WO2022006848A1

WO2022006848A1 - Techniques for transmitting uplink data after an uplink path switch

Info

Publication number: WO2022006848A1
Application number: PCT/CN2020/101315
Authority: WO
Inventors: Alvin Siu-Chung NG; Chun Chung Patrick CHAN; Yike LIU; Tak Wai Wu; Wai Bin Ken WAT; Long Duan; Kausik Ray Chaudhuri; Neelakanta Venkata Seshachalam Chimmapudi; Ming Yang
Original assignee: Qualcomm Incorporated
Priority date: 2020-07-10
Filing date: 2020-07-10
Publication date: 2022-01-13

Abstract

Methods, systems, and devices for wireless communications are described. In some systems, a user equipment (UE) may have a dual-connectivity functionality and may establish a first connection with a first cell and a second connection with a second cell. In some examples, the UE may determine to switch from communicating with the first cell to communicating with the second cell while the UE has uplink data queued for transmission to the first cell and may determine to transmit the uplink data to the second cell for tunneling to the first cell based on a tunneling configuration. The UE may transit the uplink data to the second cell along with a tunneling indicator that indicates that the uplink data is to be tunneled to the first cell. Accordingly, the second cell my tunnel the uplink data from an entity of the second cell to an entity of the first cell.

Description

TECHNIQUES FOR TRANSMITTING UPLINK DATA AFTER AN UPLINK PATH SWITCH

FIELD OF TECHNOLOGY

The following relates generally to wireless communications and more specifically to techniques for transmitting uplink data after an uplink path switch.

BACKGROUND

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

A UE may support a dual-connectivity functionality and communicate with two serving cells. In some cases, the UE may transmit uplink control data responsive to a downlink transmission from one of the serving cells over the same communication link that the UE used to receive the downlink transmission.

SUMMARY

The described techniques relate to improved methods, systems, devices, and apparatuses that support techniques for transmitting uplink data after an uplink path switch. Generally, the described techniques provide for efficiently communicating uplink data corresponding to a first connection between a first cell and a UE via a second connection with a second cell. In some implementations, the UE may determine that the second cell may tunnel data to the first cell and, as such, may determine that the second cell may tunnel the uplink data of the first connection to the first cell. One of the first cell or the second cell may transmit a tunneling configuration that the UE may use to determine a condition for tunneling the uplink data of the first connection to the first cell via the second connection with the second cell. The condition may be based on a reception of a path switch command from the first cell or based on the determination that a channel quality associated with the first connection with the first cell satisfies a threshold (e.g., is less than a threshold channel quality) . In examples in which the UE determines that the condition indicated by the tunneling configuration is satisfied, the UE may transmit uplink data via the second connection for tunneling of the uplink data to the first cell via a logical channel or via one or more core network entities, or both. For example, the UE may transmit the uplink data of the first connection within a protocol of the second connection. In some examples, the UE may transmit a tunneling indicator along with the uplink data to indicate to the second cell that the uplink data is for the first cell or to indicate a logical channel that the second cell may use for tunneling the uplink data from the second cell to the first cell, or both.

In some implementations of the techniques described herein, the UE may manage uplink data traffic to the first cell and to the second cell based on determining whether the condition is satisfied. For example, the UE may identify a first category of uplink data of the first connection and a second category of uplink data not of the first connection (e.g., uplink data that may be transmitted to either the first cell or the second cell) and may determine which cell to transmit the two categories of uplink data to based on whether the condition is satisfied. For instance, in examples in which the condition is satisfied (e.g., in examples in which the UE has switched from communicating with the first cell to communicating with the second cell) , the UE may determine to transmit the first category of the uplink data of the first connection to the first cell and to transmit the second category of the uplink data not of the first connection to the second cell. Alternatively or additionally, in examples in which the condition is not satisfied (e.g., in examples in which the UE has not switched from communicating with the first cell to communicating with the second cell) , the UE may determine to transmit both the first category of the uplink data of the first connection and the second category of the uplink data not of the first connection to the first cell over the first connection.

A method of wireless communications at a dual-connectivity UE is described. The method may include establishing a first connection with a first cell and a second connection with a second cell that differs from the first cell, receiving a tunneling configuration that indicates a condition for tunneling uplink data of the first connection to the first cell via the second connection, and transmitting, via the second connection, an uplink transmission including the uplink data of the first connection and a tunneling indicator that indicates that the uplink transmission includes the uplink data of the first connection based on the condition being satisfied.

An apparatus for wireless communications at a dual-connectivity UE is described. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to establish a first connection with a first cell and a second connection with a second cell that differs from the first cell, receive a tunneling configuration that indicates a condition for tunneling uplink data of the first connection to the first cell via the second connection, and transmit, via the second connection, an uplink transmission including the uplink data of the first connection and a tunneling indicator that indicates that the uplink transmission includes the uplink data of the first connection based on the condition being satisfied.

Another apparatus for wireless communications at a dual-connectivity UE is described. The apparatus may include means for establishing a first connection with a first cell and a second connection with a second cell that differs from the first cell, receiving a tunneling configuration that indicates a condition for tunneling uplink data of the first connection to the first cell via the second connection, and transmitting, via the second connection, an uplink transmission including the uplink data of the first connection and a tunneling indicator that indicates that the uplink transmission includes the uplink data of the first connection based on the condition being satisfied.

A non-transitory computer-readable medium storing code for wireless communications at a dual-connectivity UE is described. The code may include instructions executable by a processor to establish a first connection with a first cell and a second connection with a second cell that differs from the first cell, receive a tunneling configuration that indicates a condition for tunneling uplink data of the first connection to the first cell via the second connection, and transmit, via the second connection, an uplink transmission including the uplink data of the first connection and a tunneling indicator that indicates that the uplink transmission includes the uplink data of the first connection based on the condition being satisfied.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the uplink transmission may include operations, features, means, or instructions for transmitting, via the second connection, the uplink transmission that includes a packet that encapsulates the uplink data of the first connection within a protocol of the second connection.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the uplink transmission may include operations, features, means, or instructions for transmitting, via the second connection, the tunneling indicator that may be a bit set to indicate that the uplink transmission includes the uplink data of the first connection.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the uplink transmission may include operations, features, means, or instructions for transmitting, via the second connection, the tunneling indicator that may be logical channel identifier that indicates a logical channel for tunneling the uplink data from a second entity the second cell to a first entity of the first cell.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the first entity of the first cell includes a radio link control (RLC) entity of the first cell and the second entity of the second cell includes an RLC entity of the second cell.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the first entity of the first cell includes a packet data convergence protocol (PDCP) entity of the first cell and the second entity of the second cell includes an RLC entity of the second cell.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the tunneling configuration further may include operations, features, means, or instructions for receiving the tunneling configuration that indicates that the condition may be reception of a path switch command indicating to switch from communicating with the first cell via the first connection to communicating with the second cell via the second connection when the uplink data may be available for transmission to the first cell.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the tunneling configuration further may include operations, features, means, or instructions for receiving the tunneling configuration that indicates that the condition may be a channel quality associated with the first connection satisfying a threshold channel quality.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the dual-connectivity UE communicates with the first cell using a first radio access technology (RAT) and communicates with the second cell using a second RAT that differs from the first RAT.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the dual-connectivity UE communicates with the first cell using a first RAT via a first frequency band and communicates with the second cell using the first RAT via a second frequency band that differs from the first frequency band.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the first cell may include operations, features, means, or instructions for transmitting, via the second connection with the LTE cell, the uplink transmission including the uplink data of the first connection with the NR cell.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the uplink data of the first connection includes an NR uplink RLC control protocol data unit (PDU) .

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the first cell may include operations, features, means, or instructions for transmitting, via the second connection with the NR cell, the uplink transmission including the uplink data of the first connection with the LTE cell.

A method of wireless communications at a first cell is described. The method may include establishing a first connection with a dual-connectivity UE, transmitting, to the dual- connectivity UE, a tunneling configuration that indicates a condition for tunneling uplink data of a second connection to a second cell via the first connection, and receiving, via the first connection, an uplink transmission including the uplink data of the second connection and a tunneling indicator that indicates that the uplink transmission includes the uplink data of the second connection.

An apparatus for wireless communications at a first cell is described. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to establish a first connection with a dual-connectivity UE, transmit, to the dual-connectivity UE, a tunneling configuration that indicates a condition for tunneling uplink data of a second connection to a second cell via the first connection, and receive, via the first connection, an uplink transmission including the uplink data of the second connection and a tunneling indicator that indicates that the uplink transmission includes the uplink data of the second connection.

Another apparatus for wireless communications at a first cell is described. The apparatus may include means for establishing a first connection with a dual-connectivity UE, transmitting, to the dual-connectivity UE, a tunneling configuration that indicates a condition for tunneling uplink data of a second connection to a second cell via the first connection, and receiving, via the first connection, an uplink transmission including the uplink data of the second connection and a tunneling indicator that indicates that the uplink transmission includes the uplink data of the second connection.

A non-transitory computer-readable medium storing code for wireless communications at a first cell is described. The code may include instructions executable by a processor to establish a first connection with a dual-connectivity UE, transmit, to the dual-connectivity UE, a tunneling configuration that indicates a condition for tunneling uplink data of a second connection to a second cell via the first connection, and receive, via the first connection, an uplink transmission including the uplink data of the second connection and a tunneling indicator that indicates that the uplink transmission includes the uplink data of the second connection.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the uplink transmission may include operations, features, means, or instructions for receiving, via the first connection, the uplink transmission that includes a packet that encapsulates the uplink data of the second connection within a protocol of the first connection.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the uplink transmission may include operations, features, means, or instructions for receiving, via the first connection, the tunneling indicator that may be a bit set to indicate that the uplink transmission includes the uplink data of the second connection.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the uplink transmission may include operations, features, means, or instructions for receiving, via the first connection, the tunneling indicator that may be a logical channel identifier that indicates a logical channel for tunneling the uplink data from a first entity of the first cell to a second entity of the second cell.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for tunneling the uplink data from a first entity of the first cell to a second entity of the second cell based on the tunneling indicator.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the first entity of the first cell includes a RLC entity of the first cell and the second entity of the second cell includes an RLC entity of the second cell.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, tunneling the uplink data from the first entity of the first cell to the second entity of the second cell may include operations, features, means, or instructions for tunneling the uplink data from the first entity of the first cell to the second entity of the second cell through a third entity of the second cell.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, tunneling the uplink data from the first entity of the first cell to the second entity of the second cell through the third entity of the second cell may include operations, features, means, or instructions for tunneling the uplink data from the first entity of the first cell to the third entity of the second cell via one or more core network entities.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the first entity of the first cell includes a PDCP entity of the first cell, the second entity of the second cell includes a RLC entity of the second cell, and the third entity of the second cell includes a PDCP entity of the second cell.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the tunneling configuration further may include operations, features, means, or instructions for transmitting the tunneling configuration that indicates that the condition may be transmission of a path switch command indicating the dual-connectivity UE to switch from communicating with the second cell via the second connection to communicating with the first cell via the first connection when the uplink data may be available for transmission to the first cell.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting a path switch command indicating the dual-connectivity UE to switch from communicating with the second cell via the second connection to communicating with the first cell via the first connection.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the tunneling configuration further may include operations, features, means, or instructions for transmitting the tunneling configuration that indicates that the condition may be a channel quality associated with the second connection satisfying a threshold channel quality.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the first cell communicates with the dual-connectivity UE using a first RAT different than a second RAT associated with the second connection between the dual-connectivity UE and the second cell.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the first cell communicates with the dual-connectivity UE using a first RAT via a first frequency band different than a second frequency band used by the first RAT associated with the second connection between the dual-connectivity UE and the second cell.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the first cell may include operations, features, means, or instructions for receiving, at the LTE cell via the first connection, the uplink transmission including the uplink data of the second connection with the NR cell.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the uplink data of the second connection includes an NR uplink RLC control PDU.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the first cell may include operations, features, means, or instructions for receiving, at the NR cell via the first connection, the uplink transmission including the uplink data of the second connection with the NR cell.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGs. 1 and 2 illustrate examples of wireless communications systems that support techniques for transmitting uplink data after an uplink path switch in accordance with aspects of the present disclosure.

FIGs. 3 and 4 illustrate examples of protocol stack communication architectures that support techniques for transmitting uplink data after an uplink path switch in accordance with aspects of the present disclosure.

FIG. 5 illustrates an example of a process flow that supports techniques for transmitting uplink data after an uplink path switch in accordance with aspects of the present disclosure.

FIGs. 6 and 7 show diagrams of devices that support techniques for transmitting uplink data after an uplink path switch in accordance with aspects of the present disclosure.

FIG. 8 shows a diagram of a communications manager that supports techniques for transmitting uplink data after an uplink path switch in accordance with aspects of the present disclosure.

FIG. 9 shows a diagram of a system including a device that supports techniques for transmitting uplink data after an uplink path switch in accordance with aspects of the present disclosure.

FIGs. 10 and 11 show diagrams of devices that support techniques for transmitting uplink data after an uplink path switch in accordance with aspects of the present disclosure.

FIG. 12 shows a diagram of a communications manager that supports techniques for transmitting uplink data after an uplink path switch in accordance with aspects of the present disclosure.

FIG. 13 shows a diagram of a system including a device that supports techniques for transmitting uplink data after an uplink path switch in accordance with aspects of the present disclosure.

FIGs. 14 through 17 show flowcharts illustrating methods that support techniques for transmitting uplink data after an uplink path switch in accordance with aspects of the present disclosure.

DETAILED DESCRIPTION

In some wireless communications systems, a UE may support dual-connectivity functionality and may establish wireless connections with two cells or base stations. In such systems, the UE may establish a connection with each cell (e.g., a first connection with a first cell and a second connection with a second cell) and may determine a priority status of the two cells. For example, the UE may determine that the first cell is a secondary cell and that the second cell is a primary cell. In some cases, the UE may have uplink data queued for transmission to the secondary cell. To transmit the uplink data to the secondary cell, the UE may transmit one or more scheduling requests to the secondary cell requesting an uplink resource grant that the UE may use to transmit the uplink data to the secondary cell. In some cases, however, the connection (e.g., the channel quality of the connection) between the secondary cell and the UE may deteriorate and the second cell may fail to successfully receive the scheduling request.

The secondary cell, based on the poor connection between the secondary cell and the UE, may transmit a path switch command to the UE to request the UE to switch from communicating with the secondary cell to communicating with the primary cell. In cases in which the uplink data queued for transmission to the secondary cell is of the first connection between the secondary cell and the UE (e.g., in cases in which the uplink data is specific to the first connection, such as in cases in which the uplink data is feedback information for the secondary cell) , the UE may continue to transmit scheduling requests to the secondary cell even after receiving the path switch command, which may result in increased latency of communications from the UE and, in some cases, a random access procedure and the potential for radio link failure if a threshold number of scheduling requests are transmitted by the UE.

In some implementations of the present disclosure, the UE may determine whether to continue transmitting scheduling requests to the secondary cell after receiving a path switch command (or after otherwise determining to switch from communicating with the secondary cell to communicating with the primary cell) based on a category of the uplink data queued for transmission to the secondary cell. For example, if the uplink data queued for transmission to the secondary cell is specific to the first connection between the secondary cell and the UE (e.g., if the uplink data is feedback information responsive to a downlink transmission from the secondary cell to the UE) , the UE may determine that such uplink data belongs to a first category and to continue transmitting scheduling requests for an uplink grant for transmitting such uplink data. If some or all of the uplink data is not specific to the first connection between the secondary cell and the UE, the UE may determine that such uplink data belongs to a second category and to refrain from transmitting scheduling requests to the secondary cell for an uplink grant for transmitting such uplink data to the secondary cell and may instead attempt to transmit such uplink data to the primary cell. Accordingly, the UE may continue transmitting scheduling requests to the secondary cell for uplink data that belongs to the first category and may dequeue uplink data queued for transmission to the secondary cell and re-queue such uplink data for transmission to the primary cell if the uplink data belongs to the second category.

In some other implementations of the present disclosure, the UE may receive a tunneling configuration from one or both of the primary cell and the secondary cell for tunneling uplink data of the first connection with the secondary cell (e.g., uplink data that is specific to the first connection with the secondary cell) to the secondary cell via the second connection with the primary cell. For example, the tunneling configuration may indicate a condition for determining to tunnel the uplink data of the first connection to the secondary cell via the primary cell. In examples in which the condition is satisfied, the UE may transmit the uplink data of the first connection to the primary cell over the second connection and may additionally transmit a tunneling indicator to the primary cell indicating that the uplink data is to be tunneled from the primary cell to the secondary cell. Likewise, based on receiving the uplink data and the tunneling indicator, the primary cell may determine to tunnel the uplink data to the secondary cell via a logical channel or via one or more core network entities, or both.

Particular aspects of the subject matter described herein may be implemented to realize one or more potential advantages. The described techniques may be implemented by a dual-connectivity UE and one or more serving cells to reduce latency, increase the likelihood for successful communications between the UE and the one or more serving cells, achieve greater spectral efficiency, and to improve the power savings at the UE. For example, based on either managing uplink traffic between a primary cell and a secondary cell based on whether uplink data is specific to one of the primary cell or the secondary cell or based on determining to tunnel uplink data to one cell via the other cell in examples in which the UE has received a path switch command or has otherwise determined to switch cells, the UE may reduce latency of the uplink data to the primary cell or the secondary cell, or both, by potentially avoiding transmitting a number of scheduling requests, and thus potentially avoiding performing a random access procedure or a radio link failure event.

Further, in examples in which the uplink data is tunneled to the secondary cell via the primary cell, the UE may potentially avoid attempts to transmit the uplink data to the secondary cell over a connection associated with a poor channel quality and, as such, tunneling the uplink data to the secondary cell via the primary cell may result in a greater likelihood for successful reception of the uplink data at the secondary cell. Based on potentially transmitting fewer scheduling requests, avoiding random access procedures or radio link failure, and increasing the likelihood for successful communications, the system including the UE and the primary and secondary cells may experience greater spectral efficiency as the UE and the serving cells may exchange less control signaling. Moreover, the UE may experience improved power savings based on potentially transmitting fewer scheduling requests and avoiding performing unnecessary random access procedures.

Aspects of the disclosure are initially described in the context of wireless communications systems. Aspects of the disclosure are additionally described in the context of protocol stack communication architectures and a process flow. Aspects of the disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flowcharts that relate to techniques for transmitting uplink data after an uplink path switch.

FIG. 1 illustrates an example of a wireless communications system 100 that supports techniques for transmitting uplink data after an uplink path switch 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 an 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 another network equipment) , as shown in FIG. 1.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

The wireless communications system 100 may operate using one or more frequency bands, sometimes in the range of 300 megahertz (MHz) to 300 gigahertz (GHz) . Generally, the region from 300 MHz to 3 GHz is known as the ultra-high frequency (UHF) region or decimeter band because the wavelengths range from approximately one decimeter to one meter in length. The UHF waves may be blocked or redirected by buildings and environmental features, but the waves may penetrate structures sufficiently for a macro cell to provide service to the UEs 115 located indoors. The transmission of UHF waves may be associated with smaller antennas and shorter ranges (e.g., less than 100 kilometers) compared to transmission using the smaller frequencies and longer waves of the high frequency (HF) or very high frequency (VHF) portion of the spectrum below 300 MHz.

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

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

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

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

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

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

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

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

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

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

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

In some cases, a UE 115 may have dual-connectivity functionality and may establish communication links or wireless connections with multiple base stations 105. In some cases, the multiple base stations 105 may use a common RAT. For instance, the multiple base stations 105 that the UE 115 may communicate with may all use LTE technology, may all use NR technology, or may all use some other RAT. In such cases, the different base stations 105 may communicate with the UE 115 using different frequency bands or may be associated with different qualities of service based on the relative location of the UE 115. In some other cases, the multiple base stations 105 that the UE 115 may communicate with may use different RATs. For instance, the UE 115 may communicate with a first base station 105 using NR technology and may communicate with a second base station 105 using LTE technology. In such cases, the UE 115 may feature an E-UTRA New Radio –dual connectivity (EN-DC) connection between an NR cell and an LTE cell. Such a UE 115 may operate in a non-standalone mode using various option configurations, including an option 3 (e.g., 3/3a/3x) configuration, an option 4 configuration, or an option 7 configuration.

In some examples, the UE 115 may establish a first connection with a first base station 105 (e.g., an NR base station 105) and a second connection with the second base station 105 (e.g., an LTE base station 105) and may identify an uplink path to one of the first base station 105 or the second base station 105 based on which connection is active. In some cases, the UE 115 may determine that the first connection to the first base station 105 is active and, accordingly, that the uplink path from the UE 115 is to the first base station 105 over the first connection. In some implementations of the present disclosure, the UE 115 may determine to switch the uplink path from the first connection with the first base station 105 to the second connection with the second base station 105 while there is still uplink data queued for transmission to the first base station 105 and may manage the uplink data based on the path switch and a category of the uplink data.

For example, the UE 115 may partition the uplink data into a first category and a second category, where the first category includes uplink data of the first connection (e.g., uplink data that is specific to the first connection with the first base station 105) and the second category includes uplink data not of the first connection (e.g., uplink data that is not specific to the first connection with the first base station 105) . In some implementations, the UE 115 may maintain the uplink data included in the first category in the queue for transmission to the first base station 105 over the first connection and may dequeue the uplink data included in the second category from the queue for transmission to the first base station 105 and re-queue such uplink data in a queue for transmission to the second base station 105 over the second connection.

In some other implementations, the UE 115 may receive a configuration for tunneling uplink data between the first base station 105 and the second base station 105. The configuration may indicate a condition that, when satisfied, may provide an indication to the UE 115 that uplink data may be tunneled between the first base station 105 and the second base station 105. In examples in which the UE 115 determines that the condition is satisfied, the UE 115 may queue the uplink data included in the first category for transmission to the second base station 105 over the second connection and may indicate that the uplink data included in the first category is to be tunneled from the second base station 105 to the first base station 105 via a tunneling indicator. In such examples, the UE 115 may refrain from attempting to transmit the uplink data of the first connection directly to the first base station 105 and instead transmit the uplink data of the first connection to the second cell over the second connection. As such, the UE 115 may avoid the latency associated with attempting to obtain an uplink grant from the first base station 105 for transmitting the uplink data included in the first category after the path switch (which may be unlikely due to possible deterioration in the channel quality associated with the first connection) .

FIG. 2 illustrates an example of a wireless communications system 200 that supports techniques for transmitting uplink data after an uplink path switch in accordance with aspects of the present disclosure. In some examples, the wireless communications system 200 may implement aspects of the wireless communications system 100. The wireless communications system 200 may include a UE 115-a, a base station 105-a, and a base station 105-b, which may be examples of corresponding devices as described herein. In some implementations, the UE 115-a (e.g., a dual-connectivity UE 115-a) may transmit an uplink transmission 220 to the base station 105-a over the communication link 205-b including uplink data 225 and a tunneling indicator that the base station 105-a may use to determine to tunnel the uplink data 225 to the base station 105-b.

In some cases, the base station 105-a and the base station 105-b may operate using different RATs. For example, the base station 105-a may use LTE technology (e.g., the base station 105-a may function as an LTE cell, such as an eNB) and the base station 105-b may use NR technology (e.g., the base station 105-b may function as an NR cell, such as a gNB) , or vice-versa. In some other cases, the base station 105-a and the base station 105-b may operate using the same RAT (e.g., both may use LTE technology, or both may use NR technology) . In such cases, the base station 105-a and the base station 105-b may use different frequency bands to communicate with the UE 115-a. For example, the base station 105-a may use a first frequency band and the base station 105-b may use a second frequency band. In some cases, the first frequency band may be a lower frequency band and the second frequency band may be a higher frequency band, or vice-versa. In either case, the base station 105-a may function as an anchor or a master cell and the base station 105-b may function as a secondary cell for the UE 115-a.

The UE 115-a may establish a first communication link 205 with the base station 105-a and a second communication link 210 with the base station 105-b and may identify an uplink path to one of the base station 105-a or the base station 105-b based on which communication link is active. In some cases, the UE 115-a may determine that the communication link 210 to the base station 105-b is active and, accordingly, that the uplink path from the UE 115-a is to the base station 105-b over the communication link 210. In some aspects, the active communication link may be referred to as a primary path and may be configured by the network. In some aspects, the network may indicate the primary path to the UE 115-a via a cellgroup parameter, which may be set to 0 or 1 to indicate either that either the communication link 210 or the communication link 205 is the primary path.

In some examples, the UE 115 may have uplink data 225 to transmit to the base station 105-b and may transmit a scheduling request to the base station 105-b to request an uplink grant over which the UE 115 may transmit the uplink data 225. In some cases, however, the base station 105-b may unsuccessfully receive the scheduling request and the UE 115-a may repetitively transmit one or more additional scheduling requests to the base station 105-b until either the UE 115-a receives an uplink grant from the base station 105-b or until the UE 115-a has transmitted a threshold number of scheduling requests. For example, the UE 115-a may be configured with an upper limit (e.g., a maximum number) of scheduling request transmissions, which may be defined by the configurable parameter sr-TransMax.

In some cases, the UE 115-a may receive a path switch command 235 from the network while transmitting scheduling requests (e.g., in the middle of scheduling request transmission) to the base station 105-b that indicates the UE 115-a to switch from communicating with the base station 105-b via the communication link 210 to communicating with the base station 105-a via the communication link 205. Although shown as being transmitted to the UE 115-a from the base station 105-b, the network may additionally or alternatively transmit the path switch command 235 to the UE 115-a from the base station 105-a without exceeding the scope of the present disclosure.

In some aspects, the UE 115-a may receive the path switch command 235 as a cellgroup parameter and may determine to switch to communicating with the base station 105-a via the communication link 205 based on the value of the cellgroup parameter. In some cases, however, the uplink data 225 may be specific to the communication link 210 to the base station 105-b and the UE 115-a may continue to transmit scheduling requests to the base station 105-b despite receiving the path switch command 235. For example, the uplink data 225 may be responsive to a downlink transmission from the base station 105-b (e.g., the uplink data 225 may include feedback information associated with a downlink transmission from the base station 105-b) and the UE 115-a may be configured to attempt to transmit the uplink data 225 to the base station 105-b regardless of a path switch from the communication link 210 to the communication link 205.

For example, the base station 105-b may be associated with a PDCP split (e.g., the PDCP entity of the base station 105-b may split to the RLC entity of the base station 105-a and to the RLC entity of the base station 105-b) and the uplink data 225 may include uplink RLC layer data responsive to a downlink transmission from the RLC entity of the base station 105-b and, as such, the UE 115-b may be unable to communicate the uplink RLC layer data to the base station 105-b via the base station 105-a because the RLC entity of the base station 105-b is below the PDCP split. In some specific examples, the uplink data 225 may include an uplink RLC control PDU, which may be referred to as an UL RLC control PDU, that provides feedback (e.g., acknowledgement (ACK) or negative acknowledgement (NACK) ) for a downlink RLC acknowledged mode (AM) PDU transmitted from the base station 105-b, which may be referred to as a DL RLC AM PDU or a DL RLC AM data PDU, and the UE 115-a may be configured to transmit the UL RLC control PDU to the base station 105-b over the same communication link 210 used to transmit the DL RLC AM PDU to the UE 115-a. For instance, if the base station 105-b functions as an NR cell and transmits DL RLC AM PDU to the UE 115-a via an NR connection (e.g., on the NR side) or if there is any outstanding (i.e., unacknowledged) DL RLC AM data PDU awaiting acknowledgement on the NR side, or both, the UE 115-a may send the UL RLC control PDU to the base station 105-b on the NR side regardless of the reception of a path switch command 235 because the base station 105-a may be unable to communicate with the RLC entity of the base station 105-b. Such uplink data 225 that is responsive to a downlink transmission from the base station 105-b and that may be associated with an entity of the base station 105-b below a split may be referred to herein as uplink data 225 of the communication link 210 or uplink data 225 that is specific to the base station 105-b.

In some cases, however, the network may transmit the path switch command 235 to the UE 115-a based on a deterioration or a decrease of the channel quality associated with the communication link 210 between the UE 115-a and the base station 105-b, which may adversely affect the likelihood of successful reception of a scheduling request at the base station 105-b. For instance, in examples in which the base station 105-b functions as an NR cell or in examples in which the base station 105-b uses a higher frequency band than the base station 105-a, the channel quality associated with the communication link 210 may occasionally fall below a threshold channel quality based on interference, movement of the UE 115-a, or the presence of an object between the base station 105-b and the UE 115-a. As such, the likelihood of the base station 105-b to successfully receive the scheduling request from the UE 115-a may be below a threshold likelihood. Accordingly, in some cases, the UE 115-a may reach the upper limit of scheduling request transmissions (e.g., the UE 115-a may exhaust scheduling request transmission) prior to receiving an uplink grant from the base station 105-b. Upon transmitting the upper limit of scheduling requests (e.g., a number of scheduling requests equal to or greater than the value of sr-TransMax) , the UE 115-a may initiate a random access procedure, such as a contention-based random access procedure, to attempt to re-connect to the base station 105-b. In some aspects, the UE 115-a may perform the random access procedure using a configured random access channel (RACH) . If the channel quality associated with the communication link 210 has not improved, however, the random access procedure attempts may fail. In some cases, the UE 115-a may declare a radio link failure upon attempting a threshold number of failed random access procedures.

Such repetitive transmission of scheduling requests and potential random access procedure attempts may result in latency of communications between the base stations 105 and the UE 115-a. For example, by configuring the UE 115-a to continue transmitting scheduling requests when some of the uplink data 225 includes data that is specific to the base station 105-b, the UE 115-a may maintain other data also in the queue for transmission to the base station 105-b, which may either result in latency or unnecessary duplication of the other data.

In some implementations of the present disclosure, the UE 115-a may manage the traffic of the uplink data 225 based on a category of the uplink data 225 in examples in which the UE 115-a has switched from communicating with the base station 105-b over the communication link 210 to communicating with the base station 105-a over the communication link 205. In some examples, the UE 115-a may define and maintain two categories (e.g., uplink categories) for queueing the uplink data 225. In a first category, the UE 115-a may maintain the uplink data 225 of the communication link 210 (e.g., the uplink data 225 that is specific to the base station 105-b) . In examples in which the base station 105-b is an NR cell, the first category of the uplink data 225 may include NR path only data, such as UL RLC control PDU, that is meant for an entity of the base station 105-b below a split of the base station 105-b (e.g., for the RLC layer data for the NR cell below a PDCP split) or for any entity of the base station 105-b in examples in which the base station 105-b has a non-split bearer. As such, in some aspects, the first category may include an NR path only data queue.

In a second category, the UE 115-a may maintain the uplink data 225 not of the communication link 210 (e.g., uplink data 225 that is not specific to the base station 105-b) . For example, the UE 115-a may include data that may be transmitted to either the base station 105-a or the base station 105-b within the second category of the uplink data 225. For instance, the uplink data 225 that the UE 115-a may include in the second category of the uplink data 225 may include hypertext transfer protocol (HTTP) data, transmission control protocol (TCP) data, or TCP ACK/NACK, among other examples. In examples in which the base station 105-b functions as an NR cell and the base station 105-a functions as an LTE cell or uses any other RAT, the second category of the uplink data 225 may include non-NR path only data (e.g., data that may be transmitted to a cell using a different RAT other than NR) and, as such, may include a non-NR path only data queue. In some specific examples, the non-NR path only data queue may include UL RLC PDU that may be non-exclusively sent on the NR side or the LTE side.

Upon reception of the path switch command 235 or upon otherwise determining to switch from the base station 105-b to the base station 105-a, the UE 115-a may identify the data queues in the first category and the second category and may manage the uplink traffic from the UE 115-a accordingly. For example, if the UE 115-a has uplink data 225 from the first category queued for transmission (e.g., if the UE 115-a is transmitting a scheduling request to the base station 105-b for an uplink grant to use to transmit the uplink data 225 included in the first category) , the UE 115-a may determine to continue transmitting scheduling requests for such uplink data 225 to the base station 105-b.

Alternatively, if the UE 115-a has uplink data 225 from the second category queued for transmission (e.g., if the UE 115-a is transmitting a scheduling request to the base station 105-b for an uplink grant to use to transmit the uplink data 225 included in the second category) , the UE 115-a may determine to stop transmitting scheduling requests for such uplink data 225 to the base station 105-b. For example, the UE 115-a may determine to stop all scheduling request transmissions to the base station 105-b upon reception of the path switch command 235 and to initiate scheduling request transmissions to the base station 105-a for an uplink grant to use to transmit the uplink data 225 included in the second category to the base station 105-a. In examples in which there is uplink data 225 already in the queue for transmission to the base station 105-a, the UE 115-a may dequeue the uplink data 225 from the existing queue (which may be a non-NR path only queue in examples in which the base station 105-a is a non-NR cell, such as an LTE cell) and the UE 115-a may move the uplink data 225 from the queue onto the non-NR protocol stack (e.g., an LTE stack) so that the UE 115-a may transmit the uplink data 225 on the non-NR side (e.g., the LTE side) . As such, the UE 115-a may transmit uplink data 225 that may be transmitted to either the base station 105-a or the base station 105-b, such as RLC AM data PDUs, to the base station 105-a and may transmit uplink data 225 that may be specific to the base station 105-b, such as RLC control PDU, to the base station 105-b.

In some other implementations of the present disclosure, the base stations 105 may feature a condition for tunneling the uplink data 225 that is specific to the base station 105-b to the base station 105-b from the base station 105-a over a communication link 215 and, as such, the UE 115-a may transmit all of the uplink data 225 to the base station 105-a. For example, upon determining that the condition for tunneling the uplink data 225 is satisfied, the UE 115-a may dequeue all the uplink data 225 from the queue for transmission to the base station 105-b (and therefore stop transmitting scheduling requests to the base station 105-a) and move the uplink data 225 to the queue for transmission to the base station 105-a. In some examples, the UE 115-a may receive a tunneling configuration 230 indicating the condition for tunneling the uplink data 225 to the base station 105-b via the base station 105-a over the communication link 205-b. Although shown as being transmitted to the UE 115-a from the base station 105-a, the UE 115-a may additionally or alternatively receive the tunneling configuration from the base station 105-b. Alternatively or additionally, the UE 115-a may be pre-configured with the tunneling configuration 230 (e.g., the tunneling configuration 230 may be defined by a specification) . The condition for tunneling the uplink data 225 to the base station 105-b via the base station 105-a may include the reception of the path switch command 235 or a determination by the UE 115-a that the channel quality associated with the communication link 210 between the base station 105-b and the UE 115-a satisfies a threshold (e.g., is less than a threshold channel quality) . For example, the UE 115-a may determine a signal-to-interference-plus-noise ratio (SINR) , a reference signal receive power (RSRP) , a channel quality indicator (CQI) , or any other channel quality metric associated with the communication link 210 and may compare the determined channel quality metric to a threshold channel quality metric (such as a threshold SINR measurement, a threshold RSRP measurement, or a threshold CQI) .

In examples in which the UE 115-adetermines that the condition is satisfied, the UE 115-a may transmit an uplink transmission 220 to the base station 105-a including the uplink data 225 and a tunneling indicator. In some aspects, the uplink data 225 that is specific to the base station 105-b may be encapsulated within a protocol associated with the base station 105-a. For instance, in examples in which the base station 105-a functions as an LTE cell and the base station 105-b functions as an NR cell, the UE 115-a may encapsulate the uplink data 225 that is specific to the NR side within an LTE protocol. In some examples, the tunneling indicator may include a bit that may be set to a value to indicate that the uplink transmission 220 includes the uplink data 225 that is specific to the base station 105-b. Additionally or alternatively, the tunneling indicator may include a logical channel identifier that indicates a logical channel that the base station 105-a may use for tunneling the uplink data 225 from an entity of the base station 105-a to an entity of the base station 105-b. In some aspects, the base station 105-a may tunnel the uplink data 225 from an RLC entity of the base station 105-a to an RLC entity of the base station 105-b. In some other aspects, the base station 105-a may tunnel the uplink data 225 from a PDCP entity of the base station 105-a to an RLC entity of the base station 105-b through a PDCP entity of the base station 105-b. Additional details relating to tunneling the uplink data 225 from an RLC entity of the base station 105-a to an RLC entity of the base station 105-b through a PDCP entity of the base station 105-b are described herein, including with reference to FIG. 3. Further, additional details relating to tunneling the uplink data 225 from a PDCP entity of the base station 105-a to the PDCP entity of the base station 105-b are described herein, including with reference to FIG. 4.

As such, the base station 105-b may receive the uplink data 225 via the base station 105-a. In some examples, based on receiving the uplink data 225 via the base station 105-a, the base station 105-b may have a greater likelihood of successfully receiving the uplink data 225 compared to cases in which the UE 115-b attempts to transmit the uplink data 225 to the base station 105-b in poor channel conditions. Additionally or alternatively, the base station 105-b may receive the uplink data 225 with lower latency compared to cases in which the UE 115-b continues to transmit scheduling requests for an uplink grant from the base station 105-b, which may be associated with a lower likelihood of successful reception by the base station 105-b in poor channel conditions.

FIG. 3 illustrates an example of a protocol stack communication architecture 300 that supports techniques for transmitting uplink data after an uplink path switch in accordance with aspects of the present disclosure. In some examples, the protocol stack communication architecture 300 may implement aspects of wireless communications system 100 and the wireless communications system 200. The protocol stack communication architecture 300 may illustrate communications between an eNB 325, a gNB 345, and a UE 115. The eNB 325 and the gNB 345 may be examples of base stations 105 as described herein. For instance, in some specific examples, the eNB 325 may be an example of a base station 105-a and the gNB 345 may be an example of a base station 105-b in examples in which the base station 105-a functions as an LTE cell and the base station 105-b functions as an NR cell, as described in more detail with reference to FIG. 2. The protocol stack communication architecture 300 may illustrate a split bearer configuration, such as an option 3/3x configuration, and may include a split at a PDCP _NR 340 of the gNB 345 (which may be a secondary cell group split bearer) .

The eNB 325 may include a number of entities including a MAC _LTE 310-a, a MAC _LTE 310-b, an RLC _LTE 315-a, an RLC _LTE 315-b, and a PDCP _LTE 320. The gNB 345 may include a number of entities including a MAC _NR 330, an RLC _NR 335, and a PDCP _NR 340. In some cases, the eNB 325 may function as an anchor or a master cell and, as such, may be equivalently referred to as an MeNB 325. Accordingly, the gNB 345 may function as a secondary cell and, as such, may be equivalently referred to as an SgNB 345. The eNB 325 and the gNB 345 may communicate with core network entities 350 via communication link 355-a and communication link 355-b, respectively. The communication links 355 may be wired or wireless connections. In some examples, the core network entities 350 may include an S-GW or a P-GW, or both, and, in some cases, may be referred to as 5GC. In examples in which the protocol stack communication architecture 300 is operating in non-standalone mode using EN-DC option 3 (e.g., 3/3a/3x) configuration, the S-GW may handle the user plane interface at the core network and the interface between the S-GW and the eNB 325 and between the S-GW and the gNB 345 may be an S1 user plane (S1-U) interface. In examples in which the protocol stack communication architecture 300 is operating in non-standalone mode using EN-DC option 4 configuration or EN-DC option 7 configuration, the interface between the 5GC and the eNB 325 and the gNB 345 may be an N3 interface.

In some implementations, the UE 115 may receive a tunneling configuration indicating a condition for tunneling uplink data to the gNB 345 (e.g., uplink data of a connection between the UE 115 and the gNB 345, such as uplink data included in the first category) via the eNB 325. The configuration may include a condition which, when satisfied, may indicate the UE 115 to transmit uplink data specific to the gNB 345 to the eNB 325 for tunneling to the gNB 345. In examples in which the UE 115 determines that the condition is satisfied, the UE 115 may determine to transmit uplink data to the eNB 325 for tunneling to the gNB 345. In some examples, the UE 115 may encapsulate the uplink data within a protocol of the connection with the eNB 325, which may be an example of an LTE connection. For example, the uplink data may be an NR UL RLC control PDU (e.g., UL RLC ACK/NACK control data or other NR RLC data) and the UE 115 may encapsulate the NR UL RLC control PDU within an LTE RLC data PDU 305, which also may be referred to as an LTE UL RLC data PDU packet 305.

The UE 115 may transmit the LTE RLC data PDU 305 (which may be encapsulating the NR UL RLC control PDU) and a tunneling indicator to the RLC _LTE 315-b of the eNB 325. The RLC _LTE 315-b may forward the encapsulated packet to the PDCP _NR 340. The tunneling indicator, which may be a change in the protocol, may provide an indication to the eNB 325 and the gNB 345 that the LTE RLC data PDU 305 (e.g., the data encapsulated by the LTE RLC data PDU 305) may be channeled through the PDCP _NR 340 and routed to the RLC _NR 335. In some examples, the tunneling indicator is one bit set in the protocol to indicate that the LTE RLC data PDU 305 is to be channeled through the PDCP _NR 340 and routed to the RLC _NR 335. Additionally or alternatively, the tunneling indicator may include a logical channel identifier for channeling from the PDCP _NR 340 to the RLC _NR 335. As such, the PDCP _NR 340 of the gNB 345 may receive the LTE RLC data PDU 305 (e.g., the encapsulated packet) from the RLC _LTE 315-b and forward the LTE RLC data PDU 305 to the RLC _NR 335 at the gNB 345 when the bit (e.g., the bit included in the tunneling indicator) is set or when a logical channel identifier is used (e.g., when the logical channel identifier is included in the tunneling indicator) .

In some cases, there may be additional distance between the PDCP _LTE 320 and the PDCP _NR 340 compared to the distance between the UE 115 and the gNB 345 due to non-collocation, but delay associated with such the additional distance may be compensated for by reducing latency in other areas of the system (e.g., by avoiding potentially long scheduling request transmission durations) . Further, the UE 115 may transmit UL RLC control PDUs relatively infrequently compared to receiving DL RLC AM data PDUs from the gNB 345 and an RLC window associated with reception of the UL RLC control PDUs may be relatively long compared to windows associated with reception of physical layer transmissions. Moreover, during any such delay resulting from the additional distance may be used by the UE 115 to continue attempting to transmit UL RLC control PDUs to the gNB 345 (e.g., on the NR side) to help the UE 115 to acknowledge the gNB 345 for any outstanding or new DL RLC data PDU that is waiting for acknowledgement when gNB 345 fails to provide the UE 115 with an NR uplink grant. Accordingly, any such delay may be mitigated or erased by saving latency in other areas and by using the delay to help the UE 115 acknowledge outstanding downlink transmissions from the gNB 445 when the uplink path has been switched.

Although described in a context in which the UE 115 switches from communicating with a gNB 345 to communicating with an eNB 325, the described techniques may be equally applicable in examples in which the UE 115 switches from communicating with an eNB 435 to communicating with a gNB 345. Further, although described in the context in which the UE 115 communicates with an eNB 325 and a gNB 345, the described techniques may be equally applicable to contexts in which the UE 115 communicates with two eNBs 325, two gNBs 325, or any other pair of base stations or parent nodes. Likewise, the base stations or parent nodes that the UE 115 may communicate with may use different RATs or the same RAT, different frequency bands or the same frequency band, or may be located at the same geographic location or at different geographic locations.

FIG. 4 illustrates an example of a protocol stack communication architecture 400 that supports techniques for transmitting uplink data after an uplink path switch in accordance with aspects of the present disclosure. In some examples, the protocol stack communication architecture 400 may implement aspects of wireless communications system 100 and the wireless communications system 200. The protocol stack communication architecture 400 may illustrate communications between an eNB 425, a gNB 445, and a UE 115. The eNB 425 and the gNB 445 may be examples of base stations 105 as described herein. For instance, in some specific examples, the eNB 425 may be an example of a base station 105-a and the gNB 445 may be an example of a base station 105-b in examples in which the base station 105-a functions as an LTE cell and the base station 105-b functions as an NR cell, as described in more detail with reference to FIG. 2. The protocol stack communication architecture 400 may illustrate a non-split bearer configuration, such as may be the case when there existed PDCP _LTE 420 and PDCP _NR 440. For example, the protocol stack communication architecture 400 may be an example of non-split bearer configurations associated with an option 3a configuration, LTE –wireless local area network (WLAN) aggregation (LWA) , and NN-DC, among other examples.

The eNB 425 may include a number of entities including a MAC _LTE 410, an RLC _LTE 415, and a PDCP _LTE 420. The gNB 445 may include a number of entities including a MAC _NR 430, an RLC _NR 435, and a PDCP _NR 440. In some cases, the eNB 425 may function as an anchor or a master cell and, as such, may be equivalently referred to as an MeNB 425. Accordingly, the gNB 445 may function as a secondary cell and, as such, may be equivalently referred to as an SgNB 445. The eNB 425 and the gNB 445 may communicate with core network entities 450 via communication link 455-a and communication link 455-b, respectively. The communication links 455 may be wired or wireless connections. In some examples, the core network entities 450 may include an S-GW or a P-GW, or both, and, in some cases, may be referred to as 5GC. In some examples, the interface between the core network entities 450 and the eNB 425 and between the S-GW and the gNB 445 may be an S1-U interface. In some other examples, the interface between the core network entities 450 and the eNB 425 and the gNB 445 may be an N3 interface.

In some implementations, the UE 115 may receive a tunneling configuration indicating a condition for tunneling uplink data to the gNB 445 (e.g., uplink data of a connection between the UE 115 and the gNB 445, such as uplink data included in the first category) via the eNB 425. The configuration may include a condition which, when satisfied, may indicate the UE 115 to transmit uplink data specific to the gNB 445 to the eNB 425 for tunneling to the gNB 445. In examples in which the UE 115 determines that the condition is satisfied, the UE 115 may determine to transmit uplink data to the eNB 425 for tunneling to the gNB 445. In some examples, the UE 115 may encapsulate the uplink data within a protocol of the connection with the eNB 425, which may be an example of an LTE connection. For example, the uplink data may be an NR UL RLC control PDU (e.g., UL RLC ACK/NACK control data or other NR RLC data) and the UE 115 may encapsulate the NR UL RLC control PDU within an LTE RLC data PDU 405, which also may be referred to as an LTE UL RLC data PDU packet 405.

The UE 115 may transmit the LTE RLC data PDU 405 (which may be encapsulating the NR UL RLC control PDU) and a tunneling indicator to the PDCP _LTE 420 of the eNB 425. In some implementations, the eNB 425, upon receiving the LTE RLC data PDU 405 (e.g., the encapsulated packet) , may forward the LTE RLC data PDU 405 from the PDCP _LTE 420 to the PDCP _NR 440 via either an S1-U interface tunnel or an N3 interface tunnel that connects the PDCP _LTE 420 and the PDCP _NR 440. For example, the eNB 425 may tunnel the LTE RLC data PDU 405 from the PDCP _LTE 420 to the PDCP _NR 440 via one or more core network entities 450 (e.g., the S-GW or the P-GW, or both) .

The tunneling indicator, which may be a change in the protocol, may provide an indication to the eNB 425 and the gNB 445 that the LTE RLC data PDU 405 (e.g., the data encapsulated by the LTE RLC data PDU 405) may be channeled through the PDCP _NR 440 and routed to the RLC _NR 435. In some examples, the tunneling indicator is one bit set in the protocol to indicate that the LTE RLC data PDU 405 is to be channeled through the PDCP _NR 440 and routed to the RLC _NR 435. Additionally or alternatively, the tunneling indicator may include a logical channel identifier for channeling from the PDCP _NR 440 to the RLC _NR 435. As such, the PDCP _NR 440 of the gNB 445 may receive the LTE RLC data PDU 405 (e.g., the encapsulated packet) from the PDCP _LTE 420 and forward the LTE RLC data PDU 405 to the RLC _NR 435 at the gNB 445 when the bit (e.g., the bit included in the tunneling indicator) is set or when a logical channel identifier is used (e.g., when the logical channel identifier is included in the tunneling indicator) .

In some cases, there may be additional distance between the PDCP _LTE 420 and the PDCP _NR 440 compared to the distance between the UE 115 and the gNB 445 due to non-collocation, but delay associated with such the additional distance may be compensated for by reducing latency in other areas of the system (e.g., by avoiding potentially long scheduling request transmission durations) . Further, the UE 115 may transmit UL RLC control PDUs relatively infrequently compared to receiving DL RLC AM data PDUs from the gNB 445 and an RLC window associated with reception of the UL RLC control PDUs may be relatively long compared to windows associated with reception of physical layer transmissions. Moreover, during any such delay resulting from the additional distance may be used by the UE 115 to continue attempting to transmit UL RLC control PDUs to the gNB 445 (e.g., on the NR side) to help the UE 115 to acknowledge the gNB 445 for any outstanding or new DL RLC data PDU that is waiting for acknowledgement when gNB 445 fails to provide the UE 115 with an NR uplink grant. Accordingly, any such delay may be mitigated or erased by saving latency in other areas and by using the delay to help the UE 115 acknowledge outstanding downlink transmissions from the gNB 445 when the uplink path has been switched.

Although described in a context in which the UE 115 switches from communicating with a gNB 445 to communicating with an eNB 425, the described techniques may be equally applicable in examples in which the UE 115 switches from communicating with an eNB 425 to communicating with a gNB 445. Further, although described in the context in which the UE 115 communicates with an eNB 425 and a gNB 445, the described techniques may be equally applicable to contexts in which the UE 115 communicates with two eNBs 425, two gNBs 425, or any other pair of base stations or parent nodes. Likewise, the base stations or parent nodes that the UE 115 may communicate with may use different RATs or the same RAT, different frequency bands or the same frequency band, or may be located at the same geographic location or at different geographic locations.

FIG. 5 illustrates an example of a process flow 500 that supports techniques for transmitting uplink data after an uplink path switch in accordance with aspects of the present disclosure. In some examples, the process flow 500 may implement aspects of wireless communication system 100. The process flow may illustrate communications between a UE 115-b, which may function as a dual-connectivity UE 115, a base station 105-c, and a base station 105-d, which may be examples of corresponding devices as described herein. In some implementations, the UE 115-b may receive a tunneling configuration for tunneling uplink data to the base station 105-d via the base station 105-c. Alternative examples of the following may be implemented, where some processes are performed in a different order than described or are not performed at all. In some implementations, processes may include additional features not mentioned below, or further processes may be added.

At 505, the UE 115-b may establish a first connection with the base station 105-d. The base station 105-d may be an example of a first cell. In some aspects, the base station 105-d may operate using a first RAT (e.g., the base station 105-d may function as an NR cell or as an LTE cell) . Additionally or alternatively, the base station 105-d may operate using a first frequency band.

At 510, the UE 115-b may establish a second connection with the base station 105-c. The base station 105-c may be an example of a second cell. In some aspects, the base station 105-c may operate using the first RAT or a second RAT (e.g., the base station 105-d may function as an NR cell or as an LTE cell) . Additionally or alternatively, the base station 105-c may operate using a second frequency band.

At 515, the base station 105-c may transmit, to the UE 115-b (e.g., the dual-connectivity UE 115) , a tunneling configuration that indicates a condition for tunneling uplink data of the first connection to the base station 105-d via the second connection (e.g., the connection with the base station 105-c) . In some examples, the condition may be a reception of a path switch command indicating the UE 115-b to switch from communicating with the base station 105-d via the first connection to communicating with the base station 105-c via the second connection when the uplink data is available for transmission to the base station 105-d (e.g., when the uplink data is queued for transmission to the base station 105-d, such as when the UE 115-b is transmitting scheduling requests for an uplink grant from the base station 105-d) . In some other examples, the condition may be a channel quality associated with the first connection satisfying a threshold channel quality. For example, the UE 115-b may determine that the condition is satisfied based on determining that the channel quality associated with the first connection between the UE 115-b and the base station 105-d is less than a threshold channel quality. In some implementations, the channel quality may include or be an example of an SINR measurement, an RSRP measurement, or a CQI.

At 520, the base station 105-c may, in some implementations, transmit a path switch command indicating the UE 115-b to switch from communicating with the base station 105-d via the first connection to communicating with the base station 105-c via the second connection. In some examples, the UE 115-b may determine that the condition of the tunneling configuration is satisfied based on receiving the path switch command.

At 525, the UE 115-b may determine that that the condition (which may be equivalently referred to as a tunneling condition) for tunneling uplink data of the first connection to the base station 105-d via the second connection is satisfied. In some examples, the UE 115-b may determine that the condition is satisfied based on receiving the path switch command at 520. In some other examples, the UE 115-b may determine that the condition is satisfied based on determining that a channel quality associated with the first connection between the UE 115-b and the base station 105-d satisfies a threshold channel quality (e.g., is less than a threshold channel quality) . For example, the UE 115-b may determine that an SINR measurement is less than a threshold SINR measurement, that an RSRP measurement is less than a threshold RSRP measurement, that a CQI is less than a threshold CQI, or any combination thereof.

At 530, the UE 115-b may transmit, via the second connection, an uplink transmission including the uplink data of the first connection (e.g., uplink data specific to the base station 105-d) and a tunneling indicator that indicates that the uplink transmission includes the uplink data of the first connection. In some examples, the UE 115-b may transmit the uplink transmission based on determining that the condition of the tunneling configuration is satisfied. In some implementations, the tunneling indicator includes a bit set to indicate that the uplink transmission includes the uplink data of the first connection. Additionally or alternatively, the tunneling indicator includes a logical channel identifier that indicates a logical channel for tunneling the uplink data from an entity of the base station 105-c to an entity of the base station 105-d. Additional details relating to the tunneling of the uplink data from an entity of the base station 105-c to an entity of the base station 105-d are described herein, including with reference to FIGs. 3 and 4.

At 535, the base station 105-c may tunnel the uplink data from the entity of the base station 105-c to the entity of the base station 105-d based on the tunneling indicator. In some examples, the base station 105-c may tunnel the uplink data from an RLC entity of the base station 105-c to an RLC entity of the base station 105-d. In some other examples, the base station 105-c may tunnel the uplink data from a PDCP entity of the base station 105-c to a PDCP entity of the base station 105-d via one or more core network entities and may route the uplink data from the PDCP entity of the base station 105-d to an RLC entity of the base station 105-d. Additional details relating to the tunneling of the uplink data from an entity of the base station 105-c to an entity of the base station 105-d are described herein, including with reference to FIGs. 3 and 4.

FIG. 6 shows a diagram 600 of a device 605 that supports techniques for transmitting uplink data after an uplink path switch in accordance with aspects of the present disclosure. The device 605 may be an example of aspects of a UE 115 as described herein. The device 605 may include a receiver 610, a communications manager 615, and a transmitter 620. The device 605 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses) .

The receiver 610 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to techniques for transmitting uplink data after an uplink path switch, etc. ) . Information may be passed on to other components of the device 605. The receiver 610 may be an example of aspects of the transceiver 920 described with reference to FIG. 9. The receiver 610 may utilize a single antenna or a set of antennas.

The communications manager 615 may establish a first connection with a first cell and a second connection with a second cell that differs from the first cell, receive a tunneling configuration that indicates a condition for tunneling uplink data of the first connection to the first cell via the second connection, and transmit, via the second connection, an uplink transmission including the uplink data of the first connection and a tunneling indicator that indicates that the uplink transmission includes the uplink data of the first connection based on the condition being satisfied. The communications manager 615 may be an example of aspects of the communications manager 910 described herein.

The communications manager 615, or its sub-components, may be implemented in hardware, code (e.g., software or firmware) executed by a processor, or any combination thereof. If implemented in code executed by a processor, the functions of the communications manager 615, or its sub-components may be executed by a general-purpose processor, a digital signal processor (DSP) , an application-specific integrated circuit (ASIC) , a field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in the present disclosure.

The communications manager 615, or its sub-components, may be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations by one or more physical components. In some examples, the communications manager 615, or its sub-components, may be a separate and distinct component in accordance with various aspects of the present disclosure. In some examples, the communications manager 615, 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 620 may transmit signals generated by other components of the device 605. In some examples, the transmitter 620 may be collocated with a receiver 610 in a transceiver module. For example, the transmitter 620 may be an example of aspects of the transceiver 920 described with reference to FIG. 9. The transmitter 620 may utilize a single antenna or a set of antennas.

In some examples, the communications manager 615 may be implemented as an integrated circuit or chipset for a device modem, and the receiver 610 and the transmitter 620 may be implemented as analog components (for example, amplifiers, filters, antennas) coupled with the device modem to enable wireless transmission and reception over one or more bands.

The communications manager 615 as described herein may be implemented to realize one or more potential advantages. In some implementations, the communications manager 615 may determine to tunnel uplink data of a first connection (e.g., NR data) to a first cell (e.g., an NR cell) via a second cell (e.g., an LTE cell) upon determining that a condition of a tunneling configuration is satisfied. For example, the communications manager 615 may determine to tunnel the uplink data to the first cell via the second cell based on receiving a path switch command to switch from communicating with the first cell to communicating with the second cell or based on otherwise determining to switch from communicating with the first cell to communicating with the second cell (e.g., based on a channel quality associated with the first connection with the first cell) . As such, the communications manager 615 may avoid transmitting a number of scheduling requests to the first cell for an uplink grant to the first cell, which may be associated with a low likelihood for successful reception by the first cell. Accordingly, the communications manager 615 may reduce latency associated with transmitting the number of scheduling requests and, in some cases, may avoid performing a number of random access procedure attempts or declaring radio link failure.

Based on avoiding the transmission of a number of scheduling requests associated with a low likelihood of successful reception by the first cell and instead tunneling uplink data to the first cell via the second cell, the communications manager 615 may perform fewer transmissions and potentially avoid monitoring a number of monitoring occasions associated with a random access procedure. As such, the communications manager 615, or one or more components of the communications manager 615, may turn off more frequency or for longer durations, or both, which may result in improved power savings and battery life at the device 605.

FIG. 7 shows a diagram 700 of a device 705 that supports techniques for transmitting uplink data after an uplink path switch in accordance with aspects of the present disclosure. The device 705 may be an example of aspects of a device 605, or a UE 115 as described herein. The device 705 may include a receiver 710, a communications manager 715, and a transmitter 735. 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 techniques for transmitting uplink data after an uplink path switch, 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 920 described with reference to FIG. 9. The receiver 710 may utilize a single antenna or a set of antennas.

The communications manager 715 may be an example of aspects of the communications manager 615 as described herein. The communications manager 715 may include a connection manager 720, a configuration manager 725, and an uplink manager 730. The communications manager 715 may be an example of aspects of the communications manager 910 described herein.

The connection manager 720 may establish a first connection with a first cell and a second connection with a second cell that differs from the first cell. The configuration manager 725 may receive a tunneling configuration that indicates a condition for tunneling uplink data of the first connection to the first cell via the second connection. The uplink manager 730 may transmit, via the second connection, an uplink transmission including the uplink data of the first connection and a tunneling indicator that indicates that the uplink transmission includes the uplink data of the first connection based on the condition being satisfied.

The transmitter 735 may transmit signals generated by other components of the device 705. In some examples, the transmitter 735 may be collocated with a receiver 710 in a transceiver module. For example, the transmitter 735 may be an example of aspects of the transceiver 920 described with reference to FIG. 9. The transmitter 735 may utilize a single antenna or a set of antennas.

FIG. 8 shows a diagram 800 of a communications manager 805 that supports techniques for transmitting uplink data after an uplink path switch in accordance with aspects of the present disclosure. The communications manager 805 may be an example of aspects of a communications manager 615, a communications manager 715, or a communications manager 910 described herein. The communications manager 805 may include a connection manager 810, a configuration manager 815, an uplink manager 820, and a tunneling manager 825. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses) .

The connection manager 810 may establish a first connection with a first cell and a second connection with a second cell that differs from the first cell. In some cases, the dual-connectivity UE communicates with the first cell using a first RAT and communicates with the second cell using a second RAT that differs from the first RAT. In some cases, the dual-connectivity UE communicates with the first cell using a first RAT via a first frequency band and communicates with the second cell using the first RAT via a second frequency band that differs from the first frequency band.

The configuration manager 815 may receive a tunneling configuration that indicates a condition for tunneling uplink data of the first connection to the first cell via the second connection. In some examples, the configuration manager 815 may receive the tunneling configuration that indicates that the condition is reception of a path switch command indicating to switch from communicating with the first cell via the first connection to communicating with the second cell via the second connection when the uplink data is available for transmission to the first cell. In some examples, the configuration manager 815 may receive the tunneling configuration that indicates that the condition is a channel quality associated with the first connection satisfying a threshold channel quality.

The uplink manager 820 may transmit, via the second connection, an uplink transmission including the uplink data of the first connection and a tunneling indicator that indicates that the uplink transmission includes the uplink data of the first connection based on the condition being satisfied. In some examples, the uplink manager 820 may transmit, via the second connection, the uplink transmission that includes a packet that encapsulates the uplink data of the first connection within a protocol of the second connection.

In some examples, the uplink manager 820 may transmit, via the second connection with the LTE cell, the uplink transmission including the uplink data of the first connection with the NR cell. In some examples, the uplink manager 820 may transmit, via the second connection with the NR cell, the uplink transmission including the uplink data of the first connection with the LTE cell. In some cases, the uplink data of the first connection includes an NR uplink RLC control PDU.

The tunneling manager 825 may transmit, via the second connection, the tunneling indicator that is a bit set to indicate that the uplink transmission includes the uplink data of the first connection. In some examples, the tunneling manager 825 may transmit, via the second connection, the tunneling indicator that is logical channel identifier that indicates a logical channel for tunneling the uplink data from a second entity the second cell to a first entity of the first cell.

In some cases, the first entity of the first cell includes a RLC entity of the first cell and the second entity of the second cell includes an RLC entity of the second cell. In some cases, the first entity of the first cell includes a PDCP entity of the first cell and the second entity of the second cell includes a RLC entity of the second cell.

FIG. 9 shows a diagram of a system 900 including a device 905 that supports techniques for transmitting uplink data after an uplink path switch in accordance with aspects of the present disclosure. The device 905 may be an example of or include the components of device 605, device 705, or a UE 115 as described herein. The device 905 may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including a communications manager 910, an I/O controller 915, a transceiver 920, an antenna 925, memory 930, and a processor 940. These components may be in electronic communication via one or more buses (e.g., bus 945) .

The communications manager 910 may establish a first connection with a first cell and a second connection with a second cell that differs from the first cell, receive a tunneling configuration that indicates a condition for tunneling uplink data of the first connection to the first cell via the second connection, and transmit, via the second connection, an uplink transmission including the uplink data of the first connection and a tunneling indicator that indicates that the uplink transmission includes the uplink data of the first connection based on the condition being satisfied.

The I/O controller 915 may manage input and output signals for the device 905. The I/O controller 915 may also manage peripherals not integrated into the device 905. In some cases, the I/O controller 915 may represent a physical connection or port to an external peripheral. In some cases, the I/O controller 915 may utilize an operating system such as

or another known operating system. In other cases, the I/O controller 915 may represent or interact with a modem, a keyboard, a mouse, a touchscreen, or a similar device. In some cases, the I/O controller 915 may be implemented as part of a processor. In some cases, a user may interact with the device 905 via the I/O controller 915 or via hardware components controlled by the I/O controller 915.

The transceiver 920 may communicate bi-directionally, via one or more antennas, wired, or wireless links as described herein. For example, the transceiver 920 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 920 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 925. However, in some cases the device may have more than one antenna 925, which may be capable of concurrently transmitting or receiving multiple wireless transmissions.

The memory 930 may include random-access memory (RAM) and read-only memory (ROM) . The memory 930 may store computer-readable, computer-executable code 935 including instructions that, when executed, cause the processor to perform various functions described herein. In some cases, the memory 930 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 940 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 940 may be configured to operate a memory array using a memory controller. In other cases, a memory controller may be integrated into the processor 940. The processor 940 may be configured to execute computer-readable instructions stored in a memory (e.g., the memory 930) to cause the device 905 to perform various functions (e.g., functions or tasks supporting techniques for transmitting uplink data after an uplink path switch) .

The code 935 may include instructions to implement aspects of the present disclosure, including instructions to support wireless communications. The code 935 may be stored in a non-transitory computer-readable medium such as system memory or other type of memory. In some cases, the code 935 may not be directly executable by the processor 940 but may cause a computer (e.g., when compiled and executed) to perform functions described herein.

FIG. 10 shows a diagram 1000 of a device 1005 that supports techniques for transmitting uplink data after an uplink path switch in accordance with aspects of the present disclosure. The device 1005 may be an example of aspects of a base station 105 as described herein. The device 1005 may include a receiver 1010, a communications manager 1015, and a transmitter 1020. The device 1005 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses) .

The receiver 1010 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to techniques for transmitting uplink data after an uplink path switch, etc. ) . Information may be passed on to other components of the device 1005. The receiver 1010 may be an example of aspects of the transceiver 1320 described with reference to FIG. 13. The receiver 1010 may utilize a single antenna or a set of antennas.

The communications manager 1015 may establish a first connection with a dual-connectivity UE, transmit, to the dual-connectivity UE, a tunneling configuration that indicates a condition for tunneling uplink data of a second connection to a second cell via the first connection, and receive, via the first connection, an uplink transmission including the uplink data of the second connection and a tunneling indicator that indicates that the uplink transmission includes the uplink data of the second connection. The communications manager 1015 may be an example of aspects of the communications manager 1310 described herein.

The communications manager 1015, or its sub-components, may be implemented in hardware, code (e.g., software or firmware) executed by a processor, or any combination thereof. If implemented in code executed by a processor, the functions of the communications manager 1015, or its sub-components may be executed by a general-purpose processor, a DSP, an ASIC, 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 in the present disclosure.

The communications manager 1015, or its sub-components, may be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations by one or more physical components. In some examples, the communications manager 1015, or its sub-components, may be a separate and distinct component in accordance with various aspects of the present disclosure. In some examples, the communications manager 1015, 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 1020 may transmit signals generated by other components of the device 1005. In some examples, the transmitter 1020 may be collocated with a receiver 1010 in a transceiver module. For example, the transmitter 1020 may be an example of aspects of the transceiver 1320 described with reference to FIG. 13. The transmitter 1020 may utilize a single antenna or a set of antennas.

The communications manager 1015 as described herein may be implemented to realize one or more potential advantages. For example, the communications manager 1015, based on tunneling uplink data to another cell for a UE, may reduce the amount of scheduling requests the UE may transmit over the air, which may reduce interference that may adversely affect other devices in the system and also reduce the spectral congestion of the system. Similarly, by reducing the number of scheduling requests transmitted by the UE and potentially avoiding one or more random access procedure attempts (or a radio link failure event) , the communications manager 1015 may increase the spectral efficiency of the system, which may enable the communications manager 1015 to allocate more resources to devices in the system for data transmission, thus increasing the overall system throughput.

FIG. 11 shows a diagram 1100 of a device 1105 that supports techniques for transmitting uplink data after an uplink path switch in accordance with aspects of the present disclosure. The device 1105 may be an example of aspects of a device 1005, or a base station 105 as described herein. The device 1105 may include a receiver 1110, a communications manager 1115, and a transmitter 1135. 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 techniques for transmitting uplink data after an uplink path switch, 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 1320 described with reference to FIG. 13. The receiver 1110 may utilize a single antenna or a set of antennas.

The communications manager 1115 may be an example of aspects of the communications manager 1015 as described herein. The communications manager 1115 may include a connection manager 1120, a configuration manager 1125, and an uplink manager 1130. The communications manager 1115 may be an example of aspects of the communications manager 1310 described herein.

The connection manager 1120 may establish a first connection with a dual-connectivity UE. The configuration manager 1125 may transmit, to the dual-connectivity UE, a tunneling configuration that indicates a condition for tunneling uplink data of a second connection to a second cell via the first connection. The uplink manager 1130 may receive, via the first connection, an uplink transmission including the uplink data of the second connection and a tunneling indicator that indicates that the uplink transmission includes the uplink data of the second connection.

The transmitter 1135 may transmit signals generated by other components of the device 1105. In some examples, the transmitter 1135 may be collocated with a receiver 1110 in a transceiver module. For example, the transmitter 1135 may be an example of aspects of the transceiver 1320 described with reference to FIG. 13. The transmitter 1135 may utilize a single antenna or a set of antennas.

FIG. 12 shows a diagram 1200 of a communications manager 1205 that supports techniques for transmitting uplink data after an uplink path switch in accordance with aspects of the present disclosure. The communications manager 1205 may be an example of aspects of a communications manager 1015, a communications manager 1115, or a communications manager 1310 described herein. The communications manager 1205 may include a connection manager 1210, a configuration manager 1215, an uplink manager 1220, a tunneling manager 1225, and a path-switch manager 1230. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses) .

The connection manager 1210 may establish a first connection with a dual-connectivity UE. In some cases, the first cell communicates with the dual-connectivity UE using a first RAT different than a second RAT associated with the second connection between the dual-connectivity UE and the second cell. In some cases, the first cell communicates with the dual-connectivity UE using a first RAT via a first frequency band different than a second frequency band used by the first RAT associated with the second connection between the dual-connectivity UE and the second cell.

The configuration manager 1215 may transmit, to the dual-connectivity UE, a tunneling configuration that indicates a condition for tunneling uplink data of a second connection to a second cell via the first connection. In some examples, the configuration manager 1215 may transmit the tunneling configuration that indicates that the condition is transmission of a path switch command indicating the dual-connectivity UE to switch from communicating with the second cell via the second connection to communicating with the first cell via the first connection when the uplink data is available for transmission to the first cell. In some examples, the configuration manager 1215 may transmit the tunneling configuration that indicates that the condition is a channel quality associated with the second connection satisfying a threshold channel quality.

The uplink manager 1220 may receive, via the first connection, an uplink transmission including the uplink data of the second connection and a tunneling indicator that indicates that the uplink transmission includes the uplink data of the second connection. In some examples, the uplink manager 1220 may receive, via the first connection, the uplink transmission that includes a packet that encapsulates the uplink data of the second connection within a protocol of the first connection. In some examples, the uplink manager 1220 may receive, at the LTE cell via the first connection, the uplink transmission including the uplink data of the second connection with the NR cell.

In some examples, the uplink manager 1220 may receive, at the NR cell via the first connection, the uplink transmission including the uplink data of the second connection with the NR cell. In some cases, the uplink data of the second connection includes an NR uplink RLC control PDU.

The tunneling manager 1225 may receive, via the first connection, the tunneling indicator that is a bit set to indicate that the uplink transmission includes the uplink data of the second connection. In some examples, the tunneling manager 1225 may receive, via the first connection, the tunneling indicator that is a logical channel identifier that indicates a logical channel for tunneling the uplink data from a first entity of the first cell to a second entity of the second cell.

In some examples, the tunneling manager 1225 may tunnel the uplink data from a first entity of the first cell to a second entity of the second cell based on the tunneling indicator. In some examples, the tunneling manager 1225 may tunnel the uplink data from the first entity of the first cell to the second entity of the second cell through a third entity of the second cell. In some examples, the tunneling manager 1225 may tunnel the uplink data from the first entity of the first cell to the third entity of the second cell via one or more core network entities.

In some cases, the first entity of the first cell includes a RLC entity of the first cell and the second entity of the second cell includes an RLC entity of the second cell. In some cases, the first entity of the first cell includes a PDCP entity of the first cell, the second entity of the second cell includes a RLC entity of the second cell, and the third entity of the second cell includes a PDCP entity of the second cell.

The path-switch manager 1230 may transmit a path switch command indicating the dual-connectivity UE to switch from communicating with the second cell via the second connection to communicating with the first cell via the first connection.

FIG. 13 shows a diagram of a system 1300 including a device 1305 that supports techniques for transmitting uplink data after an uplink path switch in accordance with aspects of the present disclosure. The device 1305 may be an example of or include the components of device 1005, device 1105, or a base station 105 as described herein. The device 1305 may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including a communications manager 1310, a network communications manager 1315, a transceiver 1320, an antenna 1325, memory 1330, a processor 1340, and an inter-station communications manager 1345. These components may be in electronic communication via one or more buses (e.g., bus 1350) .

The communications manager 1310 may establish a first connection with a dual-connectivity UE, transmit, to the dual-connectivity UE, a tunneling configuration that indicates a condition for tunneling uplink data of a second connection to a second cell via the first connection, and receive, via the first connection, an uplink transmission including the uplink data of the second connection and a tunneling indicator that indicates that the uplink transmission includes the uplink data of the second connection.

The network communications manager 1315 may manage communications with the core network (e.g., via one or more wired backhaul links) . For example, the network communications manager 1315 may manage the transfer of data communications for client devices, such as one or more UEs 115.

The transceiver 1320 may communicate bi-directionally, via one or more antennas, wired, or wireless links as described herein. For example, the transceiver 1320 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 1320 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 1325. However, in some cases the device may have more than one antenna 1325, which may be capable of concurrently transmitting or receiving multiple wireless transmissions.

The memory 1330 may include RAM, ROM, or a combination thereof. The memory 1330 may store computer-readable code 1335 including instructions that, when executed by a processor (e.g., the processor 1340) cause the device to perform various functions described herein. In some cases, the memory 1330 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 1340 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 1340 may be configured to operate a memory array using a memory controller. In some cases, a memory controller may be integrated into processor 1340. The processor 1340 may be configured to execute computer-readable instructions stored in a memory (e.g., the memory 1330) to cause the device 1305 to perform various functions (e.g., functions or tasks supporting techniques for transmitting uplink data after an uplink path switch) .

The inter-station communications manager 1345 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 1345 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 1345 may provide an X2 interface within an LTE/LTE-A wireless communication network technology to provide communication between base stations 105.

The code 1335 may include instructions to implement aspects of the present disclosure, including instructions to support wireless communications. The code 1335 may be stored in a non-transitory computer-readable medium such as system memory or other type of memory. In some cases, the code 1335 may not be directly executable by the processor 1340 but may cause a computer (e.g., when compiled and executed) to perform functions described herein.

FIG. 14 shows a flowchart illustrating a method 1400 that supports techniques for transmitting uplink data after an uplink path switch in accordance with aspects of the present disclosure. The operations of method 1400 may be implemented by a UE 115 or its components as described herein. For example, the operations of method 1400 may be performed by a communications manager as described with reference to FIGs. 6 through 9. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the functions described herein. Additionally or alternatively, a UE may perform aspects of the functions described herein using special-purpose hardware.

At 1405, the UE may establish a first connection with a first cell and a second connection with a second cell that differs from the first cell. The operations of 1405 may be performed according to the methods described herein. In some examples, aspects of the operations of 1405 may be performed by a connection manager as described with reference to FIGs. 6 through 9.

At 1410, the UE may receive a tunneling configuration that indicates a condition for tunneling uplink data of the first connection to the first cell via the second connection. The operations of 1410 may be performed according to the methods described herein. In some examples, aspects of the operations of 1410 may be performed by a configuration manager as described with reference to FIGs. 6 through 9.

At 1415, the UE may transmit, via the second connection, an uplink transmission including the uplink data of the first connection and a tunneling indicator that indicates that the uplink transmission includes the uplink data of the first connection based on the condition being satisfied. The operations of 1415 may be performed according to the methods described herein. In some examples, aspects of the operations of 1415 may be performed by an uplink manager as described with reference to FIGs. 6 through 9.

FIG. 15 shows a flowchart illustrating a method 1500 that supports techniques for transmitting uplink data after an uplink path switch in accordance with aspects of the present disclosure. The operations of method 1500 may be implemented by a base station 105 or its components as described herein. For example, the operations of method 1500 may be performed by a communications manager as described with reference to FIGs. 10 through 13. 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 herein. Additionally or alternatively, a base station may perform aspects of the functions described herein using special-purpose hardware.

At 1505, the base station may establish a first connection with a dual-connectivity UE. The operations of 1505 may be performed according to the methods described herein. In some examples, aspects of the operations of 1505 may be performed by a connection manager as described with reference to FIGs. 10 through 13.

At 1510, the base station may transmit, to the dual-connectivity UE, a tunneling configuration that indicates a condition for tunneling uplink data of a second connection to a second cell via the first connection. 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 configuration manager as described with reference to FIGs. 10 through 13.

At 1515, the base station may receive, via the first connection, an uplink transmission including the uplink data of the second connection and a tunneling indicator that indicates that the uplink transmission includes the uplink data of the second connection. 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 manager as described with reference to FIGs. 10 through 13.

FIG. 16 shows a flowchart illustrating a method 1600 that supports techniques for transmitting uplink data after an uplink path switch in accordance with aspects of the present disclosure. The operations of method 1600 may be implemented by a base station 105 or its components as described herein. For example, the operations of method 1600 may be performed by a communications manager as described with reference to FIGs. 10 through 13. 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 herein. Additionally or alternatively, a base station may perform aspects of the functions described herein using special-purpose hardware.

At 1605, the base station may establish a first connection with a dual-connectivity UE. The operations of 1605 may be performed according to the methods described herein. In some examples, aspects of the operations of 1605 may be performed by a connection manager as described with reference to FIGs. 10 through 13.

At 1610, the base station may transmit, to the dual-connectivity UE, a tunneling configuration that indicates a condition for tunneling uplink data of a second connection to a second cell via the first connection. 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 configuration manager as described with reference to FIGs. 10 through 13.

At 1615, the base station may receive, via the first connection, an uplink transmission including the uplink data of the second connection and a tunneling indicator that indicates that the uplink transmission includes the uplink data of the second connection. 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 an uplink manager as described with reference to FIGs. 10 through 13.

At 1620, the base station may tunnel the uplink data from a first entity of the first cell to a second entity of the second cell based on the tunneling indicator. The operations of 1620 may be performed according to the methods described herein. In some examples, aspects of the operations of 1620 may be performed by a tunneling manager as described with reference to FIGs. 10 through 13.

FIG. 17 shows a flowchart illustrating a method 1700 that supports techniques for transmitting uplink data after an uplink path switch in accordance with aspects of the present disclosure. The operations of method 1700 may be implemented by a base station 105 or its components as described herein. For example, the operations of method 1700 may be performed by a communications manager as described with reference to FIGs. 10 through 13. 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 herein. Additionally or alternatively, a base station may perform aspects of the functions described herein using special-purpose hardware.

At 1705, the base station may establish a first connection with a dual-connectivity UE. The operations of 1705 may be performed according to the methods described herein. In some examples, aspects of the operations of 1705 may be performed by a connection manager as described with reference to FIGs. 10 through 13.

At 1710, the base station may transmit, to the dual-connectivity UE, a tunneling configuration that indicates a condition for tunneling uplink data of a second connection to a second cell via the first connection. 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 configuration manager as described with reference to FIGs. 10 through 13.

At 1715, the base station may transmit a path switch command indicating the dual-connectivity UE to switch from communicating with the second cell via the second connection to communicating with the first cell via the first connection. 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 path-switch manager as described with reference to FIGs. 10 through 13.

At 1720, the base station may receive, via the first connection, an uplink transmission including the uplink data of the second connection and a tunneling indicator that indicates that the uplink transmission includes the uplink data of the second connection. 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 manager as described with reference to FIGs. 10 through 13.

At 1725, the base station may tunnel the uplink data from a first entity of the first cell to a second entity of the second cell based on the tunneling indicator. 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 tunneling manager as described with reference to FIGs. 10 through 13.

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

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

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

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

The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope and spirit of the disclosure and appended claims. For example, due to the nature of software, functions described herein can 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. As used herein, including in the claims, the term “and/or, ” when used in a list of two or more items, means that any one of the listed items can be employed by itself, or any combination of two or more of the listed items can be employed. For example, if a composition is described as containing components A, B, and/or C, the composition can contain A alone; B alone; C alone; A and B in combination; A and C in combination; B and C in combination; or A, B, and C in combination. Also, as used herein, including in the claims, “or” as used in a list of items (for example, a list of items prefaced by a phrase such as “at least one of” or “one or more of” ) indicates a disjunctive list such that, for example, a list of “at least one of A, B, or C” means A or B or C or AB or AC or BC or ABC (i.e., A and B and C) .

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.

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 diagram or 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 dual-connectivity user equipment (UE) , comprising:

establishing a first connection with a first cell and a second connection with a second cell that differs from the first cell;

receiving a tunneling configuration that indicates a condition for tunneling uplink data of the first connection to the first cell via the second connection; and

transmitting, via the second connection, an uplink transmission comprising the uplink data of the first connection and a tunneling indicator that indicates that the uplink transmission comprises the uplink data of the first connection based at least in part on the condition being satisfied.
The method of claim 1, wherein transmitting the uplink transmission comprises:

transmitting, via the second connection, the uplink transmission that comprises a packet that encapsulates the uplink data of the first connection within a protocol of the second connection.
The method of claim 1, wherein transmitting the uplink transmission comprises:

transmitting, via the second connection, the tunneling indicator that is a bit set to indicate that the uplink transmission comprises the uplink data of the first connection.
The method of claim 1, wherein transmitting the uplink transmission comprises:

transmitting, via the second connection, the tunneling indicator that is logical channel identifier that indicates a logical channel for tunneling the uplink data from a second entity the second cell to a first entity of the first cell.
The method of claim 4, wherein the first entity of the first cell comprises a radio link control (RLC) entity of the first cell and the second entity of the second cell comprises an RLC entity of the second cell.
The method of claim 4, wherein the first entity of the first cell comprises a packet data convergence protocol (PDCP) entity of the first cell and the second entity of the second cell comprises a radio link control (RLC) entity of the second cell.
The method of claim 1, wherein receiving the tunneling configuration further comprises:

receiving the tunneling configuration that indicates that the condition is reception of a path switch command indicating to switch from communicating with the first cell via the first connection to communicating with the second cell via the second connection when the uplink data is available for transmission to the first cell.
The method of claim 1, wherein receiving the tunneling configuration further comprises:

receiving the tunneling configuration that indicates that the condition is a channel quality associated with the first connection satisfying a threshold channel quality.
The method of claim 1, wherein the dual-connectivity UE communicates with the first cell using a first radio access technology (RAT) and communicates with the second cell using a second RAT that differs from the first RAT.
The method of claim 1, wherein the dual-connectivity UE communicates with the first cell using a first radio access technology (RAT) via a first frequency band and communicates with the second cell using the first RAT via a second frequency band that differs from the first frequency band.
The method of claim 1, wherein the first cell comprises a New Radio (NR) cell and the second cell comprises a Long Term Evolution (LTE) cell, and wherein transmitting the uplink transmission comprises:

transmitting, via the second connection with the LTE cell, the uplink transmission comprising the uplink data of the first connection with the NR cell.
The method of claim 11, wherein the uplink data of the first connection comprises a New Radio (NR) uplink radio link control (RLC) control protocol data unit (PDU) .
The method of claim 1, wherein the first cell comprises a Long Term Evolution (LTE) cell and the second cell comprises a New Radio (NR) cell, and wherein transmitting the uplink transmission comprises:

transmitting, via the second connection with the NR cell, the uplink transmission comprising the uplink data of the first connection with the LTE cell.
A method for wireless communications at a first cell, comprising:

establishing a first connection with a dual-connectivity user equipment (UE) ;

transmitting, to the dual-connectivity UE, a tunneling configuration that indicates a condition for tunneling uplink data of a second connection to a second cell via the first connection; and

receiving, via the first connection, an uplink transmission comprising the uplink data of the second connection and a tunneling indicator that indicates that the uplink transmission comprises the uplink data of the second connection.
The method of claim 14, wherein receiving the uplink transmission comprises:

receiving, via the first connection, the uplink transmission that comprises a packet that encapsulates the uplink data of the second connection within a protocol of the first connection.
The method of claim 14, wherein receiving the uplink transmission comprises:

receiving, via the first connection, the tunneling indicator that is a bit set to indicate that the uplink transmission comprises the uplink data of the second connection.
The method of claim 14, wherein receiving the uplink transmission comprises:

receiving, via the first connection, the tunneling indicator that is a logical channel identifier that indicates a logical channel for tunneling the uplink data from a first entity of the first cell to a second entity of the second cell.
The method of claim 14, further comprising:

tunneling the uplink data from a first entity of the first cell to a second entity of the second cell based at least in part on the tunneling indicator.
The method of claim 18, wherein the first entity of the first cell comprises a radio link control (RLC) entity of the first cell and the second entity of the second cell comprises an RLC entity of the second cell.
The method of claim 18, wherein tunneling the uplink data from the first entity of the first cell to the second entity of the second cell comprises:

tunneling the uplink data from the first entity of the first cell to the second entity of the second cell through a third entity of the second cell.
The method of claim 20, wherein tunneling the uplink data from the first entity of the first cell to the second entity of the second cell through the third entity of the second cell comprises:

tunneling the uplink data from the first entity of the first cell to the third entity of the second cell via one or more core network entities.
The method of claim 20, wherein the first entity of the first cell comprises a packet data convergence protocol (PDCP) entity of the first cell, the second entity of the second cell comprises a radio link control (RLC) entity of the second cell, and the third entity of the second cell comprises a PDCP entity of the second cell.
The method of claim 14, wherein transmitting the tunneling configuration further comprises:

transmitting the tunneling configuration that indicates that the condition is transmission of a path switch command indicating the dual-connectivity UE to switch from communicating with the second cell via the second connection to communicating with the first cell via the first connection when the uplink data is available for transmission to the first cell.
The method of claim 14, further comprising:

transmitting a path switch command indicating the dual-connectivity UE to switch from communicating with the second cell via the second connection to communicating with the first cell via the first connection.
The method of claim 14, wherein transmitting the tunneling configuration further comprises:

transmitting the tunneling configuration that indicates that the condition is a channel quality associated with the second connection satisfying a threshold channel quality.
The method of claim 14, wherein the first cell communicates with the dual-connectivity UE using a first radio access technology (RAT) different than a second RAT associated with the second connection between the dual-connectivity UE and the second cell.
The method of claim 14, wherein the first cell communicates with the dual-connectivity UE using a first radio access technology (RAT) via a first frequency band different than a second frequency band used by the first RAT associated with the second connection between the dual-connectivity UE and the second cell.
The method of claim 14, wherein the first cell comprises a Long Term Evolution (LTE) cell and the second cell comprises a New Radio (NR) cell, and wherein receiving the uplink transmission comprises:

receiving, at the LTE cell via the first connection, the uplink transmission comprising the uplink data of the second connection with the NR cell.
The method of claim 28, wherein the uplink data of the second connection comprises a New Radio (NR) uplink radio link control (RLC) control protocol data unit (PDU) .
The method of claim 14, wherein the first cell comprises a New Radio (NR) cell and the second cell comprises a Long Term Evolution (LTE) cell, and wherein receiving the uplink transmission comprises:

receiving, at the NR cell via the first connection, the uplink transmission comprising the uplink data of the second connection with the NR cell.
An apparatus for wireless communications at a dual-connectivity user equipment (UE) , comprising:

a processor,

memory coupled with the processor; and

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

establish a first connection with a first cell and a second connection with a second cell that differs from the first cell;

receive a tunneling configuration that indicates a condition for tunneling uplink data of the first connection to the first cell via the second connection; and

transmit, via the second connection, an uplink transmission comprising the uplink data of the first connection and a tunneling indicator that indicates that the uplink transmission comprises the uplink data of the first connection based at least in part on the condition being satisfied.
The apparatus of claim 31, wherein the instructions to transmit the uplink transmission are executable by the processor to cause the apparatus to:

transmit, via the second connection, the uplink transmission that comprises a packet that encapsulates the uplink data of the first connection within a protocol of the second connection.
The apparatus of claim 31, wherein the instructions to transmit the uplink transmission are executable by the processor to cause the apparatus to:

transmit, via the second connection, the tunneling indicator that is a bit set to indicate that the uplink transmission comprises the uplink data of the first connection.
The apparatus of claim 31, wherein the instructions to transmit the uplink transmission are executable by the processor to cause the apparatus to:

transmit, via the second connection, the tunneling indicator that is logical channel identifier that indicates a logical channel for tunneling the uplink data from a second entity the second cell to a first entity of the first cell.
The apparatus of claim 34, wherein the first entity of the first cell comprises a radio link control (RLC) entity of the first cell and the second entity of the second cell comprises an RLC entity of the second cell.
The apparatus of claim 34, wherein the first entity of the first cell comprises a packet data convergence protocol (PDCP) entity of the first cell and the second entity of the second cell comprises a radio link control (RLC) entity of the second cell.
The apparatus of claim 31, wherein the instructions to receive the tunneling configuration further are executable by the processor to cause the apparatus to:

receive the tunneling configuration that indicates that the condition is reception of a path switch command indicating to switch from communicating with the first cell via the first connection to communicating with the second cell via the second connection when the uplink data is available for transmission to the first cell.
The apparatus of claim 31, wherein the instructions to receive the tunneling configuration further are executable by the processor to cause the apparatus to:

receive the tunneling configuration that indicates that the condition is a channel quality associated with the first connection satisfying a threshold channel quality.
The apparatus of claim 31, wherein the dual-connectivity UE communicates with the first cell using a first radio access technology (RAT) and communicates with the second cell using a second RAT that differs from the first RAT.
The apparatus of claim 31, wherein the dual-connectivity UE communicates with the first cell using a first radio access technology (RAT) via a first frequency band and communicates with the second cell using the first RAT via a second frequency band that differs from the first frequency band.
The apparatus of claim 31, wherein the first cell comprises a New Radio (NR) cell and the second cell comprises a Long Term Evolution (LTE) cell, and comprises:

transmit, via the second connection with the LTE cell, the uplink transmission comprising the uplink data of the first connection with the NR cell.
The apparatus of claim 41, wherein the uplink data of the first connection comprises a New Radio (NR) uplink radio link control (RLC) control protocol data unit (PDU) .
The apparatus of claim 31, wherein the first cell comprises a Long Term Evolution (LTE) cell and the second cell comprises a New Radio (NR) cell, and comprises:

transmit, via the second connection with the NR cell, the uplink transmission comprising the uplink data of the first connection with the LTE cell.
An apparatus for wireless communications at a first cell, comprising:

a processor,

memory coupled with the processor; and

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

establish a first connection with a dual-connectivity user equipment (UE) ;

transmit, to the dual-connectivity UE, a tunneling configuration that indicates a condition for tunneling uplink data of a second connection to a second cell via the first connection; and

receive, via the first connection, an uplink transmission comprising the uplink data of the second connection and a tunneling indicator that indicates that the uplink transmission comprises the uplink data of the second connection.
The apparatus of claim 44, wherein the instructions to receive the uplink transmission are executable by the processor to cause the apparatus to:

receive, via the first connection, the uplink transmission that comprises a packet that encapsulates the uplink data of the second connection within a protocol of the first connection.
The apparatus of claim 44, wherein the instructions to receive the uplink transmission are executable by the processor to cause the apparatus to:

receive, via the first connection, the tunneling indicator that is a bit set to indicate that the uplink transmission comprises the uplink data of the second connection.
The apparatus of claim 44, wherein the instructions to receive the uplink transmission are executable by the processor to cause the apparatus to:

receive, via the first connection, the tunneling indicator that is a logical channel identifier that indicates a logical channel for tunneling the uplink data from a first entity of the first cell to a second entity of the second cell.
The apparatus of claim 44, wherein the instructions are further executable by the processor to cause the apparatus to:

tunnel the uplink data from a first entity of the first cell to a second entity of the second cell based at least in part on the tunneling indicator.
The apparatus of claim 48, wherein the first entity of the first cell comprises a radio link control (RLC) entity of the first cell and the second entity of the second cell comprises an RLC entity of the second cell.
The apparatus of claim 48, wherein the instructions to tunnel the uplink data from the first entity of the first cell to the second entity of the second cell are executable by the processor to cause the apparatus to:

tunnel the uplink data from the first entity of the first cell to the second entity of the second cell through a third entity of the second cell.
The apparatus of claim 50, wherein the instructions to tunnel the uplink data from the first entity of the first cell to the second entity of the second cell through the third entity of the second cell are executable by the processor to cause the apparatus to:

tunnel the uplink data from the first entity of the first cell to the third entity of the second cell via one or more core network entities.
The apparatus of claim 50, wherein the first entity of the first cell comprises a packet data convergence protocol (PDCP) entity of the first cell, the second entity of the second cell comprises a radio link control (RLC) entity of the second cell, and the third entity of the second cell comprises a PDCP entity of the second cell.
The apparatus of claim 44, wherein the instructions to transmit the tunneling configuration further are executable by the processor to cause the apparatus to:

transmit the tunneling configuration that indicates that the condition is transmission of a path switch command indicating the dual-connectivity UE to switch from communicating with the second cell via the second connection to communicating with the first cell via the first connection when the uplink data is available for transmission to the first cell.
The apparatus of claim 44, wherein the instructions are further executable by the processor to cause the apparatus to:

transmit a path switch command indicating the dual-connectivity UE to switch from communicating with the second cell via the second connection to communicating with the first cell via the first connection.
The apparatus of claim 44, wherein the instructions to transmit the tunneling configuration further are executable by the processor to cause the apparatus to:

transmit the tunneling configuration that indicates that the condition is a channel quality associated with the second connection satisfying a threshold channel quality.
The apparatus of claim 44, wherein the first cell communicates with the dual-connectivity UE using a first radio access technology (RAT) different than a second RAT associated with the second connection between the dual-connectivity UE and the second cell.
The apparatus of claim 44, wherein the first cell communicates with the dual-connectivity UE using a first radio access technology (RAT) via a first frequency band different than a second frequency band used by the first RAT associated with the second connection between the dual-connectivity UE and the second cell.
The apparatus of claim 44, wherein the first cell comprises a Long Term Evolution (LTE) cell and the second cell comprises a New Radio (NR) cell, and comprises:

receive, at the LTE cell via the first connection, the uplink transmission comprising the uplink data of the second connection with the NR cell.
The apparatus of claim 58, wherein the uplink data of the second connection comprises a New Radio (NR) uplink radio link control (RLC) control protocol data unit (PDU) .
The apparatus of claim 44, wherein the first cell comprises a New Radio (NR) cell and the second cell comprises a Long Term Evolution (LTE) cell, and comprises:

receive, at the NR cell via the first connection, the uplink transmission comprising the uplink data of the second connection with the NR cell.
An apparatus for wireless communications at a dual-connectivity user equipment (UE) , comprising:

means for establishing a first connection with a first cell and a second connection with a second cell that differs from the first cell;

means for receiving a tunneling configuration that indicates a condition for tunneling uplink data of the first connection to the first cell via the second connection; and

means for transmitting, via the second connection, an uplink transmission comprising the uplink data of the first connection and a tunneling indicator that indicates that the uplink transmission comprises the uplink data of the first connection based at least in part on the condition being satisfied.
An apparatus for wireless communications at a first cell, comprising:

means for establishing a first connection with a dual-connectivity user equipment (UE) ;

means for transmitting, to the dual-connectivity UE, a tunneling configuration that indicates a condition for tunneling uplink data of a second connection to a second cell via the first connection; and

means for receiving, via the first connection, an uplink transmission comprising the uplink data of the second connection and a tunneling indicator that indicates that the uplink transmission comprises the uplink data of the second connection.
A non-transitory computer-readable medium storing code for wireless communications at a dual-connectivity user equipment (UE) , the code comprising instructions executable by a processor to:

establish a first connection with a first cell and a second connection with a second cell that differs from the first cell;

receive a tunneling configuration that indicates a condition for tunneling uplink data of the first connection to the first cell via the second connection; and

transmit, via the second connection, an uplink transmission comprising the uplink data of the first connection and a tunneling indicator that indicates that the uplink transmission comprises the uplink data of the first connection based at least in part on the condition being satisfied.
A non-transitory computer-readable medium storing code for wireless communications at a first cell, the code comprising instructions executable by a processor to:

establish a first connection with a dual-connectivity user equipment (UE) ;

transmit, to the dual-connectivity UE, a tunneling configuration that indicates a condition for tunneling uplink data of a second connection to a second cell via the first connection; and

receive, via the first connection, an uplink transmission comprising the uplink data of the second connection and a tunneling indicator that indicates that the uplink transmission comprises the uplink data of the second connection.