WO2021139523A1

WO2021139523A1 - Timing advance control transmission in downlink control information for secondary cell group suspension

Info

Publication number: WO2021139523A1
Application number: PCT/CN2020/138254
Authority: WO
Inventors: Peng Cheng; Xiaoxia Zhang; Huilin Xu
Original assignee: Qualcomm Incorporated
Priority date: 2020-01-07
Filing date: 2020-12-22
Publication date: 2021-07-15
Also published as: WO2021138791A1

Abstract

Methods, systems, and devices for wireless communications are described. A user equipment (UE) may communicate with both a master cell group (MCG) and a secondary cell group (SCG) and may transmit an uplink message to a primary secondary cell (PSCell) of the SCG after communications with the SCG have been suspended. Subsequently, the PSCell may respond with downlink control information (DCI) that includes timing advance (TA) information for the UE to use for subsequent communications with the SCG. In some cases, the UE may transmit a random access message to the PSCell to reestablish communications with the SCG, and the PSCell may respond with DCI that includes the TA information. Additionally or alternatively, the UE may transmit a preconfigured uplink message to the PSCell, and the PSCell may respond with DCI as an acknowledgment message, where the DCI includes the TA information.

Description

TIMING ADVANCE CONTROL TRANSMISSION IN DOWNLINK CONTROL INFORMATION FOR SECONDARY CELL GROUP SUSPENSION

CROSS REFERENCES

The present Application for Patent claims priority to PCT Patent Application No. PCT/CN2020/070591 by Cheng, et al., entitled “Timing Advance Control Transmission in Downlink Control Information for Secondary Cell Group Suspension, ” filed January 7, 2020, which is assigned to the assignee hereof.

FIELD OF TECHNOLOGY

The following relates generally to wireless communications and more specifically to timing advance (TA) control transmission in downlink control information (DCI) for secondary cell group (SCG) suspension.

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 a number of base stations or network access nodes, each simultaneously supporting communication for multiple communication devices which may be otherwise known as user equipments (UEs) . A UE may be configured to simultaneously connect to and communicate with a network using multiple cells, such as in dual connectivity (DC) and carrier aggregation (CA) operations. In some cases, the UE may resume communications with one or more of the cells after a period of inactivity. Techniques to efficiently resume communications between the UE and network are desired.

SUMMARY

The described techniques relate to improved methods, systems, devices, and apparatuses that support timing advance (TA) control transmission in downlink control information (DCI) for secondary cell group (SCG) suspension. Generally, the described techniques provide for a user equipment (UE) communicating with both a master cell group (MCG) and an SCG (e.g., for a dual connectivity (DC) deployment, carrier aggregation (CA) configuration, etc. ) to transmit an uplink message to a primary secondary cell (PSCell) of the SCG after communications with the SCG have been suspended, where the PSCell responds with a DCI that includes TA information for the UE to use for subsequent communications with the SCG.

In some cases, the UE may transmit a physical random access channel (PRACH) preamble message to the PSCell to reestablish communications with the SCG. The PSCell may respond with a DCI that includes TA information to enable the UE to transmit subsequent uplink messages to the PSCell such that the uplink messages are received at the PSCell aligned to downlink frames (e.g., downlink transmission time intervals (TTIs) , downlink subframes, etc. ) configured at the PSCell. Additionally or alternatively, the UE may transmit a preconfigured uplink message (e.g., a preconfigured physical uplink shared channel (PUSCH) transmission configured via radio resource control (RRC) signaling) to the PSCell, and the PSCell may respond with a DCI to acknowledge the preconfigured uplink message was successfully received and decoded, where the DCI includes the TA information for aligning the subsequent uplink messages. The DCI transmitted by the PSCell may be scrambled with a cell radio network temporary identifier (C-RNTI) for the UE, a dedicated TA radio network temporary identifier (RNTI) , a random access RNTI (RA-RNTI) , an RNTI corresponding to a control resource set (CORESET) for the UE, an RNTI corresponding to a search space for the UE, or a combination thereof.

Additionally, the UE may receive a monitoring configuration (e.g., via RRC signaling from a master node in the MCG) for monitoring for and receiving the DCI from the PSCell. For example, the monitoring configuration may include a configured duration that the UE monitors for the DCI, an indication of a CORESET and/or search space where the UE monitors for the DCI, or a combination thereof. In some cases, the PSCell may also receive the monitoring configuration (e.g., from the master node in the MCG) to identify when and where to transmit the DCI or may signal the monitoring configuration to the UE (e.g., via the master node) . Additionally, the UE (and the PSCell) may receive one or more parameters for the preconfigured uplink message (e.g., via RRC signaling) , where the one or more parameters include a periodicity, a frequency location, a number of repetitions, a CORESET configuration, a search space configuration, a frequency hopping configuration, a modulation and coding scheme (MCS) , a transmission configuration indicator (TCI) , or a combination thereof for transmitting (and receiving at the PSCell) the preconfigured uplink message.

A method of wireless communications at a UE is described. The method may include identifying a configuration for communicating with an MCG and an SCG, receiving, from a master node in the MCG, a release message indicating a suspension of communications with the SCG, transmitting an uplink message to a PSCell of the SCG after the communications have been suspended with the SCG, and monitoring a bandwidth part (BWP) for DCI from the PSCell of the SCG, the DCI including a TA parameter for the communications with the SCG.

An apparatus for wireless communications 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 identify a configuration for communicating with an MCG and an SCG, receive, from a master node in the MCG, a release message indicating a suspension of communications with the SCG, transmit an uplink message to a PSCell of the SCG after the communications have been suspended with the SCG, and monitor a BWP for DCI from the PSCell of the SCG, the DCI including a TA parameter for the communications with the SCG.

Another apparatus for wireless communications at a UE is described. The apparatus may include means for identifying a configuration for communicating with an MCG and an SCG, receiving, from a master node in the MCG, a release message indicating a suspension of communications with the SCG, transmitting an uplink message to a PSCell of the SCG after the communications have been suspended with the SCG, and monitoring a BWP for DCI from the PSCell of the SCG, the DCI including a TA parameter for the communications with the SCG.

A non-transitory computer-readable medium storing code for wireless communications at a UE is described. The code may include instructions executable by a processor to identify a configuration for communicating with an MCG and an SCG, receive, from a master node in the MCG, a release message indicating a suspension of communications with the SCG, transmit an uplink message to a PSCell of the SCG after the communications have been suspended with the SCG, and monitor a BWP for DCI from the PSCell of the SCG, the DCI including a TA parameter for the communications with the SCG.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the uplink message to the PSCell of the SCG may include operations, features, means, or instructions for determining to reestablish the communications with the SCG after the communications may have been suspended with the SCG, and transmitting, to the PSCell of the SCG, a random access message based on the determination.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the random access message may be a random access preamble dedicated to the UE.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the random access message may be transmitted at a time resource, frequency resource, beam resource location, or a combination thereof dedicated to the UE.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the uplink message to the PSCell of the SCG may include operations, features, means, or instructions for receiving an uplink channel configuration for transmitting a preconfigured uplink message, and transmitting, to the PSCell of the SCG, the preconfigured uplink message based on the uplink channel configuration.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving, via RRC signaling, a configuration for the preconfigured uplink message.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the configuration for the preconfigured uplink message includes a periodicity, a frequency location, a number of repetitions, a CORESET configuration, a search space configuration, a frequency hopping configuration, an MCS, a TCI, or a combination thereof for transmitting the preconfigured uplink message.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the uplink channel configuration includes a periodic allocation of time resources, frequency resources, beam resource locations, 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 receiving, via RRC signaling, a monitoring configuration for the monitoring of the BWP for the DCI, where the BWP may be monitored for one configured duration based on the monitoring configuration.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining the one configured duration expires prior to receiving the DCI, and transmitting, to a PSCell of the SCG, the uplink message an additional time based on the one configured duration expiring.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving, via RRC signaling, a configuration of a CORESET, a search space, or a combination thereof dedicated to the UE, where the BWP may be monitored based on the configuration of the CORESET, the search space, or the combination thereof.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the DCI may be scrambled with a C-RNTI for the UE, a dedicated TA-RNTI, an RA-RNTI, an RNTI corresponding to a CORESET for the UE, an RNTI corresponding to a search space for the UE, or a combination thereof.

A method of wireless communications at a base station is described. The method may include identifying that the base station is operating in a communication configuration with a UE, where the base station includes a PSCell with respect to the communication configuration with the UE, receiving, from a master node in the communication configuration, a release message indicating a suspension of secondary node communications with the UE, the secondary node communications including the PSCell, receiving, from the UE, an uplink message after the communications have been suspended with the UE, and transmitting, to the UE, DCI based on receiving the uplink message, the DCI including a TA parameter for the communications with the SCG.

An apparatus for wireless communications 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 identify that the base station is operating in a communication configuration with a UE, where the base station includes a PSCell with respect to the communication configuration with the UE, receive, from a master node in the communication configuration, a release message indicating a suspension of secondary node communications with the UE, the secondary node communications including the PSCell, receive, from the UE, an uplink message after the communications have been suspended with the UE, and transmit, to the UE, DCI based on receiving the uplink message, the DCI including a TA parameter for the communications with the SCG.

Another apparatus for wireless communications at a base station is described. The apparatus may include means for identifying that the base station is operating in a communication configuration with a UE, where the base station includes a PSCell with respect to the communication configuration with the UE, receiving, from a master node in the communication configuration, a release message indicating a suspension of secondary node communications with the UE, the secondary node communications including the PSCell, receiving, from the UE, an uplink message after the communications have been suspended with the UE, and transmitting, to the UE, DCI based on receiving the uplink message, the DCI including a TA parameter for the communications with the SCG.

A non-transitory computer-readable medium storing code for wireless communications at a base station is described. The code may include instructions executable by a processor to identify that the base station is operating in a communication configuration with a UE, where the base station includes a PSCell with respect to the communication configuration with the UE, receive, from a master node in the communication configuration, a release message indicating a suspension of secondary node communications with the UE, the secondary node communications including the PSCell, receive, from the UE, an uplink message after the communications have been suspended with the UE, and transmit, to the UE, DCI based on receiving the uplink message, the DCI including a TA parameter for the communications with the SCG.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the uplink message may include operations, features, means, or instructions for receiving, from the UE, a random access message to reestablish the suspended secondary node communications.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the random access message may be received at a time resource, frequency resource, beam resource location, or a combination thereof dedicated to the UE.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the uplink message may include operations, features, means, or instructions for receiving, from the master node, an uplink channel configuration for receiving a preconfigured uplink message from the UE, and receiving, from the UE, the preconfigured uplink message based on the uplink channel configuration.

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 master node, a configuration for the preconfigured uplink message.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the configuration for the preconfigured uplink message includes a periodicity, a frequency location, a number of repetitions, a CORESET configuration, a search space configuration, a frequency hopping configuration, an MCS, a TCI, or a combination thereof for receiving the preconfigured uplink message.

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 master node, a configuration of a CORESET, a search space, or a combination thereof dedicated to the UE, where the DCI may be transmitted based on the configuration of the CORESET, the search space, or the 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 transmitting, to the UE via RRC signaling, a configuration of a CORESET, a search space, or a combination thereof dedicated to the UE, where the DCI may be transmitted based on the configuration of the CORESET, the search space, or the 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 scrambling the DCI with a C-RNTI for the UE, a dedicated TA-RNTI, an RA-RNTI, an RNTI corresponding to a CORESET for the UE, an RNTI corresponding to a search space for the UE, or a combination thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example of a system for wireless communications that supports timing advance (TA) control transmission in downlink control information (DCI) for secondary cell group (SCG) suspension in accordance with aspects of the present disclosure.

FIGs. 2 and 3 illustrate examples of wireless communications systems that support TA control in DCI for SCG suspension in accordance with aspects of the present disclosure.

FIG. 4 illustrates an example of an SCG suspension process that supports TA control in DCI for SCG suspension in accordance with aspects of the present disclosure.

FIG. 5 illustrates an example of a TA configuration that supports TA control in DCI for SCG suspension in accordance with aspects of the present disclosure.

FIG. 6 illustrates an example of a process flow that supports TA control in DCI for SCG suspension in accordance with aspects of the present disclosure.

FIGs. 7 and 8 show block diagrams of devices that support TA control transmission in DCI for SCG suspension in accordance with aspects of the present disclosure.

FIG. 9 shows a block diagram of a user equipment (UE) communications manager that supports TA control transmission in DCI for SCG suspension in accordance with aspects of the present disclosure.

FIG. 10 shows a diagram of a system including a device that supports TA control transmission in DCI for SCG suspension in accordance with aspects of the present disclosure.

FIGs. 11 and 12 show block diagrams of devices that support TA control transmission in DCI for SCG suspension in accordance with aspects of the present disclosure.

FIG. 13 shows a block diagram of a base station communications manager that supports TA control transmission in DCI for SCG suspension in accordance with aspects of the present disclosure.

FIG. 14 shows a diagram of a system including a device that supports TA control transmission in DCI for SCG suspension in accordance with aspects of the present disclosure.

FIGs. 15 through 20 show flowcharts illustrating methods that support TA control transmission in DCI for SCG suspension in accordance with aspects of the present disclosure.

DETAILED DESCRIPTION

In some wireless communications systems, a user equipment (UE) may communicate with a network using dual connectivity (DC) . In such cases, the UE may simultaneously communicate with different base stations, where a first base station may provide a first cell and be referred to as a master node. Likewise, a second base station providing a second cell of the DC deployment may be referred to as a secondary node, and the first and second cells may each be associated with a same or different radio access technology (RAT) . As such, various DC deployments may be referred to as evolved universal mobile telecommunication system terrestrial radio access (E-UTRA) new radio (NR) -dual connectivity (EN-DC) , NR E-UTRA-DC (NE-DC) , NR NR-DC, LTE LTE-DC, or may include other types of multi-radio access technology-dual connectivity (MR-DC) deployments based on the RAT implemented by each cell. In any case, the different cells a UE communicates on for DC may use the same or different radio frequency (RF) spectrum bands.

Additionally or alternatively, a UE may communicate with a single base station using multiple carriers (e.g., component carriers (CCs) ) . In such cases, a CC may refer to each of the carriers used by a UE in carrier aggregation (CA) operations. Further, a serving cell of a base station may correspond to each CC used in CA operation, where each serving cell may be different (e.g., based on the path loss experienced by different CCs on different RF spectrum bands) . In some examples, one carrier may be designated as a primary carrier, or primary CC (PCC) , for the UE, which may be served by a primary cell (PCell) . Additional carriers may be designated as secondary carriers, or secondary CCs (SCCs) , which may be served by secondary cells (SCells) of the base station. CA operations may also use the same or different RF bands for communications.

A UE may not continuously communicate with one or more base stations, and the UE may accordingly operate in various communication states, for example, to save power when not transmitting or receiving data. For instance, the UE may operate in an idle communication state (e.g., a radio resource control (RRC) idle state) , where the UE may be “on standby” and thus, may not be assigned to a particular serving base station. Additionally, the UE may operate in a connected communication state (e.g., an RRC connected state) where the UE may be “active” and may transmit data to/receive data from a serving cell. The UE may accordingly transition from the RRC idle state to the RRC connected state, and vice versa, based on its activity.

In some systems, a UE may support additional communication states. For example, an inactive communication state (e.g., an RRC inactive state) between the connected communication state and the idle communication state may be used to enable transitions from the inactive communication state to the connected communication state more quickly (as compared to the transition from the idle communication state to the connected communication state) . When transitioning to the inactive communication state, a UE context (e.g., an access stratum (AS) context) may be retained at the UE and the network, and both the UE and network may further store higher-layer configurations (e.g., for respective cells of DC/CA deployments) while simultaneously releasing lower-layer configurations (as the lower-layer configurations may change, for example, due to the UE’s mobility) . Then, when resuming communications with the network and moving out of the inactive communication state, the UE may apply the stored higher-layer configurations.

When a UE is communicating with a master cell group (MCG) and a secondary cell group (SCG) (e.g., in DC configurations, CA configurations, etc. ) , communications with the SCG may be suspended. When the SCG is suspended, the UE may put the SCG (e.g., including a primary SCell (PSCell) ) into dormancy for power saving purposes. However, it may be beneficial to maintain or know a timing advance (TA) corresponding to the PSCell (e.g., an indication of when to transmit uplink messages such that the uplink messages are received at the PSCell aligned with downlink frame boundaries) in case the UE needs to begin communications with the PSCell again after the communications have been suspended. Conventionally, the UE may have to decode a downlink channel (e.g., a physical downlink shared channel (PDSCH) ) to determine TA information (e.g., a timing advance control, timing advance command message, etc. ) included in a random access response (RAR) message as well as to transmit an uplink message (e.g., in a physical uplink shared channel (PUSCH) ) to acknowledge the RAR was received and decoded successfully, thereby increasing latency and signaling overhead.

As described herein, the dormant PSCell may transmit downlink control information (DCI) to the UE that includes TA information for the UE to use for subsequent communications. For example, the UE may transmit a random access message (e.g., a physical random access channel (PRACH) preamble) to the PSCell based on reactivating communications with the SCG, and the PSCell may transmit DCI that includes the TA information in response to the PRACH preamble. Additionally or alternatively, the UE may transmit a preconfigured PUSCH (e.g., configured via RRC configuration) on configured periodic dedicated time/frequency/beam resource locations, and the PSCell may transmit the DCI that includes the TA information in response to the PUSCH (e.g., the DCI is transmitted as an acknowledgment message in response to receiving and decoding the PUSCH) .

Subsequently, the UE may monitor for the DCI and corresponding TA information. In some cases, the UE may be allowed to monitor for the corresponding DCI in a dormant bandwidth part (BWP) for one RRC configured duration (e.g., network configures the duration that the UE monitors for the DCI via RRC signaling) . Additionally, the UE may be configured by RRC with a dedicated control resource set (CORESET) and/or a dedicated search space to monitor for the DCI. In some cases, the DCI may be scrambled with a cell radio network temporary identifier (C-RNTI) for the UE, a dedicated radio network temporary identifier (RNTI) for the TA (e.g., a TA-RNTI) , a random access RNTI (RA-RNTI) , an RNTI that corresponds (e.g., maps) from the configured CORESET and/or search space, or a combination thereof. In some cases, a new DCI format that contains a field for the TA may be defined. Additionally, the DCI size may be matched with that of a fallback DCI size (e.g., DCI format 1_0, DCI format 0_0, etc. ) for the cell where the DCI is monitored or may not be matched with a fallback DCI size. Additionally or alternatively, fields of an existing fallback DCI may be repurposed to include the TA information.

Aspects of the disclosure are initially described in the context of wireless communications systems. Additionally, aspects of the disclosure are illustrated through additional wireless communications systems, a TA configuration, and examples of process flows. Aspects of the disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flowcharts that relate to TA control in DCI for SCG suspension.

FIG. 1 illustrates an example of a wireless communications system 100 that supports TA control in DCI for SCG suspension 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 an 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 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 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 (Δ? ) 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 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.

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 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.

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 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 attempting to access a wireless network may perform an initial cell search by detecting a primary synchronization signal (PSS) from a base station 105. The PSS may enable synchronization of slot timing and may indicate a physical layer identity value. The UE 115 may then receive a secondary synchronization signal (SSS) . The SSS may enable radio frame synchronization, and may provide a cell identity value, which may be combined with the physical layer identity value to identify the cell. The SSS may also enable detection of a duplexing mode and a cyclic prefix length. Some systems, such as TDD systems, may transmit an SSS but not a PSS. Both the PSS and the SSS may be located in the central 62 and 72 subcarriers of a carrier, respectively. In some cases, a base station 105 may transmit synchronization signals (e.g., PSS SSS, and the like) using multiple beams in a beam-sweeping manner through a cell coverage area. In some cases, PSS, SSS, and/or broadcast information (e.g., a physical broadcast channel (PBCH) ) may be transmitted within different synchronization signal (SS) blocks on respective directional beams, where one or more SS blocks may be included within an SS burst.

After receiving the PSS and SSS, the UE 115 may receive an MIB, which may be transmitted in the PBCH. The MIB may contain system bandwidth information, an SFN, and a physical HARQ indicator channel (PHICH) configuration. After decoding the MIB, the UE 115 may receive one or more SIBs. For example, SIB1 may contain cell access parameters and scheduling information for other SIBs. Decoding SIB1 may enable the UE 115 to receive SIB2. SIB2 may contain RRC configuration information related to random access channel (RACH) procedures, paging, physical uplink control channel (PUCCH) , PUSCH, power control, SRS, and cell barring.

After completing initial cell synchronization, a UE 115 may decode the MIB, SIB1 and SIB2 prior to accessing the network. The MIB may be transmitted on PBCH and may utilize the first 4 OFDMA symbols of the second slot of the first subframe of each radio frame. It may use the middle 6 RBs (72 subcarriers) in the frequency domain. The MIB carries a few important pieces of information for UE initial access, including: downlink channel bandwidth in term of RBs, PHICH configuration (duration and resource assignment) , and SFN. A new MIB may be broadcast every fourth radio frame (SFN mod 4 = 0) at and rebroadcast every frame (10ms) . Each repetition is scrambled with a different scrambling code.

After reading a MIB (either a new version or a copy) , the UE 115 may try different phases of a scrambling code until it gets a successful CRC check. The phase of the scrambling code (0, 1, 2 or 3) may enable the UE 115 to identify which of the four repetitions has been received. Thus, the UE 115 may determine the current SFN by reading the SFN in the decoded transmission and adding the scrambling code phase. After receiving the MIB, a UE may receive one or more SIBs. Different SIBs may be defined according to the type of system information conveyed. A new SIB1 may be transmitted in the fifth subframe of every eighth frame (SFN mod 8 = 0) and rebroadcast every other frame (20ms) . SIB1 includes access information, including cell identity information, and it may indicate whether a UE is allowed to camp on a cell. SIB1 also includes cell selection information (or cell selection parameters) . Additionally, SIB1 includes scheduling information for other SIBs. SIB2 may be scheduled dynamically according to information in SIB1, and includes access information and parameters related to common and shared channels. The periodicity of SIB2 can be set to 8, 16, 32, 64, 128, 256 or 512 radio frames.

After the UE 115 decodes SIB2, it may transmit a RACH preamble to a base station 105. For example, the RACH preamble may be randomly selected from a set of 64 predetermined sequences. This may enable the base station 105 to distinguish between multiple UEs 115 trying to access the system simultaneously. The base station 105 may respond with a random access response that provides an uplink resource grant, a timing advance, and a temporary C-RNTI. The UE 115 may then transmit an RRC connection request along with a temporary mobile subscriber identity (TMSI) (if the UE 115 has previously been connected to the same wireless network) or a random identifier. The RRC connection request may also indicate the reason the UE 115 is connecting to the network (e.g., emergency, signaling, data exchange, etc. ) . The base station 105 may respond to the connection request with a contention resolution message addressed to the UE 115, which may provide a new C-RNTI. If the UE 115 receives a contention resolution message with the correct identification, it may proceed with RRC setup. If the UE 115 does not receive a contention resolution message (e.g., if there is a conflict with another UE 115) it may repeat the RACH process by transmitting a new RACH preamble. Such exchange of messages between the UE 115 and base station 105 for random access may be referred to as a four-step RACH procedure.

In some wireless communications systems, a UE 115 may be in various states (e.g., RRC states) of being connected to a base station 105 or the network. For example, the UE 115 may operate in an idle communication state (e.g., a radio resource control (RRC) idle state) , where the UE 115 may be “on standby” and thus, may not be assigned to a particular serving base station. Additionally, the UE 115 may operate in a connected communication state (e.g., an RRC connected state) where the UE 115 may be “active” and transmit data to/receive data from a serving cell. The UE 115 may accordingly transition from the RRC idle state to the RRC connected state, and vice versa, based on its activity.

In some cases, an additional state may be used for the UE 115 that is an intermediary between the idle communication state and the connected communication state. For example, an inactive communication state (e.g., an RRC inactive state) between the connected communication state and the idle communication state may be used to enable transitions from the inactive communication state to the connected communication state with reduced latency (e.g., as compared to the transition from the idle communication state to the connected communication state) . When transitioning to the inactive communication state, a UE context (e.g., an AS context) may be retained at the UE 115 and the network (e.g., the base station 105, the RAN, etc. ) , and both the UE 115 and network may further store higher-layer configurations (e.g., for respective cells of DC/CA deployments) while simultaneously releasing lower-layer configurations (as the lower-layer configurations may change, for example, due to the UE’s mobility) . Then, when resuming communications with the network and moving out of the inactive communication state, the UE 115 may apply the stored higher-layer configurations.

However, due to the release of the lower-layer configurations, the UE 115 may not be able to operate using the previously-established DC and/or CA schemes immediately after leaving the inactive communication state. For example, the UE 115 may not maintain a TA for cells in an SCG (e.g., PSCell, SCells for the SCG, etc. ) when the lower-layer configurations are released. As such, if the UE 115 attempts to communicate with the cells in the SCG, uplink messages transmitted by the UE 115 may be received at the cells in the SCG outside of TTI boundaries (e.g., subframes, frames, etc. ) , across TTI boundaries, etc., such that the cells are unable to correctly process the uplink messages. In some cases, a master node of an MCG for the UE 115 may transmit TA information for the cells of the SCG when the communications with the SCG are reactivated, or the UE 115 may need to decode additional downlink messages from the cells of the SCG and to transmit an acknowledgment message back to the cells of the SCG to determine and use a TA for the cells of the SCG. Accordingly, in both cases, by decoding the downlink messages from the master node and/or cells of the SCG and transmitting acknowledgment feedback before using the TA, the UE 115 may increase latency and signaling overhead in order to use a TA to communicate with the cells of the SC.

Wireless communications system 100 may support efficient techniques for a UE 115 communicating with both an MCG and an SCG to transmit an uplink message to a PSCell of the SCG after communications with the SCG have been suspended, where the PSCell responds with DCI that includes TA information for the UE 115 to use for subsequent communications with the SCG. For example, the UE may transmit a PRACH preamble message (e.g., random access message) to the PSCell to reestablish communications with the SCG, and the PSCell may respond with DCI that includes TA information for aligning the subsequent uplink messages. Additionally or alternatively, the UE may transmit a preconfigured uplink message (e.g., a preconfigured PUSCH) to the PSCell, and the PSCell may respond with a DCI to acknowledge the preconfigured uplink message was successfully received and decoded, where the DCI includes the TA information. The DCI transmitted by the PSCell may be scrambled with a C-RNTI for the UE 115, a TA-RNTI, an RA-RNTI, an RNTI corresponding to a configured CORESET and/or search space for the UE 115, or a combination thereof. In some cases, the UE 115 (e.g., and the PSCell) may receive a configuration for transmitting/monitoring for the DCI, transmitting/receiving the preconfigured uplink message, etc. (e.g., via RRC signaling) .

FIG. 2 illustrates an example of a wireless communications system 200 that supports TA control in DCI for SCG suspension in accordance with aspects of the present disclosure. In some examples, wireless communications system 200 may implement aspects of wireless communications system 100. For example, wireless communications system 200 includes a first base station 105-a, a second base station 105-b, and a UE 115-a, which may be examples of the corresponding devices described with reference to FIG. 1. Wireless communications system 200 may support the use of techniques that enhance the resumption of communications in CA and DC deployments after a UE leaves an RRC inactive state.

In wireless communications system 200, a UE 115-a may communicate with a network using a DC configuration. In such cases, UE 115-a may simultaneously communicate with different base stations 105 (e.g., first base station 105-a and second base station 105-b) . First base station 105-a may provide a first cell 205-a and first base station 105-a may be referred to as a master node. First cell 205-a may correspond to a PCell in the DC deployment. Additionally, second base station 105-b may provide a second cell 205-b of the DC configuration, and second base station 105-b may be referred to as a secondary node. In some cases, second cell 205-b may correspond to a PSCell in the DC deployment, which may be configured with time-frequency resources for PUCCH. Additional SCells may associated with each base station 105-a and 105-b, where a set of cells (e.g., SCells) associated with the master node may correspond to a master cell group (MCG) and another set of SCells associated with the secondary node may correspond to a secondary cell group (SCG) .

In some cases, the different base stations 105 and corresponding cells of the DC deployment may be associated with a same or different RAT. For instance, first base station 105-a and second base station 105-b may communicate using a first RAT and a second RAT, respectively. The first RAT and/or the second RAT may be the same or different and may include, for example, LTE, NR, or another RAT. As such, various DC deployments may sometimes be referred to as EN-DC, NE-DC, NR NR-DC, LTE LTE-DC, enhanced LTE (eLTE) eLTE-DC, or may include other types of MR-DC deployments based on the RAT that is used by each base station 105. In any case, the different cells of a DC deployment may use the same or different RF spectrum bands for communication with UE 115-a.

In some cases, DC deployments may use different radio bearers for transmitted messages for each cell. For instance, when first base station 105-a is configured as a master node that provides a set of serving cells corresponding to the MCG, first base station 105-a may use a first set of signaling radio bearers (SRBs) (e.g., SRB1, SRB2) to transport messages for the MCG, such as RRC messages. Additionally, when second base station 105-b is configured as a secondary node, second base station 105-b may provide another set of serving cells that correspond to the SCG and may use a second set of SRBs (e.g., SRB3) to transport messages for the SCG. In some examples, a split bearer configuration may be supported, where a particular protocol layer (e.g., a packet data convergence protocol (PDCP) layer) for both the master node and secondary node may be used to route data streams to/from UE 115-a. Here, an SRB (e.g., SRB1/SRB2) may be split between the master node and the secondary node, and downlink messages sent from the master node to UE 115-a may be routed via lower-layers (e.g., radio link control (RLC) , medium access control (MAC) , physical (PHY) , etc. ) of either first base station 105-a (e.g., the master node) or second base station 105-b (e.g., the secondary node) . In other cases, downlink messages may be routed via the lower-layers of both the master and secondary nodes. In the uplink, RRC messages from UE 115-a may be transmitted to the master node via the secondary node using the split bearer (e.g., via a “leg” associated with the secondary node) . For the signaling of data in the user plane, respective data radio bearers (DRBs) may be used by the MCG and SCG.

Additionally or alternatively, UE 115-a may communicate with a single base station 105 (e.g., first base station 105-a) using multiple carriers (e.g., CCs, which may also be referred to as layers, channels, etc. ) . In such cases, a CC may refer to each of the carriers used by UE 115-a in CA operations. Further, a serving cell of first base station 105-a may correspond to each CC used in CA operation, where each serving cell may be different (e.g., based on the path loss experienced by different CCs on different RF spectrum bands) . In some examples, one carrier may be designated as a primary carrier, or primary CC (PCC) , for UE 115-a, which may be served by a PCell of first base station 105-a. Additional carriers may be designated as secondary carriers, or secondary CCs (SCCs) , which may be served by SCells of first base station 105-a. CA operations may use the same or different RF bands for communications.

UE 115-a may operate in different RRC states when communicating with one or more base stations 105. For instance, and as illustrated by state diagram 210, UE 115-a may operate in an RRC connected state 215 where UE 115-a may be “active” and transmit data to/receive data from a serving cell. Additionally, UE 115-a may operate in an RRC idle state 220, in which case UE 115-a may be “on standby” and thus, may not be assigned to a particular serving base station 105 while saving power. In the RRC idle state 220, radio bearers for the system may be released (e.g., to avoid re-routing should UE 115-a move to another cell) , but UE 115-a may still perform various functions, such as cell reselection and discontinuous reception (DRX) for page messages, among other functions. UE 115-a may accordingly transition from the RRC idle state 220 to the RRC connected state 215, and vice versa, based on its activity. When transitioning to the RRC connected state 215 from the RRC idle state 220, UE 115-a may transmit, to a base station 105, a setup request message (e.g., RRCSetupRequest) . Alternatively, when transitioning from the RRC connected state 215 to the RRC idle state 220, UE 115-a may receive a release message (e.g., RRCRelease) .

In wireless communications system 200, UE 115-a may support an additional RRC state. For example, an RRC inactive state 225 between the RRC connected state 215 and the RRC idle state 220 may be used to enable a faster transition to the RRC connected state 215 (e.g., as compared to the state transition from the RRC idle state 220 to the RRC connected state 215) . When UE 115-a is in the RRC inactive state 225, it may receive system information, perform cell measurements, and perform other functions. UE 115-a may transition to the RRC connected state 215 from the RRC inactive state 225 when downlink data is available for UE 115-a, or UE 115-a has uplink data to transmit, or both, and UE 115-a may accordingly transmit a resume request message (e.g., RRCResumeRequest) to resume communications with a base station 105. When transitioning from the RRC connected state 215 to the RRC inactive state 225, UE 115-a may receive a release message (e.g., RRCRelease) from a base station 105. Likewise, when moving from the RRC inactive state 225 to the RRC idle state, UE 115-a may receive a release message from the base station 105.

When entering into the RRC inactive state 225, a UE context (e.g., an AS context) may be retained at UE 115-a and the network, and both UE 115-a and the network may store higher-layer configurations (e.g., for a DC/CA deployment) while simultaneously releasing lower-layer configurations (as the lower-layer configurations may change, for example, due to UE 115-a being mobile (i.e., non-stationary) ) . More specifically, UE 115-a, first base station 105-a (e.g., providing the MCG) , and second base station 105-b (e.g., providing the SCG) may store PDCP/SDAP configurations for both MCG and SCG when UE 115-a transitions to the RRC inactive state 225. Additionally, UE 115-a may release lower-layer configurations for both the MCG and SCG when in the RRC inactive state 225. When resuming communications with either first base station 105-a or second base station 105-b by transitioning to the RRC connected state 215 from the RRC inactive state 225, UE 115-a may apply the stored upper-layer (PDCP and/or SDAP) configurations of the MCG and SCG.

However, due to the release of the lower-layer configurations, UE 115-a may not be able to immediately operate using DC (or CA) communications after transitioning from the RRC inactive state 225. For example, when entering the RRC inactive state 225, UE 115-a may later require multiple reconfiguration messages (e.g., RRC reconfiguration messages) to obtain a full configuration, including the lower-layer configurations for the MCG and SCG (and any updates thereto) , to establish communication with first base station 105-a and/or second base station 105-b (or another, different, base station 105) of the DC deployment. Additionally, UE 115-a may require additional downlink messages and be required to transmit acknowledgment messages to decode and use a TA for communicating with the SCG. This signaling overhead may reduce efficiency in the system through added delays in resuming and/or modifying the DC configuration that UE 115-a operated with prior to entering into the RRC inactive state 225. CA operations may be similarly affected when transitioning out of the RRC inactive state 225.

As described herein, techniques are described for indicating TA information in DCI for UE 115-a to use for transmitting uplink messages to a PSCell of second base station 105-b (e.g., SCG) after communications with second base station 105-b have been suspended. For example, UE 115-a may transmit a random access message (e.g., PRACH preamble) to second base station 105-b to reestablish communications with the SCG, and second base station 105-b may respond with DCI that includes TA information for aligning the subsequent uplink messages. Additionally or alternatively, UE 115-a may transmit a preconfigured uplink message (e.g., a preconfigured PUSCH) to second base station 105-b, and second base station 105-b may respond with a DCI to acknowledge the preconfigured uplink message was successfully received and decoded, where the DCI includes the TA information. In some cases, the DCI transmitted by second base station 105-b may be scrambled with a C-RNTI for UE 115-a, a TA-RNTI, an RA-RNTI, an RNTI corresponding to a configured CORESET and/or search space for UE 115-a, or a combination thereof. Additionally, UE 115-a (e.g., and second base station 105-b) may receive a configuration for transmitting/monitoring for the DCI, transmitting/receiving the preconfigured uplink message, etc. (e.g., via RRC signaling) .

It is noted that aspects of the present disclosure are described in the context of DC deployments (e.g., NE-DC, EN-DC, or the like) when UE 115-a resumes communications from the RRC inactive state 225; however, the techniques may be applicable to other deployments and configurations not explicitly described herein. For example, the described techniques may also be applicable to CA configurations when UE 115-a transitions out of the RRC inactive state 225. Additionally or alternatively, the described techniques may be applicable to scenarios where UE 115-a is connected with a single base station to efficiently set up DC or CA when UE 115-a resumes communications from an RRC inactive state 225.

FIG. 3 illustrates an example of a wireless communications system 300 that supports TA control in DCI for SCG suspension in accordance with aspects of the present disclosure. In some examples, wireless communications system 300 may implement aspects of wireless communications systems 100 and/or 200. For example, wireless communications system 300 includes a first base station 105-c, a second base station 105-d, and a UE 115-b, which may be examples of the corresponding devices described with reference to FIGs. 1 and 2. UE 115-b may communicate with first base station 105-c on resources of a carrier 305 and communicate with second base station 105-d on resources of a carrier 310. Additionally, first base station 105-c and second base station 105-d may communicate with each other via a backhaul link 120-a. Wireless communications system 300 may support the use of techniques that enhance the resumption of communications in CA and DC deployments after a UE leaves an RRC inactive state, including determining a TA to use for resuming the communications.

As described above with reference to FIG. 2, UE 115-b may be in communications with both first base station 105-c and second base station 105-d, where first base station 105-c represents a master node/MCG and base station 105-d represents a secondary node/SCG. Additionally, first base station 105-c may provide a first cell (e.g., a PCell) for communicating with UE 115-b, and second base station 105-d may provide a second cell (e.g., a PSCell) for communicating with UE 115-b. First base station 105-c and second base station 105-d may also provide additional cells (e.g., SCells) to support communications with UE 115-b. However, in some cases, UE 115-b may suspend communications with second base station 105-d (e.g., the SCG) based on a determination made by first base station 105-c. For example, first base station 105-c may determine to suspend SCG communications for UE 115-b based on measurement reports from UE 115-b (e.g., indicating the communications with second base station 105-d are deteriorating) , to save power at UE 115-b by not communicating with two base stations 105/cells at the same time, communications with both base stations 105 is not needed, etc.

Subsequently, first base station 105-c may then transmit indications or requests to both second base station 105-d (e.g., via backhaul link 120-a) and to UE 115-b (e.g., via carrier 305) for suspending the SCG communications. For example, first base station 105-c may transmit an SCG suspend request 315-a to second base station 105-d via backhaul link 120-a and may transmit an SCG suspend request 315-b to UE 115-b via carrier 305. Accordingly, based on receiving SCG suspend request 315-b, UE 115-b may place the SCG into dormancy, including second base station 105-d (e.g., PSCell) . That is, while the SCG is in dormancy, UE 115-b may store configurations for the SCG but may not monitor downlink channels (e.g., physical downlink control channels (PDCCHs) ) of cells (e.g., PSCell and SCell (s) ) of the SCG.

In some cases, UE 115-b may determine to transmit an uplink message 320 to second base station 105-d. For example, UE 115-b may determine to reestablish the SCG connection and communicate with second base station 105-d again and, as such, may initiate a random access procedure with second base station 105-d (e.g., via a RACH preamble) . Additionally or alternatively, UE 115-b may identify uplink data to be transmitted to second base station 105-d and transmit a scheduling request to second base station 105-d requesting uplink resources for transmitting the uplink data on carrier 310. In some cases, UE 115-b may determine to transmit uplink message 320 based on an indication from first base station 105-c (e.g., MN, MCG, PCell, etc. ) , such as an indication to reactivate the SCG communications, an indication to transmit uplink data, etc.

Accordingly, as described herein, after UE 115-b transmits uplink message 320 (e.g., based on determining to transmit uplink message 320, receiving an indication from first base station 105-c to transmit uplink message 320) , second base station 105-d (e.g., dormancy PSCell, dormancy SCG, etc. ) may transmit a DCI with TA information 325 to UE 115-b. For example, second base station 105-d may transmit the DCI to UE 115-b in response to uplink message 320 and may include TA information with the DCI, where UE 115-b uses the TA information to transmit subsequent uplink messages to second base station 105-d such that the uplink messages are received at second base station 105-d within configured uplink TTIs for second base station 105-d to receive uplink messages (e.g., aligned with the uplink TTIs) .

As described above, UE 115-b may transmit a random access message for uplink message 320 (e.g., to reestablish communications with second base station 105-d, with the SCG, etc. ) . For example, UE 115-b may send a dedicated PRACH preamble in the dormancy PSCell (e.g., second base station 105-d) , and the PSCell may send DCI with TA information 325 (e.g., including the TA) in a dormant BWP of the PSCell (e.g., a part of the bandwidth of carrier 310) . The dedicated PRACH preamble may include a dedicated preamble (e.g., that indicates for second base station 105-d to transmit DCI with TA information 325 based on receiving the dedicated PRACH preamble) or a dedicated time/frequency/beam resource location for transmitting the PRACH preamble.

Upon transmitting the PRACH preamble, UE 115-b may monitor for the corresponding DCI (e.g., DCI with TA information 325) in the dormant BWP for one RRC configured duration. For example, first base station 105-c may transmit an indication via RRC signaling of how long UE 115-b is to monitor for the DCI from second base station 105-d. If the duration expires and no DCI is received, UE 115-b may need to retransmit uplink message 320 (e.g., the PRACH preamble) to receive the TA information.

Additionally, UE 115-b may be configured by RRC (e.g., from first base station 105-c, master node, MCG, etc. ) with a dedicated CORESET and/or a dedicated search space (e.g., dedicated for UE 115-b) where UE 115-b is to monitor for the DCI with TA information 325. In some cases, second base station 105-d may also receive an indication of the dedicated CORESET and/or dedicated search space (e.g., via backhaul link 120-a) to identify where to transmit DCI with TA information 325 for UE 115-b to receive the DCI. Additionally or alternatively, second base station 105-d may determine the CORESET and/or search space for UE 115-b to monitor and receive the DCI and may transmit an indication of the CORESET and/or search space (e.g., directly to UE 115-b, through first base station 105-c, etc. ) .

When transmitting DCI with TA information 325, second base station 105-d may scramble the DCI with a C-RNTI specific to UE 115-b, with a dedicated RNTI for including the TA information (e.g., a TA-RNTI) , with an RNTI for the random access procedure (e.g., an RA-RNTI, with an RNTI that corresponds to (e.g., mapping from) the configured CORESET and/or search space for UE 115-b to monitor for DCI with TA information 325.

Additionally or alternatively, when uplink message 320 includes uplink data or another type of uplink transmission, the network (e.g., first base station 105-c) may configure a periodic dedicated time/frequency/beam resource location for UE 115-b to send a preconfigured uplink message (e.g., a preconfigured PUSCH, a preconfigured configuration for transmitting uplink message 320, etc. ) . Subsequently, upon reception of uplink message 320 when uplink message 320 carries a preconfigured PUSCH transmission, the PSCell (e.g., second base station 105-d) may send DCI with TA information 325 (e.g., as an acknowledgment message) in a dormant BWP of the PSCell. In some cases, UE 115-b may receive an RRC configuration (e.g., from first base station 105-c, master node, MCG, etc. ) of the preconfigured periodic PUSCH that includes a periodicity, a frequency location, a number of repetitions, a CORESET and/or search space configuration, frequency hopping configurations for channels associated with the preconfigured periodic PUSCH, an MCS of the periodic PUSCH, a TCI associated with the periodic PUSCH, or a combination thereof.

Upon transmitting the preconfigured PUSCH for uplink message 320, UE 115-b may monitor for the corresponding DCI (e.g., as the acknowledgment message) in the dormant BWP for one RRC configured duration as described above. For example, if the duration expires and no DCI (e.g., as the acknowledgment message) is received, UE 115-b may retransmit the preconfigured PUSCH to receive the TA information. Additionally, UE 115-b may be configured by RRC with a dedicated CORESET and/or a dedicated search space to monitor for DCI with TA information 325 (e.g., as the acknowledgment message) . When transmitting DCI with TA information 325, second base station 105-d may scramble the DCI with the C-RNTI specific to UE 115-b, with the dedicated RNTI for including the TA information (e.g., a TA-RNTI) , with an RNTI that corresponds to (e.g., mapping from) the configured CORESET and/or search space for UE 115-b to monitor for DCI with TA information 325.

The TA information may be a set of bits (e.g., six (6) bits) . However, the DCI format and payload design may vary based on the type of RNTI used by second base station 105-d for scrambling the DCI. For example, when the C-RNTI is used to scramble the DCI, a new DCI format may be defined that contains the TA field. Accordingly, the DCI size may be matched with that of a fallback DCI (e.g., DCI format 1_0, DCI format 0_0, etc. ) for the cell where the DCI is monitored by adding reserved bits. In some cases, matching the DCI size to the fallback DCI may assume that this DCI (e.g., DCI with TA information 325 from second base station 105-d) is monitored and the existing fallback DCI is not monitored in the serving cell (e.g., from first base station 105-c) as UE 115-b is not able to differentiate between the two DCIs. Additionally or alternatively, the DCI size for DCI with TA information 325 may not be matched with the fallback DCI size in the serving cell. In some cases, a DCI size budget (e.g., up to three (3) DCI sizes when using the C-RNTI and a total four (4) DCI sizes for all RNTIs) may not be increased after this new DCI is not defined.

Additionally or alternatively, when the C-RNTI is used to scramble the DCI, fields of an existing fallback DCI may be repurposed for DCI with TA information 325. For example, second base station 105-d may transmit DCI with TA information 325 based on a scheduling DCI and repurpose existing field (s) of the scheduling DCI. In some cases, second base station 105-d may repurpose the existing fields and/or may add at least one bit to indicate whether the DCI is used to carry the TA information. Additionally, an existing non-fallback DCI format (e.g., DCI format 1_1, DCI format 0_1, etc. ) may be used when repurposing the existing fields of a DCI (e.g., scheduling DCI) to transmit DCI with TA information 325. In some cases, when the C-RNTI is used to scramble the DCI and the fields of an existing fallback DCI are repurposed for DCI with TA information 325, second base station 105-d may transmit DCI with TA information 325 based on a PDCCH order. For example, second base station 105-d may use reserved bits (e.g., 10 bits) in the PDCCH to carry the TA information. Additionally or alternatively, second base station 105-d may repurpose existing field (s) of the DCI.

In some cases, when second base station 105-d uses the dedicated RNTI (e.g., TA-RNTI) to scramble the DCI or an RNTI mapping from the configured CORESET and/or search space, the DCI size may be matched with the fallback DCI size (e.g., for DCI format 1_0, DCI format 0_0, etc. ) . Additionally or alternatively, the DCI size may not be matched with the fallback DCI size in the serving cell. When the DCI size is not matched, the DCI size budget (e.g., up to three (3) DCI sizes for C-RNTI and total four (4) DCI sizes for all RNTIs) may not be increased, which may be similar to defining a new DCI format that contains the TA field/information and the PDCCH is scrambled by a C-RNTI.

When the RA-RNTI is used to scrambled DCI with TA information 325, reserved bits (e.g., 16 bits) may be used to carry the TA information. Additionally or alternatively, second base station 105-d may repurpose existing field (s) of the DCI (e.g., similar to PDCCH order) .

FIG. 4 illustrates an example of an SCG suspension process 400 that supports TA control in DCI for SCG suspension in accordance with aspects of the present disclosure. In some examples, SCG suspension process 400 may implement aspects of

wireless communications systems

100, 200, and/or 300. SCG suspension process 400 may include a UE 115-c, which may be an example of a UE 115 as described above with reference to FIGs. 1-3. Additionally, SCG suspension process 400 may include a master node (MN) 402 and a secondary node (SN) 403, which may be examples of base stations 105 as described above with reference to FIGs. 1-3. For example, UE 115-c may support communications with both master node 402 and secondary node 403 in a communications configuration that includes an MCG with master node 402 and an SCG with secondary node 403 (e.g., DC deployment, CA configuration, etc. ) .

At 405, master node 402 may transmit an SCG suspend request to secondary node 403 to suspend SCG communications between secondary node 403 and UE 115-c. Subsequently, at 410, secondary node 403 may transmit an SCG suspend complete message to master node 402.

Accordingly, after the SCG communications have been suspended at secondary node 403, at 415, master node 402 may transmit an SCG suspend indication 415 to UE 115-c. For example, master node 402 may use layer 1 (L1) signaling (e.g., DCI) to indicate UE 115-c to suspend SCG/secondary node for a while and reactivate the SCG/secondary node quickly.

At 420, UE 115-b may enter an SCG suspend state based on receiving the SCG suspend indication. Additionally, at 425, when the SCG is suspended, UE 115-c may put its SCG (e.g., including a PSCell, secondary node 403, etc. ) in dormancy for power saving purpose. Based on putting the SCG in dormancy, the SCG configuration may be stored in UE 115-c, but UE 115-c may not monitor PDCCH of PSCell/SCell of the SCG. In some cases, during the SCG suspension, UE 115-c may be configured to perform radio resource management (RRM) and channel state information (CSI) measurements for the SCG and may report measurement results of the SCG to master node 402.

In some cases, at 430, UE 115-c may transmit an SCG activation request to master node 402 for reactivating communications with secondary node 403 (e.g., to reactivate SCG communications) . At 435, master node 402 may determine to activate communications between UE 115-c and the SCG (e.g., secondary node 403) . For example, master node 402 may determine to activate the SCG based on the activation request received from UE 115-c. Additionally or alternatively, master node 402 may determine to reactivate the SCG communications based on measurement reports received from UE 115-c.

At 440, master node 402 may transmit an SCG activation request to secondary node 403 based on determining to reactivate the SCG communications. Subsequently, at 445, secondary node 403 may transmit an SCG activation complete message to master node 402 to indicate that the SCG communications have been reactivated at secondary node 403.

At 450, master node 402 may transmit an SCG activation indication message to UE 115-c to reactivate the SCG communications at UE 115-c. Accordingly, at 455, based on receiving the SCG reactivation indication message, UE 115-c may enter an activated state for communications with the SCG.

At 460, after entering the activated state, UE 115-c and secondary node 403 may perform a RACH procedure to reestablish communications with each other. In some cases, UE 115-c may send a dedicated PRACH preamble in a dormancy uplink profile of a PSCell of secondary node 403, and the PSCell may send an RAR with a TA in a dormancy downlink profile of the PSCell. Upon transmitting the PRACH preamble, UE 115-c may monitor for the RAR in the dormancy downlink profile for one RRC configured duration. If the duration expires and no RAR is received, UE 115-c may need to retransmit the PRACH preamble to acquire TA information. However, UE 115-c may have to decode a PDSCH for the TA information (e.g., TA command, TA control, etc. ) included in the RAR, and may also need to send a PUSCH to acknowledge the RAR.

As such, as described herein, to reduce the amount of decoding (e.g., the RAR) and transmitting the PUSCH to acknowledge the RAR to receive and use the TA, secondary node 403 may transmit DCI with the TA information after receiving the PRACH preamble.

Subsequently, at 465, after receiving the TA information, UE 115-c may communicate data with master node 402 and/or secondary node 403 (e.g., according to the TA) . Additionally or alternatively, UE 115-c may transmit a preconfigured PUSCH to secondary node 403 and receive DCI including the TA information from secondary node 403 in response to the preconfigured PUSCH.

FIG. 5 illustrates an example of a TA configuration 500 that supports TA control in DCI for SCG suspension in accordance with aspects of the present disclosure. In some examples, TA configuration 500 may implement aspects of

wireless communications systems

100, 200, and/or 300. TA configuration 500 may include a UE 115-d and a base station 105-e, which may be examples of UEs 115 and base stations 105, respectively, as described above with reference to FIGs. 1-4. As described herein, base station 105-e (e.g., a secondary node, PSCell, SCG, second base station, etc. ) may receive an uplink transmission 505 from UE 115-d based on a TA 510. For example, base station 105-e may transmit information for the TA 510 in DCI to UE 115-d based on receiving an uplink message (e.g., PRACH preamble, preconfigured PUSCH transmission, etc. ) .

Accordingly, UE 115-d may use TA 510 to transmit uplink transmission 505 at a time 515-a, such that the uplink transmission 505 is received at base station 105-e at a time 515-b. In some cases, time 515-b may correspond to a start of an uplink frame 520 for base station 105-e. Uplink frame 520 may be a configured time interval where base station 105-e can receive uplink messages from different UEs 115 (e.g., including UE 115-d) . Uplink frame 520 may include a duration of a frame, a subframe, or a different length TTI that base station 105-e can use for receiving uplink messages. In some cases, uplink frame 520 may last from time 515-b to a time 515-c. Based on TA 510, uplink transmission 505 may be received at base station 105-e at aligned times for base station 105-e.

TAs 510 may vary per UE 115 communicating with base station 105-e such that uplink transmissions received from each UE 115 are aligned with uplink frame 520 (e.g., so that base station 105-e is receiving multiple uplink messages at different times and/or outside durations that base station 105-e is able to receive uplink transmissions) . For example, the different UEs 115 may experience different propagation delays based on being farther away or closer to base station 105-e. Additionally, in some cases, a single TA or multiple TAs may be configured per UE 115.

FIG. 6 illustrates an example of a process flow 600 that supports TA control in DCI for SCG suspension in accordance with aspects of the present disclosure. In some examples, process flow 600 may implement aspects of

wireless communications systems

100, 200, and/or 300. For instance, process flow 600 includes a UE 115-e, which may be an example of a UE 115 described with reference to FIGs. 1-5. Further, process flow 600 includes a master node (MN) 602 and a secondary node (SN) 603 which may be configured for operation in a DC deployment (e.g., and/or a CA configuration) with UE 115-e. Master node 602 and secondary node 603 may each be an example of a base station 105 as described with reference to FIGs. 1-5. Process flow 600 may illustrate a UE 115 transitioning from an inactive communication state (e.g., RRC inactive) and resuming communications within a DC deployment using TA information signaled by secondary node 603 (e.g., a PSCell) in DCI.

In the following description of the process flow 600, the operations between UE 115-e, master node 602, and secondary node 603 may be performed in different orders or at different times. Certain operations may also be left out of the process flow 600, or other operations may be added to the process flow 600. It is to be understood that while UE 115-e, master node 602, and secondary node 603 are shown performing a number of the operations of process flow 600, any wireless device may perform the operations shown.

At 605, UE 115-e may identify a configuration for communicating with an MCG and an SCG. Additionally, secondary node 603 may identify a communication configuration with UE 115-e, where secondary node 603 includes a PSCell with respect to the communication configuration with UE 115-e.

At 610, secondary node 603 may receive, from master node 602 in the communication configuration, a release message indicating a suspension of secondary node communications (e.g., SCG communications) with UE 115-e, where the secondary node communications include the PSCell.

At 615, UE 115-e may receive, from master node 602 in the MCG, a release message indicating a suspension of communications with the SCG (e.g., secondary node 603, PSCell, etc. ) .

At 620, UE 115-e may receive, via RRC signaling, a configuration for a preconfigured uplink message. For example, the configuration for the preconfigured uplink message may include a periodicity, a frequency location, a number of repetitions, a CORESET configuration, a search space configuration, a frequency hopping configuration, an MCS, a TCI, or a combination thereof for transmitting the preconfigured uplink message.

At 625, secondary node 603 may receive, from master node 602, an uplink channel configuration for receiving the preconfigured uplink message from UE 115-e. For example, the uplink channel configuration may include a periodic allocation of time resources, frequency resources, beam resource locations, or a combination thereof for receiving the preconfigured uplink message. Additionally, secondary node 603 may receive, from master node 602, a configuration for the preconfigured uplink message. For example, the configuration for the preconfigured uplink message may include the periodicity, the frequency location, the number of repetitions, the CORESET configuration, the search space configuration, the frequency hopping configuration, the MCS, the TCI, or a combination thereof for receiving the preconfigured uplink message.

At 630, UE 115-e may transmit an uplink message to the PSCell of the SCG after the communications have been suspended with the SCG. For example, secondary node 603 may receive, from UE 115-e, an uplink message after the communications have been suspended with UE 115-e. In some cases, secondary node 603 may receive, from UE 115-e, the preconfigured uplink message based on the uplink channel configuration.

In some cases, UE 115-e may determine to reestablish the communications with the SCG after the communications have been suspended with the SCG and may transmit, to the PSCell of the SCG, a random access message (e.g., PRACH preamble) based on the determination. For example, the random access message may be a random access preamble dedicated to UE 115-e. In some cases, the random access message may be transmitted at a time resource, frequency resource, beam resource location, or a combination thereof dedicated to UE 115-e.

Additionally or alternatively, UE 115-e may receive an uplink channel configuration for transmitting the preconfigured uplink message and may transmit, to the PSCell of the SCG, the preconfigured uplink message based on the uplink channel configuration. In some cases, the uplink channel configuration may include a periodic allocation of time resources, frequency resources, beam resource locations, or a combination thereof.

At 635, UE 115-e may receive, via RRC signaling, a monitoring configuration for monitoring of a BWP for DCI, where the BWP is monitored for one configured duration based on the monitoring configuration. Additionally, UE 115-e may receive, via RRC signaling, a configuration of a CORESET, a search space, or a combination thereof dedicated to UE 115-e, where the BWP is monitored based on the configuration of the CORESET, the search space, or the combination thereof.

At 640, secondary node 603 may receive, from master node 602, a configuration of the CORESET, the search space, or the combination thereof dedicated to UE 115-e, where DCI is transmitted based on the configuration of the CORESET, the search space, or the combination thereof. Additionally or alternatively, secondary node 603 may transmit, to UE 115-e via RRC signaling, a configuration of the CORESET, the search space, or the combination thereof dedicated to UE 115-e, where DCI is transmitted based on the configuration of the CORESET, the search space, or the combination thereof.

At 645, secondary node 603 may transmit, to UE 115-e, DCI based on receiving the uplink message, where the DCI includes a TA parameter (e.g., TA information) for the communications with the SCG. In some cases, secondary node 603 may scramble the DCI with a C-RNTI for UE 115-e, a dedicated TA-RNTI, an RA-RNTI, an RNTI corresponding to the CORESET for UE 115-e, an RNTI corresponding to the search space for UE 115-e, or a combination thereof.

At 650, UE 115-e may monitor a BWP for the DCI from the PSCell of the SCG, where the DCI includes the TA parameter for the communications with the SCG. In some cases, UE 115-e may determine the one configured duration expires prior to receiving the DCI and may transmit, to the PSCell of the SCG, the uplink message an additional time (e.g., retransmission) based on the one configured duration expiring.

FIG. 7 shows a block diagram 700 of a device 705 that supports TA control transmission in DCI for SCG suspension in accordance with aspects of the present disclosure. The device 705 may be an example of aspects of a UE 115 as described herein. The device 705 may include a receiver 710, a UE communications manager 715, and a transmitter 720. The device 705 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 710 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 TA control transmission in DCI for SCG suspension, etc. ) . Information may be passed on to other components of the device 705. The receiver 710 may be an example of aspects of the transceiver 1020 described with reference to FIG. 10. The receiver 710 may utilize a single antenna or a set of antennas.

The UE communications manager 715 may identify a configuration for communicating with a master cell group and a secondary cell group. In some cases, the UE communications manager 715 may receive, from a master node in the master cell group, a release message indicating a suspension of communications with the secondary cell group. Additionally, the UE communications manager 715 may transmit an uplink message to a primary secondary cell of the secondary cell group after the communications have been suspended with the secondary cell group. Subsequently, the UE communications manager 715 may monitor a bandwidth part for downlink control information from the primary secondary cell of the secondary cell group, the downlink control information including a timing advance parameter for the communications with the secondary cell group. The UE communications manager 715 may be an example of aspects of the UE communications manager 1010 described herein.

The actions performed by the UE communications manager 715 as described herein may be implemented to realize one or more potential advantages. One implementation may allow a UE 115 to gain efficiency by reducing signaling overhead associated with the release of the lower-layer configurations. Another implementation may provide improved quality and reliability of service at the UE 115, as latency and the number of separate resources allocated to the UE 115 may be reduced.

The UE communications manager 715, 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 UE communications manager 715, 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 UE communications manager 715, 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 UE communications manager 715, or its sub-components, may be a separate and distinct component in accordance with various aspects of the present disclosure. In some examples, the UE communications manager 715, 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 720 may transmit signals generated by other components of the device 705. In some examples, the transmitter 720 may be collocated with a receiver 710 in a transceiver module. For example, the transmitter 720 may be an example of aspects of the transceiver 1020 described with reference to FIG. 10. The transmitter 720 may utilize a single antenna or a set of antennas.

FIG. 8 shows a block diagram 800 of a device 805 that supports TA control transmission in DCI for SCG suspension in accordance with aspects of the present disclosure. The device 805 may be an example of aspects of a device 705, or a UE 115 as described herein. The device 805 may include a receiver 810, a UE communications manager 815, and a transmitter 840. The device 805 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 810 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 TA control transmission in DCI for SCG suspension, etc. ) . Information may be passed on to other components of the device 805. The receiver 810 may be an example of aspects of the transceiver 1020 described with reference to FIG. 10. The receiver 810 may utilize a single antenna or a set of antennas.

The UE communications manager 815 may be an example of aspects of the UE communications manager 715 as described herein. The UE communications manager 815 may include a communication configuration component 820, a SCG suspension component 825, an uplink message transmission component 830, and a DCI monitoring component 835. The UE communications manager 815 may be an example of aspects of the UE communications manager 1010 described herein.

The communication configuration component 820 may identify a configuration for communicating with a master cell group and a secondary cell group.

The SCG suspension component 825 may receive, from a master node in the master cell group, a release message indicating a suspension of communications with the secondary cell group.

The uplink message transmission component 830 may transmit an uplink message to a primary secondary cell of the secondary cell group after the communications have been suspended with the secondary cell group.

The DCI monitoring component 835 may monitor a bandwidth part for downlink control information from the primary secondary cell of the secondary cell group, the downlink control information including a timing advance parameter for the communications with the secondary cell group.

The transmitter 840 may transmit signals generated by other components of the device 805. In some examples, the transmitter 840 may be collocated with a receiver 810 in a transceiver module. For example, the transmitter 840 may be an example of aspects of the transceiver 1020 described with reference to FIG. 10. The transmitter 840 may utilize a single antenna or a set of antennas.

FIG. 9 shows a block diagram 900 of a UE communications manager 905 that supports TA control transmission in DCI for SCG suspension in accordance with aspects of the present disclosure. The UE communications manager 905 may be an example of aspects of a UE communications manager 715, a UE communications manager 815, or a UE communications manager 1010 described herein. The UE communications manager 905 may include a communication configuration component 910, a SCG suspension component 915, an uplink message transmission component 920, a DCI monitoring component 925, a random access message component 930, a preconfigured uplink message component 935, a monitoring duration component 940, and a monitoring resources component 945. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses) .

The communication configuration component 910 may identify a configuration for communicating with a master cell group and a secondary cell group.

The SCG suspension component 915 may receive, from a master node in the master cell group, a release message indicating a suspension of communications with the secondary cell group.

The uplink message transmission component 920 may transmit an uplink message to a primary secondary cell of the secondary cell group after the communications have been suspended with the secondary cell group.

The DCI monitoring component 925 may monitor a bandwidth part for downlink control information from the primary secondary cell of the secondary cell group, the downlink control information including a timing advance parameter for the communications with the secondary cell group. In some cases, the downlink control information may be scrambled with a cell radio network temporary identifier for the UE, a dedicated timing advance radio network temporary identifier, a random access radio network temporary identifier, a radio network temporary identifier corresponding to a control resource set for the UE, a radio network temporary identifier corresponding to a search space for the UE, or a combination thereof.

The random access message component 930 may determine to reestablish the communications with the secondary cell group after the communications have been suspended with the secondary cell group. In some examples, the random access message component 930 may transmit, to the primary secondary cell of the secondary cell group, a random access message based on the determination. In some cases, the random access message is a random access preamble dedicated to the UE. In some cases, the random access message is transmitted at a time resource, frequency resource, beam resource location, or a combination thereof dedicated to the UE.

The preconfigured uplink message component 935 may receive an uplink channel configuration for transmitting a preconfigured uplink message. In some examples, the preconfigured uplink message component 935 may transmit, to the primary secondary cell of the secondary cell group, the preconfigured uplink message based on the uplink channel configuration. In some examples, the preconfigured uplink message component 935 may receive, via radio resource control signaling, a configuration for the preconfigured uplink message.

In some cases, the configuration for the preconfigured uplink message includes a periodicity, a frequency location, a number of repetitions, a control resource set configuration, a search space configuration, a frequency hopping configuration, a modulation and coding scheme, a transmission configuration indicator, or a combination thereof for transmitting the preconfigured uplink message. In some cases, the uplink channel configuration includes a periodic allocation of time resources, frequency resources, beam resource locations, or a combination thereof.

The monitoring duration component 940 may receive, via radio resource control signaling, a monitoring configuration for the monitoring of the bandwidth part for the downlink control information, where the bandwidth part is monitored for one configured duration based on the monitoring configuration. In some examples, the monitoring duration component 940 may determine the one configured duration expires prior to receiving the downlink control information. In some examples, the monitoring duration component 940 may transmit, to a primary secondary cell of the secondary cell group, the uplink message an additional time based on the one configured duration expiring.

The monitoring resources component 945 may receive, via radio resource control signaling, a configuration of a control resource set, a search space, or a combination thereof dedicated to the UE, where the bandwidth part is monitored based on the configuration of the control resource set, the search space, or the combination thereof.

FIG. 10 shows a diagram of a system 1000 including a device 1005 that supports TA control transmission in DCI for SCG suspension in accordance with aspects of the present disclosure. The device 1005 may be an example of or include the components of device 705, device 805, or a UE 115 as described herein. The device 1005 may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including a UE communications manager 1010, an I/O controller 1015, a transceiver 1020, an antenna 1025, memory 1030, and a processor 1040. These components may be in electronic communication via one or more buses (e.g., bus 1045) .

The UE communications manager 1010 may identify a configuration for communicating with a master cell group and a secondary cell group. In some cases, the UE communications manager 1010 may receive, from a master node in the master cell group, a release message indicating a suspension of communications with the secondary cell group. Additionally, the UE communications manager 1010 may transmit an uplink message to a primary secondary cell of the secondary cell group after the communications have been suspended with the secondary cell group. Subsequently, the UE communications manager 1010 may monitor a bandwidth part for downlink control information from the primary secondary cell of the secondary cell group, the downlink control information including a timing advance parameter for the communications with the secondary cell group.

The I/O controller 1015 may manage input and output signals for the device 1005. The I/O controller 1015 may also manage peripherals not integrated into the device 1005. In some cases, the I/O controller 1015 may represent a physical connection or port to an external peripheral. In some cases, the I/O controller 1015 may utilize an operating system such as

or another known operating system. In other cases, the I/O controller 1015 may represent or interact with a modem, a keyboard, a mouse, a touchscreen, or a similar device. In some cases, the I/O controller 1015 may be implemented as part of a processor. In some cases, a user may interact with the device 1005 via the I/O controller 1015 or via hardware components controlled by the I/O controller 1015.

The transceiver 1020 may communicate bi-directionally, via one or more antennas, wired, or wireless links as described above. For example, the transceiver 1020 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 1020 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 1025. However, in some cases the device may have more than one antenna 1025, which may be capable of concurrently transmitting or receiving multiple wireless transmissions.

The memory 1030 may include random-access memory (RAM) and read-only memory (ROM) . The memory 1030 may store computer-readable, computer-executable code 1035 including instructions that, when executed, cause the processor to perform various functions described herein. In some cases, the memory 1030 may contain, among other things, a basic I/O system (BIOS) which may control basic hardware or software operation such as the interaction with peripheral components or devices.

The processor 1040 may include an intelligent hardware device, (e.g., a general-purpose processor, a DSP, a central processing unit (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 1040 may be configured to operate a memory array using a memory controller. In other cases, a memory controller may be integrated into the processor 1040. The processor 1040 may be configured to execute computer-readable instructions stored in a memory (e.g., the memory 1030) to cause the device 1005 to perform various functions (e.g., functions or tasks supporting TA control transmission in DCI for SCG suspension) .

The code 1035 may include instructions to implement aspects of the present disclosure, including instructions to support wireless communications. The code 1035 may be stored in a non-transitory computer-readable medium such as system memory or other type of memory. In some cases, the code 1035 may not be directly executable by the processor 1040 but may cause a computer (e.g., when compiled and executed) to perform functions described herein.

FIG. 11 shows a block diagram 1100 of a device 1105 that supports TA control transmission in DCI for SCG suspension in accordance with aspects of the present disclosure. The device 1105 may be an example of aspects of a base station 105 as described herein. The device 1105 may include a receiver 1110, a base station communications manager 1115, and a transmitter 1120. The device 1105 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 1110 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 TA control transmission in DCI for SCG suspension, etc. ) . Information may be passed on to other components of the device 1105. The receiver 1110 may be an example of aspects of the transceiver 1420 described with reference to FIG. 14. The receiver 1110 may utilize a single antenna or a set of antennas.

The base station communications manager 1115 may identify that the base station is operating in a communication configuration with a UE, where the base station includes a primary secondary cell of a secondary cell group with respect to the communication configuration with the UE. In some cases, the base station communications manager 1115 may receive, from a master node in the communication configuration, a release message indicating a suspension of secondary node communications with the UE, the secondary node communications including the primary secondary cell. Additionally, the base station communications manager 1115 may receive, from the UE, an uplink message after the communications have been suspended with the UE. Subsequently, the base station communications manager 1115 may transmit, to the UE, downlink control information based on receiving the uplink message, the downlink control information including a timing advance parameter for the communications with the secondary cell group. The base station communications manager 1115 may be an example of aspects of the base station communications manager 1410 described herein.

The actions performed by the base station communications manager 1115 as described herein may be implemented to realize one or more potential advantages. One implementation may allow a base station 105 to gain efficiency by reducing signaling overhead associated with the release of the lower-layer configurations. Another implementation may provide improved quality and reliability of service at the base station 105, as latency may be reduced.

The base station communications manager 1115, 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 base station communications manager 1115, 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 base station communications manager 1115, 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 base station communications manager 1115, or its sub-components, may be a separate and distinct component in accordance with various aspects of the present disclosure. In some examples, the base station communications manager 1115, 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 1120 may transmit signals generated by other components of the device 1105. In some examples, the transmitter 1120 may be collocated with a receiver 1110 in a transceiver module. For example, the transmitter 1120 may be an example of aspects of the transceiver 1420 described with reference to FIG. 14. The transmitter 1120 may utilize a single antenna or a set of antennas.

FIG. 12 shows a block diagram 1200 of a device 1205 that supports TA control transmission in DCI for SCG suspension in accordance with aspects of the present disclosure. The device 1205 may be an example of aspects of a device 1105, or a base station 105 as described herein. The device 1205 may include a receiver 1210, a base station communications manager 1215, and a transmitter 1240. The device 1205 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 1210 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 TA control transmission in DCI for SCG suspension, etc. ) . Information may be passed on to other components of the device 1205. The receiver 1210 may be an example of aspects of the transceiver 1420 described with reference to FIG. 14. The receiver 1210 may utilize a single antenna or a set of antennas.

The base station communications manager 1215 may be an example of aspects of the base station communications manager 1115 as described herein. The base station communications manager 1215 may include a communication configuration identifier 1220, a SCG suspension indication receiver 1225, an uplink message reception component 1230, and a DCI transmission component 1235. The base station communications manager 1215 may be an example of aspects of the base station communications manager 1410 described herein.

The communication configuration identifier 1220 may identify that the base station is operating in a communication configuration with a UE, where the base station includes a primary secondary cell of a secondary cell group with respect to the communication configuration with the UE.

The SCG suspension indication receiver 1225 may receive, from a master node in the communication configuration, a release message indicating a suspension of secondary node communications with the UE, the secondary node communications including the primary secondary cell.

The uplink message reception component 1230 may receive, from the UE, an uplink message after the communications have been suspended with the UE.

The DCI transmission component 1235 may transmit, to the UE, downlink control information based on receiving the uplink message, the downlink control information including a timing advance parameter for the communications with the secondary cell group.

The transmitter 1240 may transmit signals generated by other components of the device 1205. In some examples, the transmitter 1240 may be collocated with a receiver 1210 in a transceiver module. For example, the transmitter 1240 may be an example of aspects of the transceiver 1420 described with reference to FIG. 14. The transmitter 1240 may utilize a single antenna or a set of antennas.

FIG. 13 shows a block diagram 1300 of a base station communications manager 1305 that supports TA control transmission in DCI for SCG suspension in accordance with aspects of the present disclosure. The base station communications manager 1305 may be an example of aspects of a base station communications manager 1115, a base station communications manager 1215, or a base station communications manager 1410 described herein. The base station communications manager 1305 may include a communication configuration identifier 1310, a SCG suspension indication receiver 1315, an uplink message reception component 1320, a DCI transmission component 1325, a random access message reception component 1330, a preconfigured uplink message reception component 1335, and a DCI resource component 1340. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses) .

The communication configuration identifier 1310 may identify that the base station is operating in a communication configuration with a UE, where the base station includes a primary secondary cell of a secondary cell group with respect to the communication configuration with the UE.

The SCG suspension indication receiver 1315 may receive, from a master node in the communication configuration, a release message indicating a suspension of secondary node communications with the UE, the secondary node communications including the primary secondary cell.

The uplink message reception component 1320 may receive, from the UE, an uplink message after the communications have been suspended with the UE.

The DCI transmission component 1325 may transmit, to the UE, downlink control information based on receiving the uplink message, the downlink control information including a timing advance parameter for the communications with the secondary cell group. In some examples, the DCI transmission component 1325 may scramble the downlink control information with a cell radio network temporary identifier for the UE, a dedicated timing advance radio network temporary identifier, a random access radio network temporary identifier, a radio network temporary identifier corresponding to a control resource set for the UE, a radio network temporary identifier corresponding to a search space for the UE, or a combination thereof.

The random access message reception component 1330 may receive, from the UE, a random access message to reestablish the suspended secondary node communications. In some cases, the random access message is a random access preamble dedicated to the UE. In some cases, the random access message is received at a time resource, frequency resource, beam resource location, or a combination thereof dedicated to the UE.

The preconfigured uplink message reception component 1335 may receive, from the master node, an uplink channel configuration for receiving a preconfigured uplink message from the UE. In some examples, the preconfigured uplink message reception component 1335 may receive, from the UE, the preconfigured uplink message based on the uplink channel configuration. In some examples, the preconfigured uplink message reception component 1335 may receive, from the master node, a configuration for the preconfigured uplink message.

In some cases, the configuration for the preconfigured uplink message includes a periodicity, a frequency location, a number of repetitions, a control resource set configuration, a search space configuration, a frequency hopping configuration, a modulation and coding scheme, a transmission configuration indicator, or a combination thereof for receiving the preconfigured uplink message. In some cases, the uplink channel configuration includes a periodic allocation of time resources, frequency resources, beam resource locations, or a combination thereof.

The DCI resource component 1340 may receive, from the master node, a configuration of a control resource set, a search space, or a combination thereof dedicated to the UE, where the downlink control information is transmitted based on the configuration of the control resource set, the search space, or the combination thereof. In some examples, the DCI resource component 1340 may transmit, to the UE via radio resource control signaling, a configuration of a control resource set, a search space, or a combination thereof dedicated to the UE, where the downlink control information is transmitted based on the configuration of the control resource set, the search space, or the combination thereof.

FIG. 14 shows a diagram of a system 1400 including a device 1405 that supports TA control transmission in DCI for SCG suspension in accordance with aspects of the present disclosure. The device 1405 may be an example of or include the components of device 1105, device 1205, or a base station 105 as described herein. The device 1405 may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including a base station communications manager 1410, a network communications manager 1415, a transceiver 1420, an antenna 1425, memory 1430, a processor 1440, and an inter-station communications manager 1445. These components may be in electronic communication via one or more buses (e.g., bus 1450) .

The base station communications manager 1410 may identify that the base station is operating in a communication configuration with a UE, where the base station includes a primary secondary cell of a secondary cell group with respect to the communication configuration with the UE. In some cases, the base station communications manager 1410 may receive, from a master node in the communication configuration, a release message indicating a suspension of secondary node communications with the UE, the secondary node communications including the primary secondary cell. Additionally, the base station communications manager 1410 may receive, from the UE, an uplink message after the communications have been suspended with the UE. Subsequently, the base station communications manager 1410 may transmit, to the UE, downlink control information based on receiving the uplink message, the downlink control information including a timing advance parameter for the communications with the secondary cell group.

The network communications manager 1415 may manage communications with the core network (e.g., via one or more wired backhaul links) . For example, the network communications manager 1415 may manage the transfer of data communications for client devices, such as one or more UEs 115.

The transceiver 1420 may communicate bi-directionally, via one or more antennas, wired, or wireless links as described above. For example, the transceiver 1420 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 1420 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 1425. However, in some cases the device may have more than one antenna 1425, which may be capable of concurrently transmitting or receiving multiple wireless transmissions.

The memory 1430 may include RAM, ROM, or a combination thereof. The memory 1430 may store computer-readable code 1435 including instructions that, when executed by a processor (e.g., the processor 1440) cause the device to perform various functions described herein. In some cases, the memory 1430 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 1440 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 1440 may be configured to operate a memory array using a memory controller. In some cases, a memory controller may be integrated into processor 1440. The processor 1440 may be configured to execute computer-readable instructions stored in a memory (e.g., the memory 1430) to cause the device 1405 to perform various functions (e.g., functions or tasks supporting TA control transmission in DCI for SCG suspension) .

The inter-station communications manager 1445 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 1445 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 1445 may provide an X2 interface within an LTE/LTE-A wireless communication network technology to provide communication between base stations 105.

The code 1435 may include instructions to implement aspects of the present disclosure, including instructions to support wireless communications. The code 1435 may be stored in a non-transitory computer-readable medium such as system memory or other type of memory. In some cases, the code 1435 may not be directly executable by the processor 1440 but may cause a computer (e.g., when compiled and executed) to perform functions described herein.

FIG. 15 shows a flowchart illustrating a method 1500 that supports TA control transmission in DCI for SCG suspension 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 UE communications manager as described with reference to FIGs. 7 through 10. 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 identify a configuration for communicating with a master cell group and a secondary cell group. 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 communication configuration component as described with reference to FIGs. 7 through 10.

At 1510, the UE may receive, from a master node in the master cell group, a release message indicating a suspension of communications with the secondary cell group. 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 SCG suspension component as described with reference to FIGs. 7 through 10.

At 1515, the UE may transmit an uplink message to a primary secondary cell of the secondary cell group after the communications have been suspended with the secondary cell group. 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 an uplink message transmission component as described with reference to FIGs. 7 through 10.

At 1520, the UE may monitor a bandwidth part for downlink control information from the primary secondary cell of the secondary cell group, the downlink control information including a timing advance parameter for the communications with the secondary cell group. 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 DCI monitoring component as described with reference to FIGs. 7 through 10.

FIG. 16 shows a flowchart illustrating a method 1600 that supports TA control transmission in DCI for SCG suspension in accordance with aspects of the present disclosure. The operations of method 1600 may be implemented by a UE 115 or its components as described herein. For example, the operations of method 1600 may be performed by a UE communications manager as described with reference to FIGs. 7 through 10. 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 1605, the UE may identify a configuration for communicating with a master cell group and a secondary cell group. 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 communication configuration component as described with reference to FIGs. 7 through 10.

At 1610, the UE may receive, from a master node in the master cell group, a release message indicating a suspension of communications with the secondary cell group. 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 SCG suspension component as described with reference to FIGs. 7 through 10.

At 1615, the UE may determine to reestablish the communications with the secondary cell group after the communications have been suspended with the secondary cell group. 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 random access message component as described with reference to FIGs. 7 through 10.

At 1620, the UE may transmit an uplink message to a primary secondary cell of the secondary cell group after the communications have been suspended with the secondary cell group. 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 an uplink message transmission component as described with reference to FIGs. 7 through 10.

At 1625, the UE may transmit, to the primary secondary cell of the secondary cell group, a random access message based on the determination. The operations of 1625 may be performed according to the methods described herein. In some examples, aspects of the operations of 1625 may be performed by a random access message component as described with reference to FIGs. 7 through 10.

At 1630, the UE may monitor a bandwidth part for downlink control information from the primary secondary cell of the secondary cell group, the downlink control information including a timing advance parameter for the communications with the secondary cell group. The operations of 1630 may be performed according to the methods described herein. In some examples, aspects of the operations of 1630 may be performed by a DCI monitoring component as described with reference to FIGs. 7 through 10.

FIG. 17 shows a flowchart illustrating a method 1700 that supports TA control transmission in DCI for SCG suspension in accordance with aspects of the present disclosure. The operations of method 1700 may be implemented by a UE 115 or its components as described herein. For example, the operations of method 1700 may be performed by a UE communications manager as described with reference to FIGs. 7 through 10. 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 1705, the UE may identify a configuration for communicating with a master cell group and a secondary cell group. 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 communication configuration component as described with reference to FIGs. 7 through 10.

At 1710, the UE may receive, from a master node in the master cell group, a release message indicating a suspension of communications with the secondary cell group. 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 SCG suspension component as described with reference to FIGs. 7 through 10.

At 1715, the UE may receive an uplink channel configuration for transmitting a preconfigured uplink message. 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 preconfigured uplink message component as described with reference to FIGs. 7 through 10.

At 1720, the UE may transmit an uplink message to a primary secondary cell of the secondary cell group after the communications have been suspended with the secondary cell group. 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 an uplink message transmission component as described with reference to FIGs. 7 through 10.

At 1725, the UE may transmit, to the primary secondary cell of the secondary cell group, the preconfigured uplink message based on the uplink channel configuration. 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 preconfigured uplink message component as described with reference to FIGs. 7 through 10.

At 1730, the UE may monitor a bandwidth part for downlink control information from the primary secondary cell of the secondary cell group, the downlink control information including a timing advance parameter for the communications with the secondary cell group. 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 DCI monitoring component as described with reference to FIGs. 7 through 10.

FIG. 18 shows a flowchart illustrating a method 1800 that supports TA control transmission in DCI for SCG suspension in accordance with aspects of the present disclosure. The operations of method 1800 may be implemented by a UE 115 or its components as described herein. For example, the operations of method 1800 may be performed by a UE communications manager as described with reference to FIGs. 7 through 10. 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 1805, the UE may identify a configuration for communicating with a master cell group and a secondary cell group. The operations of 1805 may be performed according to the methods described herein. In some examples, aspects of the operations of 1805 may be performed by a communication configuration component as described with reference to FIGs. 7 through 10.

At 1810, the UE may receive, from a master node in the master cell group, a release message indicating a suspension of communications with the secondary cell group. The operations of 1810 may be performed according to the methods described herein. In some examples, aspects of the operations of 1810 may be performed by a SCG suspension component as described with reference to FIGs. 7 through 10.

At 1815, the UE may transmit an uplink message to a primary secondary cell of the secondary cell group after the communications have been suspended with the secondary cell group. The operations of 1815 may be performed according to the methods described herein. In some examples, aspects of the operations of 1815 may be performed by an uplink message transmission component as described with reference to FIGs. 7 through 10.

At 1820, the UE may receive, via radio resource control signaling, a monitoring configuration for the monitoring of the bandwidth part for the downlink control information, where the bandwidth part is monitored for one configured duration based on the monitoring configuration. The operations of 1820 may be performed according to the methods described herein. In some examples, aspects of the operations of 1820 may be performed by a monitoring duration component as described with reference to FIGs. 7 through 10.

At 1825, the UE may monitor a bandwidth part for downlink control information from the primary secondary cell of the secondary cell group, the downlink control information including a timing advance parameter for the communications with the secondary cell group. The operations of 1825 may be performed according to the methods described herein. In some examples, aspects of the operations of 1825 may be performed by a DCI monitoring component as described with reference to FIGs. 7 through 10.

FIG. 19 shows a flowchart illustrating a method 1900 that supports TA control transmission in DCI for SCG suspension in accordance with aspects of the present disclosure. The operations of method 1900 may be implemented by a base station 105 or its components as described herein. For example, the operations of method 1900 may be performed by a base station communications manager as described with reference to FIGs. 11 through 14. 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 1905, the base station may identify that the base station is operating in a communication configuration with a UE, where the base station includes a primary secondary cell of a secondary cell group with respect to the communication configuration with the UE. The operations of 1905 may be performed according to the methods described herein. In some examples, aspects of the operations of 1905 may be performed by a communication configuration identifier as described with reference to FIGs. 11 through 14.

At 1910, the base station may receive, from a master node in the communication configuration, a release message indicating a suspension of secondary node communications with the UE, the secondary node communications including the primary secondary cell. The operations of 1910 may be performed according to the methods described herein. In some examples, aspects of the operations of 1910 may be performed by a SCG suspension indication receiver as described with reference to FIGs. 11 through 14.

At 1915, the base station may receive, from the UE, an uplink message after the communications have been suspended with the UE. The operations of 1915 may be performed according to the methods described herein. In some examples, aspects of the operations of 1915 may be performed by an uplink message reception component as described with reference to FIGs. 11 through 14.

At 1920, the base station may transmit, to the UE, downlink control information based on receiving the uplink message, the downlink control information including a timing advance parameter for the communications with the secondary cell group. The operations of 1920 may be performed according to the methods described herein. In some examples, aspects of the operations of 1920 may be performed by a DCI transmission component as described with reference to FIGs. 11 through 14.

FIG. 20 shows a flowchart illustrating a method 2000 that supports TA control transmission in DCI for SCG suspension in accordance with aspects of the present disclosure. The operations of method 2000 may be implemented by a base station 105 or its components as described herein. For example, the operations of method 2000 may be performed by a base station communications manager as described with reference to FIGs. 11 through 14. 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 2005, the base station may identify that the base station is operating in a communication configuration with a UE, where the base station includes a primary secondary cell of a secondary cell group with respect to the communication configuration with the UE. The operations of 2005 may be performed according to the methods described herein. In some examples, aspects of the operations of 2005 may be performed by a communication configuration identifier as described with reference to FIGs. 11 through 14.

At 2010, the base station may receive, from a master node in the communication configuration, a release message indicating a suspension of secondary node communications with the UE, the secondary node communications including the primary secondary cell. The operations of 2010 may be performed according to the methods described herein. In some examples, aspects of the operations of 2010 may be performed by a SCG suspension indication receiver as described with reference to FIGs. 11 through 14.

At 2015, the base station may receive, from the UE, an uplink message after the communications have been suspended with the UE. The operations of 2015 may be performed according to the methods described herein. In some examples, aspects of the operations of 2015 may be performed by an uplink message reception component as described with reference to FIGs. 11 through 14.

At 2020, the base station may scramble the downlink control information with a cell radio network temporary identifier for the UE, a dedicated timing advance radio network temporary identifier, a random access radio network temporary identifier, a radio network temporary identifier corresponding to a control resource set for the UE, a radio network temporary identifier corresponding to a search space for the UE, or a combination thereof. The operations of 2020 may be performed according to the methods described herein. In some examples, aspects of the operations of 2020 may be performed by a DCI transmission component as described with reference to FIGs. 11 through 14.

At 2025, the base station may transmit, to the UE, downlink control information based on receiving the uplink message, the downlink control information including a timing advance parameter for the communications with the secondary cell group. The operations of 2025 may be performed according to the methods described herein. In some examples, aspects of the operations of 2025 may be performed by a DCI transmission component as described with reference to FIGs. 11 through 14.

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.

SUMMARY OF ASPECTS

The following provides an overview of aspects of the present disclosure:

Aspect 1: A method for wireless communications at a UE, comprising: identifying a configuration for communicating with a master cell group and a secondary cell group; receiving, from a master node in the master cell group, a release message indicating a suspension of communications with the secondary cell group; transmitting an uplink message to a primary secondary cell of the secondary cell group after the communications have been suspended with the secondary cell group; and monitoring a bandwidth part for downlink control information from the primary secondary cell of the secondary cell group, the downlink control information comprising a timing advance parameter for the communications with the secondary cell group.

Aspect 2: The method of aspect 1, wherein transmitting the uplink message to the primary secondary cell of the secondary cell group comprises: determining to reestablish the communications with the secondary cell group after the communications have been suspended with the secondary cell group; and transmitting, to the primary secondary cell of the secondary cell group, a random access message based at least in part on the determination.

Aspect 3: The method of aspect 2, wherein the random access message is a random access preamble dedicated to the UE.

Aspect 4: The method of any of aspects 2 through 3, wherein the random access message is transmitted at a time resource, frequency resource, beam resource location, or a combination thereof dedicated to the UE.

Aspect 5: The method of any of aspects 1 through 4, wherein transmitting the uplink message to the primary secondary cell of the secondary cell group comprises: receiving an uplink channel configuration for transmitting a preconfigured uplink message; and transmitting, to the primary secondary cell of the secondary cell group, the preconfigured uplink message based at least in part on the uplink channel configuration.

Aspect 6: The method of aspect 5, further comprising: receiving, via radio resource control signaling, a configuration for the preconfigured uplink message.

Aspect 7: The method of aspect 6, wherein the configuration for the preconfigured uplink message comprises a periodicity, a frequency location, a number of repetitions, a control resource set configuration, a search space configuration, a frequency hopping configuration, a modulation and coding scheme, a transmission configuration indicator, or a combination thereof for transmitting the preconfigured uplink message.

Aspect 8: The method of any of aspects 5 through 7, wherein the uplink channel configuration comprises a periodic allocation of time resources, frequency resources, beam resource locations, or a combination thereof.

Aspect 9: The method of any of aspects 1 through 8, further comprising: receiving, via radio resource control signaling, a monitoring configuration for the monitoring of the bandwidth part for the downlink control information, wherein the bandwidth part is monitored for one configured duration based at least in part on the monitoring configuration.

Aspect 10: The method of aspect 9, further comprising: determining the one configured duration expires prior to receiving the downlink control information; and transmitting, to the primary secondary cell of the secondary cell group, the uplink message an additional time based at least in part on the one configured duration expiring.

Aspect 11: The method of any of aspects 1 through 10, further comprising: receiving, via radio resource control signaling, a configuration of a control resource set, a search space, or a combination thereof dedicated to the UE, wherein the bandwidth part is monitored based at least in part on the configuration of the control resource set, the search space, or the combination thereof.

Aspect 12: The method of any of aspects 1 through 11, wherein the downlink control information is scrambled with a cell radio network temporary identifier for the UE, a dedicated timing advance radio network temporary identifier, a random access radio network temporary identifier, a radio network temporary identifier corresponding to a control resource set for the UE, a radio network temporary identifier corresponding to a search space for the UE, or a combination thereof.

Aspect 13: A method for wireless communications at a base station, comprising: identifying that the base station is operating in a communication configuration with a UE, wherein the base station comprises a primary secondary cell of a secondary cell group with respect to the communication configuration with the UE; receiving, from a master node in the communication configuration, a release message indicating a suspension of secondary node communications with the UE, the secondary node communications comprising the primary secondary cell; receiving, from the UE, an uplink message after the communications have been suspended with the UE; and transmitting, to the UE, downlink control information based at least in part on receiving the uplink message, the downlink control information comprising a timing advance parameter for the communications with the secondary cell group.

Aspect 14: The method of aspect 13, wherein receiving the uplink message comprises: receiving, from the UE, a random access message to reestablish the suspended secondary node communications.

Aspect 15: The method of aspect 14, wherein the random access message is a random access preamble dedicated to the UE.

Aspect 16: The method of any of aspects 14 through 15, wherein the random access message is received at a time resource, frequency resource, beam resource location, or a combination thereof dedicated to the UE.

Aspect 17: The method of any of aspects 13 through 16, wherein receiving the uplink message comprises: receiving, from the master node, an uplink channel configuration for receiving a preconfigured uplink message from the UE; and receiving, from the UE, the preconfigured uplink message based at least in part on the uplink channel configuration.

Aspect 18: The method of aspect 17, further comprising: receiving, from the master node, a configuration for the preconfigured uplink message.

Aspect 19: The method of aspect 18, wherein the configuration for the preconfigured uplink message comprises a periodicity, a frequency location, a number of repetitions, a control resource set configuration, a search space configuration, a frequency hopping configuration, a modulation and coding scheme, a transmission configuration indicator, or a combination thereof for receiving the preconfigured uplink message.

Aspect 20: The method of any of aspects 17 through 19, wherein the uplink channel configuration comprises a periodic allocation of time resources, frequency resources, beam resource locations, or a combination thereof.

Aspect 21: The method of any of aspects 13 through 20, further comprising: receiving, from the master node, a configuration of a control resource set, a search space, or a combination thereof dedicated to the UE, wherein the downlink control information is transmitted based at least in part on the configuration of the control resource set, the search space, or the combination thereof.

Aspect 22: The method of any of aspects 13 through 21, further comprising: transmitting, to the UE via radio resource control signaling, a configuration of a control resource set, a search space, or a combination thereof dedicated to the UE, wherein the downlink control information is transmitted based at least in part on the configuration of the control resource set, the search space, or the combination thereof.

Aspect 23: The method of any of aspects 13 through 22, further comprising: scrambling the downlink control information with a cell radio network temporary identifier for the UE, a dedicated timing advance radio network temporary identifier, a random access radio network temporary identifier, a radio network temporary identifier corresponding to a control resource set for the UE, a radio network temporary identifier corresponding to a search space for the UE, or a combination thereof.

Aspect 24: An apparatus for wireless communications at a 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 perform a method of any of aspects 1 through 12.

Aspect 25: An apparatus for wireless communications at a UE, comprising at least one means for performing a method of any of aspects 1 through 12.

Aspect 26: A non-transitory computer-readable medium storing code for wireless communications at a UE, the code comprising instructions executable by a processor to perform a method of any of aspects 1 through 12.

Aspect 27: An apparatus for wireless communications 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 perform a method of any of aspects 13 through 23.

Aspect 28: An apparatus for wireless communications at a base station, comprising at least one means for performing a method of any of aspects 13 through 23.

Aspect 29: A non-transitory computer-readable medium storing code for wireless communications at a base station, the code comprising instructions executable by a processor to perform a method of any of aspects 13 through 23.

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 RAM, 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 communications at a user equipment (UE) , comprising:

identifying a configuration for communicating with a master cell group and a secondary cell group;

receiving, from a master node in the master cell group, a release message indicating a suspension of communications with the secondary cell group;

transmitting an uplink message to a primary secondary cell of the secondary cell group after the communications have been suspended with the secondary cell group; and

monitoring a bandwidth part for downlink control information from the primary secondary cell of the secondary cell group, the downlink control information comprising a timing advance parameter for the communications with the secondary cell group.
The method of claim 1, wherein transmitting the uplink message to the primary secondary cell of the secondary cell group comprises:

determining to reestablish the communications with the secondary cell group after the communications have been suspended with the secondary cell group; and

transmitting, to the primary secondary cell of the secondary cell group, a random access message based at least in part on the determination.
The method of claim 2, wherein the random access message is a random access preamble dedicated to the UE.
The method of claim 2, wherein the random access message is transmitted at a time resource, frequency resource, beam resource location, or a combination thereof dedicated to the UE.
The method of claim 1, wherein transmitting the uplink message to the primary secondary cell of the secondary cell group comprises:

receiving an uplink channel configuration for transmitting a preconfigured uplink message; and

transmitting, to the primary secondary cell of the secondary cell group, the preconfigured uplink message based at least in part on the uplink channel configuration.
The method of claim 5, further comprising:

receiving, via radio resource control signaling, a configuration for the preconfigured uplink message.
The method of claim 6, wherein the configuration for the preconfigured uplink message comprises a periodicity, a frequency location, a number of repetitions, a control resource set configuration, a search space configuration, a frequency hopping configuration, a modulation and coding scheme, a transmission configuration indicator, or a combination thereof for transmitting the preconfigured uplink message.
The method of claim 5, wherein the uplink channel configuration comprises a periodic allocation of time resources, frequency resources, beam resource locations, or a combination thereof.
The method of claim 1, further comprising:

receiving, via radio resource control signaling, a monitoring configuration for the monitoring of the bandwidth part for the downlink control information, wherein the bandwidth part is monitored for one configured duration based at least in part on the monitoring configuration.
The method of claim 9, further comprising:

determining the one configured duration expires prior to receiving the downlink control information; and

transmitting, to the primary secondary cell of the secondary cell group, the uplink message an additional time based at least in part on the one configured duration expiring.
The method of claim 1, further comprising:

receiving, via radio resource control signaling, a configuration of a control resource set, a search space, or a combination thereof dedicated to the UE, wherein the bandwidth part is monitored based at least in part on the configuration of the control resource set, the search space, or the combination thereof.
The method of claim 1, wherein the downlink control information is scrambled with a cell radio network temporary identifier for the UE, a dedicated timing advance radio network temporary identifier, a random access radio network temporary identifier, a radio network temporary identifier corresponding to a control resource set for the UE, a radio network temporary identifier corresponding to a search space for the UE, or a combination thereof.
An apparatus for wireless communications 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:

identify a configuration for communicating with a master cell group and a secondary cell group;

receive, from a master node in the master cell group, a release message indicating a suspension of communications with the secondary cell group;

transmit an uplink message to a primary secondary cell of the secondary cell group after the communications have been suspended with the secondary cell group; and

monitor a bandwidth part for downlink control information from the primary secondary cell of the secondary cell group, the downlink control information comprising a timing advance parameter for the communications with the secondary cell group.
The apparatus of claim 13, wherein the instructions to transmit the uplink message to the primary secondary cell of the secondary cell group are executable by the processor to cause the apparatus to:

determine to reestablish the communications with the secondary cell group after the communications have been suspended with the secondary cell group; and

transmit, to the primary secondary cell of the secondary cell group, a random access message based at least in part on the determination.
The apparatus of claim 14, wherein the random access message is a random access preamble dedicated to the UE.
The apparatus of claim 14, wherein the random access message is transmitted at a time resource, frequency resource, beam resource location, or a combination thereof dedicated to the UE.
The apparatus of claim 13, wherein the instructions to transmit the uplink message to the primary secondary cell of the secondary cell group are executable by the processor to cause the apparatus to:

receive an uplink channel configuration for transmitting a preconfigured uplink message; and

transmit, to the primary secondary cell of the secondary cell group, the preconfigured uplink message based at least in part on the uplink channel configuration.
The apparatus of claim 17, wherein the instructions are further executable by the processor to cause the apparatus to:

receive, via radio resource control signaling, a configuration for the preconfigured uplink message.
The apparatus of claim 18, wherein the configuration for the preconfigured uplink message comprises a periodicity, a frequency location, a number of repetitions, a control resource set configuration, a search space configuration, a frequency hopping configuration, a modulation and coding scheme, a transmission configuration indicator, or a combination thereof for transmitting the preconfigured uplink message.
The apparatus of claim 17, wherein the uplink channel configuration comprises a periodic allocation of time resources, frequency resources, beam resource locations, or a combination thereof.
The apparatus of claim 13, wherein the instructions are further executable by the processor to cause the apparatus to:

receive, via radio resource control signaling, a monitoring configuration for the monitoring of the bandwidth part for the downlink control information, wherein the bandwidth part is monitored for one configured duration based at least in part on the monitoring configuration.
The apparatus of claim 21, wherein the instructions are further executable by the processor to cause the apparatus to:

determine the one configured duration expires prior to receiving the downlink control information; and

transmit, to the primary secondary cell of the secondary cell group, the uplink message an additional time based at least in part on the one configured duration expiring.
The apparatus of claim 13, wherein the instructions are further executable by the processor to cause the apparatus to:

receive, via radio resource control signaling, a configuration of a control resource set, a search space, or a combination thereof dedicated to the UE, wherein the bandwidth part is monitored based at least in part on the configuration of the control resource set, the search space, or the combination thereof.
The apparatus of claim 13, wherein the downlink control information is scrambled with a cell radio network temporary identifier for the UE, a dedicated timing advance radio network temporary identifier, a random access radio network temporary identifier, a radio network temporary identifier corresponding to a control resource set for the UE, a radio network temporary identifier corresponding to a search space for the UE, or a combination thereof.
An apparatus for wireless communications at a user equipment (UE) , comprising:

means for identifying a configuration for communicating with a master cell group and a secondary cell group;

means for receiving, from a master node in the master cell group, a release message indicating a suspension of communications with the secondary cell group;

means for transmitting an uplink message to a primary secondary cell of the secondary cell group after the communications have been suspended with the secondary cell group; and

means for monitoring a bandwidth part for downlink control information from the primary secondary cell of the secondary cell group, the downlink control information comprising a timing advance parameter for the communications with the secondary cell group.
The apparatus of claim 25, wherein the means for transmitting the uplink message to the primary secondary cell of the secondary cell group comprises:

means for determining to reestablish the communications with the secondary cell group after the communications have been suspended with the secondary cell group; and

means for transmitting, to the primary secondary cell of the secondary cell group, a random access message based at least in part on the determination.
The apparatus of claim 26, wherein the random access message is a random access preamble dedicated to the UE.
The apparatus of claim 26, wherein the random access message is transmitted at a time resource, frequency resource, beam resource location, or a combination thereof dedicated to the UE.
The apparatus of claim 25, wherein the means for transmitting the uplink message to the primary secondary cell of the secondary cell group comprises:

means for receiving an uplink channel configuration for transmitting a preconfigured uplink message; and

means for transmitting, to the primary secondary cell of the secondary cell group, the preconfigured uplink message based at least in part on the uplink channel configuration.
A non-transitory computer-readable medium storing code for wireless communications at a user equipment (UE) , the code comprising instructions executable by a processor to:

identify a configuration for communicating with a master cell group and a secondary cell group;

receive, from a master node in the master cell group, a release message indicating a suspension of communications with the secondary cell group;

transmit an uplink message to a primary secondary cell of the secondary cell group after the communications have been suspended with the secondary cell group; and

monitor a bandwidth part for downlink control information from the primary secondary cell of the secondary cell group, the downlink control information comprising a timing advance parameter for the communications with the secondary cell group.