WO2021146838A1

WO2021146838A1 - Two-level synchronization point design for load based equipment mode

Info

Publication number: WO2021146838A1
Application number: PCT/CN2020/073220
Authority: WO
Inventors: Changlong Xu; Jing Sun; Xiaoxia Zhang
Original assignee: Qualcomm Incorporated
Priority date: 2020-01-20
Filing date: 2020-01-20
Publication date: 2021-07-29

Abstract

Methods, systems, and devices for wireless communications are described. A base station may establish a connection with a user equipment (UE). The base station may identify a first set of synchronization points defining a set of time intervals, each of the first set of synchronization points associated with a channel access opportunity during which the UE and the base station can perform a channel access procedure to access a channel. The base station may identify a second set of synchronization points, each of the second set of synchronization points associated with a channel access opportunity during which the UE and the base station can perform a channel access procedure to access the channel. The base station may transmit a configuration signal identifying resources for the first set of synchronization points.

Description

TWO-LEVEL SYNCHRONIZATION POINT DESIGN FOR LOAD BASED EQUIPMENT MODE

FIELD OF TECHNOLOGY

The following relates generally to wireless communications and more specifically to two-level synchronization point design for load based equipment (LBE) mode.

BACKGROUND

Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power) . Examples of such multiple-access systems include fourth generation (4G) systems such as Long Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, or LTE-A Pro systems, and fifth generation (5G) systems which may be referred to as New Radio (NR) systems. These systems may employ technologies such as code division multiple access (CDMA) , time division multiple access (TDMA) , frequency division multiple access (FDMA) , orthogonal frequency division multiple access (OFDMA) , or discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM) . A wireless multiple-access communications system may include one or more base stations or one or more network access nodes, each simultaneously supporting communication for multiple communication devices, which may be otherwise known as user equipment (UE) .

Devices, such as base stations and UEs, may operate in a single operator network deployment. These devices may operate in a frame based equipment (FBE) operational mode, in which a fixed frame period structure is configured for the devices to use in channel acquisition. Base stations in such networks may contend for the channel using a one-shot listen-before-talk (LBT) procedure. Single operator network deployments with more flexible scheduling techniques may be desired.

SUMMARY

The described techniques relate to improved methods, systems, devices, and apparatuses that support two-level synchronization point design for load based equipment (LBE) mode. Generally, the described techniques provide for an alternative to a frame based equipment (FBE) mode for wireless devices communicating over a shared or unlicensed radio frequency spectrum band in a single operator wireless network deployment (although the described techniques are not limited to a single operator wireless network) . In particular, aspects of the described techniques provide for an LBE mode for the wireless devices using multiple (e.g., two) sets of synchronization points configured for the wireless network. That is, a plurality of base stations and their associated user equipment (UE) may be deployed by the operator for communications over the shared (e.g., shared licensed) or unlicensed radio frequency spectrum band. The multiple sets of synchronization points may include a first set of synchronization points (e.g., hard sync points) that are radio resource control (RRC) configured by base stations in the wireless network. The period between any two adjacent synchronization points in the first set of synchronization points may define time intervals for the wireless network. Each synchronization point in the first set of synchronization points may also be used as a channel access opportunity for the base stations and/or UE to perform a channel access procedure to capture the channel for a channel occupancy time.

The multiple sets of synchronization points may also include a second set of synchronization points (e.g., soft sync points) . Each synchronization point in the second set of synchronization points may also defined a channel access opportunities for base stations and/or UE to perform a channel access procedure to capture the channel for a channel occupancy time. In some aspects, the synchronization points in the second set of synchronization points may be more dense than the synchronization points in the first set of synchronization points, such that each time interval between adjacent synchronization points in the first set of synchronization points includes one or more synchronization points from the second set of synchronization points. Broadly, the second set of synchronization points may be RRC configured or may be known based on resources associated with the first set of synchronization points (e.g., preconfigured) . Accordingly, base station and/or UE operating in the single operator wireless network over the shared or unlicensed radio frequency spectrum band may perform a channel access procedure at or just before (e.g., during a gap period preceding the synchronization point) a synchronization point from the first or second sets of synchronization points to capture the channel for the channel occupancy time. In some aspects, the channel occupancy time may end prior to the end of the time interval during which the channel access procedure was performed. Accordingly, base stations and UE may perform wireless communications over the shared or unlicensed radio frequency band during the channel occupancy time.

A method of wireless communication at a UE is described. The method may include establishing a connection with a base station of a set of base stations, identifying a first set of synchronization points defining a set of time intervals, each of the first set of synchronization points associated with a channel access opportunity during which the UE and the set of base stations can perform a channel access procedure to access a channel, identifying a second set of synchronization points, each of the second set of synchronization points associated with a channel access opportunity during which the UE and the set of base stations can perform a channel access procedure to access the channel, each time interval of the set of time intervals including at least one synchronization point of the second set of synchronization points, performing, at the channel access opportunity associated with a synchronization point of the first or second set of synchronization points, the channel access procedure to access the channel for a channel occupancy time to end before a next synchronization point of the first set of synchronization points associated with the time interval for which the channel access procedure is performed, and performing wireless communications with the base station during the channel occupancy time based on a result of the channel access procedure.

An apparatus for wireless communication at a UE is described. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to establish a connection with a base station of a set of base stations, identify a first set of synchronization points defining a set of time intervals, each of the first set of synchronization points associated with a channel access opportunity during which the UE and the set of base stations can perform a channel access procedure to access a channel, identify a second set of synchronization points, each of the second set of synchronization points associated with a channel access opportunity during which the UE and the set of base stations can perform a channel access procedure to access the channel, each time interval of the set of time intervals including at least one synchronization point of the second set of synchronization points, perform, at the channel access opportunity associated with a synchronization point of the first or second set of synchronization points, the channel access procedure to access the channel for a channel occupancy time to end before a next synchronization point of the first set of synchronization points associated with the time interval for which the channel access procedure is performed, and perform wireless communications with the base station during the channel occupancy time based on a result of the channel access procedure.

Another apparatus for wireless communication at a UE is described. The apparatus may include means for establishing a connection with a base station of a set of base stations, identifying a first set of synchronization points defining a set of time intervals, each of the first set of synchronization points associated with a channel access opportunity during which the UE and the set of base stations can perform a channel access procedure to access a channel, identifying a second set of synchronization points, each of the second set of synchronization points associated with a channel access opportunity during which the UE and the set of base stations can perform a channel access procedure to access the channel, each time interval of the set of time intervals including at least one synchronization point of the second set of synchronization points, performing, at the channel access opportunity associated with a synchronization point of the first or second set of synchronization points, the channel access procedure to access the channel for a channel occupancy time to end before a next synchronization point of the first set of synchronization points associated with the time interval for which the channel access procedure is performed, and performing wireless communications with the base station during the channel occupancy time based on a result of the channel access procedure.

A non-transitory computer-readable medium storing code for wireless communication at a UE is described. The code may include instructions executable by a processor to establish a connection with a base station of a set of base stations, identify a first set of synchronization points defining a set of time intervals, each of the first set of synchronization points associated with a channel access opportunity during which the UE and the set of base stations can perform a channel access procedure to access a channel, identify a second set of synchronization points, each of the second set of synchronization points associated with a channel access opportunity during which the UE and the set of base stations can perform a channel access procedure to access the channel, each time interval of the set of time intervals including at least one synchronization point of the second set of synchronization points, perform, at the channel access opportunity associated with a synchronization point of the first or second set of synchronization points, the channel access procedure to access the channel for a channel occupancy time to end before a next synchronization point of the first set of synchronization points associated with the time interval for which the channel access procedure is performed, and perform wireless communications with the base station during the channel occupancy time based on a result of the channel access procedure.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving, from the base station, a configuration signal identifying resources for the first set of synchronization points, where identifying the first set of synchronization points may be based on the configuration signal.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving the configuration signal identifying resources for the second set of synchronization points, where identifying the second set of synchronization points may be based on the configuration signal.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, identifying the second set of synchronization points may include operations, features, means, or instructions for determining, by the UE, resources for the second set of synchronization points based on the resources for the first set of synchronization points.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the configuration signal includes at least one of a RRC signal, or a medium access control (MAC) control element (CE) signal, or a combination thereof.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining that the wireless communications with the base station may be to end within a defined time period of the next synchronization point of the first set of synchronization points occurring within the time interval, and selecting, based on the determining, the channel occupancy time to end a defined gap period before the next synchronization point.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, each synchronization point of the second set of synchronization points may be associated with a gap period.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, each synchronization point of the second set of synchronization points may be not associated with a gap period.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the set of base stations may be in a wireless network operating in a load based equipment mode.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the channel access procedure includes a category four (Cat-4) LBT procedure.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the channel occupancy time spans one or more synchronization points of the second set of synchronization points.

A method of wireless communication at a base station is described. The method may include establishing a connection with a UE, identifying a first set of synchronization points defining a set of time intervals, each of the first set of synchronization points associated with a channel access opportunity during which the UE and the base station can perform a channel access procedure to access a channel, identifying a second set of synchronization points, each of the second set of synchronization points associated with a channel access opportunity during which the UE and the base station can perform a channel access procedure to access the channel, each time interval of the set of time intervals including at least one synchronization point of the second set of synchronization points, and transmitting, to the UE, a configuration signal identifying resources for the first set of synchronization points.

An apparatus for wireless communication at a base station is described. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to establish a connection with a UE, identify a first set of synchronization points defining a set of time intervals, each of the first set of synchronization points associated with a channel access opportunity during which the UE and the base station can perform a channel access procedure to access a channel, identify a second set of synchronization points, each of the second set of synchronization points associated with a channel access opportunity during which the UE and the base station can perform a channel access procedure to access the channel, each time interval of the set of time intervals including at least one synchronization point of the second set of synchronization points, and transmit, to the UE, a configuration signal identifying resources for the first set of synchronization points.

Another apparatus for wireless communication at a base station is described. The apparatus may include means for establishing a connection with a UE, identifying a first set of synchronization points defining a set of time intervals, each of the first set of synchronization points associated with a channel access opportunity during which the UE and the base station can perform a channel access procedure to access a channel, identifying a second set of synchronization points, each of the second set of synchronization points associated with a channel access opportunity during which the UE and the base station can perform a channel access procedure to access the channel, each time interval of the set of time intervals including at least one synchronization point of the second set of synchronization points, and transmitting, to the UE, a configuration signal identifying resources for the first set of synchronization points.

A non-transitory computer-readable medium storing code for wireless communication at a base station is described. The code may include instructions executable by a processor to establish a connection with a UE, identify a first set of synchronization points defining a set of time intervals, each of the first set of synchronization points associated with a channel access opportunity during which the UE and the base station can perform a channel access procedure to access a channel, identify a second set of synchronization points, each of the second set of synchronization points associated with a channel access opportunity during which the UE and the base station can perform a channel access procedure to access the channel, each time interval of the set of time intervals including at least one synchronization point of the second set of synchronization points, and transmit, to the UE, a configuration signal identifying resources for the first set of synchronization points.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for performing, at the channel access opportunity associated with a synchronization point of the first or second set of synchronization points, the channel access procedure to access the channel for a channel occupancy time to end before a next synchronization point of the first set of synchronization points associated with the time interval for which the channel access procedure may be performed, and performing wireless communications with the UE during the channel occupancy time based on a result of the channel access procedure.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining that the wireless communications with the UE may be to end within a defined time period of the next synchronization point of the first set of synchronization points occurring within the time interval, and selecting, based on the determining, the channel occupancy time to end a defined gap period before the next synchronization point.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting the configuration signal identifying resources for the second set of synchronization points.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, identifying the second set of synchronization points may include operations, features, means, or instructions for determining, by the base station, resources for the second set of synchronization points based on the resources for the first set of synchronization points.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the base station may be in a wireless network operating in a load based equipment mode.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example of a system for wireless communications that supports two-level synchronization point design for load based equipment (LBE) mode in accordance with aspects of the present disclosure.

FIG. 2 illustrates an example of a wireless communication system that supports two-level synchronization point design for LBE mode in accordance with aspects of the present disclosure.

FIG. 3 illustrates an example of a synchronization point configuration that supports two-level synchronization point design for LBE mode in accordance with aspects of the present disclosure.

FIG. 4 illustrates an example of a process that supports two-level synchronization point design for LBE mode in accordance with aspects of the present disclosure.

FIGs. 5 and 6 show block diagrams of devices that support two-level synchronization point design for LBE mode in accordance with aspects of the present disclosure.

FIG. 7 shows a block diagram of a communications manager that supports two-level synchronization point design for LBE mode in accordance with aspects of the present disclosure.

FIG. 8 shows a diagram of a system including a device that supports two-level synchronization point design for LBE mode in accordance with aspects of the present disclosure.

FIGs. 9 and 10 show block diagrams of devices that support two-level synchronization point design for LBE mode in accordance with aspects of the present disclosure.

FIG. 11 shows a block diagram of a communications manager that supports two-level synchronization point design for LBE mode in accordance with aspects of the present disclosure.

FIG. 12 shows a diagram of a system including a device that supports two-level synchronization point design for LBE mode in accordance with aspects of the present disclosure.

FIGs. 13 through 17 show flowcharts illustrating methods that support two-level synchronization point design for LBE mode in accordance with aspects of the present disclosure.

DETAILED DESCRIPTION

Single operator wireless networks may be deployed for wireless communications over a shared or unlicensed radio frequency spectrum band. For example, the operator may deploy the wireless network in a factory setting, within a building, within a geographical area, and the like. Typically, such wireless networks are configured to operate in frame based equipment (FBE) mode utilizing a fixed frame period (FFP) design to minimize cross link blocking. That is, all base stations in the wireless network are time-aligned regarding the FFP so that they can contend for the channel at the same time without blocking each other. Within the FFP, synchronization points are also configured for the base station and/or its associated UE to perform a one-shot channel access procedure (e.g., a one-shot listen-before-talk (LBT) procedure) . To access the channel, a base station typically announces that is operating in the FBE mode and indicates (e.g., configures) the FFP details in its system information block one (SIB1) broadcast message. Only base stations are allowed to contend for the channel at the start of each FFP. UE transmissions within an FFP or conditioned on the detection of a transmission by its base station within that FFP. However, this FBE approach is rigid in terms of scheduling and often results in waste and/or loss of communication opportunities by the wireless devices in the network.

Aspects of the disclosure are initially described in the context of wireless communications systems. Generally, the described techniques provide for an alternative to a frame based equipment (FBE) mode for wireless devices communicating over a shared or unlicensed radio frequency spectrum band in a single operator wireless network deployment (although the described techniques are not limited to a single operator wireless network) . In particular, aspects of the described techniques provide for an LBE mode for the wireless devices using multiple sets of synchronization points configured for the wireless network. That is, a plurality of base stations and their associated user equipment (UE) may be deployed by the operator for communications over the shared or unlicensed radio frequency spectrum band. The multiple sets of synchronization points may include a first set of synchronization points (e.g., hard sync points) that are radio resource control (RRC) configured by base stations in the wireless network. The period between any two adjacent synchronization points in the first set of synchronization points define time intervals for the wireless network. Each synchronization point in the first set of synchronization points may also be used as a channel access opportunity for the base stations and/or UE to perform a channel access procedure to capture the channel for a channel occupancy time.

Aspects of the disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flowcharts that relate to two-level synchronization point design for LBE mode.

FIG. 1 illustrates an example of a wireless communications system 100 that supports two-level synchronization point design for LBE mode in accordance with aspects of the present disclosure. The wireless communications system 100 may include one or more base stations 105, one or more UEs 115, and a core network 130. In some examples, the wireless communications system 100 may be a Long Term Evolution (LTE) network, an LTE-Advanced (LTE-A) network, an LTE-A Pro network, or a New Radio (NR) network. In some examples, the wireless communications system 100 may support enhanced broadband communications, ultra-reliable (e.g., mission critical) communications, low latency communications, communications with low-cost and low-complexity devices, or any combination thereof.

The base stations 105 may be dispersed throughout a geographic area to form the wireless communications system 100 and may be devices in different forms or having different capabilities. The base stations 105 and the UEs 115 may wirelessly communicate via one or more communication links 125. Each base station 105 may provide a coverage area 110 over which the UEs 115 and the base station 105 may establish one or more communication links 125. The coverage area 110 may be an example of a geographic area over which a base station 105 and a UE 115 may support the communication of signals according to one or more radio access technologies.

The UEs 115 may be dispersed throughout a coverage area 110 of the wireless communications system 100, and each UE 115 may be stationary, or mobile, or both at different times. The UEs 115 may be devices in different forms or having different capabilities. Some example UEs 115 are illustrated in FIG. 1. The UEs 115 described herein may be able to communicate with various types of devices, such as other UEs 115, the base stations 105, or network equipment (e.g., core network nodes, relay devices, integrated access and backhaul (IAB) nodes, or other network equipment) , as shown in FIG. 1.

The base stations 105 may communicate with the core network 130, or with one another, or both. For example, the base stations 105 may interface with the core network 130 through one or more backhaul links 120 (e.g., via an S1, N2, N3, or other interface) . The base stations 105 may communicate with one another over the backhaul links 120 (e.g., via an X2, Xn, or other interface) either directly (e.g., directly between base stations 105) , or indirectly (e.g., via core network 130) , or both. In some examples, the backhaul links 120 may be or include one or more wireless links.

One or more of the base stations 105 described herein may include or may be referred to by a person having ordinary skill in the art as a base transceiver station, a radio base station, an access point, a radio transceiver, a NodeB, an eNodeB (eNB) , a next-generation NodeB or a giga-NodeB (either of which may be referred to as a gNB) , a Home NodeB, a Home eNodeB, or other suitable terminology.

A UE 115 may include or may be referred to as a mobile device, a wireless device, a remote device, a handheld device, or a subscriber device, or some other suitable terminology, where the “device” may also be referred to as a unit, a station, a terminal, or a client, among other examples. A UE 115 may also include or may be referred to as a personal electronic device such as a cellular phone, a personal digital assistant (PDA) , a tablet computer, a laptop computer, or a personal computer. In some examples, a UE 115 may include or be referred to as a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or a machine type communications (MTC) device, among other examples, which may be implemented in various objects such as appliances, or vehicles, meters, among other examples.

The UEs 115 described herein may be able to communicate with various types of devices, such as other UEs 115 that may sometimes act as relays as well as the base stations 105 and the network equipment including macro eNBs or gNBs, small cell eNBs or gNBs, or relay base stations, among other examples, as shown in FIG. 1.

The UEs 115 and the base stations 105 may wirelessly communicate with one another via one or more communication links 125 over one or more carriers. The term “carrier” may refer to a set of radio frequency spectrum resources having a defined physical layer structure for supporting the communication links 125. For example, a carrier used for a communication link 125 may include a portion of a radio frequency spectrum band (e.g., a bandwidth part (BWP) ) that is operated according to one or more physical layer channels for a given radio access technology (e.g., LTE, LTE-A, LTE-A Pro, NR) . Each physical layer channel may carry acquisition signaling (e.g., synchronization signals, system information) , control signaling that coordinates operation for the carrier, user data, or other signaling. The wireless communications system 100 may support communication with a UE 115 using carrier aggregation or multi-carrier operation. A UE 115 may be configured with multiple downlink component carriers and one or more uplink component carriers according to a carrier aggregation configuration. Carrier aggregation may be used with both frequency division duplexing (FDD) and time division duplexing (TDD) component carriers.

In some examples (e.g., in a carrier aggregation configuration) , a carrier may also have acquisition signaling or control signaling that coordinates operations for other carriers. A carrier may be associated with a frequency channel (e.g., an evolved universal mobile telecommunication system terrestrial radio access (E-UTRA) absolute radio frequency channel number (EARFCN) ) and may be positioned according to a channel raster for discovery by the UEs 115. A carrier may be operated in a standalone mode where initial acquisition and connection may be conducted by the UEs 115 via the carrier, or the carrier may be operated in a non-standalone mode where a connection is anchored using a different carrier (e.g., of the same or a different radio access technology) .

The communication links 125 shown in the wireless communications system 100 may include uplink transmissions from a UE 115 to a base station 105, or downlink transmissions from a base station 105 to a UE 115. Carriers may carry downlink or uplink communications (e.g., in an FDD mode) or may be configured to carry downlink and uplink communications (e.g., in a TDD mode) .

A carrier may be associated with a particular bandwidth of the radio frequency spectrum, and in some examples the carrier bandwidth may be referred to as a “system bandwidth” of the carrier or the wireless communications system 100. For example, the carrier bandwidth may be one of a number of determined bandwidths for carriers of a particular radio access technology (e.g., 1.4, 3, 5, 10, 15, 20, 40, or 80 megahertz (MHz) ) . Devices of the wireless communications system 100 (e.g., the base stations 105, the UEs 115, or both) may have hardware configurations that support communications over a particular carrier bandwidth or may be configurable to support communications over one of a set of carrier bandwidths. In some examples, the wireless communications system 100 may include base stations 105 or UEs 115 that support simultaneous communications via carriers associated with multiple carrier bandwidths. In some examples, each served UE 115 may be configured for operating over portions (e.g., a sub-band, a BWP) or all of a carrier bandwidth.

Signal waveforms transmitted over a carrier may be made up of multiple subcarriers (e.g., using multi-carrier modulation (MCM) techniques such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT-S-OFDM) ) . In a system employing MCM techniques, a resource element may consist of one symbol period (e.g., a duration of one modulation symbol) and one subcarrier, where the symbol period and subcarrier spacing are inversely related. The number of bits carried by each resource element may depend on the modulation scheme (e.g., the order of the modulation scheme, the coding rate of the modulation scheme, or both) . Thus, the more resource elements that a UE 115 receives and the higher the order of the modulation scheme, the higher the data rate may be for the UE 115. A wireless communications resource may refer to a combination of a radio frequency spectrum resource, a time resource, and a spatial resource (e.g., spatial layers or beams) , and the use of multiple spatial layers may further increase the data rate or data integrity for communications with a UE 115.

One or more numerologies for a carrier may be supported, where a numerology may include a subcarrier spacing (Δf) and a cyclic prefix. A carrier may be divided into one or more BWPs having the same or different numerologies. In some examples, a UE 115 may be configured with multiple BWPs. In some examples, a single BWP for a carrier may be active at a given time and communications for the UE 115 may be restricted to one or more active BWPs.

The time intervals for the base stations 105 or the UEs 115 may be expressed in multiples of a basic time unit which may, for example, refer to a sampling period of T _s=1/ (Δf _max·N _f) seconds, where Δf _max may represent the maximum supported subcarrier spacing, and N _f may represent the maximum supported discrete Fourier transform (DFT) size. Time intervals of a communications resource may be organized according to radio frames each having a specified duration (e.g., 10 milliseconds (ms) ) . Each radio frame may be identified by a system frame number (SFN) (e.g., ranging from 0 to 1023) .

Each frame may include multiple consecutively numbered subframes or slots, and each subframe or slot may have the same duration. In some examples, a frame may be divided (e.g., in the time domain) into subframes, and each subframe may be further divided into a number of slots. Alternatively, each frame may include a variable number of slots, and the number of slots may depend on subcarrier spacing. Each slot may include a number of symbol periods (e.g., depending on the length of the cyclic prefix prepended to each symbol period) . In some wireless communications systems 100, a slot may further be divided into multiple mini-slots containing one or more symbols. Excluding the cyclic prefix, each symbol period may contain one or more (e.g., N _f) sampling periods. The duration of a symbol period may depend on the subcarrier spacing or frequency band of operation.

A subframe, a slot, a mini-slot, or a symbol may be the smallest scheduling unit (e.g., in the time domain) of the wireless communications system 100 and may be referred to as a transmission time interval (TTI) . In some examples, the TTI duration (e.g., the number of symbol periods in a TTI) may be variable. Additionally or alternatively, the smallest scheduling unit of the wireless communications system 100 may be dynamically selected (e.g., in bursts of shortened TTIs (sTTIs) ) .

Physical channels may be multiplexed on a carrier according to various techniques. A physical control channel and a physical data channel may be multiplexed on a downlink carrier, for example, using one or more of time division multiplexing (TDM) techniques, frequency division multiplexing (FDM) techniques, or hybrid TDM-FDM techniques. A control region (e.g., a control resource set (CORESET) ) for a physical control channel may be defined by a number of symbol periods and may extend across the system bandwidth or a subset of the system bandwidth of the carrier. One or more control regions (e.g., CORESETs) may be configured for a set of the UEs 115. For example, one or more of the UEs 115 may monitor or search control regions for control information according to one or more search space sets, and each search space set may include one or multiple control channel candidates in one or more aggregation levels arranged in a cascaded manner. An aggregation level for a control channel candidate may refer to a number of control channel resources (e.g., control channel elements (CCEs) ) associated with encoded information for a control information format having a given payload size. Search space sets may include common search space sets configured for sending control information to multiple UEs 115 and UE-specific search space sets for sending control information to a specific UE 115.

Each base station 105 may provide communication coverage via one or more cells, for example a macro cell, a small cell, a hot spot, or other types of cells, or any combination thereof. The term “cell” may refer to a logical communication entity used for communication with a base station 105 (e.g., over a carrier) and may be associated with an identifier for distinguishing neighboring cells (e.g., a physical cell identifier (PCID) , a virtual cell identifier (VCID) , or others) . In some examples, a cell may also refer to a geographic coverage area 110 or a portion of a geographic coverage area 110 (e.g., a sector) over which the logical communication entity operates. Such cells may range from smaller areas (e.g., a structure, a subset of structure) to larger areas depending on various factors such as the capabilities of the base station 105. For example, a cell may be or include a building, a subset of a building, or exterior spaces between or overlapping with geographic coverage areas 110, among other examples.

A macro cell generally covers a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by the UEs 115 with service subscriptions with the network provider supporting the macro cell. A small cell may be associated with a lower-powered base station 105, as compared with a macro cell, and a small cell may operate in the same or different (e.g., licensed, unlicensed) frequency bands as macro cells. Small cells may provide unrestricted access to the UEs 115 with service subscriptions with the network provider or may provide restricted access to the UEs 115 having an association with the small cell (e.g., the UEs 115 in a closed subscriber group (CSG) , the UEs 115 associated with users in a home or office) . A base station 105 may support one or multiple cells and may also support communications over the one or more cells using one or multiple component carriers.

In some examples, a carrier may support multiple cells, and different cells may be configured according to different protocol types (e.g., MTC, narrowband IoT (NB-IoT) , enhanced mobile broadband (eMBB) ) that may provide access for different types of devices.

In some examples, a base station 105 may be movable and therefore provide communication coverage for a moving geographic coverage area 110. In some examples, different geographic coverage areas 110 associated with different technologies may overlap, but the different geographic coverage areas 110 may be supported by the same base station 105. In other examples, the overlapping geographic coverage areas 110 associated with different technologies may be supported by different base stations 105. The wireless communications system 100 may include, for example, a heterogeneous network in which different types of the base stations 105 provide coverage for various geographic coverage areas 110 using the same or different radio access technologies.

The wireless communications system 100 may support synchronous or asynchronous operation. For synchronous operation, the base stations 105 may have similar frame timings, and transmissions from different base stations 105 may be approximately aligned in time. For asynchronous operation, the base stations 105 may have different frame timings, and transmissions from different base stations 105 may, in some examples, not be aligned in time. The techniques described herein may be used for either synchronous or asynchronous operations.

Some UEs 115, such as MTC or IoT devices, may be low cost or low complexity devices and may provide for automated communication between machines (e.g., via Machine-to-Machine (M2M) communication) . M2M communication or MTC may refer to data communication technologies that allow devices to communicate with one another or a base station 105 without human intervention. In some examples, M2M communication or MTC may include communications from devices that integrate sensors or meters to measure or capture information and relay such information to a central server or application program that makes use of the information or presents the information to humans interacting with the application program. Some UEs 115 may be designed to collect information or enable automated behavior of machines or other devices. Examples of applications for MTC devices include smart metering, inventory monitoring, water level monitoring, equipment monitoring, healthcare monitoring, wildlife monitoring, weather and geological event monitoring, fleet management and tracking, remote security sensing, physical access control, and transaction-based business charging.

Some UEs 115 may be configured to employ operating modes that reduce power consumption, such as half-duplex communications (e.g., a mode that supports one-way communication via transmission or reception, but not transmission and reception simultaneously) . In some examples, half-duplex communications may be performed at a reduced peak rate. Other power conservation techniques for the UEs 115 include entering a power saving deep sleep mode when not engaging in active communications, operating over a limited bandwidth (e.g., according to narrowband communications) , or a combination of these techniques. For example, some UEs 115 may be configured for operation using a narrowband protocol type that is associated with a defined portion or range (e.g., set of subcarriers or resource blocks (RBs) ) within a carrier, within a guard-band of a carrier, or outside of a carrier.

The wireless communications system 100 may be configured to support ultra-reliable communications or low-latency communications, or various combinations thereof. For example, the wireless communications system 100 may be configured to support ultra-reliable low-latency communications (URLLC) or mission critical communications. The UEs 115 may be designed to support ultra-reliable, low-latency, or critical functions (e.g., mission critical functions) . Ultra-reliable communications may include private communication or group communication and may be supported by one or more mission critical services such as mission critical push-to-talk (MCPTT) , mission critical video (MCVideo) , or mission critical data (MCData) . Support for mission critical functions may include prioritization of services, and mission critical services may be used for public safety or general commercial applications. The terms ultra-reliable, low-latency, mission critical, and ultra-reliable low-latency may be used interchangeably herein.

In some examples, a UE 115 may also be able to communicate directly with other UEs 115 over a device-to-device (D2D) communication link 135 (e.g., using a peer-to-peer (P2P) or D2D protocol) . One or more UEs 115 utilizing D2D communications may be within the geographic coverage area 110 of a base station 105. Other UEs 115 in such a group may be outside the geographic coverage area 110 of a base station 105 or be otherwise unable to receive transmissions from a base station 105. In some examples, groups of the UEs 115 communicating via D2D communications may utilize a one-to-many (1: M) system in which each UE 115 transmits to every other UE 115 in the group. In some examples, a base station 105 facilitates the scheduling of resources for D2D communications. In other cases, D2D communications are carried out between the UEs 115 without the involvement of a base station 105.

In some systems, the D2D communication link 135 may be an example of a communication channel, such as a sidelink communication channel, between vehicles (e.g., UEs 115) . In some examples, vehicles may communicate using vehicle-to-everything (V2X) communications, vehicle-to-vehicle (V2V) communications, or some combination of these. A vehicle may signal information related to traffic conditions, signal scheduling, weather, safety, emergencies, or any other information relevant to a V2X system. In some examples, vehicles in a V2X system may communicate with roadside infrastructure, such as roadside units, or with the network via one or more network nodes (e.g., base stations 105) using vehicle-to-network (V2N) communications, or with both.

The core network 130 may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. The core network 130 may be an evolved packet core (EPC) or 5G core (5GC) , which may include at least one control plane entity that manages access and mobility (e.g., a mobility management entity (MME) , an access and mobility management function (AMF) ) and at least one user plane entity that routes packets or interconnects to external networks (e.g., a serving gateway (S-GW) , a Packet Data Network (PDN) gateway (P-GW) , or a user plane function (UPF) ) . The control plane entity may manage non-access stratum (NAS) functions such as mobility, authentication, and bearer management for the UEs 115 served by the base stations 105 associated with the core network 130. User IP packets may be transferred through the user plane entity, which may provide IP address allocation as well as other functions. The user plane entity may be connected to the network operators IP services 150. The operators IP services 150 may include access to the Internet, Intranet (s) , an IP Multimedia Subsystem (IMS) , or a Packet-Switched Streaming Service.

Some of the network devices, such as a base station 105, may include subcomponents such as an access network entity 140, which may be an example of an access node controller (ANC) . Each access network entity 140 may communicate with the UEs 115 through one or more other access network transmission entities 145, which may be referred to as radio heads, smart radio heads, or transmission/reception points (TRPs) . Each access network transmission entity 145 may include one or more antenna panels. In some configurations, various functions of each access network entity 140 or base station 105 may be distributed across various network devices (e.g., radio heads and ANCs) or consolidated into a single network device (e.g., a base station 105) .

The wireless communications system 100 may operate using one or more frequency bands, typically 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 decimeter band because the wavelengths range from approximately one decimeter to one meter in length. The UHF waves may be blocked or redirected by buildings and environmental features, but the waves may penetrate structures sufficiently for a macro cell to provide service to the UEs 115 located indoors. The transmission of UHF waves may be associated with smaller antennas and shorter ranges (e.g., less than 100 kilometers) compared to transmission using the smaller frequencies and longer waves of the high frequency (HF) or very high frequency (VHF) portion of the spectrum below 300 MHz.

The wireless communications system 100 may also operate in a super high frequency (SHF) region using frequency bands from 3 GHz to 30 GHz, also known as the centimeter band, or in an extremely high frequency (EHF) region of the spectrum (e.g., from 30 GHz to 300 GHz) , also known as the millimeter band. In some examples, the wireless communications system 100 may support millimeter wave (mmW) communications between the UEs 115 and the base stations 105, and EHF antennas of the respective devices may be smaller and more closely spaced than UHF antennas. In some examples, this may facilitate use of antenna arrays within a device. The propagation of EHF transmissions, however, may be subject to even greater atmospheric attenuation and shorter range than SHF or UHF transmissions. The techniques disclosed herein may be employed across transmissions that use one or more different frequency regions, and designated use of bands across these frequency regions may differ by country or regulating body.

The wireless communications system 100 may utilize both licensed and unlicensed radio frequency spectrum bands. For example, the wireless communications system 100 may employ License Assisted Access (LAA) , LTE-Unlicensed (LTE-U) radio access technology, or NR technology in an unlicensed band such as the 5 GHz industrial, scientific, and medical (ISM) band. When operating in unlicensed radio frequency spectrum bands, devices such as the base stations 105 and the UEs 115 may employ carrier sensing for collision detection and avoidance. In some examples, operations in unlicensed bands may be based on a carrier aggregation configuration in conjunction with component carriers operating in a licensed band (e.g., LAA) . Operations in unlicensed spectrum may include downlink transmissions, uplink transmissions, P2P transmissions, or D2D transmissions, among other examples.

A base station 105 or a UE 115 may be equipped with multiple antennas, which may be used to employ techniques such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communications, or beamforming. The antennas of a base station 105 or a UE 115 may be located within one or more antenna arrays or antenna panels, which may support MIMO operations or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays may be co-located at an antenna assembly, such as an antenna tower. In some examples, antennas or antenna arrays associated with a base station 105 may be located in diverse geographic locations. A base station 105 may have an antenna array with a number of rows and columns of antenna ports that the base station 105 may use to support beamforming of communications with a UE 115. Likewise, a UE 115 may have one or more antenna arrays that may support various MIMO or beamforming operations. Additionally or alternatively, an antenna panel may support radio frequency beamforming for a signal transmitted via an antenna port.

The base stations 105 or the UEs 115 may use MIMO communications to exploit multipath signal propagation and increase the spectral efficiency by transmitting or receiving multiple signals via different spatial layers. Such techniques may be referred to as spatial multiplexing. The multiple signals may, for example, be transmitted by the transmitting device via different antennas or different combinations of antennas. Likewise, the multiple signals may be received by the receiving device 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 (e.g., the same codeword) or different data streams (e.g., different codewords) . Different spatial layers may be associated with different antenna ports used 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 multiple-user MIMO (MU-MIMO) , where multiple spatial layers are transmitted to multiple devices.

Beamforming, which may also be referred to as spatial filtering, directional transmission, or directional reception, is a signal processing technique that may be used at a transmitting device or a receiving device (e.g., a base station 105, a UE 115) to shape or steer an antenna beam (e.g., a transmit beam, a receive beam) along a spatial path between the transmitting device and the receiving device. Beamforming may be achieved by combining the signals communicated via antenna elements of an antenna array such that some signals propagating at particular orientations with respect to an antenna array experience constructive interference while others experience destructive interference. The adjustment of signals communicated via the antenna elements may include a transmitting device or a receiving device applying amplitude offsets, phase offsets, or both to signals carried via the antenna elements associated with the device. The adjustments associated with each of the antenna elements may be defined by a beamforming weight set associated with a particular orientation (e.g., with respect to the antenna array of the transmitting device or receiving device, or with respect to some other orientation) .

A base station 105 or a UE 115 may use beam sweeping techniques as part of beam forming operations. For example, a base station 105 may use multiple antennas or antenna arrays (e.g., antenna panels) to conduct beamforming operations for directional communications with a UE 115. Some signals (e.g., synchronization signals, reference signals, beam selection signals, or other control signals) may be transmitted by a base station 105 multiple times in different directions. For example, the base station 105 may transmit a signal according to different beamforming weight sets associated with different directions of transmission. Transmissions in different beam directions may be used to identify (e.g., by a transmitting device, such as a base station 105, or by a receiving device, such as a UE 115) a beam direction for later transmission or reception by the base station 105.

Some signals, such as data signals associated with a particular receiving device, may be transmitted by a base station 105 in a single beam direction (e.g., a direction associated with the receiving device, such as a UE 115) . In some examples, the beam direction associated with transmissions along a single beam direction may be determined based on a signal that was transmitted in one or more beam directions. For example, a UE 115 may receive one or more of the signals transmitted by the base station 105 in different directions and may report to the base station 105 an indication of the signal that the UE 115 received with a highest signal quality or an otherwise acceptable signal quality.

In some examples, transmissions by a device (e.g., by a base station 105 or a UE 115) may be performed using multiple beam directions, and the device may use a combination of digital precoding or radio frequency beamforming to generate a combined beam for transmission (e.g., from a base station 105 to a UE 115) . The UE 115 may report feedback that indicates precoding weights for one or more beam directions, and the feedback may correspond to a configured number of beams across a system bandwidth or one or more sub-bands. The base station 105 may transmit a reference signal (e.g., a cell-specific reference signal (CRS) , a channel state information reference signal (CSI-RS) ) , which may be precoded or unprecoded. The UE 115 may provide feedback for beam selection, which may be a precoding matrix indicator (PMI) or codebook-based feedback (e.g., a multi-panel type codebook, a linear combination type codebook, a port selection type codebook) . Although these techniques are described with reference to signals transmitted in one or more directions by a base station 105, a UE 115 may employ similar techniques for transmitting signals multiple times in different directions (e.g., for identifying a beam direction for subsequent transmission or reception by the UE 115) or for transmitting a signal in a single direction (e.g., for transmitting data to a receiving device) .

A receiving device (e.g., a UE 115) may try multiple receive configurations (e.g., directional listening) when receiving various signals from the base station 105, such as synchronization signals, reference signals, beam selection signals, or other control signals. For example, a receiving device may try multiple receive directions by receiving via different antenna subarrays, by processing received signals according to different antenna subarrays, by receiving according to different receive beamforming weight sets (e.g., different directional listening weight sets) applied to signals received at multiple antenna elements of an antenna array, or by processing received signals according to different receive beamforming weight sets applied to signals received at multiple antenna elements of an antenna array, any of which may be referred to as “listening” according to different receive configurations or receive directions. In some examples, a receiving device may use a single receive configuration to receive along a single beam direction (e.g., when receiving a data signal) . The single receive configuration may be aligned in a beam direction determined based on listening according to different receive configuration directions (e.g., a beam direction determined to have a highest signal strength, highest signal-to-noise ratio (SNR) , or otherwise acceptable signal quality based on listening according to multiple beam directions) .

The wireless communications system 100 may be a packet-based network that operates according to a layered protocol stack. In the user plane, communications at the bearer or Packet Data Convergence Protocol (PDCP) layer may be IP-based. A Radio Link Control (RLC) layer may perform packet segmentation and reassembly to communicate over logical channels. A Medium Access Control (MAC) layer may perform priority handling and multiplexing of logical channels into transport channels. The MAC layer may also use error detection techniques, error correction techniques, or both to support retransmissions at the MAC layer to improve link efficiency. In the control plane, the Radio Resource Control (RRC) protocol layer may provide establishment, configuration, and maintenance of an RRC connection between a UE 115 and a base station 105 or a core network 130 supporting radio bearers for user plane data. At the physical layer, transport channels may be mapped to physical channels.

The UEs 115 and the base stations 105 may support retransmissions of data to increase the likelihood that data is received successfully. Hybrid automatic repeat request (HARQ) feedback is one technique for increasing the likelihood that data is received correctly over a communication link 125. HARQ may include a combination of error detection (e.g., using a cyclic redundancy check (CRC) ) , forward error correction (FEC) , and retransmission (e.g., automatic repeat request (ARQ) ) . HARQ may improve throughput at the MAC layer in poor radio conditions (e.g., low signal-to-noise conditions) . In some examples, a device may support same-slot HARQ feedback, where the device may provide HARQ feedback in a specific slot for data received in a previous symbol in the slot. In other cases, the device may provide HARQ feedback in a subsequent slot, or according to some other time interval.

A UE 115 may establish a connection with a base station 105 of a plurality of base stations 105. The UE 115 may identify a first set of synchronization points defining a set of time intervals, each of the first set of synchronization points associated with a channel access opportunity during which the UE 115 and the plurality of base stations 105 can perform a channel access procedure to access a channel. The UE 115 may identify a second set of synchronization points, each of the second set of synchronization points associated with a channel access opportunity during which the UE 115 and the plurality of base stations 105 can perform a channel access procedure to access the channel, each time interval of the set of time intervals comprising at least one synchronization point of the second set of synchronization points. The UE 115 may perform, at the channel access opportunity associated with a synchronization point of the first or second set of synchronization points, the channel access procedure to access the channel for a channel occupancy time to end before a next synchronization point of the first set of synchronization points associated with the time interval for which the channel access procedure is performed. The UE 115 may perform wireless communications with the base station 105 during the channel occupancy time based at least in part on a result of the channel access procedure.

A base station 105 may establish a connection with a UE 115. The base station 105 may identify a first set of synchronization points defining a set of time intervals, each of the first set of synchronization points associated with a channel access opportunity during which the UE 115 and the base station 105 can perform a channel access procedure to access a channel. The base station 105 may identify a second set of synchronization points, each of the second set of synchronization points associated with a channel access opportunity during which the UE 115 and the base station 105 can perform a channel access procedure to access the channel, each time interval of the set of time intervals comprising at least one synchronization point of the second set of synchronization points. The base station 105 may transmit, to the UE 115, a configuration signal identifying resources for the first set of synchronization points.

FIG. 2 illustrates an example of a wireless communication system 200 that supports two-level synchronization point design for LBE mode in accordance with aspects of the present disclosure. In some examples, wireless communication system 200 may implement aspects of wireless communication system 100. Wireless communication system 200 may be an example of a single operator network 205 deployment using a plurality of base stations 210 and UEs 215, which may be examples of the corresponding devices described herein. Although the techniques described herein are generally discussed in terms of a single operator network 205, it is to be understood that these techniques may be applicable for any wireless device communicating in any network deployment scenario. In some aspects, wireless communication system 200 operates over a shared (e.g., shared licensed) or unlicensed radio frequency spectrum band.

In some aspects, wireless communication system 200 may provide enhancements to ensure feature compatibility with communications in a shared or unlicensed radio frequency spectrum band in a controlled environment. The communications may include ultra-reliable/low-latency communications (URLLC) , IoT communications (e.g., industrial IoT (IIoT) ) , and the like. One example use case of a controlled environment may be a single operator network 205 (e.g., a factory owner) with the ability to control the deployment and the interference environment. Other example use cases may also be considered.

Typically, such wireless network deployments utilize an FBE operational mode. One advantage of the FBE operational mode is that there may be no need for a category four (Cat-4) LBT procedure due to the rigid scheduling implementing the FFP structure. The FBE operational mode typically includes each base station in the wireless network announcing that it is operating in the FBE mode and indicating (e.g., configuring) the FFP in its SIB1 broadcast message. Only the base stations in the network can contend for the channel using a one-shot LBT procedure at the beginning of each FFP. An idle duration (e.g., a gap period) may be designed at the end of one FFP/before the beginning of the next FFP to allow the LBT procedure to be performed. UE transmissions within an FFP are conditioned on the UE detecting a transmission by its source or serving base station in the same FFP. A certain processing timeline may be used for the UE to detect the downlink signal (e.g., the base station transmission) and respond.

In the FBE operational mode, cross link blocking may be handled by scheduler implementation. This may include aligning the FFP of all base stations in the wireless network so that they are contending for the channel at the same time, and therefore will not block each other. Within an FFP, there are also fixed synchronization points configured for the base station or UE to begin transmissions after a one-shot LBT procedure is performed (e.g., if >25 micro-second gaps are needed) .

However, wireless networks operating according to an FBE operational mode typically experience waste in that many of the resources within the FFP often go unused. For example, a base station may capture an FFP for a small downlink burst, but its UEs may not have information to communicate during the FFP. This not only wastes the resources within the FFP, but also blocks out neighboring base stations and/or UEs from communicating during the FFP because it was captured by another base station. Furthermore, this FBE operational mode is rigid in its synchronization and deployment, which limits the ability of the network to adapt to changing communication requirements. That is, changes to the FFP structure would require an update by all devices operating within the wireless network. This technique does not provide flexibility for a base station to control the frequency (e.g., periodicity) of its synchronization points within the FFP. Lastly, this FBE operational mode prevents a UE from capturing an FFP for wireless communications, which may be especially problematic in the situation where the UE has information ready to communicate, but its base station does not (and therefore does not capture the channel) .

Accordingly, aspects of the described techniques implement an LBE operational mode within a wireless network, which may provide numerous advantages. For example, the LBE operational mode may not use a fixed periodic structure, which may improve flexibility for the wireless devices operating in the wireless network, such as base stations 210 and/or UE 215. The LBE operational mode supports sending uplink information signals or channels at the beginning of the FFP. Moreover, a UE (such as UE 215) is not required to detect a downlink signal or channel (e.g., a transmission from its base station) before performing an uplink transmission. Aspects of the described LBE operational mode address techniques for avoiding cross link interference-based blocking (e.g., an LBT failure due to another base station 210 or UE 215 transmitting nearby) , for reducing the overhead of a Cat-4 LBT procedure (e.g., shorter time gaps) , and the like.

In particular, aspects of the described techniques provide for a dual-level synchronization point design for wireless communication systems operating in an LBE operational mode. This may include a first set of synchronization points 220 (which may also be referred to as level 1 sync points or hard sync points) being configured by base stations 210 for UEs 215 operating in the wireless network. That is, the scheduler may reserve the first set of synchronization points 220 (e.g., the hard sync points) that all nodes in the neighborhood may observe. Broadly, the first set of synchronization points 220 defined time intervals for the wireless network. That is, the interval between adjacent synchronization points (e.g., between synchronization point 220-a and 220-b, or between synchronization point 220-b and 220-c) may define a fixed or known time interval for the wireless devices operating in the LBE mode.

Broadly, each synchronization point in the first set of synchronization points 220 may also provide a channel access opportunity (e.g., a point in time) at which the base stations 210 and/or UEs 215 can perform a channel access procedure (e.g., an LBT procedure, such as a Cat-4 LBT procedure) to access the channel. In some aspects, a transmission during one time interval may stop a certain time period before (e.g., a gap) the next synchronization point in the first set of synchronization points 220, e.g., to leave room for other nodes to perform an LBT procedure during the gap, such as a Cat-4 or category two (Cat-2) LBT procedure. In some cases the Cat-4 LBT procedure may be associated with a first time duration longer than a second time durations associated with the Cat-2 LBT procedure. That is, the channel access procedure can start at any synchronization point in the first set of synchronization points 220, but may stop before the next synchronization point in the first set of synchronization points 220, e.g., the channel occupancy time may end before the next synchronization point in the first set of synchronization points 220.

In some aspects, base stations 210 may configure UEs 215 with the first set of synchronization points 220. For example, base stations 210 may transmit a configuration signal (e.g., an RRC signal, a MAC CE signal, and the like) identifying resources (e.g., time and/or frequency resources) for the first set of synchronization points. In some aspects, the configuration signaling may include the first set of synchronization points 220 being configured via RRC signaling, SIB messaging (e.g., a SIB 1) , or the like. In the case of SIB messaging, each UE 215 that receives the SIB from a base station 210 via a broadcast or shared channel may share the first set of synchronization points 220. In the case of RRC signaling, each UE 215 may be separately configured with the same or different first sets of synchronization points 220. In some cases, a UE 215 may signal the amount of data or a quality of service (QoS) associated with data to be transmitted by the UE 215 to a base station 210. The base station 205 may select the first set of synchronization points 220 for the UE 215 based on the signaled amount of data or QoS. More particularly, a UE 215 with a relatively high amount of data, or high QoS (e.g., over a QoS threshold) , or both, may receive more synchronization points 220 in the first set of synchronization points 220 (e.g., the periodicity of the synchronization points may be smaller, making the synchronization points closer together in the time domain) that may be used for channel acquisition. On the other hand, a UE 215 with a relatively low amount of data or low QoS may receive fewer synchronization points 220 (e.g., the periodicity of the synchronization points may be larger, making the synchronization points farther apart in the time domain) in the first set of synchronization points 220 to use for channel acquisition.

In some examples, the first set of synchronization points 220 are not explicitly signaled to the UEs 215. That is, the UEs 215 may deduce the first set of synchronization points 220 using other information. For example, the timing of the first set of synchronization points 220 may correspond to, or may be determined based on, an uplink transmission scheduled via RRC signaling. The uplink transmission may be a configured grant uplink transmission, a sounding reference signal, an uplink control channel, or the like. Thus, upon receiving the scheduling information via RRC, the UE 215 may identify the first set of synchronization points 220 based on the starting location of the uplink transmission. That is, the first set of synchronization points 220 may be identified using a set of fixed or dynamic time periods relative to the starting location of the uplink transmission.

Aspects of the described techniques may also include a second set of synchronization points 225 (which may also be referred to as level two sync points, soft sync points, and/or channel access starting points) . In some aspects, every synchronization point in the second set of synchronization points 225 may also define a channel access opportunity during which base stations 210 and/or UEs 215 can perform a channel access procedure to access the channel. As is shown in FIG. 2, the synchronization points in the second set of access points 225 may generally be more dense (e.g., have a shorter periodicity) than the synchronization points in the first set of synchronization points 220. Although the example illustrated in FIG. 2 shows three synchronization points from the second set of synchronization points 225 within each time interval, it is to be understood that more or fewer synchronization points from the second set of synchronization points 225 may be configured within each time interval.

As discussed, every synchronization point in the second set of synchronization points 225 may provide a channel access opportunity for base stations 210 and/or UEs 215 to capture the channel for wireless communications during a channel occupancy time. However, the wireless communications may continue through one or more subsequent synchronization points in the second set of synchronization points 225, e.g., the channel occupancy time may extend past the next synchronization point in the second set of synchronization points 225. For example, a base station 210 or UE 215 may perform an LBT procedure to capture the channel at synchronization point 225-d for wireless communications during a channel occupancy time that extends past synchronization points 225-e and 225-f from the second set of synchronization points 225. However, if the node is aware of the synchronization points and intends to stop transmitting before a particular synchronization point in the second set of synchronization points 225, the node may select a duration for the channel occupancy time in order to leave a gap period before the next synchronization point, e.g., to allow another device to perform an LBT procedure prior to that synchronization point.

In some examples, the synchronization points in the second set of synchronization points 225 may be identified based on a configuration signal (e.g., an RRC signal, a MAC CE, and the like) transmitted by base stations 210. That is, base stations 210 may transmit the configuration signal that identifies resources (e.g., time and/or frequency resources) for the second set of synchronization points 225.

In another example, the synchronization points in the second set of synchronization points 225 may be preconfigured. That is, base stations 210 and UEs 215 may know, based on preconfigured information, that the synchronization points in the second set of synchronization points 225 are based on the resources for the first set of synchronization points 220. For example, the synchronization points in the second set of synchronization points 225 may be configured for every 1/Nth portion of a time interval between two adjacent synchronization points in the first set of synchronization points 220, e.g., every 1/8, 1/4, 1/3, 1/2, etc., portion of the time interval. That is, in this example the synchronization points in the second set of synchronization points 225 can be defined as a set of channel occupancy time starting points within a time interval defined by two synchronization points in the first set of synchronization points 220. In some aspects of this example, as the synchronization points in the second set of synchronization points 225 are not necessarily configured (e.g., via RRC signaling) , these synchronization points may or may not have a gap period configured before the start of each synchronization point. In this scenario, when a base station 210 or UE 215 attempts to perform a channel access procedure at a channel occupancy time starting point (e.g., a synchronization point within the second set of synchronization points 225) , it may perform a Cat-4 LBT procedure while other nodes may not intentionally avoid transmitting during the gap period.

In some aspects, the second set of synchronization points 225 may be configured differently for different time intervals. For example, more synchronization points may be configured for one time interval to support increased channel access opportunities, whereas fewer synchronization points may be configured for another time interval.

Accordingly, aspects of the described techniques support a UE 215 establishing a connection with a base station 210 of a plurality of base stations 210 (e.g., at least one of the base stations 210 of wireless communication system 200) . The UE 215 may identify the first set of synchronization points 220 defining the time intervals and providing the channel access opportunities for the nodes within wireless communication system 200. The UE 215 may also identify the second set of synchronization points 225 that also provide channel access opportunities for the nodes within wireless communication system 200. Base stations 210 may also identify the first and second sets of

synchronization points

220 and 225, respectively, e.g., as discussed above. Base stations 210 may transmit the configuration signal identifying the resources for the first set of synchronization points 220, which can be used by UEs 215 to identify the first set of synchronization points 220. In the option where the second set of synchronization points 225 are configured, the base station can also transmit the configuration signal identifying resources for the second set of synchronization points 225. As discussed, in the option where the second set of synchronization points 225 are known based on the resources for the first set of synchronization points 220, the base station 210 and/or UE 215 may identify the second set of synchronization points 225 based on the resources for the first set of synchronization points 220.

Accordingly, base stations 210 and/or UEs 215 may perform a channel access procedure (e.g., such as a Cat-4 LBT procedure) at a synchronization point from the first set of synchronization points 220 or from the second set of synchronization points 225. Depending upon the results of the channel access procedure (e.g., whether the device is able to capture the channel) , the base stations 210 and/or UEs 215 may perform wireless communication during the channel occupancy time. As discussed, the channel occupancy time may extend or otherwise span synchronization points within the second set of synchronization points 225, but may end at least before the next synchronization point in the first set of synchronization points 220 (e.g., before the time interval expires) .

As also discussed, base stations 210 and/or UEs 215 may (e.g., when selecting the duration for the channel occupancy time) select an end for the channel occupancy time just before the next synchronization point from either the first set of synchronization points 220 or the second set of synchronization points 225, e.g., in order to allow for a gap period. The gap period may be used by other nodes for performing a channel access procedure to capture the channel for wireless communications.

FIG. 3 illustrates an example of a synchronization point configuration 300 that supports two-level synchronization point design for LBE mode in accordance with aspects of the present disclosure. In some examples, synchronization point configuration 300 may implement aspects of wireless communication systems 100 and/or 200. Aspects of synchronization point configuration 300 may be implemented by a base station and/or a UE, which may be examples of the corresponding devices described herein.

As discussed above, aspects of the described techniques provide for an LBE operation mode implemented in a wireless network utilizing a first set of synchronization points 305 and a second set of synchronization points 310. The first set of synchronization points 305 (which may also be referred to as level one or hard sync points) may be configured by base stations by transmitting RRC signaling, a MAC CE, SIB messaging, and the like, for UEs operating within its coverage area. Broadly, the first set of synchronization points 305 may generally defined time intervals for the wireless network, with each synchronization point providing a channel access opportunity during which the UE and/or base station can perform a channel access procedure (an LBT procedure) to access a channel. A time interval may be defined as the time period extending between two adjacent synchronization points in the first set of synchronization points 305, e.g., between synchronization point 305-a and synchronization point 305-b.

Broadly, the second set of synchronization points 310 may also provide a channel access opportunity during which the UE and/or base station can perform a channel access procedure (e.g., an LBT procedure) to access a channel. The synchronization points in the second set of synchronization points 310 may be configured for the UEs (e.g., via RRC signaling) and/or may be based on the resources associated with the first set of synchronization points 305 (e.g., preconfigured or otherwise known) .

In some aspects, one or more gap periods may be defined or otherwise configured for the synchronization points in the first set of synchronization points 305 and/or the second set of synchronization points 310. The gap period defines a time period known by devices operating in the wireless network, which may be used for a channel access procedure (e.g., an LBT procedure) to capture the channel. In some aspects, a gap period configured for every synchronization point in the first set of synchronization points 305 may be a hard gap period in that no devices within the network are allowed to transmit during the gap period. A gap configured for a synchronization point in the second set of synchronization points 310 may be a soft gap period. That is, the gap period may be optionally configured for the synchronization points in the second set of synchronization points 310, but the UEs and/or base stations may transmit during that gap period when performing wireless communications during a channel occupancy time extending past that associated synchronization point.

The UEs and base stations within the wireless network may utilize any synchronization point within the first set of synchronization points 305 or the second set of synchronization points 310 to perform a channel access procedure, such as a Cat-4 LBT procedure. Broadly, a successful channel access procedure may capture the channel for a channel occupancy time, during which the UEs and/or base stations can perform wireless communications over the channel.

For example and during a first time interval extending between synchronization point 305-a and 305-b of the first set of synchronization points 305, a first base station (e.g., gNB0) and a second base station (e.g., gNB1) may both perform channel access procedures at synchronization point 310-afrom the second set of synchronization points 310. As the first and second base stations are far enough apart that they cannot hear each other during the channel access procedure, each base station may capture the channel for a channel occupancy time that spans synchronization points 310-b and 310-c of the second set of synchronization points 310. A third base station (e.g., gNB2) may attempt a channel access procedure at synchronization point 310-b, but may be blocked from capturing the channel due to the wireless communications being performed by the first base station (or its UEs) and/or the second base station (or its UEs) . As discussed, the channel occupancy time captured during the channel access procedure by the first and second base stations may end before the next synchronization point in the first set of synchronization points 305 (e.g., may end before synchronization point 305-b) . For example, a hard gap may be configured before the synchronization point 305-b, which is observed by each node by avoiding transmissions during the gap period.

In another example and during a second time interval extending between synchronization point 305-b and 305-c of the first set of synchronization points 305, the second base station (e.g., gNB1) and the third base station (e.g., gNB2) may both perform channel access procedures at synchronization point 310-d from the second set of synchronization points 310. As the second and third base stations are far enough apart that they cannot hear each other during the channel access procedure, each base station may capture the channel for a channel occupancy time that spans synchronization point 310-e and stops at synchronization point 310-f of the second set of synchronization points 310. The first base station (e.g., gNB0) may attempt a channel access procedure at synchronization point 310-e, but may be blocked from capturing the channel due to the wireless communications being performed by the second base station (or its UEs) and/or the third base station (or its UEs) . In this example, the channel occupancy time captured during the channel access procedure by the second and third base stations may not end before the next synchronization point in the second set of synchronization points 310 (e.g., may end at synchronization point 310-f) . For example, no gap period may be configured before the synchronization point 310-f. The first base station may attempt another channel access procedure at synchronization point 310-f and capture the channel for a channel occupancy time that ends at synchronization point 305-c of the first set of synchronization points 305. In this example, the first base station may stop transmitting during a gap period configured before synchronization point 305-c.

FIG. 4 illustrates an example of a process 400 that supports two-level synchronization point design for LBE mode in accordance with aspects of the present disclosure. In some examples, process 400 may implement aspects of wireless communication systems 100 and/or 200, and/or synchronization point configuration 300. Aspects of process 400 may be implemented by UE 405 and/or base station 410, which may be examples of corresponding devices described herein.

At 415, UE 405 and base station 410 may establish a connection. In some aspects, base station 410 may be one of a plurality of base stations operating in a single operator network over a shared or unlicensed radio frequency spectrum band. UE 405 and base station 410 may establish a connection via RRC signaling, e.g., during initial cell acquisition.

At 420, base station 410 may identify a first set of synchronization points. The first set of synchronization points may define a set of time intervals for the wireless network, with each synchronization point in the first set of synchronization points being associated with, or otherwise providing, a channel access opportunity during which UE 405 and/or base station 410 can perform a channel access procedure to access a channel. Base station 410 may identify the first set of synchronization points based on UE scheduling needs (e.g., based on an uplink transmission received from UE 405) , based on network congestion levels, based on recent communication requirements from UE 405 and other UEs served by base station 410, and the like.

At 425, base station 410 may identify a second set of synchronization points, with each synchronization point in the second set of synchronization points associated with, or otherwise providing, a channel access opportunity during which UE 405 and/or base station 410 can perform a channel access procedure to access the channel. In some aspects, each time interval of the set of time intervals defined by the first set of synchronization points may include at least one or more synchronization points of the second set of synchronization points. Base station 410 may identify the second set of synchronization points based on the resources of the first set of synchronization points, based on preconfigured or known information, and the like.

At 430, base station 410 may transmit (and UE 405 may receive) a configuration signal identifying resources for at least the first set of synchronization points. For example, the configuration signal may include RRC signaling, a MAC CE, SIB messaging, and the like, transmitted in a broadcast, multicast, and/or unicast transmission. In some examples, the configuration signal may also identify resources for the second set of synchronization points. In some aspects, base station 410 may identify the second set of synchronization points based on resources for the first set of synchronization points. Accordingly, the synchronization signal may not explicitly identify the resources for the second set of synchronization points. In some aspects, each synchronization point in the second set of synchronization points may, or may not, be associated with a gap period.

At 435, UE 405 may identify the first set of synchronization points defining the set of time intervals for the wireless network. UE 405 may determine that each synchronization point in the first set of synchronization points are associated with, or otherwise provide, a channel access opportunity during which UE 405 and/or base station 410 may perform a channel access procedure. In some aspects, UE 405 may identify the first set of synchronization points based on a configuration signal received from base station 410, based on an uplink transmission to base station 410, and the like.

At 440, UE 405 may identify the second set of synchronization points, with each synchronization point in the second set of synchronization points being associated with, or otherwise providing, a channel access opportunity during which the UE 405 and/or base station 410 can perform a channel access procedure to access the channel. In some aspects, each time interval in the set of time intervals may include at least one synchronization point from the second set of synchronization points.

In some aspects, UE 405 may identify the second set of synchronization points based on the configuration signal received from base station 410. For example, the configuration signal may identify resources for the first set of synchronization points, which UE 405 then uses to determine the second set of synchronization points. In another example, the configuration signal may identify the resources for the second set of synchronization points.

At 445, UE 405 may perform the channel access procedure (e.g., an LBT procedure, such as a Cat-4 LBT procedure) at any synchronization point of the first or second sets of synchronization points. The channel access procedure may access the channel for a channel occupancy time that ends before the next synchronization point in the first set of synchronization points (e.g., the channel occupancy time may end before expiration of the time interval during which the channel access procedure was performed) .

At 450, UE 405 and base station 410 may perform wireless communications during the channel occupancy time based on a result of the channel access procedure. That is, UE 405 may capture the channel based on a successful channel access procedure for the channel occupancy time for wireless communications. In some aspects, UE 405 and/or base station 410 may determine that the wireless communications are to end within a defined time period of the next synchronization point from the first set of synchronization points. Accordingly, UE 405 and/or base station 410 may select the channel occupancy time to end a defined gap period before the next synchronization point.

FIG. 5 shows a block diagram 500 of a device 505 that supports two-level synchronization point design for LBE mode in accordance with aspects of the present disclosure. The device 505 may be an example of aspects of a UE 115 as described herein. The device 505 may include a receiver 510, a communications manager 515, and a transmitter 520. The device 505 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses) .

The receiver 510 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to two-level synchronization point design for LBE mode, etc. ) . Information may be passed on to other components of the device 505. The receiver 510 may be an example of aspects of the transceiver 820 described with reference to FIG. 8. The receiver 510 may utilize a single antenna or a set of antennas.

The communications manager 515 may establish a connection with a base station of a set of base stations, identify a first set of synchronization points defining a set of time intervals, each of the first set of synchronization points associated with a channel access opportunity during which the UE and the set of base stations can perform a channel access procedure to access a channel, identify a second set of synchronization points, each of the second set of synchronization points associated with a channel access opportunity during which the UE and the set of base stations can perform a channel access procedure to access the channel, each time interval of the set of time intervals including at least one synchronization point of the second set of synchronization points, perform, at the channel access opportunity associated with a synchronization point of the first or second set of synchronization points, the channel access procedure to access the channel for a channel occupancy time to end before a next synchronization point of the first set of synchronization points associated with the time interval for which the channel access procedure is performed, and perform wireless communications with the base station during the channel occupancy time based on a result of the channel access procedure. The communications manager 515 may be an example of aspects of the communications manager 810 described herein.

The communications manager 515, or its sub-components, may be implemented in hardware, code (e.g., software or firmware) executed by a processor, or any combination thereof. If implemented in code executed by a processor, the functions of the communications manager 515, or its sub-components may be executed by 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 in the present disclosure.

The communications manager 515, or its sub-components, may be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations by one or more physical components. In some examples, the communications manager 515, or its sub-components, may be a separate and distinct component in accordance with various aspects of the present disclosure. In some examples, the communications manager 515, or its sub-components, may be combined with one or more other hardware components, including but not limited to an input/output (I/O) component, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof in accordance with various aspects of the present disclosure.

The transmitter 520 may transmit signals generated by other components of the device 505. In some examples, the transmitter 520 may be collocated with a receiver 510 in a transceiver module. For example, the transmitter 520 may be an example of aspects of the transceiver 820 described with reference to FIG. 8. The transmitter 520 may utilize a single antenna or a set of antennas.

FIG. 6 shows a block diagram 600 of a device 605 that supports two-level synchronization point design for LBE mode in accordance with aspects of the present disclosure. The device 605 may be an example of aspects of a device 505, or a UE 115 as described herein. The device 605 may include a receiver 610, a communications manager 615, and a transmitter 645. The device 605 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses) .

The receiver 610 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to two-level synchronization point design for LBE mode, etc. ) . Information may be passed on to other components of the device 605. The receiver 610 may be an example of aspects of the transceiver 820 described with reference to FIG. 8. The receiver 610 may utilize a single antenna or a set of antennas.

The communications manager 615 may be an example of aspects of the communications manager 515 as described herein. The communications manager 615 may include a connection manager 620, a hard sync point manager 625, a soft sync point manager 630, a LBT manager 635, and a channel occupancy manager 640. The communications manager 615 may be an example of aspects of the communications manager 810 described herein.

The connection manager 620 may establish a connection with a base station of a set of base stations.

The hard sync point manager 625 may identify a first set of synchronization points defining a set of time intervals, each of the first set of synchronization points associated with a channel access opportunity during which the UE and the set of base stations can perform a channel access procedure to access a channel.

The soft sync point manager 630 may identify a second set of synchronization points, each of the second set of synchronization points associated with a channel access opportunity during which the UE and the set of base stations can perform a channel access procedure to access the channel, each time interval of the set of time intervals including at least one synchronization point of the second set of synchronization points.

The LBT manager 635 may perform, at the channel access opportunity associated with a synchronization point of the first or second set of synchronization points, the channel access procedure to access the channel for a channel occupancy time to end before a next synchronization point of the first set of synchronization points associated with the time interval for which the channel access procedure is performed.

The channel occupancy manager 640 may perform wireless communications with the base station during the channel occupancy time based on a result of the channel access procedure.

The transmitter 645 may transmit signals generated by other components of the device 605. In some examples, the transmitter 645 may be collocated with a receiver 610 in a transceiver module. For example, the transmitter 645 may be an example of aspects of the transceiver 820 described with reference to FIG. 8. The transmitter 645 may utilize a single antenna or a set of antennas.

FIG. 7 shows a block diagram 700 of a communications manager 705 that supports two-level synchronization point design for LBE mode in accordance with aspects of the present disclosure. The communications manager 705 may be an example of aspects of a communications manager 515, a communications manager 615, or a communications manager 810 described herein. The communications manager 705 may include a connection manager 710, a hard sync point manager 715, a soft sync point manager 720, a LBT manager 725, a channel occupancy manager 730, a configuration manager 735, and a gap manager 740. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses) .

The connection manager 710 may establish a connection with a base station of a set of base stations. In some cases, the set of base stations are in a wireless network operating in a load based equipment mode.

The hard sync point manager 715 may identify a first set of synchronization points defining a set of time intervals, each of the first set of synchronization points associated with a channel access opportunity during which the UE and the set of base stations can perform a channel access procedure to access a channel.

The soft sync point manager 720 may identify a second set of synchronization points, each of the second set of synchronization points associated with a channel access opportunity during which the UE and the set of base stations can perform a channel access procedure to access the channel, each time interval of the set of time intervals including at least one synchronization point of the second set of synchronization points. In some cases, each synchronization point of the second set of synchronization points is associated with a gap period. In some cases, each synchronization point of the second set of synchronization points is not associated with a gap period.

The LBT manager 725 may perform, at the channel access opportunity associated with a synchronization point of the first or second set of synchronization points, the channel access procedure to access the channel for a channel occupancy time to end before a next synchronization point of the first set of synchronization points associated with the time interval for which the channel access procedure is performed. In some cases, the channel access procedure includes a Cat-4 LBT procedure.

The channel occupancy manager 730 may perform wireless communications with the base station during the channel occupancy time based on a result of the channel access procedure. In some cases, the channel occupancy time spans one or more synchronization points of the second set of synchronization points.

The configuration manager 735 may receive, from the base station, a configuration signal identifying resources for the first set of synchronization points, where identifying the first set of synchronization points is based on the configuration signal. In some examples, the configuration manager 735 may receive the configuration signal identifying resources for the second set of synchronization points, where identifying the second set of synchronization points is based on the configuration signal. In some examples, the configuration manager 735 may determine, by the UE, resources for the second set of synchronization points based on the resources for the first set of synchronization points. In some cases, the configuration signal includes at least one of a RRC signal, or a MAC CE signal, or a combination thereof.

The gap manager 740 may determine that the wireless communications with the base station is to end within a defined time period of the next synchronization point of the first set of synchronization points occurring within the time interval. In some examples, the gap manager 740 may select, based on the determining, the channel occupancy time to end a defined gap period before the next synchronization point.

FIG. 8 shows a diagram of a system 800 including a device 805 that supports two-level synchronization point design for LBE mode in accordance with aspects of the present disclosure. The device 805 may be an example of or include the components of device 505, device 605, or a UE 115 as described herein. The device 805 may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including a communications manager 810, an I/O controller 815, a transceiver 820, an antenna 825, memory 830, and a processor 840. These components may be in electronic communication via one or more buses (e.g., bus 845) .

The communications manager 810 may establish a connection with a base station of a set of base stations, identify a first set of synchronization points defining a set of time intervals, each of the first set of synchronization points associated with a channel access opportunity during which the UE and the set of base stations can perform a channel access procedure to access a channel, identify a second set of synchronization points, each of the second set of synchronization points associated with a channel access opportunity during which the UE and the set of base stations can perform a channel access procedure to access the channel, each time interval of the set of time intervals including at least one synchronization point of the second set of synchronization points, perform, at the channel access opportunity associated with a synchronization point of the first or second set of synchronization points, the channel access procedure to access the channel for a channel occupancy time to end before a next synchronization point of the first set of synchronization points associated with the time interval for which the channel access procedure is performed, and perform wireless communications with the base station during the channel occupancy time based on a result of the channel access procedure.

The I/O controller 815 may manage input and output signals for the device 805. The I/O controller 815 may also manage peripherals not integrated into the device 805. In some cases, the I/O controller 815 may represent a physical connection or port to an external peripheral. In some cases, the I/O controller 815 may utilize an operating system such as

or another known operating system. In other cases, the I/O controller 815 may represent or interact with a modem, a keyboard, a mouse, a touchscreen, or a similar device. In some cases, the I/O controller 815 may be implemented as part of a processor. In some cases, a user may interact with the device 805 via the I/O controller 815 or via hardware components controlled by the I/O controller 815.

The transceiver 820 may communicate bi-directionally, via one or more antennas, wired, or wireless links as described above. For example, the transceiver 820 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 820 may also include a modem to modulate the packets and provide the modulated packets to the antennas for transmission, and to demodulate packets received from the antennas.

In some cases, the wireless device may include a single antenna 825. However, in some cases the device may have more than one antenna 825, which may be capable of concurrently transmitting or receiving multiple wireless transmissions.

The memory 830 may include random access memory (RAM) and read-only memory (ROM) . The memory 830 may store computer-readable, computer-executable code 835 including instructions that, when executed, cause the processor to perform various functions described herein. In some cases, the memory 830 may contain, among other things, a basic input/output system (BIOS) which may control basic hardware or software operation such as the interaction with peripheral components or devices.

The processor 840 may include an intelligent hardware device, (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof) . In some cases, the processor 840 may be configured to operate a memory array using a memory controller. In other cases, a memory controller may be integrated into the processor 840. The processor 840 may be configured to execute computer-readable instructions stored in a memory (e.g., the memory 830) to cause the device 805 to perform various functions (e.g., functions or tasks supporting two-level synchronization point design for LBE mode) .

The code 835 may include instructions to implement aspects of the present disclosure, including instructions to support wireless communications. The code 835 may be stored in a non-transitory computer-readable medium such as system memory or other type of memory. In some cases, the code 835 may not be directly executable by the processor 840 but may cause a computer (e.g., when compiled and executed) to perform functions described herein.

FIG. 9 shows a block diagram 900 of a device 905 that supports two-level synchronization point design for LBE mode in accordance with aspects of the present disclosure. The device 905 may be an example of aspects of a base station 105 as described herein. The device 905 may include a receiver 910, a communications manager 915, and a transmitter 920. The device 905 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses) .

The receiver 910 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to two-level synchronization point design for LBE mode, etc. ) . Information may be passed on to other components of the device 905. The receiver 910 may be an example of aspects of the transceiver 1220 described with reference to FIG. 12. The receiver 910 may utilize a single antenna or a set of antennas.

The communications manager 915 may establish a connection with a UE, identify a first set of synchronization points defining a set of time intervals, each of the first set of synchronization points associated with a channel access opportunity during which the UE and the base station can perform a channel access procedure to access a channel, identify a second set of synchronization points, each of the second set of synchronization points associated with a channel access opportunity during which the UE and the base station can perform a channel access procedure to access the channel, each time interval of the set of time intervals including at least one synchronization point of the second set of synchronization points, and transmit, to the UE, a configuration signal identifying resources for the first set of synchronization points. The communications manager 915 may be an example of aspects of the communications manager 1210 described herein.

The communications manager 915, or its sub-components, may be implemented in hardware, code (e.g., software or firmware) executed by a processor, or any combination thereof. If implemented in code executed by a processor, the functions of the communications manager 915, or its sub-components may be executed by a general-purpose processor, a DSP, an ASIC, a FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in the present disclosure.

The communications manager 915, or its sub-components, may be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations by one or more physical components. In some examples, the communications manager 915, or its sub-components, may be a separate and distinct component in accordance with various aspects of the present disclosure. In some examples, the communications manager 915, or its sub-components, may be combined with one or more other hardware components, including but not limited to an I/O component, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof in accordance with various aspects of the present disclosure.

The transmitter 920 may transmit signals generated by other components of the device 905. In some examples, the transmitter 920 may be collocated with a receiver 910 in a transceiver module. For example, the transmitter 920 may be an example of aspects of the transceiver 1220 described with reference to FIG. 12. The transmitter 920 may utilize a single antenna or a set of antennas.

FIG. 10 shows a block diagram 1000 of a device 1005 that supports two-level synchronization point design for LBE mode in accordance with aspects of the present disclosure. The device 1005 may be an example of aspects of a device 905, or a base station 105 as described herein. The device 1005 may include a receiver 1010, a communications manager 1015, and a transmitter 1040. The device 1005 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses) .

The receiver 1010 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to two-level synchronization point design for LBE mode, etc. ) . Information may be passed on to other components of the device 1005. The receiver 1010 may be an example of aspects of the transceiver 1220 described with reference to FIG. 12. The receiver 1010 may utilize a single antenna or a set of antennas.

The communications manager 1015 may be an example of aspects of the communications manager 915 as described herein. The communications manager 1015 may include a connection manager 1020, a hard sync point manager 1025, a soft sync point manager 1030, and a configuration manager 1035. The communications manager 1015 may be an example of aspects of the communications manager 1210 described herein.

The connection manager 1020 may establish a connection with a UE.

The hard sync point manager 1025 may identify a first set of synchronization points defining a set of time intervals, each of the first set of synchronization points associated with a channel access opportunity during which the UE and the base station can perform a channel access procedure to access a channel.

The soft sync point manager 1030 may identify a second set of synchronization points, each of the second set of synchronization points associated with a channel access opportunity during which the UE and the base station can perform a channel access procedure to access the channel, each time interval of the set of time intervals including at least one synchronization point of the second set of synchronization points.

The configuration manager 1035 may transmit, to the UE, a configuration signal identifying resources for the first set of synchronization points.

The transmitter 1040 may transmit signals generated by other components of the device 1005. In some examples, the transmitter 1040 may be collocated with a receiver 1010 in a transceiver module. For example, the transmitter 1040 may be an example of aspects of the transceiver 1220 described with reference to FIG. 12. The transmitter 1040 may utilize a single antenna or a set of antennas.

FIG. 11 shows a block diagram 1100 of a communications manager 1105 that supports two-level synchronization point design for LBE mode in accordance with aspects of the present disclosure. The communications manager 1105 may be an example of aspects of a communications manager 915, a communications manager 1015, or a communications manager 1210 described herein. The communications manager 1105 may include a connection manager 1110, a hard sync point manager 1115, a soft sync point manager 1120, a configuration manager 1125, a channel occupancy manager 1130, and a LBT manager 1135. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses) .

The connection manager 1110 may establish a connection with a UE. In some cases, the base station is in a wireless network operating in a load based equipment mode.

The hard sync point manager 1115 may identify a first set of synchronization points defining a set of time intervals, each of the first set of synchronization points associated with a channel access opportunity during which the UE and the base station can perform a channel access procedure to access a channel.

The soft sync point manager 1120 may identify a second set of synchronization points, each of the second set of synchronization points associated with a channel access opportunity during which the UE and the base station can perform a channel access procedure to access the channel, each time interval of the set of time intervals including at least one synchronization point of the second set of synchronization points. In some examples, the soft sync point manager 1120 may transmit the configuration signal identifying resources for the second set of synchronization points. In some examples, the soft sync point manager 1120 may determine, by the base station, resources for the second set of synchronization points based on the resources for the first set of synchronization points. In some cases, each synchronization point of the second set of synchronization points is associated with a gap period. In some cases, each synchronization point of the second set of synchronization points is not associated with a gap period.

The configuration manager 1125 may transmit, to the UE, a configuration signal identifying resources for the first set of synchronization points. In some cases, the configuration signal includes at least one of a RRC signal, or a MAC CE signal, or a combination thereof.

The channel occupancy manager 1130 may perform, at the channel access opportunity associated with a synchronization point of the first or second set of synchronization points, the channel access procedure to access the channel for a channel occupancy time to end before a next synchronization point of the first set of synchronization points associated with the time interval for which the channel access procedure is performed. In some examples, the channel occupancy manager 1130 may perform wireless communications with the UE during the channel occupancy time based on a result of the channel access procedure.

In some examples, the channel occupancy manager 1130 may determine that the wireless communications with the UE are to end within a defined time period of the next synchronization point of the first set of synchronization points occurring within the time interval. In some examples, the channel occupancy manager 1130 may select, based on the determining, the channel occupancy time to end a defined gap period before the next synchronization point. In some cases, the channel occupancy time spans one or more synchronization points of the second set of synchronization points.

The LBT manager 1135 may monitor, control, or otherwise manage aspects of the channel access procedure including a Cat-4 LBT procedure.

FIG. 12 shows a diagram of a system 1200 including a device 1205 that supports two-level synchronization point design for LBE mode in accordance with aspects of the present disclosure. The device 1205 may be an example of or include the components of device 905, device 1005, or a base station 105 as described herein. The device 1205 may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including a communications manager 1210, a network communications manager 1215, a transceiver 1220, an antenna 1225, memory 1230, a processor 1240, and an inter-station communications manager 1245. These components may be in electronic communication via one or more buses (e.g., bus 1250) .

The communications manager 1210 may establish a connection with a UE, identify a first set of synchronization points defining a set of time intervals, each of the first set of synchronization points associated with a channel access opportunity during which the UE and the base station can perform a channel access procedure to access a channel, identify a second set of synchronization points, each of the second set of synchronization points associated with a channel access opportunity during which the UE and the base station can perform a channel access procedure to access the channel, each time interval of the set of time intervals including at least one synchronization point of the second set of synchronization points, and transmit, to the UE, a configuration signal identifying resources for the first set of synchronization points.

The network communications manager 1215 may manage communications with the core network (e.g., via one or more wired backhaul links) . For example, the network communications manager 1215 may manage the transfer of data communications for client devices, such as one or more UEs 115.

The transceiver 1220 may communicate bi-directionally, via one or more antennas, wired, or wireless links as described above. For example, the transceiver 1220 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 1220 may also include a modem to modulate the packets and provide the modulated packets to the antennas for transmission, and to demodulate packets received from the antennas.

In some cases, the wireless device may include a single antenna 1225. However, in some cases the device may have more than one antenna 1225, which may be capable of concurrently transmitting or receiving multiple wireless transmissions.

The memory 1230 may include RAM, ROM, or a combination thereof. The memory 1230 may store computer-readable code 1235 including instructions that, when executed by a processor (e.g., the processor 1240) cause the device to perform various functions described herein. In some cases, the memory 1230 may contain, among other things, a BIOS which may control basic hardware or software operation such as the interaction with peripheral components or devices.

The processor 1240 may include an intelligent hardware device, (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof) . In some cases, the processor 1240 may be configured to operate a memory array using a memory controller. In some cases, a memory controller may be integrated into processor 1240. The processor 1240 may be configured to execute computer-readable instructions stored in a memory (e.g., the memory 1230) to cause the device 1205 to perform various functions (e.g., functions or tasks supporting two-level synchronization point design for LBE mode) .

The inter-station communications manager 1245 may manage communications with other base station 105, and may include a controller or scheduler for controlling communications with UEs 115 in cooperation with other base stations 105. For example, the inter-station communications manager 1245 may coordinate scheduling for transmissions to UEs 115 for various interference mitigation techniques such as beamforming or joint transmission. In some examples, the inter-station communications manager 1245 may provide an X2 interface within an LTE/LTE-A wireless communication network technology to provide communication between base stations 105.

The code 1235 may include instructions to implement aspects of the present disclosure, including instructions to support wireless communications. The code 1235 may be stored in a non-transitory computer-readable medium such as system memory or other type of memory. In some cases, the code 1235 may not be directly executable by the processor 1240 but may cause a computer (e.g., when compiled and executed) to perform functions described herein.

FIG. 13 shows a flowchart illustrating a method 1300 that supports two-level synchronization point design for LBE mode in accordance with aspects of the present disclosure. The operations of method 1300 may be implemented by a UE 115 or its components as described herein. For example, the operations of method 1300 may be performed by a communications manager as described with reference to FIGs. 5 through 8. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, a UE may perform aspects of the functions described below using special-purpose hardware.

At 1305, the UE may establish a connection with a base station of a set of base stations. The operations of 1305 may be performed according to the methods described herein. In some examples, aspects of the operations of 1305 may be performed by a connection manager as described with reference to FIGs. 5 through 8.

At 1310, the UE may identify a first set of synchronization points defining a set of time intervals, each of the first set of synchronization points associated with a channel access opportunity during which the UE and the set of base stations can perform a channel access procedure to access a channel. The operations of 1310 may be performed according to the methods described herein. In some examples, aspects of the operations of 1310 may be performed by a hard sync point manager as described with reference to FIGs. 5 through 8.

At 1315, the UE may identify a second set of synchronization points, each of the second set of synchronization points associated with a channel access opportunity during which the UE and the set of base stations can perform a channel access procedure to access the channel, each time interval of the set of time intervals including at least one synchronization point of the second set of synchronization points. The operations of 1315 may be performed according to the methods described herein. In some examples, aspects of the operations of 1315 may be performed by a soft sync point manager as described with reference to FIGs. 5 through 8.

At 1320, the UE may perform, at the channel access opportunity associated with a synchronization point of the first or second set of synchronization points, the channel access procedure to access the channel for a channel occupancy time to end before a next synchronization point of the first set of synchronization points associated with the time interval for which the channel access procedure is performed. The operations of 1320 may be performed according to the methods described herein. In some examples, aspects of the operations of 1320 may be performed by a LBT manager as described with reference to FIGs. 5 through 8.

At 1325, the UE may perform wireless communications with the base station during the channel occupancy time based on a result of the channel access procedure. The operations of 1325 may be performed according to the methods described herein. In some examples, aspects of the operations of 1325 may be performed by a channel occupancy manager as described with reference to FIGs. 5 through 8.

FIG. 14 shows a flowchart illustrating a method 1400 that supports two-level synchronization point design for LBE mode in accordance with aspects of the present disclosure. The operations of method 1400 may be implemented by a UE 115 or its components as described herein. For example, the operations of method 1400 may be performed by a communications manager as described with reference to FIGs. 5 through 8. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, a UE may perform aspects of the functions described below using special-purpose hardware.

At 1405, the UE may establish a connection with a base station of a set of base stations. The operations of 1405 may be performed according to the methods described herein. In some examples, aspects of the operations of 1405 may be performed by a connection manager as described with reference to FIGs. 5 through 8.

At 1410, the UE may receive, from the base station, a configuration signal identifying resources for the first set of synchronization points, where identifying the first set of synchronization points is based on the configuration signal. The operations of 1410 may be performed according to the methods described herein. In some examples, aspects of the operations of 1410 may be performed by a configuration manager as described with reference to FIGs. 5 through 8.

At 1415, the UE may identify a first set of synchronization points defining a set of time intervals, each of the first set of synchronization points associated with a channel access opportunity during which the UE and the set of base stations can perform a channel access procedure to access a channel. The operations of 1415 may be performed according to the methods described herein. In some examples, aspects of the operations of 1415 may be performed by a hard sync point manager as described with reference to FIGs. 5 through 8.

At 1420, the UE may identify a second set of synchronization points, each of the second set of synchronization points associated with a channel access opportunity during which the UE and the set of base stations can perform a channel access procedure to access the channel, each time interval of the set of time intervals including at least one synchronization point of the second set of synchronization points. The operations of 1420 may be performed according to the methods described herein. In some examples, aspects of the operations of 1420 may be performed by a soft sync point manager as described with reference to FIGs. 5 through 8.

At 1425, the UE may perform, at the channel access opportunity associated with a synchronization point of the first or second set of synchronization points, the channel access procedure to access the channel for a channel occupancy time to end before a next synchronization point of the first set of synchronization points associated with the time interval for which the channel access procedure is performed. The operations of 1425 may be performed according to the methods described herein. In some examples, aspects of the operations of 1425 may be performed by a LBT manager as described with reference to FIGs. 5 through 8.

At 1430, the UE may perform wireless communications with the base station during the channel occupancy time based on a result of the channel access procedure. The operations of 1430 may be performed according to the methods described herein. In some examples, aspects of the operations of 1430 may be performed by a channel occupancy manager as described with reference to FIGs. 5 through 8.

FIG. 15 shows a flowchart illustrating a method 1500 that supports two-level synchronization point design for LBE mode in accordance with aspects of the present disclosure. The operations of method 1500 may be implemented by a UE 115 or its components as described herein. For example, the operations of method 1500 may be performed by a communications manager as described with reference to FIGs. 5 through 8. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, a UE may perform aspects of the functions described below using special-purpose hardware.

At 1505, the UE may establish a connection with a base station of a set of base stations. The operations of 1505 may be performed according to the methods described herein. In some examples, aspects of the operations of 1505 may be performed by a connection manager as described with reference to FIGs. 5 through 8.

At 1510, the UE may identify a first set of synchronization points defining a set of time intervals, each of the first set of synchronization points associated with a channel access opportunity during which the UE and the set of base stations can perform a channel access procedure to access a channel. The operations of 1510 may be performed according to the methods described herein. In some examples, aspects of the operations of 1510 may be performed by a hard sync point manager as described with reference to FIGs. 5 through 8.

At 1515, the UE may identify a second set of synchronization points, each of the second set of synchronization points associated with a channel access opportunity during which the UE and the set of base stations can perform a channel access procedure to access the channel, each time interval of the set of time intervals including at least one synchronization point of the second set of synchronization points. The operations of 1515 may be performed according to the methods described herein. In some examples, aspects of the operations of 1515 may be performed by a soft sync point manager as described with reference to FIGs. 5 through 8.

At 1520, the UE may perform, at the channel access opportunity associated with a synchronization point of the first or second set of synchronization points, the channel access procedure to access the channel for a channel occupancy time to end before a next synchronization point of the first set of synchronization points associated with the time interval for which the channel access procedure is performed. The operations of 1520 may be performed according to the methods described herein. In some examples, aspects of the operations of 1520 may be performed by a LBT manager as described with reference to FIGs. 5 through 8.

At 1525, the UE may determine that the wireless communications with the base station is to end within a defined time period of the next synchronization point of the first set of synchronization points occurring within the time interval. The operations of 1525 may be performed according to the methods described herein. In some examples, aspects of the operations of 1525 may be performed by a gap manager as described with reference to FIGs. 5 through 8.

At 1530, the UE may select, based on the determining, the channel occupancy time to end a defined gap period before the next synchronization point. The operations of 1530 may be performed according to the methods described herein. In some examples, aspects of the operations of 1530 may be performed by a gap manager as described with reference to FIGs. 5 through 8.

At 1535, the UE may perform wireless communications with the base station during the channel occupancy time based on a result of the channel access procedure. The operations of 1535 may be performed according to the methods described herein. In some examples, aspects of the operations of 1535 may be performed by a channel occupancy manager as described with reference to FIGs. 5 through 8.

FIG. 16 shows a flowchart illustrating a method 1600 that supports two-level synchronization point design for LBE mode in accordance with aspects of the present disclosure. The operations of method 1600 may be implemented by a base station 105 or its components as described herein. For example, the operations of method 1600 may be performed by a communications manager as described with reference to FIGs. 9 through 12. In some examples, a base station may execute a set of instructions to control the functional elements of the base station to perform the functions described below. Additionally or alternatively, a base station may perform aspects of the functions described below using special-purpose hardware.

At 1605, the base station may establish a connection with a UE. The operations of 1605 may be performed according to the methods described herein. In some examples, aspects of the operations of 1605 may be performed by a connection manager as described with reference to FIGs. 9 through 12.

At 1610, the base station may identify a first set of synchronization points defining a set of time intervals, each of the first set of synchronization points associated with a channel access opportunity during which the UE and the base station can perform a channel access procedure to access a channel. The operations of 1610 may be performed according to the methods described herein. In some examples, aspects of the operations of 1610 may be performed by a hard sync point manager as described with reference to FIGs. 9 through 12.

At 1615, the base station may identify a second set of synchronization points, each of the second set of synchronization points associated with a channel access opportunity during which the UE and the base station can perform a channel access procedure to access the channel, each time interval of the set of time intervals including at least one synchronization point of the second set of synchronization points. The operations of 1615 may be performed according to the methods described herein. In some examples, aspects of the operations of 1615 may be performed by a soft sync point manager as described with reference to FIGs. 9 through 12.

At 1620, the base station may transmit, to the UE, a configuration signal identifying resources for the first set of synchronization points. The operations of 1620 may be performed according to the methods described herein. In some examples, aspects of the operations of 1620 may be performed by a configuration manager as described with reference to FIGs. 9 through 12.

FIG. 17 shows a flowchart illustrating a method 1700 that supports two-level synchronization point design for LBE mode in accordance with aspects of the present disclosure. The operations of method 1700 may be implemented by a base station 105 or its components as described herein. For example, the operations of method 1700 may be performed by a communications manager as described with reference to FIGs. 9 through 12. In some examples, a base station may execute a set of instructions to control the functional elements of the base station to perform the functions described below. Additionally or alternatively, a base station may perform aspects of the functions described below using special-purpose hardware.

At 1705, the base station may establish a connection with a UE. The operations of 1705 may be performed according to the methods described herein. In some examples, aspects of the operations of 1705 may be performed by a connection manager as described with reference to FIGs. 9 through 12.

At 1710, the base station may identify a first set of synchronization points defining a set of time intervals, each of the first set of synchronization points associated with a channel access opportunity during which the UE and the base station can perform a channel access procedure to access a channel. The operations of 1710 may be performed according to the methods described herein. In some examples, aspects of the operations of 1710 may be performed by a hard sync point manager as described with reference to FIGs. 9 through 12.

At 1715, the base station may identify a second set of synchronization points, each of the second set of synchronization points associated with a channel access opportunity during which the UE and the base station can perform a channel access procedure to access the channel, each time interval of the set of time intervals including at least one synchronization point of the second set of synchronization points. The operations of 1715 may be performed according to the methods described herein. In some examples, aspects of the operations of 1715 may be performed by a soft sync point manager as described with reference to FIGs. 9 through 12.

At 1720, the base station may transmit, to the UE, a configuration signal identifying resources for the first set of synchronization points. The operations of 1720 may be performed according to the methods described herein. In some examples, aspects of the operations of 1720 may be performed by a configuration manager as described with reference to FIGs. 9 through 12.

At 1725, the base station may perform, at the channel access opportunity associated with a synchronization point of the first or second set of synchronization points, the channel access procedure to access the channel for a channel occupancy time to end before a next synchronization point of the first set of synchronization points associated with the time interval for which the channel access procedure is performed. The operations of 1725 may be performed according to the methods described herein. In some examples, aspects of the operations of 1725 may be performed by a channel occupancy manager as described with reference to FIGs. 9 through 12.

At 1730, the base station may perform wireless communications with the UE during the channel occupancy time based on a result of the channel access procedure. The operations of 1730 may be performed according to the methods described herein. In some examples, aspects of the operations of 1730 may be performed by a channel occupancy manager as described with reference to FIGs. 9 through 12.

It should be noted that the methods described herein describe possible implementations, and that the operations and the steps may be rearranged or otherwise modified and that other implementations are possible. Further, aspects from two or more of the methods may be combined.

Although aspects of an LTE, LTE-A, LTE-A Pro, or NR system may be described for purposes of example, and LTE, LTE-A, LTE-A Pro, or NR terminology may be used in much of the description, the techniques described herein are applicable beyond LTE, LTE-A, LTE-A Pro, or NR networks. For example, the described techniques may be applicable to various other wireless communications systems such as Ultra Mobile Broadband (UMB) , Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi) , IEEE 802.16 (WiMAX) , IEEE 802.20, Flash-OFDM, as well as other systems and radio technologies not explicitly mentioned herein.

Information and signals described herein may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

The various illustrative blocks and components described in connection with the disclosure herein may be implemented or performed with a general-purpose processor, a DSP, an ASIC, a CPU, an 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. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration) .

The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope of the disclosure and appended claims. For example, due to the nature of software, functions described herein may be implemented using software executed by a processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations.

Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A non-transitory storage medium may be any available medium that may be accessed by a general-purpose or special purpose computer. By way of example, and not limitation, non-transitory computer-readable media may include random-access memory (RAM) , read-only memory (ROM) , electrically erasable programmable ROM (EEPROM) , flash memory, compact disk (CD) ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that may be used to carry or store desired program code means in the form of instructions or data structures and that may be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) , or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of computer-readable medium. Disk and disc, as used herein, include 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 are also included within the scope of computer-readable media.

As used herein, including in the claims, “or” as used in a list of items (e.g., a list of items prefaced by a phrase such as “at least one of” or “one or more of” ) indicates an inclusive 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) . Also, as used herein, the phrase “based on” shall not be construed as a reference to a closed set of conditions. For example, an example step that is described as “based on condition A” may be based on both a condition A and a condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase “based on” shall be construed in the same manner as the phrase “based at least in part on. ”

In the appended figures, similar components or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label by a dash and a second label that distinguishes among the similar components. If just the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label, or other subsequent reference label.

The description set forth herein, in connection with the appended drawings, describes example configurations and does not represent all the examples that may be implemented or that are within the scope of the claims. The term “example” used herein means “serving as an example, instance, or illustration, ” and not “preferred” or “advantageous over other examples. ” The detailed description includes specific details for the purpose of providing an understanding of the described techniques. These techniques, however, may be practiced without these specific details. In some instances, known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the described examples.

The description herein is provided to enable a person having ordinary skill in the art to make or use the disclosure. Various modifications to the disclosure will be apparent to a person having ordinary skill in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not limited to the examples and designs described herein, but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein.

Claims

A method for wireless communication at a user equipment (UE) , comprising:

establishing a connection with a base station of a plurality of base stations;

identifying a first set of synchronization points defining a set of time intervals, each of the first set of synchronization points associated with a channel access opportunity during which the UE and the plurality of base stations can perform a channel access procedure to access a channel;

identifying a second set of synchronization points, each of the second set of synchronization points associated with a channel access opportunity during which the UE and the plurality of base stations can perform a channel access procedure to access the channel, each time interval of the set of time intervals comprising at least one synchronization point of the second set of synchronization points;

performing, at the channel access opportunity associated with a synchronization point of the first or second set of synchronization points, the channel access procedure to access the channel for a channel occupancy time to end before a next synchronization point of the first set of synchronization points associated with the time interval for which the channel access procedure is performed; and

performing wireless communications with the base station during the channel occupancy time based at least in part on a result of the channel access procedure.
The method of claim 1, further comprising:

receiving, from the base station, a configuration signal identifying resources for the first set of synchronization points, wherein identifying the first set of synchronization points is based at least in part on the configuration signal.
The method of claim 2, further comprising:

receiving the configuration signal identifying resources for the second set of synchronization points, wherein identifying the second set of synchronization points is based at least in part on the configuration signal.
The method of claim 2, wherein identifying the second set of synchronization points comprises:

determining, by the UE, resources for the second set of synchronization points based at least in part on the resources for the first set of synchronization points.
The method of claim 2, wherein the configuration signal comprises at least one of a radio resource control (RRC) signal, or a medium access control (MAC) control element (CE) signal, or a combination thereof.
The method of claim 1, further comprising:

determining that the wireless communications with the base station is to end within a defined time period of the next synchronization point of the first set of synchronization points occurring within the time interval; and

selecting, based at least in part on the determining, the channel occupancy time to end a defined gap period before the next synchronization point.
The method of claim 1, wherein each synchronization point of the second set of synchronization points is associated with a gap period.
The method of claim 1, wherein each synchronization point of the second set of synchronization points is not associated with a gap period.
The method of claim 1, wherein the plurality of base stations are in a wireless network operating in a load based equipment mode.
The method of claim 1, wherein the channel access procedure comprises a category four (Cat-4) listen-before-talk (LBT) procedure.
The method of claim 1, wherein the channel occupancy time spans one or more synchronization points of the second set of synchronization points.
A method for wireless communication at a base station, comprising:

establishing a connection with a user equipment (UE) ;

identifying a first set of synchronization points defining a set of time intervals, each of the first set of synchronization points associated with a channel access opportunity during which the UE and the base station can perform a channel access procedure to access a channel;

identifying a second set of synchronization points, each of the second set of synchronization points associated with a channel access opportunity during which the UE and the base station can perform a channel access procedure to access the channel, each time interval of the set of time intervals comprising at least one synchronization point of the second set of synchronization points; and

transmitting, to the UE, a configuration signal identifying resources for the first set of synchronization points.
The method of claim 12, further comprising:

performing, at the channel access opportunity associated with a synchronization point of the first or second set of synchronization points, the channel access procedure to access the channel for a channel occupancy time to end before a next synchronization point of the first set of synchronization points associated with the time interval for which the channel access procedure is performed; and

performing wireless communications with the UE during the channel occupancy time based at least in part on a result of the channel access procedure.
The method of claim 13, further comprising:

determining that the wireless communications with the UE are to end within a defined time period of the next synchronization point of the first set of synchronization points occurring within the time interval; and

selecting, based at least in part on the determining, the channel occupancy time to end a defined gap period before the next synchronization point.
The method of claim 12, further comprising:

transmitting the configuration signal identifying resources for the second set of synchronization points.
The method of claim 12, wherein identifying the second set of synchronization points comprises:

determining, by the base station, resources for the second set of synchronization points based at least in part on the resources for the first set of synchronization points.
The method of claim 12, wherein the configuration signal comprises at least one of a radio resource control (RRC) signal, or a medium access control (MAC) control element (CE) signal, or a combination thereof.
The method of claim 12, wherein each synchronization point of the second set of synchronization points is associated with a gap period.
The method of claim 12, wherein each synchronization point of the second set of synchronization points is not associated with a gap period.
The method of claim 12, wherein the base station is in a wireless network operating in a load based equipment mode.
The method of claim 12, wherein the channel access procedure comprises a category four (Cat-4) listen-before-talk (LBT) procedure.
The method of claim 12, wherein the channel occupancy time spans one or more synchronization points of the second set of synchronization points.
An apparatus for wireless communication at a user equipment (UE) , comprising:

a processor,

memory coupled with the processor; and

instructions stored in the memory and executable by the processor to cause the apparatus to:

establish a connection with a base station of a plurality of base stations;

identify a first set of synchronization points defining a set of time intervals, each of the first set of synchronization points associated with a channel access opportunity during which the UE and the plurality of base stations can perform a channel access procedure to access a channel;

identify a second set of synchronization points, each of the second set of synchronization points associated with a channel access opportunity during which the UE and the plurality of base stations can perform a channel access procedure to access the channel, each time interval of the set of time intervals comprising at least one synchronization point of the second set of synchronization points;

perform, at the channel access opportunity associated with a synchronization point of the first or second set of synchronization points, the channel access procedure to access the channel for a channel occupancy time to end before a next synchronization point of the first set of synchronization points associated with the time interval for which the channel access procedure is performed; and

perform wireless communications with the base station during the channel occupancy time based at least in part on a result of the channel access procedure.
The apparatus of claim 23, wherein the instructions are further executable by the processor to cause the apparatus to:

receive, from the base station, a configuration signal identifying resources for the first set of synchronization points, wherein identifying the first set of synchronization points is based at least in part on the configuration signal.
The apparatus of claim 24, wherein the instructions are further executable by the processor to cause the apparatus to:

receive the configuration signal identifying resources for the second set of synchronization points, wherein identifying the second set of synchronization points is based at least in part on the configuration signal.
The apparatus of claim 24, wherein the instructions to identify the second set of synchronization points are executable by the processor to cause the apparatus to:

determine, by the UE, resources for the second set of synchronization points based at least in part on the resources for the first set of synchronization points.
The apparatus of claim 24, wherein the configuration signal comprises at least one of a radio resource control (RRC) signal, or a medium access control (MAC) control element (CE) signal, or a combination thereof.
The apparatus of claim 23, wherein the instructions are further executable by the processor to cause the apparatus to:

determine that the wireless communications with the base station is to end within a defined time period of the next synchronization point of the first set of synchronization points occurring within the time interval; and

select, based at least in part on the determining, the channel occupancy time to end a defined gap period before the next synchronization point.
The apparatus of claim 23, wherein each synchronization point of the second set of synchronization points is associated with a gap period.
The apparatus of claim 23, wherein each synchronization point of the second set of synchronization points is not associated with a gap period.
The apparatus of claim 23, wherein the plurality of base stations are in a wireless network operating in a load based equipment mode.
The apparatus of claim 23, wherein the channel access procedure comprises a category four (Cat-4) listen-before-talk (LBT) procedure.
The apparatus of claim 23, wherein the channel occupancy time spans one or more synchronization points of the second set of synchronization points.
An apparatus for wireless communication at a base station, comprising:

a processor,

memory coupled with the processor; and

instructions stored in the memory and executable by the processor to cause the apparatus to:

establish a connection with a user equipment (UE) ;

identify a first set of synchronization points defining a set of time intervals, each of the first set of synchronization points associated with a channel access opportunity during which the UE and the base station can perform a channel access procedure to access a channel;

identify a second set of synchronization points, each of the second set of synchronization points associated with a channel access opportunity during which the UE and the base station can perform a channel access procedure to access the channel, each time interval of the set of time intervals comprising at least one synchronization point of the second set of synchronization points; and

transmit, to the UE, a configuration signal identifying resources for the first set of synchronization points.
The apparatus of claim 34, wherein the instructions are further executable by the processor to cause the apparatus to:

perform, at the channel access opportunity associated with a synchronization point of the first or second set of synchronization points, the channel access procedure to access the channel for a channel occupancy time to end before a next synchronization point of the first set of synchronization points associated with the time interval for which the channel access procedure is performed; and

perform wireless communications with the UE during the channel occupancy time based at least in part on a result of the channel access procedure.
The apparatus of claim 35, wherein the instructions are further executable by the processor to cause the apparatus to:

determine that the wireless communications with the UE are to end within a defined time period of the next synchronization point of the first set of synchronization points occurring within the time interval; and

select, based at least in part on the determining, the channel occupancy time to end a defined gap period before the next synchronization point.
The apparatus of claim 34, wherein the instructions are further executable by the processor to cause the apparatus to:

transmit the configuration signal identifying resources for the second set of synchronization points.
The apparatus of claim 34, wherein the instructions to identify the second set of synchronization points are executable by the processor to cause the apparatus to:

determine, by the base station, resources for the second set of synchronization points based at least in part on the resources for the first set of synchronization points.
The apparatus of claim 34, wherein the configuration signal comprises at least one of a radio resource control (RRC) signal, or a medium access control (MAC) control element (CE) signal, or a combination thereof.
The apparatus of claim 34, wherein each synchronization point of the second set of synchronization points is associated with a gap period.
The apparatus of claim 34, wherein each synchronization point of the second set of synchronization points is not associated with a gap period.
The apparatus of claim 34, wherein the base station is in a wireless network operating in a load based equipment mode.
The apparatus of claim 34, wherein the channel access procedure comprises a category four (Cat-4) listen-before-talk (LBT) procedure.
The apparatus of claim 34, wherein the channel occupancy time spans one or more synchronization points of the second set of synchronization points.
An apparatus for wireless communication at a user equipment (UE) , comprising:

means for establishing a connection with a base station of a plurality of base stations;

means for identifying a first set of synchronization points defining a set of time intervals, each of the first set of synchronization points associated with a channel access opportunity during which the UE and the plurality of base stations can perform a channel access procedure to access a channel;

means for identifying a second set of synchronization points, each of the second set of synchronization points associated with a channel access opportunity during which the UE and the plurality of base stations can perform a channel access procedure to access the channel, each time interval of the set of time intervals comprising at least one synchronization point of the second set of synchronization points;

means for performing, at the channel access opportunity associated with a synchronization point of the first or second set of synchronization points, the channel access procedure to access the channel for a channel occupancy time to end before a next synchronization point of the first set of synchronization points associated with the time interval for which the channel access procedure is performed; and

means for performing wireless communications with the base station during the channel occupancy time based at least in part on a result of the channel access procedure.
The apparatus of claim 45, further comprising:

means for receiving, from the base station, a configuration signal identifying resources for the first set of synchronization points, wherein identifying the first set of synchronization points is based at least in part on the configuration signal.
The apparatus of claim 46, further comprising:

means for receiving the configuration signal identifying resources for the second set of synchronization points, wherein identifying the second set of synchronization points is based at least in part on the configuration signal.
The apparatus of claim 46, wherein the means for identifying the second set of synchronization points comprises:

means for determining, by the UE, resources for the second set of synchronization points based at least in part on the resources for the first set of synchronization points.
The apparatus of claim 46, wherein the configuration signal comprises at least one of a radio resource control (RRC) signal, or a medium access control (MAC) control element (CE) signal, or a combination thereof.
The apparatus of claim 45, further comprising:

means for determining that the wireless communications with the base station is to end within a defined time period of the next synchronization point of the first set of synchronization points occurring within the time interval; and

means for selecting, based at least in part on the determining, the channel occupancy time to end a defined gap period before the next synchronization point.
The apparatus of claim 45, wherein each synchronization point of the second set of synchronization points is associated with a gap period.
The apparatus of claim 45, wherein each synchronization point of the second set of synchronization points is not associated with a gap period.
The apparatus of claim 45, wherein the plurality of base stations are in a wireless network operating in a load based equipment mode.
The apparatus of claim 45, wherein the channel access procedure comprises a category four (Cat-4) listen-before-talk (LBT) procedure.
The apparatus of claim 45, wherein the channel occupancy time spans one or more synchronization points of the second set of synchronization points.
An apparatus for wireless communication at a base station, comprising:

means for establishing a connection with a user equipment (UE) ;

means for identifying a first set of synchronization points defining a set of time intervals, each of the first set of synchronization points associated with a channel access opportunity during which the UE and the base station can perform a channel access procedure to access a channel;

means for identifying a second set of synchronization points, each of the second set of synchronization points associated with a channel access opportunity during which the UE and the base station can perform a channel access procedure to access the channel, each time interval of the set of time intervals comprising at least one synchronization point of the second set of synchronization points; and

means for transmitting, to the UE, a configuration signal identifying resources for the first set of synchronization points.
The apparatus of claim 56, further comprising:

means for performing, at the channel access opportunity associated with a synchronization point of the first or second set of synchronization points, the channel access procedure to access the channel for a channel occupancy time to end before a next synchronization point of the first set of synchronization points associated with the time interval for which the channel access procedure is performed; and

means for performing wireless communications with the UE during the channel occupancy time based at least in part on a result of the channel access procedure.
The apparatus of claim 57, further comprising:

means for determining that the wireless communications with the UE are to end within a defined time period of the next synchronization point of the first set of synchronization points occurring within the time interval; and

means for selecting, based at least in part on the determining, the channel occupancy time to end a defined gap period before the next synchronization point.
The apparatus of claim 56, further comprising:

means for transmitting the configuration signal identifying resources for the second set of synchronization points.
The apparatus of claim 56, wherein the means for identifying the second set of synchronization points comprises:

means for determining, by the base station, resources for the second set of synchronization points based at least in part on the resources for the first set of synchronization points.
The apparatus of claim 56, wherein the configuration signal comprises at least one of a radio resource control (RRC) signal, or a medium access control (MAC) control element (CE) signal, or a combination thereof.
The apparatus of claim 56, wherein each synchronization point of the second set of synchronization points is associated with a gap period.
The apparatus of claim 56, wherein each synchronization point of the second set of synchronization points is not associated with a gap period.
The apparatus of claim 56, wherein the base station is in a wireless network operating in a load based equipment mode.
The apparatus of claim 56, wherein the channel access procedure comprises a category four (Cat-4) listen-before-talk (LBT) procedure.
The apparatus of claim 56, wherein the channel occupancy time spans one or more synchronization points of the second set of synchronization points.
A non-transitory computer-readable medium storing code for wireless communication at a user equipment (UE) , the code comprising instructions executable by a processor to:

establish a connection with a base station of a plurality of base stations;

identify a first set of synchronization points defining a set of time intervals, each of the first set of synchronization points associated with a channel access opportunity during which the UE and the plurality of base stations can perform a channel access procedure to access a channel;

identify a second set of synchronization points, each of the second set of synchronization points associated with a channel access opportunity during which the UE and the plurality of base stations can perform a channel access procedure to access the channel, each time interval of the set of time intervals comprising at least one synchronization point of the second set of synchronization points;

perform, at the channel access opportunity associated with a synchronization point of the first or second set of synchronization points, the channel access procedure to access the channel for a channel occupancy time to end before a next synchronization point of the first set of synchronization points associated with the time interval for which the channel access procedure is performed; and

perform wireless communications with the base station during the channel occupancy time based at least in part on a result of the channel access procedure.
A non-transitory computer-readable medium storing code for wireless communication at a base station, the code comprising instructions executable by a processor to:

establish a connection with a user equipment (UE) ;

identify a first set of synchronization points defining a set of time intervals, each of the first set of synchronization points associated with a channel access opportunity during which the UE and the base station can perform a channel access procedure to access a channel;

identify a second set of synchronization points, each of the second set of synchronization points associated with a channel access opportunity during which the UE and the base station can perform a channel access procedure to access the channel, each time interval of the set of time intervals comprising at least one synchronization point of the second set of synchronization points; and

transmit, to the UE, a configuration signal identifying resources for the first set of synchronization points.