Handling of Listen-Before-Talk failures during Radio Resource Control procedures

Abstract

Disclosed is the handling of listen - before - talk (LBT) failures during a Radio Resource Control (RRC) procedure. A User Equipment (UE) can be configured to monitor consistent uplink and downlink LBT failures on a Bandwidth Part (BWP) configured for a target cell. When the UE determines that a consistent LBT failure has occurred regarding the BWP, the UE can determine the LBT failure status on the BWP. In response, the UE can perform a recovery procedure, which can include: selecting a new BWP associated with the target cell and having configured uplink resources; performing a cell reselection procedure; or switching to idle to perform cell selection. The UE can then report the LBT failure based on the cell identity and the BWP.

Description

[0001] Cross - Reference to Related Applications

[0002] This application claims the benefit of U.S. Patent Application No. 17 / 226,009, entitled "HANDLING OF LISTEN BEFORE TALK FAILURES DURING RADIO RESOURCE CONTROL PROCEDURES", filed on April 8, 2021, and U.S. Provisional Patent Application No. 63 / 007,754, entitled "HANDLING OF LISTEN BEFORE TALK FAILURES DURING RADIO RESOURCE CONTROL PROCEDURES", filed on April 9, 2020. The entire contents of the above - mentioned applications are hereby incorporated by reference in their entirety. Technical Field

[0003] Broadly speaking, aspects of the present disclosure relate to wireless communication systems, and more particularly, aspects of the present disclosure relate to the handling of listen - before - talk (LBT) failures during radio resource control (RRC) procedures. Background Art

[0004] Wireless communication networks are widely deployed to provide various communication services such as voice, video, packet data, messaging, broadcasting, etc. These wireless networks can be multi - access networks capable of supporting multiple user devices (UEs). Such networks (which are typically multi - access networks) support communication for multiple users by sharing available network resources. An example of such a network is the Universal Terrestrial Radio Access Network (UTRAN). The UTRAN is a radio access network (RAN) defined as part of the Universal Mobile Telecommunications System (UMTS) (the third - generation (3G) mobile phone technology supported by the Third Generation Partnership Project (3GPP)). Examples of multi - access network formats include Code Division Multiple Access (CDMA) networks, Time Division Multiple Access (TDMA) networks, Frequency Division Multiple Access (FDMA) networks, Orthogonal FDMA (OFDMA) networks, and Single - Carrier FDMA (SC - FDMA) networks.

[0005] A wireless communication network may include multiple base stations or Node Bs capable of supporting communication for multiple user devices (UEs). The UEs can communicate with the base stations via the downlink and the uplink. The downlink (or forward link) refers to the communication link from the base station to the UE, and the uplink (or reverse link) refers to the communication link from the UE to the base station.

[0006] A base station may send data and control information to a UE on a downlink, and / or may receive data and control information from the UE on an uplink. On the downlink, transmissions from the base station may encounter interference due to transmissions from neighboring base stations or transmissions from other radio frequency (RF) transmitters. On the uplink, transmissions from the UE may encounter interference from uplink transmissions of other UEs communicating with neighboring base stations or from other radio RF transmitters. This interference may degrade the performance on both the downlink and the uplink.

[0007] Due to the continuous growth of the demand for mobile broadband access, as more UEs access long-distance wireless communication networks and more short-distance wireless systems are deployed in communities, the likelihood of interfering with and congesting the network also increases. Research and development continuously drive the development of wireless technologies, not only to meet the growing demand for mobile broadband access, but also to improve and enhance the user experience of mobile communication. Summary of the Invention

[0008] In one aspect of the present disclosure, a method of wireless communication includes: receiving, by a UE, a handover command to a target cell from a source cell on a shared communication spectrum; determining, by the UE, a listen-before-talk (LBT) failure status on a current bandwidth part (BWP) configured for the target cell, where the LBT failure status is determined based on a consistent LBT failure detected on the current BWP; and performing, by the UE, a failure recovery process in response to the LBT failure status, where the failure recovery process includes one or more of the following: completion of the handover and reporting of the LBT failure status.

[0009] In an additional aspect of the present disclosure, a method of wireless communication includes: identifying, by a UE, a target cell for random access on a shared communication spectrum; initiating, by the UE, a random access process on an initial BWP associated with the target cell; determining, by the UE, an LBT failure status on the initial BWP based on a consistent LBT failure detected on the initial BWP; and performing, by the UE, a failure recovery process in response to the LBT failure status, where the failure recovery process includes one or more of the following: completion of the random access process and reporting of the LBT failure status.

[0010] In an additional aspect of the present disclosure, a method of wireless communication includes: identifying, by a UE, a target cell having an inactive connection on a shared communication spectrum, wherein the target cell is identified for connection recovery; initiating, by the UE, a connection recovery process on a BWP associated with the target cell; determining, by the UE, an LBT failure status on the BWP based on a detected consistent LBT failure on the BWP; and performing, by the UE, a failure recovery process in response to the LBT failure status, wherein the failure recovery process includes one or more of the following: completion of the random access process and reporting of the LBT failure status.

[0011] In an additional aspect of the present disclosure, a method of wireless communication includes: initiating, by a UE, an uplink communication process with a target cell on a shared communication spectrum, wherein the uplink communication process includes one of a handover command, a random access process, or a connection recovery process with the target cell; determining, by the UE, an LBT failure status on a BWP associated with the target cell, wherein the LBT failure status is determined based on a detected consistent LBT failure on the BWP; and performing, by the UE, a failure recovery process in response to the LBT failure status, wherein the failure recovery process includes one of completion of the uplink communication process and reporting of the LBT failure status.

[0012] In an additional aspect of the present disclosure, an apparatus configured for wireless communication includes: means for receiving, by a UE, a handover command to a target cell from a source cell on a shared communication spectrum; means for determining, by the UE, an LBT failure status on a current BWP configured for the target cell, wherein the LBT failure status is determined based on a detected consistent LBT failure on the current BWP; means for performing, by the UE, a failure recovery process in response to the LBT failure status, wherein the failure recovery process includes one or more of the following: completion of the handover and reporting of the LBT failure status.

[0013] In an additional aspect of the present disclosure, an apparatus configured for wireless communication includes: means for identifying, by a UE, a target cell for random access on a shared communication spectrum; means for initiating, by the UE, a random access procedure on an initial BWP associated with the target cell; means for determining, by the UE, an LBT failure status on the initial BWP based on a detected consistent LBT failure on the initial BWP; and means for performing, by the UE, a failure recovery procedure in response to the LBT failure status, wherein the failure recovery procedure includes one or more of the following: completion of the random access procedure and reporting of the LBT failure status.

[0014] In an additional aspect of the present disclosure, an apparatus configured for wireless communication includes: means for identifying, by a UE, a target cell having an inactive connection on a shared communication spectrum, wherein the target cell is identified for connection recovery; means for initiating, by the UE, a connection recovery procedure on a BWP associated with the target cell; means for determining, by the UE, an LBT failure status on the BWP based on a detected consistent LBT failure on the BWP; and means for performing, by the UE, a failure recovery procedure in response to the LBT failure status, wherein the failure recovery procedure includes one or more of the following: completion of the random access procedure and reporting of the LBT failure status.

[0015] In an additional aspect of the present disclosure, an apparatus configured for wireless communication includes: means for initiating, by a UE, an uplink communication procedure with a target cell on a shared communication spectrum, wherein the uplink communication procedure includes one of a handover command, a random access procedure, or a connection recovery procedure with the target cell; means for determining, by the UE, an LBT failure status on a BWP associated with the target cell, wherein the LBT failure status is determined based on a detected consistent LBT failure on the BWP; and means for performing, by the UE, a failure recovery procedure in response to the LBT failure status, wherein the failure recovery procedure includes one of completion of the uplink communication procedure and reporting of the LBT failure status.

[0016] In an additional aspect of the present disclosure, a non-transitory computer-readable medium having program code recorded thereon.

[0017] The program code further includes: code for receiving, by a UE, a handover command to hand over from a source cell to a target cell on a shared communication spectrum; code for determining, by the UE, a LBT failure status on a current BWP configured for the target cell, wherein the LBT failure status is determined based on a consistent LBT failure detected on the current BWP; code for performing, by the UE, a failure recovery process in response to the LBT failure status, wherein the failure recovery process includes one or more of the following: completion of the handover and reporting of the LBT failure status.

[0018] In an additional aspect of the present disclosure, a non-transitory computer-readable medium having program code recorded thereon.

[0019] The program code further includes: code for identifying, by a UE, a target cell for random access on a shared communication spectrum; code for initiating, by the UE, a random access process on an initial BWP associated with the target cell; code for determining, by the UE, a LBT failure status on the initial BWP based on a consistent LBT failure detected on the initial BWP; and code for performing, by the UE, a failure recovery process in response to the LBT failure status, wherein the failure recovery process includes one or more of the following: completion of the random access process and reporting of the LBT failure status.

[0020] In an additional aspect of the present disclosure, a non-transitory computer-readable medium having program code recorded thereon. The program code further includes: code for identifying, by a UE, a target cell having an inactive connection on a shared communication spectrum, wherein the target cell is identified for connection recovery; code for initiating, by the UE, a connection recovery process on a BWP associated with the target cell; code for determining, by the UE, a LBT failure status on the BWP based on a consistent LBT failure detected on the BWP; and code for performing, by the UE, a failure recovery process in response to the LBT failure status, wherein the failure recovery process includes one or more of the following: completion of the random access process and reporting of the LBT failure status.

[0021] In additional aspects of the present disclosure, a non-transitory computer-readable medium having program code recorded thereon. The program code further includes: code for initiating an uplink communication procedure with a target cell by a UE on a shared communication spectrum, wherein the uplink communication procedure includes one of a handover command, a random access procedure, or a connection restoration procedure with the target cell; code for determining, by the UE, a LBT failure status on a BWP associated with the target cell, wherein the LBT failure status is determined based on consistent LBT failures detected on the BWP; and code for performing, by the UE, a failure recovery procedure in response to the LBT failure status, wherein the failure recovery procedure includes one of completion of the uplink communication procedure and reporting of the LBT failure status.

[0022] In additional aspects of the present disclosure, a device configured for wireless communication is disclosed. The device includes at least one processor and a memory coupled to the processor. The processor is configured to: receive, by the UE, a handover command to a target cell from a source cell on a shared communication spectrum; determine, by the UE, a LBT failure status on a current bandwidth part (BWP) configured for the target cell, wherein the LBT failure status is determined based on consistent LBT failures detected on the current BWP; and perform, by the UE, a failure recovery procedure in response to the LBT failure status, wherein the failure recovery procedure includes one or more of the following: completion of the handover and reporting of the LBT failure status.

[0023] In additional aspects of the present disclosure, a device configured for wireless communication is disclosed. The device includes at least one processor and a memory coupled to the processor. The processor is configured to: identify, by the UE, a target cell for random access on a shared communication spectrum; initiate, by the UE, a random access procedure on an initial BWP associated with the target cell; determine, by the UE, a LBT failure status on the initial BWP based on consistent LBT failures detected on the initial BWP; and perform, by the UE, a failure recovery procedure in response to the LBT failure status, wherein the failure recovery procedure includes one or more of the following: completion of the random access procedure and reporting of the LBT failure status.

[0024] In additional aspects of the present disclosure, an apparatus configured for wireless communication is disclosed. The apparatus includes at least one processor and a memory coupled to the processor. The processor is configured to: identify, by the UE, a target cell having an inactive connection on a shared communication spectrum, wherein the target cell is identified for connection recovery; initiate, by the UE, a connection recovery process on a BWP associated with the target cell; determine, by the UE, an LBT failure status on the BWP based on a consistent LBT failure detected on the BWP; and perform, by the UE, a failure recovery process in response to the LBT failure status, wherein the failure recovery process includes one or more of the following: completion of the random access process and reporting of the LBT failure status.

[0025] In additional aspects of the present disclosure, an apparatus configured for wireless communication is disclosed. The apparatus includes at least one processor and a memory coupled to the processor. The processor is configured to: initiate, by the UE, an uplink communication process with a target cell on a shared communication spectrum, wherein the uplink communication process includes one of a handover command, a random access process, or a connection recovery process with the target cell; determine, by the UE, an LBT failure status on a BWP associated with the target cell, wherein the LBT failure status is determined based on a consistent LBT failure detected on the BWP; and perform, by the UE, a failure recovery process in response to the LBT failure status, wherein the failure recovery process includes one of completion of the uplink communication process and reporting of the LBT failure status.

[0026] The foregoing has outlined rather broadly the features and technical advantages of examples in accordance with the present disclosure so that the detailed description that follows may be better understood. Additional features and advantages will be described hereinafter. The disclosed concepts and specific examples 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 characteristics of the concepts disclosed herein, both their organization and method of operation, as well as associated advantages, will be better understood when considered in conjunction with the following description taken in connection with the accompanying drawings. Each of the drawings in the accompanying drawings is provided for purposes of illustration and description only and is not to be construed as a definition of the limits of the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] A further understanding of the nature and advantages of the present disclosure can be achieved by referring to the following drawings. In the drawings, like components or features may have the same reference numerals. Additionally, various components of the same type can be distinguished by following the reference numeral with a dash and a second numeral, which is used to distinguish between similar components. If only the first reference numeral is used in the specification, the description can apply to any one of the similar components having the same first reference numeral, regardless of the second reference numeral.

[0028] Figure 1 is a block diagram showing details of a wireless communication system.

[0029] Figure 2 is a block diagram showing the design of a base station and a UE configured according to an aspect of the present disclosure.

[0030] Figure 3 is a block diagram showing example blocks that are executed to implement an aspect of the present disclosure.

[0031] Figure 4 is a block diagram showing a UE configured to detect and recover from a consistent LBT failure during a handover process according to an aspect of the present disclosure.

[0032] Figure 5 is a block diagram showing example blocks that are executed to implement an aspect of the present disclosure.

[0033] Figure 6 is a block diagram showing a UE configured to monitor LBT failures for a random access process (such as an initial establishment or reconstruction of access) according to an aspect of the present disclosure.

[0034] Figure 7 is a block diagram showing example blocks that are executed to implement an aspect of the present disclosure.

[0035] Figure 8 is a block diagram showing a UE configured to monitor LBT failures for a connection recovery process according to an aspect of the present disclosure.

[0036] Figure 9 is a block diagram showing a UE configured to monitor LBT failures within dual-connectivity operation of an NR-U network according to aspects of the present disclosure.

[0037] Figure 10 is a block diagram showing a UE configured according to an aspect of the present disclosure. Detailed Description

[0038] The detailed description set forth below in connection with the accompanying drawings is intended as a description of various configurations and is not intended to limit the scope of the present disclosure. Rather, the detailed description includes specific details for the purpose of providing a thorough understanding of the subject matter of the invention. It will be apparent to those skilled in the art that these specific details are not required in every instance and that, in some instances, well-known structures and components are shown in block diagram form for clarity of presentation.

[0039] Generally, the present disclosure relates to providing or participating in authorized shared access between two or more wireless communication systems (also referred to as wireless communication networks). In various embodiments, the techniques and apparatus can be used in wireless communication networks and other communication networks such as the following: Code Division Multiple Access (CDMA) networks, Time Division Multiple Access (TDMA) networks, Frequency Division Multiple Access (FDMA) networks, Orthogonal FDMA (OFDMA) networks, Single Carrier FDMA (SC-FDMA) networks, LTE networks, GSM networks, Fifth Generation (5G) or New Radio (NR) networks. As described herein, the terms “network” and “system” can be used interchangeably.

[0040] OFDMA networks can implement radio technologies such as evolved UTRA (E-UTRA), IEEE 802.11, IEEE 802.16, IEEE 802.20, Flash-OFDM, etc. UTRA, E-UTRA, and Global System for Mobile Communications (GSM) are part of the Universal Mobile Telecommunications System (UMTS). Specifically, Long Term Evolution (LTE) is a version of UMTS that uses E-UTRA. UTRA, E-UTRA, GSM, UMTS, and LTE are described in documents provided by an organization named “Third Generation Partnership Project” (3GPP), and cdma2000 is described in documents from an organization named “Third Generation Partnership Project 2” (3GPP2). These various radio technologies and standards are known or are under development. For example, the Third Generation Partnership Project (3GPP) is a cooperation between telecommunications association groups aimed at defining globally applicable third-generation (3G) mobile phone specifications. 3GPP Long Term Evolution (LTE) is a 3GPP plan aimed at improving the Universal Mobile Telecommunications System (UMTS) mobile phone standard. 3GPP can define specifications for next-generation mobile networks, mobile systems, and mobile devices. The present disclosure relates to the evolution of wireless technologies from LTE, 4G, 5G, NR, and beyond, which have shared access to the wireless spectrum between networks using some new and different radio access technologies or wireless air interfaces.

[0041] Specifically, the 5G network is expected to enable diverse deployments, diverse spectrums, and diverse services and devices implemented using an OFDM-based unified air interface. To achieve these goals, in addition to developing new radio technologies for 5G NR networks, further enhancements to LTE and LTE-A are also considered. 5G NR will be able to scale to: (1) provide coverage for massive Internet of Things (IoT) with ultra-high density (e.g., ~1M nodes / km 2 ), ultra-low complexity (e.g., ~10s of bits / second), and ultra-low energy (e.g., ~10+ year battery life), and provide deep coverage with the ability to reach challenging locations; (2) include mission-critical control with strong security for protecting sensitive personal, financial, or confidential information, ultra-high reliability (e.g., ~99.9999% reliability), ultra-low latency (e.g., ~1ms), and users with a wide range of mobility or lack of mobility; and (3) have enhanced mobile broadband, which includes extremely high capacity (e.g., ~10 Tbps / km 2 ), extreme data rates (e.g., multi-Gbps rates, 100+ Mbps user experience rate), and advanced discovery and optimized depth perception.

[0042] 5G NR can be implemented using an optimized OFDM-based waveform with scalable numerology and transmission time interval (TTI); having a common flexible framework to efficiently multiplex services and features using dynamic low-latency time-division duplex (TDD) / frequency-division duplex (FDD) designs; and having advanced radio technologies such as massive multiple-input multiple-output (MIMO), robust millimeter-wave (mmWave) transmission, advanced channel coding, and device-centric mobility. The scalability of numerology in 5G NR (with scaling of subcarrier spacing) can efficiently address operating diverse services across diverse spectrums and diverse deployments. For example, in various outdoor and macro coverage deployments with FDD / TDD below 3 GHz, the subcarrier spacing can occur at 15 kHz, for example, over bandwidths of 1, 5, 10, 20 MHz, etc. For various other outdoor and small cell coverage deployments with TDD above 3 GHz, the subcarrier spacing can occur at 30 kHz over 80 / 100 MHz bandwidths. For various other indoor broadband implementations using TDD in the unlicensed part of the 5 GHz band, the subcarrier spacing can occur at 60 kHz over 160 MHz bandwidths. Finally, for various deployments transmitting using the millimeter-wave component at 28 GHz with TDD, the subcarrier spacing can occur at 120 kHz over 500 MHz bandwidths.

[0043] The scalable numerology of 5G NR facilitates scalable TTIs for different latency and Quality of Service (QoS) requirements. For example, shorter TTIs can be used for low latency and high reliability, while longer TTIs can be used for higher spectral efficiency. The efficient multiplexing of long and short TTIs allows transmissions to start at symbol boundaries. 5G NR also anticipates self - contained integrated subframe designs, where uplink / downlink scheduling information, data, and acknowledgments are in the same subframe. The self - contained integrated subframes support communication in unlicensed or contention - based shared spectrum, adaptive uplink / downlink (which can be flexibly configured on a per - cell basis to dynamically switch between uplink and downlink to meet current traffic demands).

[0044] Various other aspects and features of the present disclosure are described further below. It should be apparent that the teachings herein can be embodied in many different forms, and that any specific structure, function, or both disclosed herein are merely representative and not restrictive. Based on the teachings herein, those skilled in the art should recognize that the aspects disclosed herein can be implemented independently of any other aspect, and that two or more of these aspects can be combined in various ways. For example, a device can be implemented or a method can be practiced using any number of the aspects set forth herein. Additionally, such a device can be implemented or such a method can be practiced using other structures, functions, or a combination of structures and functions in addition to or different from the aspects set forth herein. For example, a method can be implemented as part of a system, apparatus, device, and / or as instructions stored on a computer - readable medium for execution on a processor or computer. Further, one aspect can include at least one element of a claim.

[0045] Figure 1 is a block diagram illustrating an example of a wireless communication system 100 that supports detecting and recovering from a consistent Listen - Before - Talk (LBT) failure in accordance with aspects of the present disclosure. The wireless communication system 100 can include a base station 105, a UE 115, and a core network 130. In some examples, the wireless communication system 100 can be a Long - Term Evolution (LTE) network, an evolved LTE (LTE - A) network, an LTE - A Pro network, or an NR network. In some cases, the wireless communication system 100 can support enhanced broadband communication, ultra - reliable (e.g., mission - critical) communication, low - latency communication, or communication with low - cost and low - complexity devices. <>

[0046] Base station 105 may communicate wirelessly with UE 115 via one or more base station antennas. The base station 105 described herein may include or may be referred to by those skilled in the art as a base station transceiver, radio base station, access point, radio transceiver, Node B, eNodeB (eNB), next-generation Node B, or Gigabit Node B (either of which may be referred to as gNB), home Node B, home eNodeB, or some other suitable term. The wireless communication system 100 may include different types of base stations 105 (e.g., macro cell base stations or small cell base stations). The UE 115 described herein may be capable of communicating with various types of base stations 105 and network devices, including macro eNBs, small cell eNBs, gNBs, relay base stations, etc.

[0047] Each base station 105 may be associated with a particular geographic coverage area 110 in which communication with various UEs 115 is supported. Each base station 105 may provide communication coverage for the corresponding geographic coverage area 110 via a communication link 125, and the communication link 125 between the base station 105 and the UE 115 may utilize one or more carriers. The communication link 125 shown in the wireless communication system 100 may include an uplink transmission from the UE 115 to the base station 105 or a downlink transmission from the base station 105 to the UE 115. Downlink transmissions may also be referred to as forward link transmissions, and uplink transmissions may also be referred to as reverse link transmissions.

[0048] The geographic coverage area 110 for the base station 105 may be divided into sectors that form part of the geographic coverage area 110, and each sector may be associated with a cell. For example, each base station 105 may provide communication coverage for a macro cell, small cell, hot spot, or other type of cell, or various combinations thereof. In some examples, the base station 105 may be movable and thus provide communication coverage for a mobile geographic service area 110. In some examples, different geographic coverage areas 110 associated with different technologies may overlap, and the overlapping geographic coverage areas 110 associated with different technologies may be supported by the same base station 105 or by different base stations 105. The wireless communication system 100 may include, for example, a heterogeneous LTE / LTE-A / LTE-A Pro or NR network, where different types of base stations 105 provide coverage for respective geographic areas 110.

[0049] The term "cell" refers to a logical communication entity for communication with the base station 105 (e.g., on a carrier), and may be associated with an identifier (e.g., Physical Cell Identifier (PCID), Virtual Cell Identifier (VCID)) that can distinguish it from neighboring cells operating on the same or different carriers. In some examples, a carrier may support multiple cells, and different cells may be configured according to different protocol types (e.g., Machine Type Communication (MTC), NarrowBand Internet of Things (NB-IoT), Enhanced Mobile Broadband (eMBB), or other protocols) that can provide access for different types of devices. In some cases, the term "cell" may refer to a part (e.g., a sector) of the geographical coverage area 110 over which the logical entity operates.

[0050] UEs 115 may be scattered throughout the wireless communication system 100, and each UE 115 may be stationary or mobile. A UE 115 may also be referred to as a mobile device, wireless device, remote device, handheld device, or user equipment, or some other suitable term, where "device" may also be referred to as a unit, station, terminal, or client. A UE 115 may also be a personal electronic device, such as a cellular phone (UE 115a), a Personal Digital Assistant (PDA), a wearable device (UE 115d), a tablet computer, a laptop computer (UE 115g), or a personal computer. In some examples, a UE 115 may also refer to a Wireless Local Loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or an MTC device, etc., which may be implemented in, for example, appliances, vehicles (UE 115e and UE 115f), meters (UE 115b and UE 115c), etc.

[0051] Some UEs 115 (such as MTC or IoT devices) may be low-cost or low-complexity devices, and may provide automated communication between machines (e.g., Machine-to-Machine (M2M) communication). M2M communication or MTC may refer to a data communication technology that allows devices to communicate with each other or with a base station without human intervention. In some examples, M2M communication or MTC may include communication from devices integrated with sensors or meters to measure or capture information and relay that information to a central server or application, where the central server or application may utilize the information or present the information to a person interacting with the program or application. Some UEs 115 may be designed to collect information or implement automated behavior of machines. Examples of applications for MTC devices include smart metering, inventory monitoring, water level monitoring, device monitoring, healthcare monitoring, wildlife monitoring, climate and geological event monitoring, fleet management and tracking, remote security sensing, physical access control, and transaction-based business billing.

[0052] Some UEs 115 may be configured to operate in a power consumption-reduced mode, such as half-duplex communication (e.g., a mode that supports one-way communication via transmission or reception rather than simultaneous transmission and reception). In some examples, the half-duplex communication may be performed at a reduced peak rate. Other power saving techniques for the UE 115 include: entering a power-saving "deep sleep" mode when not participating in active communication or operating on a limited bandwidth (e.g., according to narrowband communication). In other cases, the UE 115 may be designed to support critical functions (e.g., mission-critical functions), and the wireless communication system 100 may be configured to provide ultra-reliable communication for these functions.

[0053] In some cases, the UE 115 is also capable of communicating directly with other UEs 115 (e.g., using peer-to-peer (P2P) or device-to-device (D2D) protocols). One or more UEs 115 in a group of UEs 115 utilizing D2D communication may be within the geographical coverage area 110 of the base station 105. Other UEs 115 in such a group may be outside the geographical coverage area 110 of the base station 105 or otherwise unable to receive transmissions from the base station 105. In some cases, multiple groups of UEs 115 communicating via D2D communication may utilize a one-to-many (1:M) system, where each UE 115 transmits to each other UE 115 in the group. In some cases, the base station 105 may facilitate the scheduling of resources for D2D communication. In other cases, D2D communication may be performed between UEs 115 without involving the base station 105.

[0054] The base stations 105 may communicate with the core network 130 and with each other. For example, the base stations 105 may interface with the core network 130 via a backhaul link 132 (e.g., via S1 or other interfaces). The base stations 105 may communicate with each other directly (e.g., directly between the base stations 105) or indirectly (e.g., via the core network 130) on a backhaul link 134 (e.g., via X2, Xn or other interfaces).

[0055] The core network 130 can provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. The core network 130 can be an evolved packet core (EPC), which can include at least one mobility management entity (MME), at least one serving gateway (S-GW), and at least one packet data network (PDN) gateway (P-GW). The MME can manage non-access stratum (e.g., control plane) functions such as mobility, authentication, and bearer management for a UE 115 served by a base station 105 associated with the EPC. User IP packets can be transmitted through the S-GW, which itself can be connected to the P-GW. The P-GW can provide IP address allocation and other functions. The P-GW can be connected to network operator IP services. The operator IP services can include access to the Internet, an intranet, an IP multimedia subsystem (IMS), or packet-switched (PS) streaming services.

[0056] At least some of the network devices (such as the base station 105) in the network can include subcomponents such as access network entities, which can be examples of access node controllers (ANCs). Each access network entity can communicate with the UE 115 through a plurality of other access network transmission entities (which can be referred to as radio heads, intelligent radio heads, or transmit / receive points (TRPs)). In some configurations, the various functions of each access network entity or the base station 105 can be distributed across various network devices (e.g., radio heads and access network controllers) or consolidated into a single network device (e.g., the base station 105).

[0057] The wireless communication system 100 can operate using one or more frequency bands (generally in the range of 300 megahertz (MHz) to 300 gigahertz (GHz)). Generally, the region from 300 MHz to 3 GHz is known as the ultra-high frequency (UHF) region or the decimeter band because the wavelength range is approximately from one decimeter to one meter in length. UHF waves can be blocked or redirected by buildings and environmental features. However, the waves can be sufficient to penetrate structures to serve a UE 115 located indoors in a macrocell. Compared to transmissions using smaller frequencies and longer waves in the high frequency (HF) or very high frequency (VHF) portions of the spectrum below 300 MHz, transmissions of UHF waves can be associated with smaller antennas and shorter distances (e.g., less than 100 km).

[0058] The wireless communication system 100 can also operate in the super-high frequency (SHF) region using frequency bands from 3 GHz to 30 GHz (also known as the centimeter band). The SHF region includes frequency bands such as the 5 GHz industrial, scientific, and medical (ISM) band, which can be opportunistically used by devices that can tolerate interference from other users.

[0059] The wireless communication system 100 may also operate in the extremely high frequency (EHF) region of the spectrum (e.g., from 30 GHz to 300 GHz) (also referred to as the millimeter band). In some examples, the wireless communication system 100 may support millimeter wave (mmW) communication between the UE 115 and the base station 105, and the EHF antennas of the corresponding devices may be even smaller and more closely spaced compared to UHF antennas. In some cases, this may facilitate the use of antenna arrays within the UE 115. However, the propagation of EHF transmissions may suffer even greater atmospheric attenuation and shorter distances compared to SHF or UHF transmissions. The techniques disclosed herein may be employed across transmissions using one or more different frequency regions, and the designation of frequency bands across these frequency regions may vary according to the country or regulatory body.

[0060] The wireless communication system 100 may include operations performed by different network operating entities (e.g., network operators), where each network operator may share the spectrum. In some instances, one network operating entity may be configured to use the entire designated shared spectrum for at least a period of time before another network operating entity uses the entire designated shared spectrum during a different period of time. Thus, in order to allow network operating entities to use the full designated shared spectrum and to mitigate interfering communications between different network operating entities, certain resources (e.g., time) may be partitioned and allocated to different network operating entities for certain types of communication.

[0061] For example, certain time resources may be allocated to a network operating entity that are reserved for exclusive communication by that network operating entity using the entire shared spectrum. Other time resources may also be allocated to a network operating entity in which that entity is given a higher priority than other network operating entities to use the shared spectrum for communication. These time resources that are prioritized for use by a network operating entity may be used by other network operating entities on an opportunistic basis if the prioritized network operating entity does not use these resources. Additional time resources may be allocated for any network operator to use on an opportunistic basis.

[0062] The access to the shared spectrum and the arbitration of time resources between different network operating entities may be centrally controlled by a separate entity, determined autonomously by a predefined arbitration scheme, or determined dynamically based on the interaction between the wireless nodes of the network operators.

[0063] In various implementations, wireless communication system 100 may use both licensed and unlicensed radio frequency spectrum bands. For example, wireless communication system 100 may employ licensed-assisted access (LAA), LTE unlicensed (LTE-U) radio access technology, or NR technology in an unlicensed frequency band (NR-U), such as the 5 GHz ISM band. In some cases, UE 115 and base station 105 in wireless communication system 100 may operate in a shared radio frequency spectrum band, which may include licensed or unlicensed (e.g., contention-based) spectrum. In the unlicensed frequency portion of the shared radio frequency spectrum band, UE 115 or base station 105 may conventionally perform a medium sensing process to compete for access to the spectrum. For example, UE 115 or base station 105 may perform a listen-before-talk (LBT) process (e.g., clear channel assessment (CCA)) before communication to determine whether the shared channel is available.

[0064] CCA may include an energy detection process to determine whether there is any other active transmission on the shared channel. For example, a device may infer that a change in the received signal strength indicator (RSSI) of a power meter indicates that the channel is occupied. Specifically, signal power concentrated in a certain bandwidth and exceeding a predetermined background noise may indicate another wireless transmitter. CCA may also include message detection of a specific sequence used to indicate the use of the channel. For example, another device may send a specific preamble before transmitting a data sequence. In some cases, the LBT process may include: a wireless node adjusting its own backoff window based on the amount of energy detected on the channel and / or the acknowledgment / negative acknowledgment (ACK / NACK) feedback for a packet sent by itself as a proxy for contention.

[0065] Generally, four categories of LBT processes have been proposed to sense a shared channel for signals that may indicate that the channel has been occupied. In the first category (CAT 1 LBT), no LBT or CCA is applied to detect the occupancy of the shared channel. The second category (CAT 2 LBT) (which may also be referred to as shortened LBT, single-shot LBT, or 25-μs LBT) provides that a node performs CCA to detect energy above a predetermined threshold or to detect a message or preamble that occupies the shared channel. CAT 2 LBT performs CCA without using a random backoff operation, which results in its shortened length relative to the next category.

[0066] The third category (CAT 3LBT) performs CCA to detect energy or messages on the shared channel, but also uses random backoff and a fixed contention window. Thus, when a node initiates CAT 3LBT, it performs a first CCA to detect the occupancy of the shared channel. If the shared channel is idle during the duration of the first CCA, the node can continue to transmit. However, if the first CCA detects a signal occupying the shared channel, the node selects a random backoff based on the fixed contention window size and performs an extended CCA. If the shared channel is detected to be idle during the extended CCA and the random number has decremented to 0, the node can start transmission on the shared channel. Otherwise, the node decrements the random number and performs another extended CCA. The node will continue to perform the extended CCA until the random number reaches 0. If the random number reaches 0 without detecting channel occupancy in any of the extended CCAs, the node can then transmit on the shared channel. If at any extended CCA, the node detects channel occupancy, the node can reselect a new random backoff based on the fixed contention window size to start counting down again.

[0067] The fourth category (CAT 4LBT) (which may also be referred to as the full LBT process) performs CCA using energy or message detection with random backoff and a variable contention window size. The sequence of CCA detection is similar to the process of CAT 3LBT, except that the contention window size is variable for the CAT 4LBT process.

[0068] Using a medium sensing process to compete for access to an unlicensed shared spectrum can lead to communication inefficiency. This can be particularly evident when multiple network operating entities (e.g., network operators) are attempting to access the shared resource. In the wireless communication network 100, the base station 105 and the UE 115 can be operated by the same or different network operating entities. In some examples, a single base station 105 or UE 115 can be operated by more than one network operating entity. In other examples, each base station 105 and UE 115 can be operated by a single network operating entity. Requiring each base station 105 and UE 115 of different network operating entities to compete for the shared resource can result in increased signaling overhead and communication latency.

[0069] In some cases, operation in the unlicensed band can be based on a carrier aggregation configuration that combines component carriers operating in a licensed band (e.g., LAA). Operations in the unlicensed spectrum can include downlink transmission, uplink transmission, peer-to-peer transmission, or a combination of these. Duplexing in the unlicensed spectrum can be based on frequency division duplexing (FDD), time division duplexing (TDD), or a combination of both.

[0070] In some examples, the base station 105 or the UE 115 may be equipped with multiple antennas, which can be used to employ techniques such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communication, or beamforming. For example, the wireless communication system 100 may use a transmission scheme between a transmitting device (e.g., the base station 105) and a receiving device (e.g., the UE 115), where the transmitting device is equipped with multiple antennas and the receiving device is equipped with one or more antennas. MIMO communication can utilize multipath signal propagation to improve spectral efficiency by transmitting or receiving multiple signals via different spatial layers (which can be referred to as spatial multiplexing). For example, the transmitting device may transmit multiple signals via different antennas or different combinations of antennas. Similarly, the receiving device may receive multiple signals via different antennas or different combinations of antennas. Each of the multiple signals may be referred to as a separate spatial stream and may carry bits associated with the same data stream or different data streams (e.g., different codewords). Different spatial layers may be associated with different antenna ports for channel measurement and reporting. MIMO techniques include single-user MIMO (SU-MIMO) (where multiple spatial layers are transmitted to the same receiving device) and multi-user MIMO (MU-MIMO) (where multiple spatial layers are transmitted to multiple devices).

[0071] Beamforming (which may also be referred to as spatial filtering, directional transmission, or directional reception) is a signal processing technique that can be used at a transmitting device or a receiving device (e.g., the base station 105 or the UE 115) to form or direct an antenna beam (e.g., a transmit beam or a receive beam) along a spatial path between the transmitting device and the receiving device. Beamforming can be achieved by combining signals transmitted via the antenna elements of an antenna array such that signals propagating in a particular orientation relative to the antenna array experience constructive interference while other signals experience destructive interference. The adjustment of the signals transmitted via the antenna elements may include the transmitting device or the receiving device applying certain amplitude offsets and phase offsets to the signals carried by each of the antenna elements associated with the device. The adjustment associated with each antenna element can be defined by a set of beamforming weights associated with a particular orientation (e.g., relative to the antenna array of the transmitting device or the receiving device, or relative to some other orientation).

[0072] In one example, the base station 105 may use multiple antennas or antenna arrays to perform beamforming operations for directional communication with the UE 115. For example, the base station 105 may transmit some signals (e.g., synchronization signals, reference signals, beam selection signals, or other control signals) multiple times in different directions, and these signals may include signals transmitted according to different sets of beamforming weights associated with different transmission directions. Transmissions in different beam directions may be used (e.g., by the base station 105 or a receiving device such as the UE 115) to identify the beam direction for subsequent transmissions and / or receptions performed by the base station 105.

[0073] The base station 105 may transmit some signals (e.g., data signals associated with the receiving device) in a single beam direction (e.g., the direction associated with a particular receiving device such as the UE 115). In some examples, the beam direction associated with a transmission along a single beam direction may be determined at least in part based on signals transmitted in different beam directions. For example, the UE 115 may receive one or more of the signals transmitted by the base station 105 in different directions, and the UE 115 may report to the base station 105 an indication of the signal that it received with the highest signal quality or otherwise acceptable signal quality. Although these techniques are described with reference to signals transmitted by the base station 105 in one or more directions, the UE 115 may employ similar techniques to transmit signals multiple times in different directions (e.g., to identify the beam direction for subsequent transmissions or receptions performed by the UE 115) or to transmit signals in a single direction (e.g., to transmit data to a receiving device).

[0074] When receiving various signals (such as synchronization signals, reference signals, beam selection signals, or other control signals) from base station 105, a receiving device (e.g., UE 115, which can be an example of a mmW receiving device) can attempt multiple receive beams. For example, the receiving device can attempt multiple receive directions by receiving via different antenna sub-arrays, by processing received signals according to different antenna sub-arrays, by receiving according to different sets of receive beamforming weights applied to signals received at multiple antenna elements of an antenna array, or by processing received signals according to different sets of receive beamforming weights applied to signals received at multiple antenna elements of an antenna array (any of the above operations can be referred to as "listening" according to different receive beams or receive directions). In some examples, the receiving device can use a single receive beam to receive along a single beam direction (e.g., when receiving a data signal). The single receive beam can be aligned in a beam direction determined at least in part based on listening according to different receive beam directions (e.g., a beam direction determined to have the highest signal strength, highest signal-to-noise ratio, or otherwise acceptable signal quality based at least in part on listening according to multiple beam directions).

[0075] In certain implementations, the antennas of base station 105 or UE 115 can be located within one or more antenna arrays or antenna arrays (which can support MIMO operations, or transmit or receive beamforming). For example, one or more base station antennas or antenna arrays can be co-located at an antenna assembly, such as an antenna tower. In some cases, the antennas or antenna arrays associated with base station 105 can be located at different geographical locations. Base station 105 can have an antenna array with multiple rows and columns of antenna ports that base station 105 can use to support beamforming for communication with UE 115. Similarly, UE 115 can have one or more antenna arrays that can support various MIMO or beamforming operations.

[0076] In additional cases, the UE 115 and the base station 105 may support retransmission of data to increase the likelihood that the data is successfully received. HARQ feedback is a technique that increases the likelihood that data is correctly received over the communication link 125. HARQ may include a combination of error detection (e.g., using cyclic redundancy check (CRC)), forward error correction (FEC), and retransmission (e.g., automatic repeat request (ARQ)). HARQ can improve throughput at the MAC layer in poor radio conditions (e.g., signal-to-noise conditions). In some cases, a wireless device may support same-slot HARQ feedback, where the device may provide HARQ feedback for data received in previous symbols in a particular slot in that slot, while in other cases, the device may provide HARQ feedback in a subsequent slot or according to some other time interval.

[0077] Time intervals in LTE or NR can be expressed as multiples of a basic time unit, which may, for example, refer to a sampling period of T s = 1 / 30,720,000 seconds. The time intervals of communication resources can be organized according to radio frames, each having a duration of 10 milliseconds (ms), where the frame period can be expressed as T f = 307,200T s . A radio frame can be identified by a system frame number (SFN) ranging from 0 to 1023. Each frame can include 10 subframes numbered from 0 to 9, and each subframe can have a duration of 1 ms. A subframe can be further divided into 2 time slots, each having a duration of 0.5 ms, and each time slot can contain 6 or 7 modulation symbol periods (e.g., depending on the length of the cyclic prefix added in front of each symbol period). Excluding the cyclic prefix, each symbol period can contain 2048 sampling periods. In some cases, a subframe can be the smallest scheduling unit of the wireless communication system 100 and can be referred to as a transmission time interval (TTI). In other cases, the smallest scheduling unit of the wireless communication system 100 can be shorter than a subframe or can be dynamically selected (e.g., in a burst of shortened TTIs (sTTIs) or in a selected component carrier using sTTIs).

[0078] In some wireless communication systems, a time slot can be further divided into multiple mini-slots containing one or more symbols. In some cases, the symbols or mini-slots of a mini-slot can be the smallest scheduling unit. The duration of each symbol can vary depending on, for example, the subcarrier spacing or the operating frequency band. Additionally, some wireless communication systems can implement time slot aggregation, where multiple time slots or mini-slots are aggregated together and used for communication between the UE 115 and the base station 105.

[0079] As used herein, the term "carrier" refers to a collection of radio frequency spectrum resources having a defined physical layer structure for supporting communication on communication link 125. For example, a carrier of communication link 125 can include a portion of a radio frequency spectrum band that operates according to the physical layer channels for a given radio access technology. Each physical layer channel can carry user data, control information, or other signaling. A carrier can be associated with a predefined frequency channel (e.g., evolved universal mobile telecommunications system terrestrial radio access (E-UTRA) absolute radio frequency channel number (EARFCN)) and can be placed according to a channel grid for discovery by UE 115. A carrier can be downlink or uplink (e.g., in FDD mode), or can be configured to carry both downlink and uplink communications (e.g., in TDD mode). In some examples, the signal waveform transmitted on a carrier can be composed of multiple subcarriers (e.g., using a multi-carrier modulation (MCM) technique such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT-S-OFDM)).

[0080] For different radio access technologies (e.g., LTE, LTE-A, LTE-A Pro, NR), the organizational structure of a carrier can be different. For example, communications on a carrier can be organized according to a TTI or a time slot, each of which can include user data and control information or signaling for supporting decoding of the user data. A carrier can also include dedicated acquisition signaling (e.g., synchronization signals or system information, etc.) and control signaling for coordinating the operation of the carrier. In some examples (e.g., in a carrier aggregation configuration), a carrier can also have acquisition signaling or control signaling for coordinating the operation of other carriers.

[0081] Physical channels can be multiplexed on a carrier according to various techniques. For example, time division multiplexing (TDM) techniques, frequency division multiplexing (FDM) techniques, or hybrid TDM-FDM techniques can be used to multiplex physical control channels and physical data channels on a downlink carrier. In some examples, the control information transmitted in a physical control channel can be distributed in a cascaded manner between different control regions (e.g., between a common control region or a common search space and one or more UE-specific control regions or UE-specific search spaces).

[0082] A carrier can be associated with a specific bandwidth of the radio frequency spectrum, and in some examples, the carrier bandwidth can be referred to as the "system bandwidth" of the carrier or the wireless communication system 100. For example, the carrier bandwidth can be one of a plurality of predetermined bandwidths of a carrier for a specific radio access technology (e.g., 1.4, 3, 5, 10, 15, 20, 40, or 80 MHz). In some examples, each served UE 115 can be configured to operate on a portion or all of the carrier bandwidth. In other examples, some UEs 115 can be configured to operate using a narrowband protocol type associated with a predefined portion or range within the carrier (e.g., a set of subcarriers or RBs) (e.g., "in-band" deployment of the narrowband protocol type).

[0083] In a system employing MCM technology, a resource element can include a symbol period (e.g., the duration of a modulation symbol) and a subcarrier, where the symbol period and the subcarrier spacing are inversely related. The number of bits carried by each resource element can depend on the modulation scheme (e.g., the order of the modulation scheme). Thus, the more resource elements received by the UE 115 and the higher the order of the modulation scheme, the higher the data rate can be for the UE 115. In an MIMO system, the wireless communication resources can refer to a combination of radio frequency spectrum resources, time resources, and spatial resources (e.g., spatial layers), and the use of multiple spatial layers can further increase the data rate for communication with the UE 115.

[0084] Devices of the wireless communication system 100 (e.g., the base station 105 or the UE 115) can have a hardware configuration that supports communication on a specific carrier bandwidth or can be configurable to support communication on one of a set of carrier bandwidths. In some examples, the wireless communication system 100 can include the base station 105 and / or the UE 115 that support simultaneous communication via carriers associated with more than one different carrier bandwidth.

[0085] The wireless communication system 100 can support communication with the UE 115 on multiple cells or carriers (a feature that can be referred to as carrier aggregation or multi-carrier operation). According to the carrier aggregation configuration, the UE 115 can be configured with multiple downlink component carriers and one or more uplink component carriers. Carrier aggregation can be used with both FDD and TDD component carriers.

[0086] In some cases, a wireless communication system 100 may utilize an enhanced component carrier (eCC). The eCC may be characterized by one or more features including: a wider carrier or frequency channel bandwidth, a shorter symbol duration, a shorter TTI duration, or a modified control channel configuration. In certain instances, the eCC may be associated with a carrier aggregation configuration or a dual connectivity configuration (e.g., when multiple serving cells have suboptimal or non-ideal backhaul links). The eCC may also be configured for use in unlicensed or shared spectrum (e.g., where more than one operator is allowed to use a spectrum such as NR shared spectrum (NR-SS)). The eCC characterized by a wide carrier bandwidth may include one or more segments that may be used by a UE 115 that cannot monitor the entire carrier bandwidth or is otherwise configured to use a limited bandwidth (e.g., to save power).

[0087] In additional cases, the eCC may utilize a symbol duration different from other component carriers, which may include using a reduced symbol duration compared to the symbol duration of other component carriers. The shorter symbol duration may be associated with an increased spacing between adjacent subcarriers. A device that utilizes the eCC (e.g., UE 115 or base station 105) may transmit a broadband signal (e.g., according to a frequency channel or carrier bandwidth of 20, 40, 60, 80 MHz, etc.) with a reduced symbol duration (e.g., 16.67 microseconds). The TTI in the eCC may include one or more symbol periods. In some cases, the TTI duration (i.e., the number of symbol periods in the TTI) may be variable.

[0088] In addition, the wireless communication system 100 may be an NR system, which may utilize any combination of licensed, shared, and unlicensed spectrum bands. The flexibility of the eCC symbol duration and subcarrier spacing may allow the eCC to be used across multiple spectrums. In some examples, NR shared spectrum may improve spectrum utilization and spectral efficiency, especially through dynamic vertical (e.g., across the frequency domain) and horizontal (e.g., across the time domain) sharing of resources.

[0089] Figure 2 A base station 105 and a UE 115 are shown, which may be Figure 1Block diagram of the design of one of the base stations and one of the UEs). At base station 105, transmit processor 220 may receive data from data source 212 and control information from controller / processor 240. The control information may be for PBCH, PCFICH, PHICH, PDCCH, EPDCCH, MPDCCH, etc. The data may be for PDSCH, etc. Transmit processor 220 may process (e.g., encode and symbol map) the data and control information respectively to obtain data symbols and control symbols. Transmit processor 220 may also generate reference symbols such as for PSS, SSS, and cell-specific reference signals. Transmit (TX) multiple-input multiple-output (MIMO) processor 230 may perform spatial processing (e.g., precoding) on the data symbols, control symbols, and / or reference symbols (if applicable), and may provide output symbol streams to modulators (MOD) 232a to 232t. Each modulator 232 may process the corresponding output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator 232 may further process (e.g., transform to analog, amplify, filter, and up-convert) the output sample stream to obtain a downlink signal. The downlink signals from modulators 232a to 232t may be transmitted via antennas 234a to 234t respectively.

[0090] At UE 115, antennas 252a to 252r may receive the downlink signals from base station 105, and may provide the received signals to demodulators (DEMOD) 254a to 254r respectively. Each demodulator 254 may condition (e.g., filter, amplify, down-convert, and digitize) the corresponding received signal to obtain input samples. Each demodulator 254 may further process the input samples (e.g., for OFDM, etc.) to obtain received symbols. MIMO detector 256 may obtain the received symbols from all demodulators 254a to 254r, perform MIMO detection on the received symbols (if applicable), and provide the detected symbols. Receive processor 258 may process (e.g., demodulate, de-interleave, and decode) the detected symbols, provide the decoded data for UE 115 to data sink 260, and provide the decoded control information to controller / processor 280.

[0091] On the uplink, at the UE 115, the transmit processor 264 may receive and process data from the data source 262 (e.g., for PUSCH) and control information from the controller / processor 280 (e.g., for PUCCH). The transmit processor 264 may also generate reference symbols for reference signals. The symbols from the transmit processor 264 may be precoded by the TX MIMO processor 266 (if applicable), further processed by the modulators 254a to 254r (e.g., for SC-FDM, etc.), and transmitted to the base station 105. At the base station 105, the uplink signal from the UE 115 may be received by the antenna 234, processed by the demodulator 232, detected by the MIMO detector 236 (if applicable), and further processed by the receive processor 238 to obtain the decoded data and control information transmitted by the UE 115. The processor 238 may provide the decoded data to the data sink 239 and the decoded control information to the controller / processor 240.

[0092] The controller / processors 240 and 280 may direct operations at the base station 105 and the UE 115, respectively. The controller / processor 240 and / or other processors and modules at the base station 105 may execute or direct the execution of various processes for the techniques described herein. The controller / processor 280 and / or other processors and modules at the UE 115 may also execute or direct the execution of Figure 3 、 5 and the functional blocks shown in 7 and / or the execution of other processes for the techniques described herein. The memories 242 and 282 may store data and program codes for the base station 105 and the UE 115, respectively. The scheduler 244 may schedule the UE for data transmission on the downlink and / or uplink.

[0093] The expected implementation of the NR-U network and operations may enable the UE to perform a listen-before-talk (LBT) process for uplink transmission, where the UE transmits on the shared communication spectrum after having detected a successful LBT process. The 3GPP community has proposed operations including detection and recovery mechanisms for consistent uplink LBT failures. For dual-connectivity deployments, when a consistent LBT failure is detected on an existing uplink bandwidth part (BWP) associated with a special cell (e.g., the primary cell (PCell) of the primary cell group (PCG) or the primary secondary cell (PSCell) of the secondary cell group (CSG)), the UE may select another BWP for the recovery process. Conversely, in the case of a consistent LBT failure detected on an SCell, the UE may report such an LBT failure status to the network.

[0094] When LBT fails consistently on the uplink, it may be beneficial to stop further transmission attempts on the corresponding cell and take further actions, e.g., by changing the cell: Existing NR grant recovery mechanisms (such as the acknowledged mode (AM) radio link failure mechanism (RLC AM)) include a maximum number of attempts that may be too slow or may not occur at all. A new mechanism for detecting consistent uplink LBT failures and recovering from them has been proposed. Similar to beamforming detection and recovery, the proposed new mechanism detects LBT failures on a per-BWP basis and is based on any type of uplink transmission within the BWP. All uplink transmission attempts are treated equally regardless of the physical channel used, the LBT type, or the channel access priority class (CAPC). For each such uplink transmission attempt, the physical layer will indicate to the MAC layer whether there is an LBT failure associated with the uplink attempt.

[0095] The proposed detection mechanism uses a timer and a counter. The LBT failure detection timer and the failure instance counter can be configured by RRC signaling. The detection timer is configured to restart upon each LBT failure indication, while the counter increments with each detected uplink LBT failure and is reset when the detection timer expires. When the counter exceeds a predetermined maximum threshold for uplink LBT failures, a compliant UE can determine the level of consistency of uplink LBT failures on the current BWP. Aspects of the present disclosure provide detection and recovery options when consistent LBT failures of both uplink and downlink LBT are detected on an active BWP during normal handover operations, initial establishment or reconstruction operations, and connection recovery procedures.

[0096] Figure 3 is a block diagram showing example boxes that are executed to implement an aspect of the present disclosure. As Figure 2 and 10 shown, example boxes will also be described with respect to UE 115. Figure 10 is a block diagram showing UE 115 configured according to an aspect of the present disclosure. UE 115 includes the structures, hardware, and components shown for UE 115 in Figure 2 For example, UE 115 includes a controller / processor 280 that operates to execute logic or computer instructions stored in a memory 282 and controls the components that provide the features and functions of UE 115. Under the control of the controller / processor 280, UE 115 transmits and receives signals via wireless radio units 1000a-r and antennas 252a-r. The wireless radio units 1000a-r include as in Figure 2For the various components and hardware shown for UE 115, including modulators / demodulators 254a-r, MIMO detector 256, receive processor 258, transmit processor 264, and TX MIMO processor 266.

[0097] At block 300, the UE receives a handover command to handover from a source cell to a target cell on a shared communication spectrum. The UE (such as UE 30 / 115) receives the handover command from the source cell via antennas 252a-r and radio unit 1000a-r of the radio. After receiving the handover command, the UE 30 / 115 executes the channel access logic 1001 stored in the memory 282 under the control of the controller / processor 280. When executing the instructions and code of the channel access logic 1001, the characteristics and functions of various channel access procedures (such as handover, initial establishment, reconstruction, recovery, etc.) are available to the UE 30 / 115. This execution of logical instructions to produce an available function is referred to as the "execution environment" of such logic.

[0098] At block 301, the UE determines the LBT failure status on the current BWP configured for the target cell, where the LBT failure status is determined based on the detected consistent LBT failures on the current BWP. When starting a handover procedure within the execution environment of the channel access logic 1001, the UE 30 / 115 executes the LBT logic 1002 stored in the memory 282 under the control of the controller / processor 280. The execution environment of the LBT logic 1002 provides the UE 30 / 115 with the function of performing various types of LBT procedures to securely access the shared communication spectrum for uplink transmission. When an LBT failure is detected, the UE 30 / 115 executes the LBT failure monitoring 1003 stored in the memory 282 under the control of the controller / processor 280. The execution environment of the LBT failure monitoring 1003 provides the UE 30 / 115 with the function of monitoring both uplink and downlink LBT failures for consistent failures. When the UE 30 / 115 observes multiple uplink and downlink LBT failures within a period of time on the current BWP within the execution environment of the LBT failure monitoring 1003, the UE 30 / 115 determines the LBT failure status according to the function of the LBT failure monitoring 1003.

[0099] At block 302, the UE performs a failure recovery process in response to an LBT failure state, where the failure recovery process includes one or more of the following: completion of a handover and reporting of the LBT failure state. When the UE 30 / 115 determines an LBT failure state within the execution context of the LBT failure monitoring 1003, the UE 30 / 115 performs a failure recovery process 1004 under the control of the controller / processor 280. Within the execution context of the failure recovery process 1004, a multi-option process for recovering from the LBT failure state can be performed. For example, the execution context of the failure recovery process 1004 provides the UE 30 / 115 with the option to select a new BWP that is configured for the cell and has configured uplink resources and continue the access type process on the new BWP. Alternatively, the execution context of the failure recovery process 1004 can provide the UE 30 / 115 with the option to perform a cell reselection process to obtain a new BWP, whether it is general or within the RNA of the UE 30 / 115. In addition, the execution context of the failure recovery process 1004 can also provide the UE 30 / 115 with the option to enter the idle state and perform cell selection. Under the execution context of the failure recovery process 1004, further recovery processes can be available for the UE 30 / 115.

[0100] Figure 4 FIG. 4 is a block diagram illustrating a UE 30 configured to detect and recover from a consistent LBT failure during a handover process in accordance with an aspect of the present disclosure. The UE 30 is currently in a connected state with a source cell 31. At least partially based on a measurement report provided by the UE 30 (not shown) to the source cell 31, the source cell 31 can send a handover command to the UE 30 at 300. In one example implementation, such a handover identified to the UE 300 via the handover command at 300 can be implemented according to the 3GPP Release 15 (Rel.15) standard. When the handover command is received at 300, the UE 30 can start monitoring for a consistent LBT failure, either directly detected by observing the failure of the LBT process performed by the UE 30 for accessing the shared communication spectrum for any type of uplink transmission, or implicitly detected by identifying a missing downlink reference signal expected from the target cell 32 at the scheduled or configured time and frequency.

[0101] The UE 30 may perform such LBT failure detection on a bandwidth part (BWP) configured for and associated with the target cell 32. The UE 30 may observe an uplink LBT failure based on an uplink random access signal or any other UL signal. The UE 30 may also implicitly determine a downlink LBT failure based on a lost downlink reference signal. Such a lost downlink reference signal may include a synchronization signal block (SSB), a channel state information-reference signal (CSI-RS). To perform and observe LBT failures, the UE 30 may use LBT parameters available from different locations or operations. In operation, the UE 30 maintains various configuration parameters for LBT, the association or configuration of BWPs in the system bandwidth of the shared spectrum, etc. in the UE context. Thus, if the UE 30 has been recently in a connected state with the target cell 32, the UE context may have both BWP information and LBT parameters that can be used to detect LBT failures.

[0102] When the UE context does not have LBT parameters or a BWP associated with the target cell 32, the UE 30 may use the LBT parameters configured in the handover command at 300 or signaled in a system information broadcast (SIB) message such as SIB1. Additionally, if such parameters are not available from the handover command or SIB, the UE 30 may receive default LBT detection parameters from the network periodically. In practice, the UE 30 may preferably use the LBT parameters in the UE context (if available), or the LBT parameters received with the handover command at 300, or any default values. Although such parameters are available in the SIB message, it may be more efficient for the UE 30 to rely on other methods first.

[0103] After sending the handover command at 300, the source cell 31 will also prepare the target cell 32 for handover via a status transfer message at 301. At 302, the UE 30 attempts to send a synchronization signal to the target cell 32. When preparing for the synchronization signal transmission, the UE 30 performs a LBT process on the shared communication spectrum. However, the UE 30 detects an LBT failure and thus cannot schedule / configure the synchronization signal for the target cell 32. To monitor the uplink LBT failure, after detecting the failed LBT process at 302, the UE 30 can increment the uplink LBT failure counter. Detecting an LBT failure at 302 also resets the LBT failure detection timer. The consistent nature of the LBT failure that supports the LBT failure state includes frequent detection of such LBT failures. The detection timer assists the UE 30 in maintaining an indication of the consistency of the LBT failure. The UE 30 also implicitly detects the downlink LBT failure of the target cell 32 by detecting the missing downlink reference signal at 303. Based on known parameters and standards, downlink reference signals from the target 32 are expected on the shared spectrum at 303. Thus, if these reference signals are not detected, the UE 30 can infer that the target cell 32 has experienced a downlink LBT failure. The UE 30 directly detects an uplink LBT failure again at 304 as it aims to ensure the shared spectrum for the synchronization signal of the target cell 32. The UE 30 is attempting to complete the handover from the source cell 31 to the target cell 32. The synchronization signal is a step to complete the handover that the UE 30 cannot obtain if the shared spectrum for the uplink transmission cannot be ensured. In the case of detecting a failed LBT at 304, the UE 30 determines that it has consistently experienced and detected an LBT failure on the BWP configured for accessing the target cell 32. In addition to implicitly observing the failed downlink LBT by identifying the missing downlink reference signal, this determination can also be mechanically made using the uplink LBT failure counter.

[0104] The UE 30 declares the LBT failure status of the current BWP at 304. At 305, the UE 30 selects a different BWP configured for the target cell 32 and a part of all the BWPs that constitute the system bandwidth of the shared communication spectrum. The selected new BWP also includes configured uplink (CUL) resources, such as configured random access resources or configured uplink data transmission resources. In the case of continuous LBT failures on additional BWPs with configured uplink resources, the UE 30 determines a failed handover. The UE 30 has maintained its connection to the source cell 31 because the handover has been committed. Therefore, the UE 30 will send an LBT failure report to the source cell 31 at 309 and an indication of the handover failure at 310. The LBT failure report at 309 identifies one or more LBT failures associated with the LBT failure status and identifies the LBT failures according to the cell identifier (ID) and BWP corresponding to each LBT failure.

[0105] It should be noted that in an alternative aspect, the selected next BWP may remain the current BWP when the network or the UE 30 does not allow a handover to the BWP corresponding to the target cell 32, or a whole or a subset of the BWP associated with the target cell 32 with configured uplink resources is selected.

[0106] Figure 5 is a block diagram showing example blocks that are executed to implement one aspect of the present disclosure. Example blocks will also be described with respect to the UE 115 as shown in Figure 2 and 10 shown.

[0107] At block 500, the UE identifies a target cell for random access on a shared communication spectrum. The UE (such as UE30 / 115) executes the channel access logic 1001 stored in the memory 282 under the control of the controller / processor 280. In the execution environment of the channel access logic 1001, the UE 30 / 115 may determine a target cell for access.

[0108] At block 501, the UE initiates a random access procedure on an initial bandwidth part (BWP) associated with the target cell. When initiating a random access procedure within the execution environment of the channel access logic 1001, the UE 30 / 115 executes the LBT logic 1002 stored in the memory 282 under the control of the controller / processor 280. The execution environment of the LBT logic 1002 provides the UE 30 / 115 with the function of performing various types of LBT procedures to randomly access the shared communication spectrum for uplink transmission.

[0109] At block 502, the UE determines the LBT failure status on the initial BWP based on the detected consistent LBT failures on the initial BWP. Within the execution environment of the LBT logic 1002, when an LBT failure is detected, the UE 30 / 115 executes the LBT failure monitoring 1003 stored in the memory 282 under the control of the controller / processor 280. The execution environment of the LBT failure monitoring 1003 provides the UE 30 / 115 with the function to monitor both uplink and downlink LBT failures for failure consistency. When the UE 30 / 115 observes multiple uplink and downlink LBT failures within a period of time in the current BWP within the execution environment of the LBT failure monitoring 1003, the UE 30 / 115 determines the LBT failure status according to the function of the LBT failure monitoring 1003.

[0110] At block 503, the UE executes a failure recovery process in response to the LBT failure status, where the failure recovery process includes one or more of the following: completion of a random access process and reporting of the LBT failure status. When the UE 30 / 115 determines the LBT failure status within the execution environment of the LBT failure monitoring 1003, the UE 30 / 115 executes the failure recovery process 1004 under the control of the controller / processor 280. Within the execution environment of the failure recovery process 1004, a multi-option process for recovering from the LBT failure status can be executed. For example, the execution environment of the failure recovery process 1004 provides the UE 30 / 115 with the option to select a new BWP that is configured for the cell and has configured uplink resources and continue the access type process on the new BWP. Alternatively, the execution environment of the failure recovery process 1004 can provide the UE 30 / 115 with the option to perform a cell reselection process to obtain a new BWP, whether it is general or within the RNA of the UE 30 / 115. In addition, the execution environment of the failure recovery process 1004 can also provide the UE 30 / 115 with the option to enter the idle state and perform cell selection. Under the execution environment of the failure recovery process 1004, further recovery processes can be available for the UE 30 / 115.

[0111] Figure 6FIG. is a block diagram of a UE 30 configured to monitor LBT failures for a random access procedure (such as an initial establishment or re - establishment of access) in accordance with one aspect of the present disclosure. At 600, the UE 30 receives a SIB message with associated random access information from a target cell 32. In the absence of a most recent connection to the target cell 32, the SIB message provides the UE 30 with an indication of the initial BWP configured for the target cell 32 and LBT parameters for performing and observing an LBT procedure. To initiate a random access procedure, the UE 30 performs an LBT procedure on the initial BWP configured for the target cell 32 to ensure a shared communication spectrum for transmitting Msg1 (random access preamble message) in a 4 - step random access procedure or combined MsgA (essentially combining Msg1 and Msg3 of the 4 - step procedure) in a 2 - step random access procedure. However, the UE 30 detects a failure of the LBT procedure. By detecting the LBT procedure, the UE 30 begins to monitor consistent LBT failures. As experienced by the UE 30, the UE 30 further implicitly detects a downlink LBT failure with a missing downlink reference signal expected at 602, followed by another direct LBT failure of the UE 30 to ensure a channel for re - transmitting Msg1 / MsgA. Through the next implicit detection of the failed downlink LBT via the missing downlink reference signal at 604, the UE 30 identifies a consistent LBT failure 60 and declares an LBT failure status.

[0112] At 605, the UE 30 selects a new BWP associated with the target cell 32 that also has a configured uplink resource. The UE 30 begins to initiate a random access procedure on the new BWP. On the new BWP, the UE 30 successfully completes a random access procedure between Msg1 / MsgA at 606 and Msg4 (contention resolution message) from the target cell 32 at 607 or MsgB (essentially combining Msg2 (random access request) and Msg4). By now establishing a connection between the UE 30 and the target cell 32 via the new BWP, at 608, the UE 30 sends an LBT failure report to the target cell 32. As described above, the LBT failure report identifies one or more LBT failures associated with the LBT failure status and identifies these LBT failures according to the cell ID and BWP corresponding to each LBT failure.

[0113] At 609, the connection between the UE 30 and the target cell 32 experiences a Radio Link Failure (RLF). The RLF causes the UE 30 to switch to the idle state in order to attempt to re - establish the connection with the target cell 32. Since the UE 30 was already connected to the target cell 32, the UE context 610 maintained at the UE 30 includes a set of LBT parameters along with the BWP configured for the target cell 32. The configured BWP from the UE context can be different from the initial BWP, which can sometimes be identified in the SIB message sent previously at 600, or can be part of the default parameters periodically transmitted to the UE 30. The configured BWP from the UE context 610 can represent the BWP used for the previous connection between the UE 30 and the target cell 32 prior to the RLF at 609, and thus can represent the last BWP in which the UE 30 was in a successful connected state with the target 32.

[0114] When attempting to re - establish the network connection, when the UE 30 attempts to re - establish the connection via the target cell 30, it can select the configured BWP within the UE context 610 and other connection parameters such as LBT parameters. If the UE 30 has moved out of the coverage area of the target cell 32, it can alternatively use the initial BWP or the default BWP and connection parameters of the new cell. For the purpose of the illustrated example, the UE 30 attempts to re - establish the network connection via the target cell 32. Thus, the UE 30 selects access parameters from the UE context 610, including the configured BWP for the target cell 32 and the corresponding LBT parameters. Before transmitting the initial random access message (Msg1 / MsgA) on the shared spectrum of the configured BWP, the UE 30 performs the LBT procedure. At 611, the UE 30 detects the failure of the LBT procedure.

[0115] While monitoring the LBT failure, the UE 30 monitors the direct and implicit uplink and downlink LBT failures between 611 and 612 and ends another period of consistent LBT failures 61. The UE 30 then declares the LBT failure state and at 613 selects a new BWP configured for the target cell 32 and having configured uplink resources such as random access resources. The UE 30 attempts to complete the random access connection re - establishment by transmitting Msg1 / MsgA. However, at 614, the UE 30 again detects the failure of the uplink LBT procedure for the new BWP. The detected failure will trigger the UE 30 to increment the uplink LBT failure counter and reset the failure detection timer 62. At the next configured random access resource, the UE 30 is again ready to transmit the initial message (Msg1 / MsgA) of the random access procedure.

[0116] At 615, the UE 30 detects the success of the LBT procedure and transmits Msg1 / MsgA to initiate a random access procedure. The UE 30 and the target 32 successfully complete the random access procedure between Msg1 / MsgA at 615 and Msg4 / MsgB at 616, thus re - establishing the connection between the UE 30 and the target cell 32. Once the connection is re - established, the UE 30 performs another successful LBT procedure and sends an LBT failure report at 617. As described above, the LBT failure report identifies the LBT failures based on the cell ID and BWP corresponding to each LBT failure. However, according to the described example aspects, the failure report sent at 617 will not include the identification of the uplink LBT failure at 614 because no additional LBT failures are detected within the failure detection timer 62. When an uplink LBT failure is detected at 614, the UE 30 increments the uplink LBT failure counter. However, when the failure detection timer 62 expires without detecting any additional LBT failures, the UE 30 resets the counter. The LBT failure report will include the LBT failures associated with each increment of the LBT failure counter. Thus, the LBT failure report sent by the UE 30 at 617 will reflect the LBT failure that triggered the LBT failure state at 612, which caused the UE 30 to select a new BWP at 613.

[0117] Figure 7 is a block diagram showing example boxes that are executed to implement one aspect of the present disclosure. Example boxes will also be described with respect to the UE 115 as shown in Figure 2 and 10 as shown.

[0118] At block 700, the UE identifies a target cell having an inactive connection on a shared communication spectrum, where the target cell is identified for connection recovery. The UE (such as UE 30 / 115) executes the channel access logic 1001 stored in the memory 282 under the control of the controller / processor 280. In the execution environment of the channel access logic 1001, the UE 30 / 115 can determine the inactive target cell for connection recovery.

[0119] At block 701, a connection recovery procedure is initiated on a bandwidth part (BWP) associated with the target cell. When a random access procedure is initiated within the execution environment of the channel access logic 1001, the UE 30 / 115 executes the LBT logic 1002 stored in the memory 282 under the control of the controller / processor 280. The execution environment of the LBT logic 1002 provides the UE 30 / 115 with the function of performing various types of LBT procedures for connection recovery to the shared communication spectrum for uplink transmission.

[0120] At block 702, the LBT failure status on the BWP is determined based on the consistent LBT failures detected on the BWP. Within the execution environment of the LBT logic 1002, when an LBT failure is detected on the current BWP, the UE 30 / 115 performs the LBT failure monitoring 1003 stored in the memory 282 under the control of the controller / processor 280. The execution environment of the LBT failure monitoring 1003 provides the UE 30 / 115 with the function to monitor both uplink and downlink LBT failures for failure consistency. When the UE 30 / 115 observes multiple uplink and downlink LBT failures within a period of time in the current BWP within the execution environment of the LBT failure monitoring 1003, the UE 30 / 115 determines the LBT failure status according to the function of the LBT failure monitoring 1003.

[0121] At block 703, a failure recovery process is performed in response to the LBT failure status, where the failure recovery process includes one or more of the following: completion of a random access process and reporting of the LBT failure status. When the UE 30 / 115 determines the LBT failure status within the execution environment of the LBT failure monitoring 1003, the UE 30 / 115 performs the failure recovery process 1004 under the control of the controller / processor 280. Within the execution environment of the failure recovery process 1004, a multi-option process for recovering from the LBT failure status can be performed. For example, the execution environment of the failure recovery process 1004 provides the UE 30 / 115 with the option to select a new BWP that is configured for the cell and has configured uplink resources and continue the access type process on the new BWP. Alternatively, the execution environment of the failure recovery process 1004 can provide the UE 30 / 115 with the option to perform a cell reselection process to obtain a new BWP, whether it is general or within the RNA of the UE 30 / 115. In addition, the execution environment of the failure recovery process 1004 can also provide the UE 30 / 115 with the option to enter the idle state and perform cell selection. Under the execution environment of the failure recovery process 1004, further recovery processes can be available for the UE 30 / 115.

[0122] Figure 8FIG. 0 is a block diagram of a UE 30 configured to monitor LBT failures for connection recovery processes in accordance with one aspect of the present disclosure. The UE 30 establishes an active connection 800 with a target cell 32. The UE 30 and the target cell 32 communicate via the active connection 800. At 801, the UE 30 becomes inactive and remains inactive throughout the inactive state 801. When the UE 30 determines to resume the connection after the inactive state 801, the UE 30 will initiate a connection recovery process, e.g., via RRC signaling, to restore its connection to the network. The UE 30 selects recovery parameters from the UE context 802. As described above, the UE context 802 includes a set of parameters that includes the configured BWP and LBT parameters used by the UE 30 during the active state 800. At 803, the target 32 sends a SIB, which the UE 30 receives and reads any additional parameters. If the parameters are not available from the UE context 802, the UE 30 may select the parameters in the SIB or default parameters in the memory at the UE 30.

[0123] Using the selected BWP and LBT parameters associated with the target cell 32, the UE 30 monitors direct uplink LBT failures based on an uplink random access transmission or any other uplink transmission attempted, and / or monitors implicit downlink LBT failures based on lost expected downlink reference signals. After receiving the SIB message at 803, the UE 30 begins the connection recovery process, e.g., by sending a random access message for resumption of activity (e.g., Msg1 / MsgA) or an RRC signal (e.g., RRC resume). However, after performing the LBT process to ensure access to the shared communication spectrum on the configured BWP, the UE 30 detects an uplink LBT failure at 804. The UE 30 may increment an uplink LBT failure counter and start a failure detection timer. The UE 30 detects sufficient uplink and downlink LBT failures between 804 and 805 to determine a consistent LBT failure 81. Once the consistent LBT failure 81 is determined, the UE 30 declares an LBT failure state. The failure state triggers the UE 30 to initiate a recovery process 806.

[0124] In accordance with aspects previously shown and described herein, the recovery process includes the UE (such as UE 30) selecting a new BWP with configured uplink resources. Once selected, the UE will attempt to conclude a basic process (e.g., handover, initial establishment / re-establishment, etc.) on the new BWP of the target cell. However, aspects of the present disclosure are not limited to a single recovery process. In accordance with Figure 8In the aspects shown, the recovery process 806 may include selecting a new BWP with configured uplink resources, as described in the previous aspects. In such an alternative aspect, the UE 30 selects a new BWP with configured uplink resources and attempts to complete the connection recovery process via two-way communication 806a with the target cell 32.

[0125] In another alternative example aspect, the recovery process 806 may include the UE 30 performing cell reselection to a different cell, such as the new target cell 80. In this alternative example aspect, the new target cell 80 is identified in a Radio Access Network (RAN) - based Notification Area (RNA), which includes a list of cells, nodes, or base stations around the last known location of the UE 30. The RNA concept in NR / NR - U operation is similar to the Tracking Area (TA) concept in the LTE network. According to the alternative example aspect, the UE 30 selects the new target cell 80 from the list of cells, gNBs, and base stations in the RNA. The UE 30 may continue the connection recovery process via two - way communication 806b in the BWP configured for the new target cell 80.

[0126] In a third alternative example aspect, the recovery process 806 may include the UE 30 switching to the idle state and performing cell selection to select and identify a new cell. For the purpose of this third alternative example aspect, the UE 30 performs cell selection and selects a new target cell 80 to initiate a new connection. The UE 30 may then establish a new connection via two - way communication 806c in the BWP configured for the new target cell 80.

[0127] In any alternative example aspect for the recovery process 806, the UE 30 may successfully recover the connection to the network, whether through the target cell 32 or the new target cell 80. Once the connection is recovered, the UE 30 may send a LBT failure report to the connected cell, the target cell 32, or the target cell 80. Alternatively, if the UE 30 cannot successfully recover the connection through the connection recovery process, the UE 30 may declare a radio link failure to attempt a new connection via the cell selection process. The new connection established with the new target cell 80 will then provide the UE 30 with a network connection to send the LBT failure report.

[0128] In connection with Figure 3-8 In the aspects shown and described, the UE 30 obtains or selects BWP and LBT parameters to attempt access and monitor LBT failures. It should be noted that in various aspects of the present disclosure, the BWP and LBT parameter configurations may vary according to the type of access attempted by the UE30. For example, for handover, connection recovery, reconstruction, or establishment, the LBT parameters may be different.

[0129] As in connection with Figure 3-8The various aspects of the present disclosure shown and described have generally described access operations and may be covered in 3GPP Release 15 operations. However, the various aspects of the present disclosure may also be applied to more advanced NR operations, such as dual-connectivity operations in NR and NR-U networks.

[0130] Figure 9 FIG. 30 is a block diagram of a UE 30 configured to monitor LBT failures within dual-connectivity operations of an NR-U network in accordance with aspects of the present disclosure. Communication with the UE 30 is provided having a dual-connectivity connection between a special cell (SpCell) 90 of a master cell group (MCG), which MCG includes either or both of a primary cell (PCell) 90-P of a primary cell group (PCG) and a primary-secondary cell (PSCell) 90-PS of a secondary cell group (SCG), which SCG is an operable primary cell within an unlicensed secondary cell group. The UE 30 is also provided with a connection via an SCell 91 to a first secondary cell group (CSG1) and a connection via an SCell 92 to a second CSG (CSG2).

[0131] At 900, the UE 30 detects a consistent LBT failure for both the uplink and downlink LBT procedures on the BWP configured for the SCell 92. When a consistent uplink LBT failure is detected on an SCell, such as SCell 92, the UE 30 reports it via a media access control-control element (MAC CE) to the corresponding node (e.g., the master node (MN) of the MCG, the secondary node (SN) of the SCG: the LBT failure report may be sent on a service cell different from the service cell in which the failure was detected. For example, after detecting a consistent LBT failure at 900, the UE 30 prepares an LBT failure report in the MAC CE. In the case where the PSCell 90-PS and / or the SCell 91 are the corresponding nodes, the UE 30 will send the LBT failure report, which is sent to the PSCell 90-PS at 904 and / or to the SCell 91 at 905. However, in the case where there are no resources available to send the LBT failure report, when the PCell 90-P is the corresponding node, the UE 30 may send a scheduling request (SR) to the PCell 90-P at 901. The PCell 90-P responds at 902 with an uplink grant and allocated uplink resources. In response, the UE 30 then sends an LBT failure report MAC CE at 903.

[0132] At 906, the UE 30 detects a consistent LBT failure on SpCell 90, e.g., on the BWP configured for PCell 90-P. In response to the determination of the consistent LBT failure, the UE 30 switches to another uplink BWP having uplink resources configured for PCell 90-P and initiates a random access procedure. When a connection to PCell 90-P is successfully established on the new BWP, the UE 30 sends an LBT failure report via a MAC CE at 908. It should be noted that when multiple BWPs having configured uplink resources are available, the UE 30 may select a desired BWP based on the UE implementation.

[0133] At 909, the UE 30 detects a consistent LBT failure on SpCell 90, which may affect either or both of PCell 90-P and PSCell 90-PS. At 910, the UE 30 determines the LBT failure status and selects a new BWP having configured uplink resources. At 911, the UE 30 continues to detect a consistent LBT failure on all available BWPs having configured uplink resources. In response to the consecutive LBT failures detected at 911, the UE 30 will declare a link failure and report the link failure to the master node. For example, on PCell 90-P, the UE 30 will declare a radio link failure (RLF) and report the RLF to PCell 90-P at 912. Similarly, on PSCell 90-PS, the UE 30 will declare an SCG RLF and report the SCG failure to PSCell 90-PS at 912.

[0134] In various operable implementations of aspects of the present disclosure, the MAC CE for LBT failure reporting may be assigned a higher access priority compared to data, but a lower priority compared to the MAC CE beamforming recovery procedure. In a selected implementation of the various aspects, the MAC CE for LBT failure reporting may include a bitmap that indicates whether the corresponding serving cell has declared the LBT failure status determined when a consistent uplink and downlink LBT failure has been detected.

[0135] As indicated with respect to Figure 9 When a consistent LBT failure is detected on PCell 90-P at 906, a failure report may be sent on the BWP to which the UE 30 switches at 907. Additionally, when reporting SCG failure information at 913, a new failure type of PSCell 90-PS reflecting the determination of the consistent LBT failure may be used. In contrast, no new reestablishment cause is required in the RRC reestablishment message. A simple mention of "other" failure will be sufficient.

[0136] It should also be noted that when the UE 30 requests resources for sending an LBT failure report at 901, an SR configuration (SRID) can be configured for such SRs triggered by consistent LBT failures detected on the SCell 92, and then this SR ID can be shared with other logical channels. When this SR configuration ID is not configured, a random access procedure can be triggered.

[0137] It should also be noted that the UE 30 can stop any ongoing random access procedure and initiate a new random access procedure after selecting a new BWP, which is triggered by a consistent LBT failure detected on the SpCell 90. Additionally, when deactivating the SCell 92, the UE 30 can cancel all LBT failures triggered for the SCell (such as the SCell 92). In operation, when the UE 30 sends an LBT failure report at one of 903 - 905, the network can respond to the failure report by deactivating the SCell 92. Similarly, when a MAC reset affects the corresponding serving cell, the UE 30 can cancel any detected LBT failures (if any).

[0138] Those skilled in the art will understand that information and signals can be represented using any of a variety of different technologies and methods. For example, the data, instructions, commands, information, signals, bits, symbols, and chips that may be referred to throughout the above description can be represented by voltage, current, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0139] Figure 3 、 5 The functional blocks and modules in 7 can include: processors, electronic devices, hardware devices, electronic components, logic circuits, memories, software code, firmware code, etc., or any combination thereof.

[0140] Those skilled in the art will also understand that the various illustrative logical blocks, modules, circuits, and algorithm steps described in conjunction with the present disclosure can be implemented as electronic hardware, computer software, or a combination of both. To clearly illustrate this interchangeability of hardware and software, the above has generally described various illustrative components, blocks, modules, circuits, and steps in terms of their functionality. Whether such functionality is implemented as hardware or software depends on the particular application and the design constraints imposed on the overall system. Those skilled in the art can implement the described functionality in a flexible manner for each particular application, but such implementation decisions should not be construed as causing a departure from the scope of the present disclosure. Those skilled in the art will also readily recognize that the order or combination of the components, methods, or interactions described herein is merely exemplary, and the components, methods, or interactions of various aspects of the present disclosure can be combined or executed in ways different from those shown and described herein.

[0141] Aspects of the present disclosure can be implemented in a variety of different ways, including methods, processes, non-transitory computer-readable media having program code recorded thereon, apparatuses having one or more processors configured with instructions to perform the described features and functions, etc. For example, a first aspect of wireless communication includes: a UE receiving a handover command to a target cell from a source cell on a shared communication spectrum; the UE determining a LBT failure status on a current BWP configured for the target cell, where the LBT failure status is determined based on consistent LBT failures detected on the current BWP; the UE performing a failure recovery process in response to the LBT failure status, where the failure recovery process includes one or more of the following: completion of the handover and reporting of the LBT failure status.

[0142] A second aspect based on the first aspect, where performing the failure recovery process includes: the UE selecting the next one or more BWPs of the system bandwidth of the shared communication spectrum in response to the LBT failure status, the next one or more BWPs having configured uplink resources to complete the handover to the target cell; and the UE signaling a handover failure to the source cell in response to determining the LBT failure status for each of the next one or more BWPs having the configured uplink resources.

[0143] A third aspect based on the second aspect, where the configured uplink resources include one or more of the following: configured random access resources; and configured uplink data transmission resources.

[0144] A fourth aspect based on the second aspect further includes: the UE sending a LBT failure report to a selected cell, where the LBT failure report includes an identification of one or more LBT failures associated with the LBT failure status.

[0145] A fifth aspect based on the fourth aspect, where the LBT failure report identifies the one or more LBT failures according to a cell ID and BWP corresponding to each of the one or more LBT failures.

[0146] A sixth aspect based on the second aspect, where the target cell includes a special cell for dual connectivity operation.

[0147] A seventh aspect based on the sixth aspect further includes: the UE detecting a failure of the handover; and the UE declaring a link failure of the special cell, where the link failure includes one of the following: a secondary cell group radio link failure when the special cell includes a primary secondary cell; or a radio link failure when the special cell includes a primary cell.

[0148] An eighth aspect based on the seventh aspect further includes: the UE sending an indication of the secondary cell group radio link failure to the primary node of the primary cell in response to the declaration of the secondary cell group radio link failure.

[0149] A ninth aspect based on the first aspect further includes: the UE determining that resources are available for transmission from the UE to a node of a serving cell; and the UE reporting an indication of the LBT failure status to the node on the resources, where the serving cell is different from the target cell, and where the node includes one of the following: a primary node when the serving cell is a primary cell, or a secondary node when the serving cell is a secondary cell.

[0150] A tenth aspect based on the ninth aspect further includes: the UE determining that the resources are not available for transmission to the node; sending a scheduling request for resources schedulable for transmission from the UE to the node of the serving cell, where reporting the indication of the LBT failure status occurs using the scheduled resources.

[0151] In an eleventh aspect based on the first aspect, each uplink LBT failure among the uplink LBT failures is detected for each unsuccessful LBT procedure performed by the UE for uplink transmission, and each downlink LBT failure among the downlink LBT failures is detected for each downlink reference signal identified as lost from a scheduled position.

[0152] A twelfth aspect based on the eleventh aspect further includes: the UE obtaining a set of LBT parameters for detection of the uplink LBT failure and the downlink LBT failure via one of the following: receiving the handover command; or identifying the set of LBT parameters in the current UE context; or retrieving a default set of LBT parameters for the set of LBT parameters.

[0153] A thirteenth aspect based on the first aspect, wherein selecting the next one or more BWPs includes one of the following: selecting the current BWP as the next one or more BWPs; or selecting the next one or more BWPs, where the next one or more BWPs include all BWPs of the system bandwidth having configured random access resources; or selecting the next one or more BWPs, where the next one or more BWPs include a subset of BWPs of the system bandwidth having configured random access resources.

[0154] A fourteenth aspect includes any combination of the first aspect to the thirteenth aspect.

[0155] A fifteenth aspect of wireless communication includes: identifying, by a UE, a target cell for random access on a shared communication spectrum; initiating, by the UE, a random access procedure on an initial BWP associated with the target cell; determining, by the UE, an LBT failure status on the initial BWP based on a detected consistent LBT failure on the initial BWP; and performing, by the UE, a failure recovery procedure in response to the LBT failure status, where the failure recovery procedure includes one or more of the following: completion of the random access procedure and reporting of the LBT failure status.

[0156] A sixteenth aspect based on the fifteenth aspect, wherein performing the failure recovery procedure includes: selecting, by the UE, the next one or more BWPs of the system bandwidth of the shared communication spectrum in response to the LBT failure status, the next one or more BWPs having configured random access resources to complete the random access procedure with the target cell; and initiating, by the UE, a cell reselection procedure in response to determination of the LBT failure status for each of the next one or more BWPs having the configured random access resources.

[0157] A seventeenth aspect based on the sixteenth aspect further includes: completing, by the UE, the cell reselection procedure with a connection to the reselected cell; and sending, by the UE, an LBT failure report to the reselected cell, where the LBT failure report includes an identification of one or more LBT failures associated with the LBT failure status.

[0158] An eighteenth aspect based on the seventeenth aspect, wherein the LBT failure report identifies the one or more LBT failures according to the cell ID and BWP corresponding to each of the one or more LBT failures.

[0159] A nineteenth aspect based on the sixteenth aspect, wherein the target cell includes a special cell for dual connectivity operation.

[0160] The twentieth aspect based on the nineteenth aspect further includes: the UE detecting the failure of the reselection process; and the UE declaring the link failure of the special cell, where the link failure includes one of the following: the secondary cell group radio link failure when the special cell includes the primary and secondary cells; or the radio link failure when the special cell includes the primary cell.

[0161] The twenty - first aspect based on the twentieth aspect further includes: the UE sending an indication of the secondary cell group radio link failure to the master node of the primary cell in response to the declaration of the secondary cell group radio link failure.

[0162] The twenty - second aspect based on the twenty - first aspect further includes: the UE determining that resources are available for transmission from the UE to the node of the serving cell; and the UE reporting an indication of the LBT failure status to the node on the resources, where the serving cell is different from the target cell, and where the node includes one of the following: the master node when the serving cell is the primary cell, or the secondary node when the serving cell is the secondary cell.

[0163] The twenty - third aspect based on the twenty - second aspect further includes: the UE determining that the resources are not available for transmission to the node; sending a scheduling request for the resources scheduled for transmission from the UE to the node of the serving cell, where the indication of the LBT failure status is reported using the scheduled resources.

[0164] The twenty - fourth aspect based on the fifteenth aspect, where the identifying the target cell for random access includes one of the following: identifying the target cell for connection re - establishment; or identifying the target cell for initial access.

[0165] The twenty - fifth aspect based on the twenty - fourth aspect further includes: the UE obtaining a set of LBT parameters for the detection of the uplink LBT failure and the downlink LBT failure via one of the following: identifying the set of LBT parameters in the current UE context; or receiving the set of LBT parameters in the system information broadcast; or retrieving the default set of LBT parameters for the LBT parameter set; or retrieving the set of LBT parameters configured for the UE during the previous connection with the target cell before the connection re - establishment.

[0166] A twenty-sixth aspect based on the fifteenth aspect, wherein each uplink LBT failure among the uplink LBT failures is detected for each unsuccessful LBT process performed by the UE for one or more of an uplink random access message and an uplink transmission, and wherein each downlink LBT failure among the downlink LBT failures is detected for each downlink reference signal identified as lost from a scheduled position.

[0167] A twenty-seventh aspect includes any combination of the fifteenth aspect to the twenty-sixth aspect.

[0168] A twenty-eighth aspect of wireless communication includes: a UE identifying a target cell having an inactive connection on a shared communication spectrum, wherein the target cell is identified for connection recovery; the UE initiating a connection recovery process on a BWP associated with the target cell; the UE determining an LBT failure status on the BWP based on a detected consistent LBT failure on the BWP; and the UE performing a failure recovery process in response to the LBT failure status, wherein the failure recovery process includes one or more of the following: completion of the random access process and reporting of the LBT failure status.

[0169] A twenty-ninth aspect based on the twenty-eighth aspect, wherein performing the failure recovery process includes: the UE determining a continuous connection recovery process in response to the LBT failure status, wherein the continuous connection recovery process includes one of the following: selecting the next one or more BWPs of the system bandwidth of the shared communication spectrum within the UE context, the next one or more BWPs having configured uplink resources to complete the continuous connection recovery process with the target cell; or identifying a new target cell in the RNA to complete the continuous connection recovery process; or performing a cell reselection process to complete the continuous connection recovery process, wherein the cell reselection process is performed after the UE switches to the idle state.

[0170] A thirtieth aspect based on the twenty-ninth aspect, wherein the configured uplink resources include one or more of the following: configured random access resources; and configured uplink data transmission resources.

[0171] A thirty-first aspect based on the thirtieth aspect further includes: the UE completing the continuous connection recovery process with a connection to another target cell; the UE sending an LBT failure report to the another target cell, wherein the LBT failure report includes an identification of one or more LBT failures associated with the LBT failure status.

[0172] A thirty-second aspect based on the thirty-first aspect, wherein the LBT failure report identifies the one or more LBT failures according to the cell ID and BWP corresponding to each of the one or more LBT failures.

[0173] A thirty-third aspect based on the twenty-ninth aspect, wherein the target cell includes a special cell for dual connectivity operation.

[0174] A thirty-fourth aspect based on the thirty-second aspect further includes: the UE detecting a failure of the continuous connection recovery process; and the UE declaring a link failure of the special cell, wherein the link failure includes one of the following: a secondary cell group radio link failure when the special cell includes a primary secondary cell; or a radio link failure when the special cell includes a primary cell.

[0175] A thirty-fifth aspect based on the thirty-fourth aspect further includes: the UE sending an indication of the secondary cell group radio link failure to the master node of the primary cell in response to the declaration of the secondary cell group radio link failure.

[0176] A thirty-sixth aspect based on the twenty-eighth aspect further includes: the UE determining that resources are available for transmission from the UE to a node of the serving cell; and the UE reporting an indication of the LBT failure status to the node on the resources, wherein the serving cell is different from the target cell, and wherein the node includes one of the following: a master node when the serving cell is a primary cell, or a secondary node when the serving cell is a secondary cell.

[0177] A thirty-seventh aspect based on the thirty-sixth aspect further includes: the UE determining that the resources are not available for transmission to the node; sending a scheduling request for resources schedulable for transmission from the UE to the node of the serving cell, wherein reporting the indication of the LBT failure status occurs using the scheduled resources.

[0178] A thirty-eighth aspect based on the twentieth aspect, wherein the selecting of the next or more BWPs and the identifying of the new target cell are further within the recovery timer period.

[0179] A thirty-ninth aspect based on the twenty-eighth aspect, wherein the BWP associated with the target cell is obtained from one of the following: UE context; or an initial BWP received by the UE in a previous system information broadcast message.

[0180] Aspect 40 based on Aspect 28 further includes: obtaining, by the UE, a set of LBT parameters for detecting the uplink LBT failure and the downlink LBT failure via one of the following: identifying the set of LBT parameters in the UE context; or receiving the set of LBT parameters in system information broadcast; or retrieving a default set of LBT parameters for the set of LBT parameters.

[0181] Aspect 41 based on Aspect 28, wherein each uplink LBT failure in the uplink LBT failures is detected for each unsuccessful LBT process performed by the UE for uplink transmission, and wherein each downlink LBT failure in the downlink LBT failures is detected for each downlink reference signal identified as lost from a scheduled position.

[0182] Aspect 42 includes any combination of Aspect 28 to Aspect 41.

[0183] The various illustrative logical blocks, modules, and circuits described in connection with the disclosure herein can be implemented or performed using a general-purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. The general-purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. The 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.

[0184] The steps of a method or algorithm described in connection with the disclosure herein can be embodied directly in hardware, in a software module executed by a processor, or in a combination of both. The software module may be located in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium may be located in an ASIC. The ASIC may be located in a user terminal. In the alternative, the processor and the storage medium may exist as discrete components in a user terminal.

[0185] In one or more exemplary designs, the described functionality may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functionality may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A computer-readable storage media may be any available media that can be accessed by a general purpose or special purpose computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a general purpose or special purpose computer or a general purpose or special purpose processor. Also, connections may be properly termed computer-readable media. For example, if software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, or digital subscriber line (DSL), then the coaxial cable, fiber optic cable, twisted pair, or DSL is included in the definition of media. 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 usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

[0186] As used herein (including in the claims), the term "and / or" when used in a list of two or more items means that any one of the listed items can be employed alone or any combination of two or more of the listed items can be employed. For example, if a composition is described as including components A, B, and / or C, the composition can include: only A; only B; only C; a combination of A and B; a combination of A and C; a combination of B and C; or a combination of A, B, and C. Further, as used herein (including in the claims), the "or" as used in a list of items that ends with "at least one of" indicates a disjunctive list such that, for example, a list of "at least one of A, B, or C" means A or B or C or AB or AC or BC or ABC (i.e., A and B and C) or any combination of any of these items.

[0187] The foregoing description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Thus, the disclosure is not intended to be limited to the examples and designs described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for wireless communication, comprising: initiating, by a user equipment (UE), an uplink communication procedure with a cell on a shared communication spectrum, wherein the uplink communication procedure includes a connection recovery procedure; determining, by the UE, a listen-before-talk (LBT) failure status on a bandwidth part (BWP) associated with the cell, wherein the LBT failure status is determined based on consistent LBT failures detected on the BWP, and wherein the consistent LBT failures include multiple uplink and downlink LBT failures within a period of time within the BWP; and performing, by the UE, a failure recovery procedure in response to the LBT failure status, wherein the failure recovery procedure includes selection of a new BWP having configured random access resources and completion of the uplink communication procedure.

2. The method according to claim 1, Among them, wherein initiating the uplink communication procedure includes: receiving, on the shared communication spectrum, a handover command to the cell from a source cell, wherein the uplink communication procedure includes the handover, wherein determining the LBT failure status includes: determining the LBT failure status on the current BWP based on detection of the consistent LBT failures on the current BWP configured for the cell, and wherein the failure recovery procedure includes one or more of the following: completion of the handover and reporting of the LBT failure status.

3. The method according to claim 2, wherein, Performing the failure recovery procedure includes: selecting, by the UE, the next one or more BWPs of the system bandwidth of the shared communication spectrum in response to the LBT failure status, the next one or more BWPs having configured uplink resources to complete the handover to the cell; and signaling, by the UE, a handover failure to the source cell in response to determination of the LBT failure status for each of the next one or more BWPs having the configured uplink resources.

4. The method according to claim 3, wherein The configured uplink resources include one or more of the following: configured random access resources; and configured uplink data transmission resources.

5. The method according to claim 3, further comprising: sending, by the UE, an LBT failure report to a selected cell, wherein the LBT failure report includes an identification of one or more LBT failures associated with the LBT failure status.

6. The method according to claim 5, wherein The LBT failure report identifies the one or more LBT failures according to a cell identifier (ID) and a BWP corresponding to each of the one or more LBT failures.

7. The method according to claim 3, further comprising selecting the next one or more BWPs, wherein, Selecting the next one or more BWPs includes one of the following: selecting the current BWP as the next one or more BWPs; or selecting the next one or more BWPs, wherein the next one or more BWPs include all BWPs of the system bandwidth having configured random access resources; or selecting the next one or more BWPs, wherein the next one or more BWPs include a subset of the BWPs of the system bandwidth having configured random access resources.

8. The method according to claim 1, Among them, initiating the uplink communication process includes: identifying the cell for random access on the shared communication spectrum; and initiating a random access process on an initial BWP associated with the cell, wherein the uplink communication process includes the random access process; wherein determining the LBT failure status includes: determining the LBT failure status on the initial BWP based on the detected consistent LBT failure on the initial BWP, and wherein the failure recovery process includes one or more of the following: completion of the random access process and reporting of the LBT failure status.

9. The method according to claim 8, wherein Performing the failure recovery process includes: selecting the next one or more BWPs of the system bandwidth of the shared communication spectrum in response to the LBT failure status, the next one or more BWPs having configured random access resources to complete the random access process with the cell; and initiating a cell reselection process in response to determination of the LBT failure status for each of the next one or more BWPs having the configured random access resources.

10. The method according to claim 9, further comprising: the UE completing the cell reselection process with a connection to the reselected cell; the UE sending an LBT failure report to the reselected cell, wherein the LBT failure report includes an identification of one or more LBT failures associated with the LBT failure status.

11. The method according to claim 10, wherein The LBT failure report identifies the one or more LBT failures according to the cell identifier (ID) and BWP corresponding to each of the one or more LBT failures.

12. The method according to claim 8, wherein, Identifying the cell for random access includes one of the following: identifying the cell for connection reestablishment; or identifying the cell for initial access.

13. The method according to claim 12, further comprising: the UE obtaining a set of LBT parameters for detection of uplink LBT failure and downlink LBT failure via one of the following: identifying the set of LBT parameters in the current UE context; or receiving the set of LBT parameters in system information broadcast; or retrieving a default set of LBT parameters for the set of LBT parameters; or retrieving the set of LBT parameters configured for the UE during a previous connection with the cell before the connection reestablishment.

14. The method according to claim 8, Among them, each uplink LBT failure among the consistent LBT failures is detected for each unsuccessful LBT process performed by the UE for one or more of an uplink random access message and uplink transmission, and wherein each downlink LBT failure among the consistent LBT failures is detected for each downlink reference signal identified as missing from a scheduled location.

15. The method according to claim 1, wherein, initiating the uplink communication process includes: Identify the cell having an inactive connection on the shared communication spectrum, wherein the cell is identified for connection recovery; Initiate a connection recovery process on the BWP associated with the cell, wherein the uplink communication process includes the connection recovery process; and Wherein the failure recovery process includes one or more of the following: completion of a random access process and reporting of the LBT failure status.

16. The method according to claim 15, wherein, The performing the failure recovery process includes: The UE determines a continuous connection recovery process in response to the LBT failure status, wherein the continuous connection recovery process includes one of the following: Selecting the next or more BWPs of the system bandwidth of the shared communication spectrum within the UE context, the next or more BWPs having configured uplink resources to complete the continuous connection recovery process with the cell; or Identifying a new cell in a radio access network (RAN) based notification area (RNA) to complete the continuous connection recovery process; or Performing a cell reselection process to complete the continuous connection recovery process, wherein the cell reselection process is performed after the UE switches to the idle state.

17. The method according to claim 16, wherein, The configured uplink resources include one or more of the following: Configured random access resources; and Configured uplink data transmission resources.

18. The method according to claim 17, further comprising: The UE completes the continuous connection recovery process having a connection to another cell; The UE sends an LBT failure report to the another cell, wherein the LBT failure report includes an identification of one or more LBT failures associated with the LBT failure status.

19. The method according to claim 18, wherein The LBT failure report identifies the one or more LBT failures according to the cell identifier (ID) and BWP corresponding to each LBT failure among the one or more LBT failures.

20. The method according to claim 16, further comprising selecting the next one or more BWPs, wherein, The selecting the next or more BWPs and the identifying the cell are also within a recovery timer period.

21. The method according to claim 15, wherein, The BWP associated with the cell is obtained from one of the following: UE context; or The initial BWP received by the UE in a previous system information broadcast message.

22. The method according to claim 15, further comprising: The UE obtains a set of LBT parameters for detection of uplink LBT failures and downlink LBT failures via one of the following: Identifying the set of LBT parameters in the UE context; or Receiving the set of LBT parameters in a system information broadcast; or Retrieving a default set of LBT parameters for the set of LBT parameters.

23. The method according to claim 15, Among them, Each uplink LBT failure among the consistent LBT failures is detected for each unsuccessful LBT process performed by the UE for uplink transmission, and Wherein each downlink LBT failure among the consistent LBT failures is detected for each downlink reference signal identified as lost from a scheduled position.

24. The method according to claim 1, wherein, The cell includes a special cell for dual connectivity operation.

25. The method according to claim 24, further comprising: detecting, by the UE, a failure of the uplink communication procedure; and declaring, by the UE, a link failure of the special cell, where the link failure includes one of the following: a secondary cell group radio link failure when the special cell includes a primary cell and a secondary cell; or a radio link failure when the special cell includes a primary cell.

26. The method according to claim 25, further comprising: sending, by the UE, an indication of the secondary cell group radio link failure to a master node of the primary cell in response to the declaration of the secondary cell group radio link failure.

27. The method according to claim 1, further comprising: determining, by the UE, that resources are available for transmission from the UE to a node of a serving cell; and reporting, by the UE, an indication of the LBT failure status on the resources to the node, where the serving cell is different from the cell, and where the node includes one of the following: a master node when the serving cell is a primary cell, or a secondary node when the serving cell is a secondary cell.

28. The method according to claim 27, further comprising: determining, by the UE, that the resources are not available for transmission to the node; sending a scheduling request for resources scheduled for transmission from the UE to the node of the serving cell, where the reporting of the indication of the LBT failure status occurs using the scheduled resources.

29. An apparatus for wireless communication, the apparatus comprising: at least one processor; and a memory coupled to the at least one processor, where the at least one processor is configured to: initiate, by a user equipment (UE), an uplink communication procedure with a cell on a shared communication spectrum, where the uplink communication procedure includes a connection recovery procedure; determine, by the UE, a listen-before-talk (LBT) failure status on a bandwidth part (BWP) associated with the cell, where the LBT failure status is determined based on consistent LBT failures detected on the BWP, and where the consistent LBT failures include a plurality of uplink and downlink LBT failures within a period of time within the BWP; and perform, by the UE, a failure recovery procedure in response to the LBT failure status, where the failure recovery procedure includes a selection of a new BWP with configured random access resources and completion of the uplink communication procedure.

30. The apparatus according to claim 29, wherein, The at least one processor being configured to determine the LBT failure status includes the at least one processor being further configured to: determine the LBT failure status on the current BWP based on detecting the consistent LBT failure on the current BWP configured for the cell.

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