or a combination thereof. In some aspects, such means may include one or more components of the base station 110 described with respect to FIG. 2.

[0053] 2 are shown as separate components, the functionality described above with respect to the blocks may be implemented in a single hardware, software, or combination component, or in various combinations of components. For example, functionality described with respect to transmit processor 264, receive processor 258, TX MIMO processor 266, or another processor may be performed by or under the control of controller / processor 280.

[0054] 3A-3E are diagrams illustrating a channel congestion measurement example 300. As shown in FIG. 3A, the example 300 includes a UE 120, one or more BSs 110, and one or more other UEs 120.

[0055] 3A by reference numeral 305, the UE 120 may perform a set of LBT procedures to attempt to access the unlicensed spectrum resources of the BS 110. For example, the UE 120 may perform the LBT procedures within or outside the channel occupancy time (COT). In some aspects, the UE 120 may perform the set of LBT procedures using a different set of frequency bands or using a different set of channel types. For example, the UE 120 may perform a first LBT procedure on a first frequency using a physical random access channel (PRACH), a second LBT procedure on a second frequency using a physical uplink control channel (PUCCH), or a third LBT procedure on a third frequency using a physical uplink shared channel (PUSCH).

[0056] In some aspects, the UE 120 may perform one or more successful LBT procedures. For example, the UE 120 may succeed in transmitting an uplink communication associated with the LBT procedure and may classify the LBT procedure as successful. Additionally or alternatively, the UE 120 may fail to transmit an uplink communication associated with the LBT procedure and may classify the LBT procedure as failed. In this case, the UE 120 may fail to transmit an uplink communication based on, for example, another UE 120 performing an LBT procedure to attempt LBT-based access to unlicensed spectrum resources. In some aspects, the UE 120 may experience multiple failures within a threshold time period. For example, during a burst set of transmissions, the UE 120 may fail each transmission of the burst set based on another UE 120 acquiring the channel on which the UE 120 is attempting to transmit.

[0057] As shown in FIG. 3A by reference numeral 310, UE 120 may determine an LBT metric based on the results of a set of LBT procedures. For example, UE 120 may determine an amount of LBT failure and increment the LBT metric by the amount of LBT failure. In this case, UE 120 may count each instance of uplink transmission independently to determine LBT failure. For example, UE 120 may count LBT failures and increment the LBT metric when UE 120 is unable to transmit on an uplink transmission instance as a result of an LBT failure. In this case, UE 120 may determine that a transmission is not complete and increment a counter based at least in part on expiration of a failure detection timer. In contrast, UE 120 may count LBT successes when UE 120 is able to transmit on an uplink transmission instance. In this case, the uplink transmission instance may include a PUSCH transmission instance, a PUCCH transmission instance, a PRACH transmission instance, or another type of uplink channel transmission instance. For example, when UE 120 receives an uplink grant to schedule multiple PUSCHs, UE 120 may count an LBT failure for each PUSCH among the multiple PUSCHs that UE 120 fails to transmit. In some aspects, UE 120 may reset the counter of LBT failures. For example, UE 120 may reset the counter of LBT failures to an initial value (0) based at least in part on expiration of a failure detection timer (without detection of failure), a reconfiguration of a failure detection timer, or a reconfiguration of a counter.

[0058] In some aspects, UE 120 may set a timer, such as a prohibition timer, and may determine an LBT metric based on one or more LBT failures or LBT successes within a time period tracked by the timer. For example, as shown in FIG. 3B by reference numeral 315-1, the timer may track a set of periods during which uplink transmission instances may occur. In this case, when all uplink transmission instances of a particular period, such as a first period and a third period, result in an LBT failure, UE 120 may determine an LBT failure for that particular period and may increment the LBT metric. In contrast, when at least one uplink transmission instance results in an LBT success, as in the case of a second period or a time period not tracked by the timer, UE 120 may determine an LBT success for that particular period and may not increment the LBT metric.

[0059] In some aspects, UE 120 may start a prohibition timer based on an LBT failure occurring. For example, UE 120 may start a prohibition timer to determine whether an uplink transmission success occurs within a threshold time period of an uplink transmission failure. In this case, UE 120 may stop the prohibition timer (and determine that an LBT failure occurred) after the threshold time period or stop the prohibition timer (and determine that an LBT success occurred) after an uplink transmission success within the threshold time period. In this case, each threshold time period results in UE 120 determining a single LBT failure or success for the entire time period, rather than multiple LBT failures for multiple failed uplink transmission instances within the time period.

[0060] In some aspects, the UE 120 may increment the LBT metric based on an amount of uplink failures during a threshold time period associated with the prohibition timer. For example, the UE 120 may increment the LBT metric by a ratio of uplink transmission failures to total uplink transmission attempts during the threshold time period. Additionally or alternatively, the UE 120 may increment the LBT metric based on whether the amount of uplink transmission failures meets a threshold. For example, the UE 120 may determine an LBT failure when a threshold amount of uplink transmission attempts are failures, rather than determining an LBT failure when all uplink transmission attempts for a particular time period are failures. As an example, when the threshold amount is two uplink transmission failures, the UE 120 may determine an LBT failure for a first time period, but not for a third time period. Additionally or alternatively, the UE 120 may stop the prohibition timer and determine an LBT success based on a threshold amount of successful uplink transmissions occurring during the threshold time period, and may determine the LBT metric based on the amount of LBT successes. In some cases, the prohibition timer may be associated with an uplink successful transmission period rather than an uplink failed transmission period.

[0061] In some aspects, UE 120 may use a set of evaluation periods to determine whether to increment an LBT metric based on an LBT failure. For example, as shown in FIG. 3C by reference numeral 315-2, UE 120 may divide a time period into a set of equally sized evaluation periods, and a single LBT result (LBT failure or LBT success) may be determined for each evaluation period. In this case, for example, UE 120 may determine LBT failure for periods 1 and 5 (wherein a failed uplink transmission occurs and no successful uplink transmission occurs), LBT success for periods 2 and 3 (wherein at least one successful uplink transmission occurs), and no result for period 4 (wherein neither a successful nor a failed uplink transmission occurs). In some aspects, the evaluation periods may have different sizes or may overlap in time.

[0062] Additionally or alternatively, the UE 120 may increment the LBT metric by a proportion of uplink transmission failures relative to total uplink transmission attempts per evaluation period. Additionally or alternatively, the UE 120 may determine an LBT failure for a particular evaluation period when an amount of uplink transmission failures meets a threshold amount. Additionally or alternatively, the UE 120 may determine an LBT success for a particular evaluation period when an amount of uplink transmission successes meets a threshold amount. In some aspects, the UE 120 may determine an LBT failure or success when a minimum amount of LBT failures or successes is observed. For example, the UE 120 may refrain from incrementing the LBT metric when only a single uplink transmission failure occurs in a single uplink transmission instance of the evaluation period.

[0063] In some aspects, the UE 120 may determine the LBT metric based on the scheduled uplink transmission. For example, as shown in FIG. 3D by reference numeral 315-3, the UE 120 may receive a set of downlink control information (DCI) including information identifying an uplink grant, a PUSCH transmission instance, or other uplink channel transmission. In this case, the UE 120 may determine an LBT failure and increment the LBT metric when the UE 120 is unable to successfully perform an uplink transmission during any instance scheduled by the DCI. For example, after a first DCI, the UE 120 may determine an LBT failure and increment the LBT metric based on each uplink transmission attempt being unsuccessful. In contrast, after a second DCI, the UE 120 may determine an LBT success based on at least one uplink transmission being successful. Additionally or alternatively, UE 120 may determine the LBT metric based on other decisions regarding the scheduled uplink transmissions, such as based on a ratio of uplink transmission failures to uplink transmission successes, or based on a threshold amount of uplink transmission failures or uplink transmission successes.

[0064] In some aspects, the UE 120 may determine the LBT metric based on an uplink transmission burst set or COT. For example, as shown in FIG. 3E by reference numeral 315-4, the UE 120 may attempt to transmit during multiple uplink transmission bursts or COTs. In this case, the UE 120 may determine an LBT failure and increment the LBT metric when each uplink transmission attempt in the uplink transmission burst or COT is a failure. In contrast, the UE 120 may determine an LBT success when at least one uplink transmission attempt in the uplink transmission burst or COT is successful. Additionally or alternatively, the UE 120 may determine the LBT metric based on other determinations regarding the uplink burst or COT, such as incrementing the LBT metric by a ratio of uplink transmission failures to uplink transmission successes, or determining the LBT metric based on a threshold amount of uplink transmission failures or uplink transmission successes in the uplink burst or COT.

[0065] In some aspects, the UE 120 may determine the LBT metric based on the uplink transmission starting point. For example, the UE 120 may determine LBT success and increment the LBT metric when the UE 120 can successfully perform uplink transmission at any available uplink transmission starting point. Additionally or alternatively, the UE 120 may increment the LBT metric by a ratio of the amount of starting points at which the UE 120 failed to attempt to perform uplink transmission to the total amount of starting points. Additionally or alternatively, the UE 120 may determine LBT success and increment the LBT metric when a threshold percentage or amount of starting points is associated with failed uplink transmission attempts. Additionally or alternatively, the UE 120 may determine the LBT metric per slot, per minislot, or per uplink grant, rather than per starting point. For example, UE 120 may determine LBT success and increment the LBT metric based on using multiple starting points within a single slot, multiple starting points within an uplink grant or uplink burst or COT, multiple slots within an uplink grant or uplink burst or COT, or multiple uplink grants within an uplink burst or COT.

[0066] In some aspects, the UE 120 may determine a plurality of different LBT metrics. For example, the UE 120 may determine a first LBT metric for a Category 2 LBT (Cat-2 LBT) based uplink transmission attempt and a second LBT metric for a Category 4 LBT (Cat-4 LBT) based uplink transmission attempt. In some aspects, the UE 120 may determine a first LBT metric for an uplink transmission attempt within an acquired COT and a second LBT metric for an uplink transmission attempt outside the acquired COT. Additionally or alternatively, the UE 120 may determine a first LBT metric for a first subband and a second LBT metric for a second subband. In this case, the UE 120 may perform Cat-4 LBT on the primary subbands of the first subband and the second subband and Cat-2 LBT on the secondary subbands of the first subband and the second subband. Additionally or alternatively, UE 120 may perform Cat-4 LBT on both the first subband and the second subband.

[0067] Additionally or alternatively, UE 120 may determine the LBT metric based on UE capabilities. For example, when UE capabilities of UE 120 allow transmission on a subset of subbands, UE 120 may determine LBT success when Cat-4 LBT or Cat-2 LBT succeeds on a first subset of subbands and fails on a second subset of subbands. In contrast, in the case of different capabilities, when UE 120 can perform uplink transmission only when the LBT procedure succeeds on each subband, UE 120 may determine LBT failure if Cat-2 LBT or Cat-4 LBT fails on any subband. In some aspects, UE 120 may determine different LBT metrics for each subband or a common LBT metric for multiple subbands.

[0068] 3A by reference numeral 320, the UE 120 may selectively trigger recovery procedures based on the LBT metric. For example, as indicated by reference numeral 320′, the UE 120 may communicate with the BS 110 to trigger a radio link failure (RLF)-based recovery action, a bandwidth part switch, or another type of recovery action.

[0069] In some aspects, the UE 120 may determine to trigger a recovery procedure based on an LBT metric satisfying a threshold. For example, an LBT metric representing an amount of LBT failures may exceed an absolute threshold, an LBT metric representing a ratio of failed uplink transmission attempts to uplink transmission opportunities may satisfy a ratio threshold for a threshold time period, or another type of threshold may be met. In some aspects, the UE 120 may determine that a threshold is met based on one or more of a plurality of LBT metrics. For example, the UE 120 may determine that an equally weighted combination of the Cat-4 LBT metric and the Cat-2 LBT metric exceeds a combined threshold. Additionally or alternatively, the UE 120 may determine that the Cat-4 LBT metric satisfies a first threshold or that the Cat-2 LBT metric satisfies a second threshold. In this case, the UE 120 may report the Cat-4 LBT metric, the Cat-2 LBT metric, or a combination of the Cat-2 LBT metric and the Cat-4 LBT metric when triggering the recovery procedure. Additionally or alternatively, UE 120 may determine that a particular subband LBT metric meets a threshold and may trigger a recovery procedure.

[0070] Additionally or alternatively, UE 120 may apply different weights to the Cat-2 LBT metrics and the Cat-4 LBT metrics when combining the Cat-2 LBT metrics and the Cat-4 LBT metrics when determining whether a combined threshold is met. For example, UE 120 may apply weights based on the percentage of time that each channel is sensed busy for Cat-2 LBT or Cat-4 LBT based on uplink transmission failures, initial LBT counter values, congestion window size, or channel access priority class.

[0071] In some aspects, based on the determination that the LBT metric is satisfied, the UE 120 may trigger a bandwidth part switch. For example, the UE 120 may switch from a first bandwidth part on which the UE 120 is operating to a second bandwidth part configured by the BS 110 that is the serving cell for the UE 120. In some aspects, the UE 120 may switch to a bandwidth part that is not an initial access bandwidth part or a default bandwidth part. For example, the UE 120 may switch from an initial access bandwidth part of a relatively narrow bandwidth to a different bandwidth part of a relatively wide bandwidth. Additionally or alternatively, the UE 120 may perform a random access channel (RACH) procedure after the bandwidth part switch (without indicating the bandwidth part switch to the BS 110 at an earlier time).

[0072] In some aspects, when uplink resources are configured or granted for UE 120, UE 120 may transmit a message to BS 110 indicating a bandwidth part switch. For example, UE 120 may transmit a radio resource control (RRC) message, a medium access control (MAC) message, or a physical layer message to indicate the bandwidth part switch. In this case, UE 120 may include information indicating that the bandwidth part switch is based on the LBT metric meeting a threshold or information identifying an amount of LBT failure.

[0073] In some aspects, UE 120 may transmit a message indicating that the LBT metric meets a threshold rather than triggering a recovery action. For example, when UE 120 determines that the LBT metric is met on the secondary cell but not on the primary cell, UE 120 may indicate to BS 110 that the LBT metric is met and may avoid triggering an RLF-based recovery action. In this case, UE 120 may indicate that an LBT failure has occurred, may identify the LBT failure metric, may perform network measurements and provide a measurement report for the secondary cell, or may include other metrics such as a COT metric or a received signal strength indicator (RSSI).

[0074] 4 illustrates an example process 400, performed, for example, by a UE. The example process 400 illustrates that a UE, such as UE 120, performs operations associated with channel congestion measurements.

[0075] 4, in some aspects, the process 400 may include performing a set of LBT procedures to access the unlicensed spectrum (block 410). For example, the UE (using the receive processor 258, the transmit processor 264, the controller / processor 280, or the memory 282) may perform the set of LBT procedures to access the unlicensed spectrum. In some aspects, the UE may include an interface for performing the set of LBT procedures.

[0076] 4, in some aspects, the process 400 may include determining an LBT metric associated with the outcome of the set of LBT procedures (block 420). For example, the UE (using the receive processor 258, the transmit processor 264, the controller / processor 280, or the memory 282) may determine an LBT metric associated with the outcome of the set of LBT procedures. In some aspects, the UE may include an interface for determining the LBT metric.

[0077] 4, in some aspects, the process 400 may include selectively triggering a recovery procedure based on the LBT metric satisfying an LBT metric threshold (block 430). For example, the UE (using the receive processor 258, the transmit processor 264, the controller / processor 280, or the memory 282) may selectively trigger the recovery procedure based on the LBT metric satisfying an LBT metric threshold. In some aspects, the UE may include an interface for selectively triggering the recovery procedure.

[0078] Process 400 may include additional aspects, such as any single aspect or any combination of aspects described below or with respect to one or more other processes described elsewhere herein.

[0079] In a first aspect, selectively triggering a recovery procedure includes at least one of triggering one or more RLF-related procedures, performing a recovery action, or reporting an LBT metric to the BS.

[0080] In a second aspect, alone or in combination with the first aspect, the LBT metric is an LBT failure metric.

[0081] In a third aspect, alone or in combination with one or more of the first and second aspects, determining the LBT metric includes determining that an LBT failure has occurred for an LBT procedure of the set of LBT procedures based on a failure to transmit on an uplink transmission instance.

[0082] In a fourth aspect, alone or in combination with one or more of the first to third aspects, the uplink transmission instance is at least one of a PUSCH transmission, a PUCCH transmission, or a PRACH transmission, or an SRS transmission.

[0083] In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, the LBT metric is incremented for each failure to transmit on an uplink transmission instance.

[0084] In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, the LBT metric is incremented based on whether at least one failure to transmit on an uplink transmission instance occurred for a threshold time period.

[0085] In a seventh aspect, alone or in combination with one or more of the first to sixth aspects, the LBT metric is incremented based on a ratio of uplink transmission failures to uplink attempts during a threshold time period.

[0086] In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, the LBT metric is incremented based on a threshold amount of uplink transmission failures occurring during a threshold time period.

[0087] In a ninth aspect, alone or in combination with one or more of the first through eighth aspects, a threshold time period associated with identifying an LBT failure associated with an LBT metric expires, and the LBT failure is not determined based on a threshold amount of successful uplink transmissions having occurred during the threshold time period.

[0088] In a tenth aspect, alone or in combination with one or more of the first to ninth aspects, the LBT metric is incremented based on whether at least one uplink transmission failure occurred during an evaluation period that includes an uplink transmission.

[0089] In an eleventh aspect, alone or in combination with one or more of the first through tenth aspects, the LBT metric is incremented based on an amount of uplink transmission failures during an evaluation period.

[0090] In a twelfth aspect, alone or in combination with one or more of the first through eleventh aspects, the LBT metric is incremented based on whether the amount of uplink transmission failures during the evaluation period meets an uplink transmission failure threshold.

[0091] In a thirteenth aspect, alone or in combination with one or more of the first to twelfth aspects, an LBT failure associated with an LBT metric is not determined when the amount of successful uplink transmissions meets an uplink transmission threshold during an evaluation period.

[0092] In a fourteenth aspect, alone or in combination with one or more of the first through thirteenth aspects, the LBT metric is incremented based on the occurrence of a scheduled uplink transmission.

[0093] In a fifteenth aspect, alone or in combination with one or more of the first to fourteenth aspects, the scheduled uplink transmission includes at least one uplink transmission instance and is at least one of an uplink grant, a PUCCH, or an uplink channel.

[0094] In a sixteenth aspect, alone or in combination with one or more of the first to fifteenth aspects, the LBT metric is incremented based on an uplink transmission failure occurring for each uplink transmission instance of a scheduled uplink transmission.

[0095] In a seventeenth aspect, alone or in combination with one or more of the first to sixteenth aspects, the LBT metric is incremented based on whether an uplink transmission failure occurred in an uplink burst or a channel occupancy time.

[0096] In an eighteenth aspect, alone or in combination with one or more of the first to seventeenth aspects, the LBT metric is incremented based on an uplink transmission failure occurring for each uplink transmission instance of an uplink burst or channel occupancy time.

[0097] In a nineteenth aspect, alone or in combination with one or more of the first through eighteenth aspects, the LBT metric is at least one of an absolute metric representing at least one LBT failure in the measurement interval, a ratio metric representing a ratio of LBT failures to the chances that an LBT failure may occur in the measurement interval, an absolute metric representing a threshold amount of LBT failures occurring in the measurement interval, or an absolute metric representing the amount of LBT failures occurring in the measurement interval.

[0098] In a twentieth aspect, alone or in combination with one or more of the first to nineteenth aspects, the measurement interval is at least one of a set of slots, a set of minislots, a set of opportunities in a single slot, or a set of uplink grants in a channel occupancy time or an uplink burst.

[0099] In a twenty-first aspect, alone or in combination with one or more of the first to twentieth aspects, the LBT metric is per LBT type.

[0100] In a twenty-second aspect, alone or in combination with one or more of the first to twenty-first aspects, the LBT metric includes a first LBT metric for a category 4 LBT and a second LBT metric for a category 2 LBT.

[0101] In a twenty-third aspect, alone or in combination with one or more of the first through twenty-second aspects, the first LBT metric and the second LBT metric are equally weighted to determine whether the LBT metric satisfies an LBT metric threshold.

[0102] In a twenty-fourth aspect, alone or in combination with one or more of the first through twenty-third aspects, selectively triggering the recovery procedure includes triggering the recovery procedure based on a first LBT metric satisfying a first threshold or a second LBT metric satisfying a second threshold.

[0103] In a twenty-fifth aspect, alone or in combination with one or more of the first through twenty-fourth aspects, a first weight is applied to a first LBT metric and a second weight is applied to a second LBT metric to determine whether the LBT metric satisfies an LBT metric threshold. In some aspects, at least one of the first weight or the second weight is determined based on at least one of a ratio of busy slots of the corresponding channel to a total amount of slots of the corresponding channel, an initial LBT counter value, a congestion window size, or a channel access priority class.

[0104] In a twenty-sixth aspect, alone or in combination with one or more of the first to twenty-fifth aspects, the LBT metric includes a first LBT metric for an outer acquired COT LBT and a second LBT metric for an inner acquired COT LBT.

[0105] In a twenty-seventh aspect, alone or in combination with one or more of the first through twenty-sixth aspects, the LBT metric is subband-specific or common to multiple subbands.

[0106] In a twenty-eighth aspect, alone or in combination with one or more of the first to twenty-seventh aspects, the LBT metric is determined based on at least one of an LBT failure on one or more subbands, an LBT success on one or more subbands, or an LBT failure on a single subband.

[0107] In a twenty-ninth aspect, alone or in combination with one or more of the first to twenty-eighth aspects, the LBT metric relates to a secondary cell, and selectively triggering the recovery procedure includes sending a report indicating that the LBT metric meets an LBT metric threshold for the secondary cell.

[0108] In a 30th aspect, alone or in combination with one or more of the first to twenty-ninth aspects, the report includes information identifying at least one of an LBT metric, a measurement report for the secondary cell, a COT metric, or an RSSI for the secondary cell.

[0109] In a thirty-first aspect, alone or in combination with one or more of the first to thirtieth aspects, the LBT metric is at least one of a metric related to the amount of LBT failures, a metric related to a channel busy state as a result of the LBT failures, or a metric related to the amount of data lost as a result of the LBT failures.

[0110] In a thirty-second aspect, alone or in combination with one or more of the first through thirty-first aspects, the LBT metric relates to the first bandwidth part. In some aspects, selectively triggering the recovery procedure includes performing a bandwidth part switch from the first bandwidth part to the second bandwidth part.

[0111] In a thirty-third aspect, alone or in combination with one or more of the first to thirty-second aspects, the second bandwidth part is different from the initial access bandwidth part or the default bandwidth part.

[0112] In a thirty-fourth aspect, alone or in combination with one or more of the first through thirty-third aspects, the process 400 may include sending a report message to the serving cell indicating triggering of a bandwidth part switch. In some aspects, the report message is at least one of an RRC message, a MAC message, or a physical layer message.

[0113] In a thirty-fifth aspect, alone or in combination with one or more of the first to thirty-fourth aspects, the reporting message includes information identifying at least one of a bandwidth part switching triggering event or an amount of LBT failure.

[0114] In a thirty-sixth aspect, alone or in combination with one or more of the first to thirty-fifth aspects, the process 400 may include sending a report message to the serving cell after the bandwidth part switch, where the report message may be a RACH message.

[0115] 4 illustrates example blocks of process 400, in some aspects process 400 may include additional, fewer, different, or differently arranged blocks compared to those illustrated in FIG 4. Additionally or alternatively, two or more of the blocks of process 400 may be performed in parallel.

[0116] 5 illustrates an example process 500, performed, for example, by a BS. The example process 500 illustrates that a BS, such as BS 110, performs operations associated with channel congestion measurements.

[0117] As shown in FIG. 5, in some aspects, the process 500 may include configuring (block 510) a second bandwidth part for a UE on a first bandwidth part to enable bandwidth part switching for the UE and with respect to the LBT metric, the second bandwidth part being different from the initial access bandwidth part or the default bandwidth part. For example, the BS (using the transmit processor 220, the receive processor 238, the controller / processor 240, or the memory 242) may configure the second bandwidth part for a UE on a first bandwidth part to enable bandwidth part switching for the UE and with respect to the LBT metric. In some aspects, the second bandwidth part is different from the initial access bandwidth part or the default bandwidth part. In some aspects, the BS may include an interface for configuring the second bandwidth part.

[0118] 5, in some aspects, the process 500 may include receiving a report message indicating a trigger of a bandwidth part switching by the UE after the LBT metric meets a threshold (block 520). For example, the BS (using the transmit processor 220, the receive processor 238, the controller / processor 240, or the memory 242) may receive the report message indicating a trigger of a bandwidth part switching by the UE after the LBT metric meets a threshold. In some aspects, the BS may include an interface for receiving the report message.

[0119] Process 500 may include additional aspects, such as any single aspect or any combination of aspects described below or with respect to one or more other processes described elsewhere herein.

[0120] In a first aspect, the reporting message is at least one of an RRC message, a MAC message, or a physical layer message.

[0121] In a second aspect, alone or in combination with the first aspect, the reporting message includes information identifying at least one of a bandwidth part switching triggering event, or an amount of LBT failures.

[0122] In a third aspect, alone or in combination with one or more of the first and second aspects, the process 500 may include receiving a RACH message after a bandwidth part switch.

[0123] 5 illustrates example blocks of process 500, in some aspects process 500 may include additional, fewer, different, or differently arranged blocks compared to those illustrated in FIG 5. Additionally or alternatively, two or more of the blocks of process 500 may be performed in parallel.

[0124] The above disclosure provides illustration and description, and is not intended to be exhaustive or to limit the embodiments to the precise form disclosed. Modifications and variations may be made in light of the above disclosure or may be acquired from practice of the embodiments.

[0125] As used herein, the term "component" shall be broadly interpreted as hardware, firmware, or a combination of hardware and software. As used herein, a processor is implemented in hardware, firmware, or a combination of hardware and software. As used herein, the phrase "based on" shall be broadly interpreted to mean "based at least in part on."

[0126] As used herein, depending on the context, "meeting a threshold" can refer to a value being greater than the threshold, greater than or equal to the threshold, less than the threshold, less than or equal to the threshold, equal to the threshold, or not equal to the threshold.

[0127] As used herein, a phrase referring to "at least one of" a list of items refers to any combination of those items, including single members. As an example, "at least one of a, b, or c" is intended to encompass a, b, c, ab, ac, bc, and abc.

[0128] The various example logic, logic blocks, modules, circuits, and algorithmic processes described in connection with the aspects disclosed herein may be implemented as electronic hardware, computer software, or a combination of both. Interchangeability of hardware and software has been described generally in terms of functionality and illustrated in the various example components, blocks, modules, circuits, and processes described above. Whether such functionality is implemented in hardware or software depends on the particular application and design constraints imposed on the overall system.

[0129] The hardware and data processing devices used to implement the various example logic, logic blocks, modules and circuits described in connection with the aspects disclosed herein may be implemented or performed with general purpose single-chip or multi-chip processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs) or other programmable logic devices, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, or any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. In some aspects, particular processes and methods may be performed by circuitry specific to a given function.

[0130] In one or more aspects, the functions described may be implemented in hardware, digital electronic circuitry, computer software, firmware, or any combination thereof, including the structures disclosed herein and their structural equivalents. Aspects of the subject matter described herein may also be implemented as one or more computer programs, i.e., one or more modules of computer program instructions encoded on a computer storage medium for execution by or to control the operation of a data processing apparatus.

[0131] If implemented in software, the functions may be stored on or transmitted over a computer-readable medium as one or more instructions or code. The processes of the methods or algorithms disclosed herein may be implemented in processor-executable software modules that may reside on a computer-readable medium. Computer-readable media includes both computer storage media and communication media, including any medium that may enable a computer program to be transferred from one place to another. A storage medium may be any available medium that may be accessed by a computer. By way of example, and not limitation, such computer-readable media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that may be used to store desired program code in the form of instructions or data structures and that may be accessed by a computer. Also, any connection may be properly referred to as a computer-readable medium. As used herein, disk and disc include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk, and Blu-ray disc, where disks typically reproduce data magnetically and discs reproduce data optically using lasers. Combinations of the above should also be included within the scope of computer-readable media. In addition, operations of a method or algorithm may reside on machine-readable and computer-readable media, which may be incorporated into a computer program product as one or any combination or set of code and instructions.

[0132] Various modifications to the embodiments described in this disclosure may be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments without departing from the spirit or scope of the disclosure. Thus, the claims are not intended to be limited to the embodiments shown herein, but are to be accorded the widest scope consistent with this disclosure, the principles and novel features disclosed herein.

[0133] In addition, those skilled in the art will readily appreciate that the terms "upper" and "lower" may be used to facilitate description of the figures, and refer to relative positions that correspond to the orientation of the figure on a suitably oriented page, and may not reflect the proper orientation of any implemented device.

[0134] Some features described herein in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented separately in multiple embodiments or in any suitable subcombination. Furthermore, although features may be described above as working in some combinations and may even be initially claimed as such, one or more features from the claimed combination may, in some cases, be deleted from the combination, and the claimed combination may be directed to a subcombination or a variation of the subcombination.

[0135] Similarly, although operations are shown in the figures in a particular order, this should not be understood as requiring such operations to be performed in the particular order shown or in a sequential order, or that all of the shown operations be performed, to achieve desirable results. Additionally, the figures may generally depict one or more exemplary processes in the form of a flow diagram. However, other operations not shown may be incorporated into the generally depicted exemplary process. For example, one or more additional operations may be performed before, after, simultaneously with, or between any of the depicted operations. In some circumstances, multitasking and parallel processing may be advantageous. Furthermore, the separation of various system components in the aspects described above should not be understood as requiring such separation in all aspects, and it should be understood that the described program components and systems may generally be integrated together in a single software product or packaged in multiple software products. Additionally, other aspects fall within the scope of the following claims. In some cases, the actions recited in the claims may be performed in a different order and still achieve desirable results. [Explanation of symbols]

[0136] 100 Wireless Network 102a Macro Cell 102b Picocell 102c Femtocell 110 BS, base station 110a BS, Macro BS 110b BS 110c BS 110d BS, relay station 120UE 120a UE 120b UE 120c UE 120d UE 120e UE 130 Network Controller 200 Examples 212 Data Source 220 Transmit Processor 230 Transmit (TX) Multiple Input Multiple Output (MIMO) Processor 232 Modulators and demodulators 232a~232t Modulator (MOD) 234 Antenna 234a~234t Antenna 236 MIMO Detector 238 Receive Processor 239 Data Sink 240 Controllers / Processors 242 Memory 244 Communication Unit 246 Scheduler 252a~252r Antenna 254 Demodulator 254a~254r Demodulators (DEMOD), Modulators 256 MIMO Detector 258 Receive Processor 260 Data Sink 262 Data Sources 264 Transmit Processor 266 TX MIMO Processor 280 Controller or Processor, Controller / Processor 282 Memory 290 Controller or Processor 292 Memory 294 Communication Unit 300 Examples 400 processes 500 processes

Claims

1. 1. A method of wireless communication performed by a user equipment (UE) device, comprising: performing a set of listen-before-talk (LBT) procedures; setting a timer associated with an LBT failure; determining an amount of LBT failures associated with outcomes of the set of LBT procedures within a time period tracked by the timer; selectively triggering a recovery procedure based on an amount of LBT failures satisfying an LBT metric threshold; selectively triggering the recovery procedure when an amount of the LBT failures meets the LBT metric threshold on a first bandwidth part; performing a bandwidth part switch from the first bandwidth part to a second bandwidth part, the second bandwidth part being configured by a serving cell for the UE; sending a Medium Access Control (MAC) message to the serving cell indicating that the LBT metric threshold has been met on the first bandwidth part; Including, selectively triggering the recovery procedure when the amount of LBT failures meets the LBT metric threshold on a secondary cell; sending a report to the serving cell indicating that the LBT metric threshold has been met on the secondary cell; and resetting an LBT metric associated with an amount of LBT failures based on at least one of a reconfiguration of the LBT metric or a reconfiguration of the timer; A method comprising:

2. The MAC message comprises: The LBT metric, measurement report, Channel Occupancy Time (COT) metric, or Received Signal Strength Indicator (RSSI) The method of claim 1 , further comprising information identifying at least one of:

3. The LBT metric is A metric related to the amount of LBT failures, Metrics related to channel busy conditions as a result of LBT failure, or A metric related to the amount of data lost as a result of an LBT failure The method of claim 1 , further associated with at least one of:

4. The method of claim 1 , wherein the second bandwidth part is different from an initial access bandwidth part or a default bandwidth part.

5. The method of claim 1, further comprising the step of performing a random access channel (RACH) procedure after the bandwidth part switching.

6. The method of claim 1, further comprising: determining that an LBT failure has occurred for an LBT procedure of the set of LBT procedures based on a failure to transmit on an uplink transmission instance; The uplink transmission instance: Physical Uplink Shared Channel (PUSCH) transmission, Physical Uplink Control Channel (PUCCH) transmission, or Physical Random Access Channel (PRACH) transmission, or Sounding Reference Signal (SRS) transmission The method of claim 1, wherein the at least one of

7. the LBT metric is incremented for each failure to transmit on an uplink transmission instance; the LBT metric is incremented based on whether at least one failure to transmit on an uplink transmission instance occurred during the time period; or The method of claim 1 , wherein the LBT metric is incremented based on a threshold amount of uplink transmission failures occurring for a threshold time period.

8. 2. The method of claim 1, wherein a threshold time period associated with identifying an LBT failure associated with the LBT metric expires, and the LBT failure is not determined based on a threshold amount of successful uplink transmissions having occurred during the threshold time period.

9. A method of wireless communication performed by a node device, comprising: the node is a serving cell for a user equipment (UE) on a first bandwidth part; configuring the second bandwidth part to enable a bandwidth part switch from the first bandwidth part to a second bandwidth part with respect to an amount of listen-before-talk (LBT) failures for the UE and within a time period associated with a timer, the second bandwidth part being different from an initial access bandwidth part or a default bandwidth part; Selectively, receiving a Medium Access Control (MAC) message indicating triggering of the bandwidth part switching by the UE when an amount of the LBT failures meets a threshold on the first bandwidth part, the bandwidth part switching being performed when the amount of the LBT failures meets the threshold on the first bandwidth part; receiving a report indicating that the amount of LBT failures meets the threshold on the secondary cell when the amount of LBT failures meets the threshold on the secondary cell, wherein an LBT metric associated with the amount of LBT failures is reset based on at least one of a reconfiguration of the LBT metric or a reconfiguration of the timer; A method comprising:

10. The MAC message: Bandwidth part switching triggering event, or Amount of LBT failures The method of claim 9, further comprising information identifying at least one of:

11. The method of claim 9, wherein a Random Access Channel (RACH) procedure is performed after the bandwidth part switching.

12. An apparatus for wireless communication in a User Equipment (UE), comprising means for performing the method according to any one of claims 1 to 8.

13. An apparatus for wireless communication in a node, the node being a serving cell for a user equipment (UE) on a first bandwidth part, the apparatus comprising means for performing a method according to any one of claims 9 to 11.

Images