Time division duplex techniques for dual connectivity to different radio access networks

Abstract

Methods, systems, and devices for wireless communication are described that support time division duplex (TDD) for dual connectivity (DC) to different radio access networks (RANs). A DC connection may be established between a user equipment (UE) and both a first RAN and a second RAN. A reference TDD configuration for the first RAN and a specified TDD configuration for both the first and second RANs may be identified. The specified TDD configuration may have a first set of uplink subframes, while the reference TDD configuration may have a second set of uplink subframes that is a subset of the first set of uplink subframes. Downlink transmissions of the first RAN may be transmitted according to the reference TDD configuration, while uplink transmissions of the first and second RANs may be transmitted according to the specified TDD configuration.

Description

[0001] This application is a divisional application of Chinese invention patent application 201980033365.5 (PCT / US2019 / 033353) with a filing date of May 21, 2019 and entitled “Time Division Duplex Technology for Dual Connectivity to Different Radio Access Networks”. Technical Field

[0002] The following relates generally to wireless communications and, more particularly, to time division duplexing techniques for dual connectivity to different radio access networks. Background Art

[0003] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, video, packet data, messaging, broadcasting, etc. These systems may be able to support communication with multiple users by sharing 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, advanced LTE (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 use various 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 OFDM (DFT-S-OFDM). A wireless multiple access communication system may include several base stations or network access nodes, each of which simultaneously supports the communication of multiple communication devices, which may be referred to as user equipment (UE).

[0004] The UE may perform a radio resource control (RRC) procedure, such as an RRC connection establishment procedure with a network node (e.g., a base station of an LTE system or an NR system). The RRC connection establishment procedure involves the UE accessing a cell and transmitting an RRC connection request to the network node. Some examples of wireless communication systems provide carrier aggregation and / or dual connectivity (DC) configurations for UEs. For example, when the UE is configured with DC, the UE may receive data transmitted by two network nodes. One network node may be a base station (e.g., an LTE base station) of a first radio access network (RAN) that may be associated with a primary cell group (MCG), and the other network may be a base station (e.g., an NR base station) of a second RAN that may be associated with a secondary cell group (SCG). DC configurations across different RANs may result in some configurations and / or uplink / downlink transmissions that may be incompatible (e.g., concurrent transmissions of the two RANs may cause interference with each other). Efficient techniques for DC communications across multiple RANs may be desired to help enhance network efficiency and reliability. Summary of the invention

[0005] The described technology relates to improved methods, systems, devices and apparatuses for supporting time division duplex (TDD) technology for dual connectivity (DC) to different radio access networks (RANs). In general, the described technology provides for establishing a DC connection between a user equipment (UE) and both a first RAN and a second RAN. In some cases, transmissions of different RANs may use time division multiplexing (TDM) to provide uplink transmissions for these different RANs from a single transmitter UE. In some cases, TDM may be achieved by selecting a TDD configuration and scheduling transmissions of different RANs in different uplink and downlink subframes. In some cases, a reference TDD configuration for the first RAN may be identified, and a specified TDD configuration for both the first and second RANs may be identified. The specified TDD configuration may have a first uplink subframe set, and the reference TDD configuration may have a second uplink subframe set that is a subset of the first uplink subframe set. Downlink transmissions of the first RAN may be transmitted according to the reference TDD configuration, and uplink transmissions of the first and second RANs may be transmitted according to the specified TDD configuration.

[0006] In some cases, an acknowledgement / negative acknowledgement (ACK / NACK) feedback corresponding to a downlink hybrid acknowledgment repeat request (HARQ) process of the first RAN is transmitted according to a reference TDD configuration. In some cases, an ACK / NACK feedback corresponding to an uplink HARQ process of the first RAN is transmitted according to a specified TDD configuration. In some cases, the first RAN may be a fourth generation (4G) or long term evolution (LTE) RAN, and the second RAN may be a fifth generation (5G) or new radio (NR) RAN, and the DC connectivity may be referred to as Evolved Universal Terrestrial Radio Access New Radio Dual Connectivity (EN-DC) or E-UTRAN-NRDC. In such cases, under the DC configuration, the LTE RAN may provide a primary carrier group (MCG) and the NR RAN may provide a secondary carrier group (SCG).

[0007] A method of wireless communication at a UE is described. The method may include: establishing, at the UE, a first connection using a RAN and a second connection using a second RAN; identifying a reference TDD configuration for the first connection and a specified TDD configuration for both the first connection and the second connection, wherein the specified TDD configuration has a first uplink subframe set and the reference TDD configuration has a second uplink subframe set that is a subset of the first uplink subframe set; receiving a downlink transmission via the first RAN according to the reference TDD configuration; and transmitting an uplink transmission via the first RAN and the second RAN according to the specified TDD configuration.

[0008] An apparatus for wireless communication at a UE is described. The apparatus may include a processor, a memory in electronic communication with the processor, and instructions stored in the memory. The instructions are executable by the processor to cause the apparatus to: establish a first connection using a first RAN and a second connection using a second RAN at the UE; identify a reference TDD configuration for the first connection and a specified TDD configuration for both the first connection and the second connection, wherein the specified TDD configuration has a first uplink subframe set, and the reference TDD configuration has a second uplink subframe set that is a subset of the first uplink subframe set; receive a downlink transmission via the first RAN according to the reference TDD configuration; and transmit an uplink transmission via the first RAN and the second RAN according to the specified TDD configuration.

[0009] Another apparatus for wireless communication at a UE is described. The apparatus may include means for: establishing at the UE a first connection using a first RAN and a second connection using a second RAN; identifying a reference TDD configuration for the first connection and a specified TDD configuration for both the first connection and the second connection, wherein the specified TDD configuration has a first set of uplink subframes and the reference TDD configuration has a second set of uplink subframes that is a subset of the first set of uplink subframes; receiving a downlink transmission via the first RAN according to the reference TDD configuration; and transmitting an uplink transmission via the first RAN and the second RAN according to the specified TDD configuration.

[0010] A non-transitory computer-readable medium storing code for wireless communication at a UE is described. The code may include instructions executable by a processor for the following operations: establishing a first connection using a first RAN and a second connection using a second RAN at the UE; identifying a reference TDD configuration for the first connection and a specified TDD configuration for both the first connection and the second connection, wherein the specified TDD configuration has a first uplink subframe set, and the reference TDD configuration has a second uplink subframe set that is a subset of the first uplink subframe set; receiving a downlink transmission via the first RAN according to the reference TDD configuration; and transmitting an uplink transmission via the first RAN and the second RAN according to the specified TDD configuration.

[0011] In some examples of the methods, apparatuses (devices), and non-transient computer-readable media described herein, ACK / NACK feedback corresponding to the downlink HARQ process of the first RAN may be transmitted according to a reference TDD configuration. In some examples of the methods, apparatuses (devices), and non-transient computer-readable media described herein, ACK / NACK feedback corresponding to the uplink HARQ process of the first RAN may be transmitted according to a specified TDD configuration. Some examples of the methods, apparatuses (devices), and non-transient computer-readable media described herein may further include operations, features, means, or instructions for the following actions: the uplink shared channel transmission of the first RAN may be transmitted according to a specified TDD configuration. In some examples of the methods, apparatuses (devices), and non-transient computer-readable media described herein, uplink ACK / NACK feedback information, uplink shared channel data, uplink control channel data, uplink reference signals, and downlink ACK / NACK feedback of the second RAN may be transmitted according to a specified TDD configuration.

[0012] Some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein may further include operations, features, means, or instructions for the following actions: receiving scheduling information for transmitting uplink transmissions of a first RAN and a second RAN, wherein the uplink transmissions of the first RAN may be scheduled in an uplink subframe different from the uplink transmissions of the second RAN in a specified TDD configuration; and transmitting the uplink transmissions of the first RAN and the second RAN according to the scheduling information. Some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein may further include operations, features, means, or instructions for the following actions: determining that both the first uplink transmission of the first RAN and the second uplink transmission of the second RAN may be scheduled in the same first TDD uplink subframe; and identifying the first TDD uplink subframe as an error situation. Some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein may further include operations, features, means, or instructions for: determining that a first uplink transmission of the first RAN and a second uplink transmission of the second RAN can both be scheduled in the same first TDD uplink subframe; discarding the second uplink transmission of the second RAN; and transmitting the first uplink transmission of the first RAN in the first TDD uplink subframe.

[0013] In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, the first RAN may be a 4G or LTE RAN, and the second RAN may be a 5G or NR RAN. In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, in a DC configuration, a first connection using the first RAN may be established as an MCG connection, and a second connection using the second RAN may be established as an SCG connection.

[0014] Some examples of the methods, apparatus (devices) and non-transitory computer-readable media described herein may further include operations, features, apparatuses or instructions for the following actions: determining the dynamic sharing capability of the UE and the single transmission capability or dual transmission capability of the UE before identifying a reference TDD configuration, and wherein the reference TDD configuration can be identified based on the dynamic sharing capability and the single transmission capability or dual transmission capability.

[0015] A method of wireless communication at a base station is described. The method may include: establishing a first connection with a UE using a first RAN, and wherein a second connection is established at the UE using a second RAN; identifying a reference TDD configuration for the first connection and a specified TDD configuration for both the first connection and the second connection, wherein the specified TDD configuration has a first uplink subframe set, and the reference TDD configuration has a second uplink subframe set that is a subset of the first uplink subframe set; transmitting a downlink transmission to the UE via the first RAN according to the reference TDD configuration; and receiving an uplink transmission from the UE via the first RAN according to the specified TDD configuration, and wherein the UE transmits the uplink transmission via the second RAN according to the specified TDD configuration.

[0016] An apparatus for wireless communication at a base station is described. The apparatus may include a processor, a memory in electronic communication with the processor, and instructions stored in the memory. The instructions are executable by the processor to cause the apparatus to: establish a first connection with a UE using a first RAN, and wherein a second connection is established at the UE using a second RAN; identify a reference TDD configuration for the first connection and a specified TDD configuration for both the first connection and the second connection, wherein the specified TDD configuration has a first uplink subframe set, and the reference TDD configuration has a second uplink subframe set that is a subset of the first uplink subframe set; transmit a downlink transmission to the UE via the first RAN according to the reference TDD configuration; and receive an uplink transmission from the UE via the first RAN according to the specified TDD configuration, and wherein the UE transmits the uplink transmission via the second RAN according to the specified TDD configuration.

[0017] Another apparatus for wireless communication at a base station is described. The apparatus may include means for: establishing a first connection with a UE using a first RAN, and wherein a second connection is established at the UE using a second RAN; identifying a reference TDD configuration for the first connection and a specified TDD configuration for both the first connection and the second connection, wherein the specified TDD configuration has a first uplink subframe set, and the reference TDD configuration has a second uplink subframe set that is a subset of the first uplink subframe set; transmitting a downlink transmission to the UE via the first RAN according to the reference TDD configuration; and receiving an uplink transmission from the UE via the first RAN according to the specified TDD configuration, and wherein the UE transmits the uplink transmission via the second RAN according to the specified TDD configuration.

[0018] A non-transitory computer-readable medium storing code for wireless communication at a base station is described. The code may include instructions executable by a processor for the following operations: establishing a first connection with a UE using a first RAN, and wherein a second connection is established at the UE using a second RAN; identifying a reference TDD configuration for the first connection and a specified TDD configuration for both the first connection and the second connection, wherein the specified TDD configuration has a first uplink subframe set, and the reference TDD configuration has a second uplink subframe set that is a subset of the first uplink subframe set; transmitting a downlink transmission to the UE via the first RAN according to the reference TDD configuration; and receiving an uplink transmission from the UE via the first RAN according to the specified TDD configuration, and wherein the UE transmits the uplink transmission via the second RAN according to the specified TDD configuration.

[0019] In some examples of the methods, apparatuses (devices), and non-transient computer-readable media described herein, ACK / NACK feedback corresponding to the downlink HARQ process of the first RAN may be transmitted according to a reference TDD configuration. In some examples of the methods, apparatuses (devices), and non-transient computer-readable media described herein, ACK / NACK feedback corresponding to the uplink HARQ process of the first RAN may be transmitted according to a specified TDD configuration. In some examples of the methods, apparatuses (devices), and non-transient computer-readable media described herein, uplink shared channel transmissions of the first RAN may be transmitted according to a specified TDD configuration. In some examples of the methods, apparatuses (devices), and non-transient computer-readable media described herein, uplink ACK / NACK feedback information, uplink shared channel data, uplink control channel data, uplink reference signals, and downlink ACK / NACK feedback of the second RAN may be transmitted according to a specified TDD configuration.

[0020] Some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein may further include operations, features, means, or instructions for the following actions: scheduling the UE for uplink transmission via the first RAN and the second RAN, wherein the uplink transmission of the first RAN may be scheduled in an uplink subframe different from the uplink transmission of the second RAN in a specified TDD configuration; and receiving the uplink transmission from the UE according to the scheduling. In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, the UE may be configured to: identify an error situation when both the first uplink transmission of the first RAN and the second uplink transmission of the second RAN may be scheduled in the same first TDD uplink subframe. Some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein may further include operations, features, means, or instructions for the following actions: when both the first uplink transmission of the first RAN and the second uplink transmission of the second RAN may be scheduled in a first TDD uplink subframe, receiving the first uplink transmission of the first RAN in the first TDD uplink subframe, and wherein the UE discards the second uplink transmission of the second RAN.

[0021] In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, the first RAN may be a 4G or LTE RAN, and the second RAN may be a 5G or NR RAN. In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, in a DC configuration, a first connection using the first RAN may be established as an MCG connection, and a second connection using the second RAN may be established as an SCG connection.

[0022] Some examples of the methods, apparatus (devices) and non-transitory computer-readable media described herein may further include operations, features, apparatus or instructions for the following actions: receiving a dynamic sharing capability of the UE and a single transmission capability or a dual transmission capability of the UE from the UE before identifying a reference TDD configuration, and wherein the reference TDD configuration may be identified based on the dynamic sharing capability and the single transmission capability or the dual transmission capability. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 An example of a wireless communication system supporting time division duplex technology for dual connectivity to different radio access networks in accordance with aspects of the present disclosure is illustrated.

[0024] Figure 2 An example of a portion of a wireless communication system supporting time division duplex technology for dual connectivity to different radio access networks in accordance with aspects of the present disclosure is illustrated.

[0025] Figure 3 An example of a process flow supporting a time division duplex technique for dual connectivity to different radio access networks in accordance with aspects of the present disclosure is illustrated.

[0026] Figure 4 An example of a TDD format supporting a time division duplex technique for dual connectivity to different radio access networks in accordance with aspects of the present disclosure is illustrated.

[0027] Figure 5 An example of a process flow supporting a time division duplex technique for dual connectivity to different radio access networks in accordance with aspects of the present disclosure is illustrated.

[0028] Figure 6 and Figure 7 A block diagram of an apparatus supporting time division duplex technology for dual connectivity to different radio access networks in accordance with aspects of the present disclosure is shown.

[0029] Figure 8 A block diagram of a communication manager supporting time division duplex technology for dual connectivity to different radio access networks in accordance with aspects of the present disclosure is shown.

[0030] Fig. 9 A diagram of a system including devices supporting time division duplex technology for dual connectivity to different radio access networks in accordance with aspects of the present disclosure is shown.

[0031] Fig.10 and Fig.11 A block diagram of an apparatus supporting time division duplex technology for dual connectivity to different radio access networks in accordance with aspects of the present disclosure is shown.

[0032] Fig.12 A block diagram of a communication manager supporting time division duplex technology for dual connectivity to different radio access networks in accordance with aspects of the present disclosure is shown.

[0033] Fig.13 A diagram of a system including devices supporting time division duplex technology for dual connectivity to different radio access networks in accordance with aspects of the present disclosure is shown.

[0034] Figures 14 to 18 A flow chart illustrating a method of supporting a time division duplex technique for dual connectivity to different radio access networks in accordance with aspects of the present disclosure is shown. DETAILED DESCRIPTION

[0035] Various aspects of the present disclosure provide a time division duplex (TDD) technique for dual connectivity (DC) to different radio access networks (RANs). In some cases, a DC connection may be established between a user equipment (UE) and a first RAN and a second RAN. Such a DC connection may be, for example, a DC connection in which a primary carrier group (MCG) is a long term evolution (LTE) RAN and a secondary carrier group (SCG) is a new radio (NR) RAN, and such a DC configuration may be referred to as EN-DC.

[0036] In some cases, a UE in such a DC configuration may have a single transmitter for transmitting both LTE communications and NR communications. In such cases, transmissions of different RANs may use time division multiplexing (TDM), which may be achieved by selecting a TDD configuration and scheduling the transmissions of different RANs in different uplink and downlink subframes. In some cases, a reference TDD configuration for a first RAN (e.g., an LTE RAN) may be identified, and a specified TDD configuration for both the first RAN and the second RAN (e.g., an NR RAN) may be identified. The specified TDD configuration may have a first set of uplink subframes, and the reference TDD configuration may have a second set of uplink subframes that is a subset of the first set of uplink subframes. Downlink transmissions of the first RAN may be transmitted according to the reference TDD configuration, and uplink transmissions of the first and second RANs may be transmitted according to the specified TDD configuration.

[0037] In some cases, ACK / NACK feedback corresponding to the downlink HARQ process of the first RAN is transmitted according to a reference TDD configuration. In some cases, ACK / NACK feedback corresponding to the uplink HARQ process of the first RAN is transmitted according to a specified TDD configuration. In some cases, the first RAN may be a fourth generation (4G) or LTE RAN, and the second RAN may be a fifth generation (5G) or NR RAN, and the DC connectivity may be referred to as EN-DC or E-UTRAN-NR DC. In such cases, under the DC configuration, the LTE RAN may provide an MCG, and the NR RAN may provide an SCG. Such techniques may provide TDM of uplink transmissions of different RANs, which may provide more efficient and reliable communications via the first RAN and the second RAN.

[0038] Aspects of the present disclosure are initially described in the context of a wireless communication system. Aspects of the present disclosure are further illustrated and described by and with reference to apparatus diagrams, system diagrams, and flow diagrams related to TDD techniques for DC to different RANs.

[0039] Figure 1An example of a wireless communication system 100 supporting a time division duplex technology for dual connectivity to different radio access networks according to various aspects of the present disclosure is illustrated. The wireless communication system 100 includes a base station 105, a UE 115, and a core network 130. In some examples, the wireless communication system 100 may be an LTE network, an advanced LTE (LTE-A) network, an LTE-A Pro network, or an NR network. In some cases, the wireless communication system 100 may support enhanced broadband communications, ultra-reliable (e.g., mission-critical) communications, low latency communications, or communications with low-cost and low-complexity devices. In some cases, one or more base stations 105 may provide connectivity to a first RAN (e.g., LTE connectivity), and one or more base stations 105 may provide connectivity to a second RAN (e.g., NR RAN). The UE 115 may connect the two RANs in DC mode, and may communicate using these different RANs according to various techniques as discussed herein.

[0040] The base station 105 may communicate wirelessly with the UE 115 via one or more base station antennas. The base station 105 described herein may include or may be referred to by those skilled in the art as a base transceiver station, a radio base station, an access point, a radio transceiver, a Node B, an evolved Node B (eNB), a next generation Node B, or a Gigabit Node B (any of which may be referred to as a gNB), a Home Node B, a Home Evolved Node B, or some other suitable terminology. The wireless communication system 100 may include different types of base stations 105 (e.g., macro cell base stations or small cell base stations). The UE 115 described herein may be able to communicate with various types of base stations 105 and network equipment (including macro eNBs, small cell eNBs, gNBs, relay base stations, etc.).

[0041] Each base station 105 may be associated with a particular geographic coverage area 110 in which it supports communications with various UEs 115. Each base station 105 may provide communications coverage for the respective geographic coverage area 110 via a communications link 125, and the communications link 125 between the base station 105 and the UE 115 may utilize one or more carriers. The communications link 125 shown in the wireless communication system 100 may include an uplink transmission from the UE 115 to the base station 105, or a downlink transmission from the base station 105 to the UE 115. Downlink transmissions may also be referred to as forward link transmissions, and uplink transmissions may also be referred to as reverse link transmissions.

[0042] The geographic coverage area 110 of the base station 105 may be divided into sectors that constitute a portion of the geographic coverage area 110, and each sector may be associated with a cell. For example, each base station 105 may provide communication coverage for a macro cell, a small cell, a hotspot, or other types of cells, or various combinations thereof. In some examples, the base station 105 may be mobile and thus provide communication coverage for a mobile geographic coverage area 110. In some examples, different geographic coverage areas 110 associated with different technologies may overlap, and the overlapping geographic coverage areas 110 associated with different technologies may be supported by the same base station 105 or different base stations 105. The wireless communication system 100 may include, for example, a heterogeneous LTE / LTE-A / LTE-A Pro or NR network, in which different types of base stations 105 provide coverage for various geographic coverage areas 110.

[0043] The term "cell" refers to a logical communication entity for communicating with base station 105 (e.g., on a carrier), and may be associated with an identifier to distinguish adjacent cells operating via the same or different carriers (e.g., physical cell identifier (PCID), virtual cell identifier (VCID)). In some examples, a carrier may support multiple cells, and different cells may be configured according to different protocol types that may provide access to different types of devices (e.g., machine type communication (MTC), narrowband Internet of Things (NB-IoT), enhanced mobile broadband (eMBB), or others). In some cases, the term "cell" may refer to a portion of a geographic coverage area 110 (e.g., a sector) on which the logical entity operates.

[0044] Each UE 115 can be dispersed throughout the wireless communication system 100, and each UE 115 can be stationary or mobile. UE 115 can also be referred to as a mobile device, a wireless device, a remote device, a handheld device, or a subscriber device, or some other suitable term, wherein "device" can also be referred to as a unit, a station, a terminal, or a client. UE 115 can also be 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, UE 115 can also refer to a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or an MTC device, etc., which can be implemented in various items (such as electrical appliances, vehicles, meters, etc.).

[0045] Some UEs 115, such as MTC or IoT devices, may be low-cost or low-complexity devices and may provide automated communication between machines (e.g., via machine-to-machine (M2M) communication). M2M communication or MTC may refer to data communication technology that allows devices to communicate with each other or with 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 the information to a central server or application, which may utilize the information or present the information to a person interacting with the program or application. Some UEs 115 may be designed to collect information or implement automated behavior of machines. Examples of applications for MTC devices include: smart metering, inventory monitoring, water level monitoring, equipment monitoring, health care monitoring, field survival monitoring, weather and geographic event monitoring, queue management and tracking, remote security sensing, physical access control, and transaction-based commercial charging.

[0046] Some UEs 115 may be configured to employ a reduced power consumption mode of operation, such as half-duplex communication (e.g., a mode that supports unidirectional communication via transmission or reception but not simultaneous transmission and reception). In some examples, half-duplex communication may be performed with a reduced peak rate. Other power saving techniques for UE 115 include entering a power saving "deep sleep" mode when not engaged in active communications, or operating over a limited bandwidth (e.g., in accordance with narrowband communications). In some cases, UE 115 may be designed to support critical functions (e.g., mission critical functions), and the wireless communication system 100 may be configured to provide ultra-reliable communications for these functions.

[0047] In some cases, UE 115 may also be able to communicate directly with other UE 115 (e.g., using a peer-to-peer (P2P) or device-to-device (D2D) protocol). One or more UEs in a group of UEs 115 utilizing D2D communication may be within the geographic coverage area 110 of the base station 105. Other UEs 115 in this group may be outside the geographic coverage area 110 of the base station 105, or may not be able to receive transmissions from the base station 105 for other reasons. In some cases, each group of UEs 115 communicating via D2D communication may utilize a one-to-many (1:M) system, in which each UE 115 transmits to each other UE 115 in the group. In some cases, the base station 105 facilitates the scheduling of resources for D2D communication. In other cases, D2D communication is performed between UEs 115 without involving the base station 105.

[0048] The base stations 105 may communicate with the core network 130 and with each other. For example, the base stations 105 may interface with the core network 130 via a backhaul link 132 (e.g., via S1, N2, N3, or other interfaces). The base stations 105 may communicate with each other over a backhaul link 134 (e.g., via X2, Xn, or other interfaces) directly (e.g., directly between the base stations 105) or indirectly (e.g., via the core network 130).

[0049] 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), which may include at least one mobility management entity (MME), at least one serving gateway (S-GW), and at least one packet data network (PDN) gateway (P-GW). The MME may manage non-access layer (e.g., control plane) functions such as mobility, authentication, and bearer management of UEs 115 served by base stations 105 associated with the EPC. User IP packets may be delivered through the S-GW, which itself may be connected to the P-GW. The P-GW may provide IP address allocation and other functions. The P-GW may be connected to network operator IP services. Operator IP services may include access to the Internet, intranets, IP multimedia subsystems (IMS), or packet switched (PS) streaming services.

[0050] At least some network devices (such as base stations 105) may include subcomponents, such as access network entities, which may be examples of access node controllers (ANCs). Each access network entity may communicate with each UE 115 through a number of other access network transport entities, which may be referred to as radio heads, smart radio heads, or transmission / reception points (TRPs). In some configurations, the various functions of each access network entity or base station 105 may be distributed across various network devices (e.g., radio heads and access network controllers) or merged into a single network device (e.g., base station 105).

[0051] The wireless communication system 100 may operate using one or more frequency bands, typically in the range of 300 MHz to 300 GHz. In general, the 300 MHz to 3 GHz region is referred to as the ultra-high frequency (UHF) region or decimeter band because the wavelengths are in the range of from about 1 decimeter to 1 meter long. UHF waves may be blocked or redirected by buildings and environmental features. However, these waves may penetrate various structures sufficiently for macro cells to provide services to UEs 115 located indoors. Transmission of UHF waves may be associated with smaller antennas and shorter ranges (e.g., less than 100 km) compared to transmission using lower frequencies and longer waves in the high frequency (HF) or very high frequency (VHF) portion of the spectrum below 300 MHz.

[0052] The wireless communication system 100 may also operate in the very high frequency (SHF) region using a frequency band from 3 GHz to 30 GHz, also known as the centimeter frequency band. The SHF region includes frequency bands that may be opportunistically used by devices that can tolerate interference from other users, such as the 5 GHz Industrial, Scientific, and Medical (ISM) band.

[0053] The wireless communication system 100 may also operate in the extremely high frequency (EHF) division of the spectrum (e.g., from 30 GHz to 300 GHz), which is also referred to as the millimeter band. In some examples, the wireless communication system 100 may support millimeter wave (mmW) communications between the UE 115 and the base station 105, and the EHF antenna of the corresponding device may be even smaller and more closely spaced than the UHF antenna. In some cases, this may facilitate the use of antenna arrays within the UE 115. However, the propagation of EHF transmissions may be subject to even greater atmospheric attenuation and shorter range than SHF or UHF transmissions. The technology disclosed herein may be adopted across transmissions using one or more different frequency divisions, and the use of frequency bands specified across these frequency divisions may differ by country or regulatory agency.

[0054] In some cases, the wireless communication system 100 may utilize both licensed and unlicensed radio frequency spectrum bands. For example, the wireless communication system 100 may adopt license assisted access (LAA), LTE unlicensed (LTE-U) radio access technology, or NR technology in an unlicensed band (such as a 5GHz ISM band). When operating in an unlicensed radio frequency spectrum band, wireless devices (such as base stations 105 and UE 115) may adopt a listen-before-talk (LBT) procedure to ensure that the frequency channel is clear before transmitting data. In some cases, operations in unlicensed bands may be based on CA configurations (e.g., LAA) in coordination with CCs operating in licensed bands. Operations in unlicensed spectrum may include downlink transmissions, uplink transmissions, peer-to-peer transmissions, or a combination of these. Duplexing in unlicensed spectrum may be based on frequency division duplexing (FDD), TDD, or a combination of both.

[0055] In some examples, the base station 105 or the 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) communication, or beamforming. For example, the wireless communication system 100 may use a transmission scheme between a transmitting device (e.g., the base station 105) and a receiving device (e.g., the UE 115), wherein the transmitting device is equipped with multiple antennas and the receiving device is equipped with one or more antennas. MIMO communication may employ multipath signal propagation to increase spectral efficiency by transmitting or receiving multiple signals via different spatial layers, which may be referred to as spatial multiplexing. For example, the transmitting device may transmit multiple signals via different antennas or different antenna combinations. Similarly, the receiving device may receive multiple signals via different antennas or different antenna combinations. Each of these 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. Different spatial layers may be associated with different antenna ports for channel measurement and reporting. MIMO technology includes single-user MIMO (SU-MIMO), in which multiple spatial layers are transmitted to the same receiving device, and multi-user MIMO (MU-MIMO), in which multiple spatial layers are transmitted to multiple devices.

[0056] 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 or a UE 115) to shape or direct an antenna beam (e.g., a transmit beam or a receive beam) along a spatial path between the transmitting device and the receiving device. Beamforming may be achieved by combining signals communicated via antenna elements of an antenna array so that signals propagating at a particular orientation relative to the antenna array experience constructive interference, while other signals experience destructive interference. Adjustments to signals communicated via antenna elements may include the transmitting device or the receiving device applying a particular amplitude and phase shift to the signal carried via each antenna element associated with the device. Adjustments associated with each antenna element may be defined by a set of beamforming weights associated with a particular orientation (e.g., relative to the antenna array of the transmitting device or the receiving device, or relative to some other orientation).

[0057] In some cases, the antennas of a base station 105 or a UE 115 may be located within one or more antenna arrays that 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 cases, the antennas or antenna arrays associated with a base station 105 may be located at different geographic locations. A base station 105 may have an antenna array having several rows and columns of antenna ports that the base station 105 may use to support beamforming for communications with a UE 115. Likewise, a UE 115 may have one or more antenna arrays that may support various MIMO or beamforming operations.

[0058] In some cases, the wireless communication system 100 can be a packet-based network that operates according to a layered protocol stack. In the user plane, the communication of the bearer or packet data convergence protocol (PDCP) layer can be based on IP. In some cases, the radio link control (RLC) layer can perform packet segmentation and reorganization to communicate on the logical channel. The media access control (MAC) layer can perform priority handling and multiplex logical channels into transport channels. The MAC layer can also use hybrid automatic repeat request (HARQ) to provide retransmission of the MAC layer, thereby improving link efficiency. In the control plane, the radio resource control (RRC) protocol layer can provide the establishment, configuration and maintenance of the RRC connection of the radio bearer supporting user plane data between the UE 115 and the base station 105 or the core network 130. In the physical (PHY) layer, the transport channel can be mapped to the physical channel.

[0059] In some cases, UE 115 and base station 105 may support retransmission of data to increase the likelihood that the data is successfully received. HARQ feedback is a technique that increases the likelihood of correctly receiving data on communication link 125. HARQ may include a combination of error detection (e.g., using cyclic redundancy check (CRC)), forward error correction (FEC), and retransmission (e.g., automatic repeat request (ARQ)). HARQ can improve the throughput of the MAC layer in poor radio conditions (e.g., signal-to-noise ratio conditions). In some cases, a wireless device may support simultaneous slot HARQ feedback, where the device may provide HARQ feedback in a specific time slot for data received in a previous symbol in the time slot. In other cases, the device may provide HARQ feedback in a subsequent time slot or according to some other time interval.

[0060] The time interval in LTE or NR can be represented by a basic time unit (which may refer to a sampling period T, for example). s =1 / 30,720,000 seconds). The time intervals of the communication resources may be organized according to radio frames each having a duration of 10 milliseconds (ms), where the frame period may be expressed as T f =307,200Ts . A radio frame may be identified by a system frame number (SFN) ranging from 0 to 1023. Each frame may include 10 subframes numbered from 0 to 9, and each subframe may have a duration of 1 ms. A subframe may be further divided into 2 time slots, each having a duration of 0.5 ms, and each time slot may contain 6 or 7 modulation codeword periods (e.g., depending on the length of the cyclic prefix added before each codeword period). Excluding the cyclic prefix, each codeword period may contain 2048 sampling periods. In some cases, a subframe may be the minimum scheduling unit of the wireless communication system 100 and may be referred to as a transmission time interval (TTI). In other cases, the minimum scheduling unit of the wireless communication system 100 may be shorter than a subframe or may be dynamically selected (e.g., in a burst of a shortened TTI (sTTI) or in a selected component carrier using sTTI).

[0061] The term "carrier" refers to a set of radio frequency spectrum resources having a defined physical layer structure for supporting communications on the communication link 125. For example, a carrier of the communication link 125 may include a portion of a radio frequency spectrum band that operates according to a physical layer channel for a given radio access technology. Each physical layer channel may carry user data, control information, or other signaling. A carrier may be associated with a predefined frequency channel (e.g., an E-UTRA Absolute Radio Frequency Channel Number (EARFCN)) and may be located according to a channel grid for discovery by a UE 115. A carrier may be downlink or uplink (e.g., in FDD mode), or may be configured to carry downlink communications and uplink communications (e.g., in TDD mode). In some examples, a signal waveform transmitted on a carrier may include multiple subcarriers (e.g., using a multi-carrier modulation (MCM) technique such as OFDM or DFT-s-OFDM).

[0062] The organization structure of the carrier may be different for different radio access technologies (e.g., LTE, LTE-A, LTE-A Pro, NR, etc.). For example, communications on a carrier may be organized according to TTIs or time slots, each of which may include user data and control information or signaling to support decoding of the user data. A carrier may also include dedicated acquisition signaling (e.g., synchronization signals or system information, etc.) and control signaling to coordinate carrier operations. In some examples (e.g., in a carrier aggregation configuration), a carrier may also have acquisition signaling or control signaling to coordinate the operations of other carriers.

[0063] Physical channels may be multiplexed on a carrier according to various techniques. Physical control channels and physical data channels may be multiplexed on a downlink carrier, for example, using TDM techniques, frequency division multiplexing (FDM) techniques, or hybrid TDM-FDM techniques. In some examples, control information transmitted in a physical control channel may be distributed in a cascaded manner between different control regions (e.g., between a common control region or a common search space and one or more UE-specific control regions or UE-specific search spaces).

[0064] 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 the "system bandwidth" of the carrier or wireless communication system 100. For example, the carrier bandwidth may be one of several predetermined bandwidths of a carrier for a particular radio access technology (e.g., 1.4, 3, 5, 10, 15, 20, 40, or 80 MHz). In some examples, each served UE 115 may be configured to operate on part or all of the carrier bandwidth. In other examples, some UEs 115 may be configured to operate using a narrowband protocol type associated with a predefined portion or range (e.g., a set of subcarriers or RBs) within a carrier (e.g., an "in-band" deployment of a narrowband protocol type).

[0065] In a system using MCM technology, a resource element may include a symbol period (e.g., the duration of a modulation symbol) and a subcarrier, where the symbol period and the subcarrier spacing are inversely related. The number of bits carried by each resource element may depend on the modulation scheme (e.g., the order of the modulation scheme). Thus, the more resource elements received by UE 115 and the higher the order of the modulation scheme, the higher the data rate of UE 115 can be. In a MIMO system, wireless communication resources may refer to a combination of radio frequency spectrum resources, time resources, and space resources (e.g., space layers), and the use of multiple space layers may further increase the data rate of communication with UE 115.

[0066] A device (e.g., base station 105 or UE 115) of wireless communication system 100 may have a hardware configuration that supports communication on a particular carrier bandwidth, or may be configurable to support communication on one carrier bandwidth in a set of carrier bandwidths. In some examples, wireless communication system 100 may include base stations 105 and / or UEs 115 that may support simultaneous communication via carriers associated with more than one different carrier bandwidths.

[0067] The wireless communication system 100 may support communication with a UE 115 on multiple cells or carriers, a feature that may be referred to as carrier aggregation (CA) or multi-carrier operation. The UE 115 may be configured with multiple downlink CCs and one or more uplink CCs according to a carrier aggregation configuration. Carrier aggregation may be used with both FDD and TDD component carriers.

[0068] In some cases, one or more base stations 105 may provide connectivity to a first RAN (such as an LTE RAN), and one or more base stations 105 may provide connectivity to a second RAN (such as an NR RAN). In such cases, a DC connection may be established between the UE 115 and the first and second RANs. Such a DC connection may be, for example, a DC connection in which the first RAN (e.g., LTE) provides an MCG and the second RAN (e.g., NR) provides an SCG. Such a DC configuration with an LTE MCG and an NR SCG may be referred to as EN-DC. In some cases, due to the more limited coverage area in some NR deployments, an LTE connection may be established for initial system access of the UE 115, and then the NR is configured so that NR communications can be utilized when the UE 115 is in the service area of ​​the NR cell.

[0069] In addition, in some cases, the UE may have a single transmitter for transmitting both LTE communications and NR communications. In such cases, transmissions of different RANs may use TDM, which may be achieved by selecting a TDD configuration and scheduling the transmissions of the different RANs in different uplink and downlink subframes. In some cases, a reference TDD configuration for the first RAN may be identified, and a specified TDD configuration for both the first RAN and the second RAN may be identified. The specified TDD configuration may have a first set of uplink subframes, and the reference TDD configuration may have a second set of uplink subframes that is a subset of the first set of uplink subframes. Downlink transmissions of the first RAN may be transmitted according to the reference TDD configuration, and uplink transmissions of the first and second RANs may be transmitted according to the specified TDD configuration.

[0070] Figure 2 An example of a wireless communication system 200 that supports time division duplex technology for dual connectivity to different radio access networks according to aspects of the present disclosure is illustrated. In some examples, the wireless communication system 200 can implement aspects of the wireless communication system 100. Figure 2 In the example of FIG. 1 , the wireless communication system 200 may include a UE 215, a first base station 205, and a second base station 210. The UE 215 may be a base station as described herein. Figure 1 In some cases, the first base station 205 may be as described herein with reference to Figure 1 The eNB of the LTE RAN described herein, and the second base station 210 may be as referred to herein Figure 1 The gNB of the described NR RAN. The first base station 205 can be associated with the coverage area 225. In addition, the second base station 210 can be associated with the coverage area 220. Both the first base station 205 and the second base station 210 can communicate with the UE 215 via the communication link 230. Various aspects of the following communication examples are described as occurring between the UE 215, the first base station 205, and the second base station 210.

[0071] As indicated above, in some cases, UE 215 may be configured for carrier aggregation or dual connectivity to improve data throughput. UE 215 may be in RRC idle mode or RRC inactive mode. RRC idle mode and / or RRC inactive mode may be an operational indication that UE 215 has no RRC connection established with a network (e.g., first base station 205 or second base station 210, or both). During RRC idle mode or RRC inactive mode, UE 215 may receive system information from first base station 205. In some cases, the system information may include relevant frequencies for UE 215 to measure on the same or different RANs. For example, the system information may indicate frequencies associated with an LTE system or an NR system. Additionally or alternatively, UE 215 may receive system information as part of a system information block (SIB) message from first base station 205.

[0072] UE 215 may initiate a connection establishment procedure to establish an RRC connection with both the first base station 205 and the second base station 210. In some cases, as discussed above, the first base station 205 may provide a primary connection on the MCG and the second base station 210 may provide a connection on the SCG. When establishing these connections with the first base station 205 and the second base station 210, the UE 215 may provide an indication of the capabilities of the UE 215. Such capabilities may include, for example, the ability to dynamically share between different RANs of a DC connection. In some cases, the UE 215 may be a single-transmitter UE, in which a single transmitter is shared for each uplink transmission on the communication link 230. In such a case, the transmitter may be used to transmit to the first base station via the first communication link 230-a during a first time period, and may be used to transmit to the second base station via the second communication link 230-b during a second time period. Thus, the transmissions of the first RAN and the second RAN may be TDMed at the UE. In other cases, the UE 215 may be a dual-transmitter UE capable of transmitting on both the first RAN and the second RAN concurrently. In some cases, even though the UE 215 may have the hardware for dual transmissions to different RANs, a single transmitter mode of operation may be selected (eg, due to power limitations or thermal limitations at the UE 215). Figure 3 The process flow associated with reporting of UE 215 capabilities and DC configuration based on UE 215 capabilities is explained.

[0073] Figure 3 An example of a process flow 300 for supporting a time division duplex technique for dual connectivity to different radio access networks according to aspects of the present disclosure is illustrated. In some examples, the process flow 300 can implement aspects of the wireless communication system 100 or 200. In this example, an EN-DC configuration can be established with an LTE RAN and an NR RAN.

[0074] At 305, a first connection may be established for the LTE RAN and a second connection may be established for the NR RAN. As discussed above, the LTE RAN may provide an MCG for the UE and the NR RAN may provide an SCG for the UE. These connections may be established, for example, according to established radio resource configuration (RRC) connection establishment techniques.

[0075] At 310, a determination may be made as to whether the UE is capable of dynamic sharing. Such a determination may be based on the UE's ability to transmit both LTE transmissions and NR transmissions in a dynamic manner. In some cases, the determination may be made when establishing a connection with the NR RAN, and in some cases may be based on the hardware capabilities of the UE (e.g., processing capabilities of the UE, transmitter configuration of the UE, etc.). In some cases, the determination may be based on conditions at the UE (e.g., power limitations or thermal limitations, etc.). In the event that the UE is not capable of dynamic sharing, one RAN may be configured, as indicated at 340.

[0076] If it is determined that the UE is capable of dynamic sharing, the UE may select from several different options. In some cases, the UE may select a first option in which the LTE RAN has restrictions on subframe subsets, as indicated at 315. In some cases, such options may be referred to as Case 1B TDM. In such cases, the UE may be configured with a single transmitter, and LTE and NR uplink transmissions may be TDMed using the single transmitter. In some cases, the LTE RAN is restricted to uplink transmissions on the configured subframe subset, while the NR RAN may not have any restrictions on the subframes that can be used for uplink transmissions. In such cases, if there is a conflict between a scheduled LTE uplink transmission and a scheduled NR uplink transmission in a subframe, the UE may discard the NR transmission associated with the SCG.

[0077] In some cases, the UE may select a dual uplink operation option in which simultaneous uplink transmissions may be used for the LTE RAN and the NR RAN, as indicated at 320. In such cases, neither the LTE RAN nor the NR RAN is restricted to designated subframes because simultaneous transmissions are supported when there is a conflict between the LTE uplink transmission and the NR uplink transmission. In such cases, the transmission length alignment between the LTE transmission and the NR transmission may be configured so that the UE does not transmit LTE using one transmitter while attempting to receive NR on the other transmitter.

[0078] In a further case, if it is determined at 310 that the UE is capable of dynamic sharing, the UE may select a second TDM option in which both LTE and NR have no restrictions on uplink subframes that may be used for uplink transmissions, as indicated at 325. In some cases, such an option may be referred to as Case 2 TDM. In such a case, the UE may be configured with a single transmitter, and LTE and NR uplink transmissions may be TDMed using the single transmitter. In such a case, if there is a conflict between a scheduled LTE uplink transmission and a scheduled NR uplink transmission in a subframe, the UE may drop the NR transmission associated with the SCG.

[0079] In some cases, the UE may signal the UE capabilities and the options selected for EN-DC transmission to the LTE base station. In the case where the option of box 315 is selected, at 330, a reference configuration may be identified, and a specified TDD configuration may be identified. In some examples, the reference configuration and the TDD configuration may limit the uplink subframes that may be used by the LTE RAN for uplink transmission. In some examples, as will be discussed in more detail below, the specified TDD configuration may have a first uplink subframe set, and the reference configuration may be selected as a different TDD configuration having a second uplink subframe set that is a subset of the first subframe set. The LTE RAN may be restricted so that the ACK / NACK transmission corresponding to the LTE downlink HARQ follows the reference configuration. In such a case, the ACK / NACK transmission corresponding to the LTE uplink HARQ and all uplink transmissions of the NR RAN may follow the specified configuration.

[0080] Such techniques for limiting uplink subframes for LTE transmissions can provide that both LTE and NR can use the same specified TDD configuration, and uplink transmissions for NR and LTE can be TDMed, while providing resources for ACK / NACK transmissions corresponding to LTE downlink HARQ that follow a reference configuration (e.g., a subset of uplink subframes according to a specified TDD configuration). In such a case, ACK / NACK transmissions corresponding to LTE uplink HARQ and all NR uplink transmissions (e.g., uplink control channel transmissions, uplink shared channel transmissions, ACK / NACK transmissions for uplink and downlink HARQ, sounding reference signal (SRS) transmissions, etc.) can follow the specified configuration. Thus, relative to limiting all uplink transmissions to the reference configuration, such techniques provide additional uplink subframes for LTE.

[0081] In block 335, the UE and each base station may communicate according to the selected uplink transmission operation. In some cases, the UE may indicate the selected uplink transmission operation to the scheduling base station, and the UE may receive an indication of the reference configuration and the specified TDD configuration. In some cases, the LTE base station and the NR base station may coordinate to avoid conflicts between LTE uplink transmissions and NR uplink transmissions. In such cases, conflicts identified at the UE may be treated as error situations for which the UE behavior is not defined. In other cases, conflicts may be allowed, and the UE may discard conflicting NR uplink transmissions and transmit LTE uplink transmissions.

[0082] As indicated above, the reference configuration may have a subset of uplink subframes configured in a specified TDD configuration.

[0083] Figure 4An example of a TDD format 400 that supports time division duplexing techniques for dual connectivity to different radio access networks in accordance with aspects of the present disclosure is illustrated. In some examples, the TDD format 400 can implement aspects of the wireless communication system 100 or 200.

[0084] For the TDD frame structure, each subframe may carry UL or DL ​​traffic, and special subframes ("S") may be used to switch between DL to UL transmissions. The allocation of UL and DL subframes within a radio frame may be symmetric or asymmetric and may be semi-statically reconfigured (e.g., via RRC messages in the backhaul, etc.). Special subframes may carry some DL and / or UL traffic and may include a guard period (GP) between DL and UL traffic. Switching from UL to DL traffic may be achieved by setting a timing advance at the UE without the use of special subframes or guard periods between UL and DL subframes. UL-DL configurations with a switching point periodicity equal to the frame period (e.g., 10 ms) or half the frame period (e.g., 5 ms) may be supported.

[0085] For LTE and NR deployments, seven different UL-DL configurations are defined that provide between 40% and 90% of DL subframes, such as Figure 4 The specific TDD UL / DL configuration used by the base station may be based on user requirements for a specific coverage area. In this example, the specified TDD configuration 405 may include two uplink subframes (SF 2 and SF 7), while the reference configuration 410 may include one uplink subframe (SF 2), such that the uplink subframe of the reference configuration 410 is a subset of the uplink subframe of the specified TDD configuration 405. It is to be understood that Figure 4 The example of is for purposes of illustration and discussion only, and other reference configurations and specified TDD configurations may be configured according to the techniques discussed herein.

[0086] Figure 5 An example of a process flow 500 for supporting a time division duplex technique for dual connectivity to different radio access networks according to aspects of the present disclosure is illustrated. In some examples, the process flow 500 can implement aspects of the wireless communication system 100 or 200. The process flow 500 can include a UE 515, a first base station 505, and a second base station 510. The UE 515 can be a base station as described herein with reference to Figure 1 and / or Figure 2 The first base station 505 may be an example of one or more UEs described herein. Figure 1 and / or Figure 2 The second base station 510 may be as described herein with reference to Figure 1 and / or Figure 2For example, the first base station 505 may be associated with an LTE system, and the second base station 510 may be associated with an NR system. Various aspects of the following communication examples are described as occurring between a UE 515, a first base station 505, and a second base station 510.

[0087] At 520, the UE 515 and the first and second base stations 505 and 510 may perform a connection establishment procedure to configure a DC connection at the UE 515. Such a connection establishment procedure may include an RRC connection establishment procedure for MCG establishment with the first base station 505 and SCG establishment with the second base station 510.

[0088] At 525, UE 515 may select a TDM option for EN-DC (such as described above with respect to Figure 3 As discussed above Figure 3 As discussed, in some cases, the TDM options may include an option in which LTE uplink subframes are restricted to a subset of uplink subframes that may be configured according to a specified TDD configuration between the UE 515 and the base stations 505 and 510. In some examples, the UE 515 may transmit an indication of the selected option 530 to the first base station 505.

[0089] At 535, the first base station 505 can configure a specified TDD configuration and a reference configuration. As discussed above, the specified TDD configuration can have a first set of uplink subframes (e.g., two UL subframes), while the reference configuration can have a second set of uplink subframes (e.g., one UL subframe with a position in the TDD frame corresponding to one of the uplink subframes in the first set of uplink subframes). The first base station 505 can transmit the TDD configuration 540 to the UE 515, which can be used by the UE 515 to identify uplink subframes that can be used for uplink transmissions to the first base station 505 and the second base station 510.

[0090] At 545, the first base station 505 and the second base station 510 may coordinate so that conflicts between uplink subframes of LTE and NR are avoided. In some cases, conflicts may be allowed, and the UE 515 may be configured to discard uplink subframes of one of the base stations in the event of a conflict (e.g., the UE may discard NR uplink transmissions). In some cases, the conflict may be an error situation, and the UE 515 behavior is not defined. The UE 515 and the second base station 510 may transmit uplink and downlink transmissions 550 according to the specified TDD configuration. The UE 515 and the first base station 505 may transmit uplink and downlink transmissions 555, wherein the downlink HARQ may follow the reference configuration and the uplink HARQ may follow the specified TDD configuration, and other transmissions follow the specified TDD configuration.

[0091] Figure 6 A block diagram 600 of a device 605 supporting time division duplex technology for dual connectivity to different radio access networks according to aspects of the present disclosure is shown. 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 communication manager 615, and a transmitter 620. The device 605 may also include a processor. Each of these components may be in communication with each other (e.g., via one or more buses).

[0092] 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 TDD technology for DC to different RANs, etc.). The information may be passed to other components of the device 605. The receiver 610 may be a reference Fig. 9 Examples of aspects of the transceiver 920 are described. The receiver 610 may utilize a single antenna or a collection of antennas.

[0093] The communication manager 615 may: establish at the UE a first connection using a first RAN and a second connection using a second RAN; identify a reference TDD configuration for the first connection and a specified TDD configuration for both the first connection and the second connection, wherein the specified TDD configuration has a first uplink subframe set and the reference TDD configuration has a second uplink subframe set that is a subset of the first uplink subframe set; receive a downlink transmission via the first RAN according to the reference TDD configuration; and transmit an uplink transmission via the first RAN and the second RAN according to the specified TDD configuration. The communication manager 615 may be an example of aspects of the communication manager 910 described herein.

[0094] The communication manager 615 or its subcomponents may be implemented in hardware, in 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 communication manager 615 or its subcomponents may be performed by a general purpose processor, a DSP, an application specific integrated circuit (ASIC), an FPGA or other programmable logic device designed to perform the functions described in the present disclosure, discrete gate or transistor logic, discrete hardware components, or any combination thereof.

[0095] The communication manager 615 or its subcomponents may be physically located at various locations, including being distributed such that portions of functionality are implemented by one or more physical components at different physical locations. In some examples, according to various aspects of the present disclosure, the communication manager 615 or its subcomponents may be separate and distinct components. In some examples, according to various aspects of the present disclosure, the communication manager 615 or its subcomponents may be combined with one or more other hardware components (including, but not limited to, input / output (I / O) components, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof).

[0096] The transmitter 620 may transmit signals generated by other components of the device 605. In some examples, the transmitter 620 may be co-located with the receiver 610 in a transceiver module. For example, the transmitter 620 may be a reference Fig. 9 Examples of aspects of the transceiver 920 are described. The transmitter 620 may utilize a single antenna or a collection of antennas.

[0097] The actions performed by the communication manager 615 as described herein may be implemented to achieve one or more potential advantages. An implementation may allow the UE 115 to adopt a DC configuration across different RANs, which may result in improved compatibility of uplink / downlink transmissions. Additionally or alternatively, the UE 115 may reduce interference of concurrent transmissions of multiple RANs. The described implementations may improve network efficiency by reducing interference and improving compatibility of uplink / downlink transmissions.

[0098] Figure 7 A block diagram 700 of a device 705 supporting time division duplex technology for dual connectivity to different radio access networks according to aspects of the present disclosure is shown. The device 705 may be an example of aspects of the device 605 or UE 115 as described herein. The device 705 may include a receiver 710, a communication manager 715, and a transmitter 740. The device 705 may also include a processor. Each of these components may be in communication with each other (e.g., via one or more buses).

[0099] 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 TDD technology for DC to different RANs, etc.). The information may be passed to other components of the device 705. The receiver 710 may be a reference Fig. 9 Examples of aspects of the described transceiver 920. The receiver 710 may utilize a single antenna or a collection of antennas.

[0100] The communication manager 715 may be an example of aspects of the communication manager 615 as described herein. The communication manager 715 may include a DC manager 720, a TDD configuration component 725, a downlink transmission component 730, and an uplink transmission component 735. The communication manager 715 may be an example of aspects of the communication manager 910 described herein.

[0101] The DC manager 720 may establish, at the UE, a first connection using the first RAN and a second connection using the second RAN.

[0102] The TDD configuration component 725 may identify a reference TDD configuration for the first connection and a designated TDD configuration for both the first connection and the second connection, wherein the designated TDD configuration has a first uplink subframe set and the reference TDD configuration has a second uplink subframe set that is a subset of the first uplink subframe set.

[0103] Downlink transmission component 730 can receive a downlink transmission via the first RAN according to a reference TDD configuration.

[0104] The uplink transmission component 735 can transmit uplink transmissions via the first RAN and the second RAN according to the specified TDD configuration.

[0105] The transmitter 740 may transmit signals generated by other components of the device 705. In some examples, the transmitter 740 may be co-located with the receiver 710 in a transceiver module. For example, the transmitter 740 may be a reference Fig. 9 Examples of aspects of the transceiver 920 are described. The transmitter 740 may utilize a single antenna or a collection of antennas.

[0106] Based on identifying the reference TDD configuration for the first connection and the specified TDD configuration for both the first connection and the second connection, the processor of the UE 115 (e.g., controls the receiver 710 or the transmitter 740 or as shown in the reference TDD configuration) Fig. 9 The transceiver 920 described herein may be implemented to achieve one or more potential advantages. One implementation may allow a processor of the UE 115 to implement and / or appropriately select a single transmission mode or a dual transmission mode, which may reduce the number of discarded transmissions and reduce conflicts that would otherwise result.

[0107] Figure 8A block diagram 800 of a communication manager 805 supporting time division duplex technology for dual connectivity to different radio access networks in accordance with aspects of the present disclosure is shown. The communication manager 805 may be an example of aspects of the communication manager 615, the communication manager 715, or the communication manager 910 described herein. The communication manager 805 may include a DC manager 810, a TDD configuration component 815, a downlink transmission component 820, an uplink transmission component 825, a HARQ manager 830, and a scheduling component 835. Each of these modules may communicate directly or indirectly with each other (e.g., via one or more buses).

[0108] The DC manager 810 may: establish, at the UE, a first connection using a first RAN and a second connection using a second RAN. In some examples, the DC manager 810 may: determine the dynamic sharing capability of the UE and the single transmission capability or the dual transmission capability of the UE before identifying a reference TDD configuration, and wherein the reference TDD configuration is identified based on the dynamic sharing capability and the single transmission capability or the dual transmission capability. In some cases, the first RAN is a 4G or LTE RAN, and the second RAN is a 5G or NRRAN. In some cases, under the DC configuration, the first connection using the first RAN is established as an MCG connection, and the second connection using the second RAN is established as an SCG connection.

[0109] The TDD configuration component 815 can: identify a reference TDD configuration for the first connection and a specified TDD configuration for both the first connection and the second connection, wherein the specified TDD configuration has a first uplink subframe set and the reference TDD configuration has a second uplink subframe set that is a subset of the first uplink subframe set. In some examples, the TDD configuration component 815 can transmit uplink ACK / NACK feedback information, uplink shared channel data, uplink control channel data, uplink reference signal, and downlink ACK / NACK feedback of the second RAN according to the specified TDD configuration.

[0110] Downlink transmission component 820 can receive downlink transmissions via the first RAN according to a reference TDD configuration.Uplink transmission component 825 can transmit uplink transmissions via the first RAN and the second RAN according to a specified TDD configuration.

[0111] The HARQ manager 830 may manage ACK / NACK feedback corresponding to a downlink HARQ process of the first RAN according to a reference TDD configuration. In some examples, the HARQ manager 830 may manage ACK / NACK feedback corresponding to an uplink HARQ process of the first RAN according to a specified TDD configuration.

[0112] The scheduling component 835 may receive scheduling information for transmitting uplink transmissions of the first RAN and the second RAN, wherein the uplink transmissions of the first RAN are scheduled in an uplink subframe that specifies a TDD configuration different from the uplink transmissions of the second RAN. In some examples, the scheduling component 835 may transmit the uplink transmissions of the first RAN and the second RAN according to the scheduling information. In some examples, the scheduling component 835 may determine that both the first uplink transmission of the first RAN and the second uplink transmission of the second RAN are scheduled in the same first TDD uplink subframe, and may identify the first TDD uplink subframe as an error situation. In some examples, the scheduling component 835 may determine that both the first uplink transmission of the first RAN and the second uplink transmission of the second RAN are scheduled in the same first TDD uplink subframe, may discard the second uplink transmission of the second RAN, and may transmit the first uplink transmission of the first RAN in the first TDD uplink subframe.

[0113] Fig. 9 A diagram of a system 900 including a device 905 supporting time division duplex technology for dual connectivity to different radio access networks according to various aspects of the present disclosure is shown. The device 905 may be an example of a device 605, a device 705, or a UE 115 as described herein or include components of the above devices. The device 905 may include components for two-way voice and data communications, including components for transmitting and receiving communications, including a communication manager 910, an I / O controller 915, a transceiver 920, an antenna 925, a memory 930, and a processor 940. These components may be in electronic communication via one or more buses (e.g., a bus 945).

[0114] The communication manager 910 may: establish, at a UE, a first connection using a first RAN and a second connection using a second RAN; identify a reference TDD configuration for the first connection and a specified TDD configuration for both the first connection and the second connection, wherein the specified TDD configuration has a first uplink subframe set and the reference TDD configuration has a second uplink subframe set that is a subset of the first uplink subframe set; receive a downlink transmission via the first RAN according to the reference TDD configuration; and transmit an uplink transmission via the first RAN and the second RAN according to the specified TDD configuration.

[0115] I / O controller 915 can manage input and output signals of device 905. I / O controller 915 can also manage peripheral devices that are not integrated into device 905. In some cases, I / O controller 915 can represent a physical connection or port to an external peripheral device. In some cases, I / O controller 915 can utilize an operating system, such as Or another known operating system. In other cases, I / O controller 915 may represent or interact with a modem, keyboard, mouse, touch screen, or similar device. In some cases, I / O controller 915 may be implemented as part of a processor. In some cases, a user may interact with device 905 via I / O controller 915 or via hardware components controlled by I / O controller 915.

[0116] The transceiver 920 can communicate bidirectionally via one or more antennas, wired or wireless links, as described above. For example, the transceiver 920 can represent a wireless transceiver and can communicate bidirectionally with another wireless transceiver. The transceiver 920 can also include a modem to modulate packets and provide the modulated packets to an antenna for transmission, and demodulate packets received from an antenna.

[0117] In some cases, a 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 transmitting or receiving multiple wireless transmissions concurrently.

[0118] The memory 930 may include RAM and ROM. The memory 930 may store computer-readable, computer-executable code 935 including instructions that, when executed, cause the processor to perform the various functions described herein. In some cases, the memory 930 may include, among other things, a BIOS that may control basic hardware or software operations, such as interaction with peripheral components or devices.

[0119] The processor 940 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 940 may be configured to operate a memory array using a memory controller. In other cases, the 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., a memory 930) to cause the device 905 to perform various functions (e.g., functions or tasks of supporting TDD technology for DC to different RANs).

[0120] The code 935 may include instructions for implementing various aspects of the present disclosure, including instructions for supporting wireless communications. The code 935 may be stored in a non-transitory computer-readable medium, such as a system memory or other type of memory. In some cases, the code 935 may not be directly executed by the processor 940, but may cause a computer (e.g., when compiled and executed) to perform the functions described herein.

[0121] Fig.10 A block diagram 1000 of a device 1005 supporting time division duplex technology for dual connectivity to different radio access networks according to aspects of the present disclosure is shown. 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 communication manager 1015, and a transmitter 1020. The device 1005 may also include a processor. Each of these components may be in communication with each other (e.g., via one or more buses).

[0122] 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 TDD technology for DC to different RANs, etc.). The information may be passed to other components of the device 1005. The receiver 1010 may be a reference Fig.13 Examples of various aspects of the transceiver 1320 are described. The receiver 1010 may utilize a single antenna or a collection of antennas.

[0123] The communication manager 1015 may: establish a first connection with a UE using a first RAN, and wherein a second connection is established at the UE using a second RAN; identify a reference TDD configuration for the first connection and a specified TDD configuration for both the first connection and the second connection, wherein the specified TDD configuration has a first uplink subframe set, and the reference TDD configuration has a second uplink subframe set that is a subset of the first uplink subframe set; transmit a downlink transmission to the UE via the first RAN according to the reference TDD configuration; and receive an uplink transmission from the UE via the first RAN according to the specified TDD configuration, and wherein the UE transmits an uplink transmission via the second RAN according to the specified TDD configuration. The communication manager 1015 may be an example of aspects of the communication manager 1310 described herein.

[0124] The communication manager 1015 or its subcomponents may be implemented in hardware, in 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 communication manager 1015 or its subcomponents may be performed by a general purpose processor, a DSP, an application specific integrated circuit (ASIC), an FPGA or other programmable logic device designed to perform the functions described in this disclosure, discrete gate or transistor logic, discrete hardware components, or any combination thereof.

[0125] The communication manager 1015 or its subcomponents may be physically located at various locations, including being distributed such that portions of functionality are implemented by one or more physical components at different physical locations. In some examples, according to various aspects of the present disclosure, the communication manager 1015 or its subcomponents may be separate and distinct components. In some examples, according to various aspects of the present disclosure, the communication manager 1015 or its subcomponents may be combined with one or more other hardware components (including, but not limited to, input / output (I / O) components, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof).

[0126] The transmitter 1020 may transmit signals generated by other components of the device 1005. In some examples, the transmitter 1020 may be co-located with the receiver 1010 in a transceiver module. For example, the transmitter 1020 may be a reference Fig.13 Examples of various aspects of the transceiver 1320 are described. The transmitter 1020 may utilize a single antenna or a collection of antennas.

[0127] Fig.11 A block diagram 1100 of a device 1105 supporting time division duplex technology for dual connectivity to different radio access networks according to aspects of the present disclosure is shown. The device 1105 may be an example of aspects of the device 1005 or base station 105 as described herein. The device 1105 may include a receiver 1110, a communication manager 1115, and a transmitter 1140. The device 1105 may also include a processor. Each of these components may be in communication with each other (e.g., via one or more buses).

[0128] 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 TDD technology for DC to different RANs, etc.). The information may be passed to other components of the device 1105. The receiver 1110 may be a reference Fig.13 Examples of various aspects of the transceiver 1320 are described. The receiver 1110 may utilize a single antenna or a collection of antennas.

[0129] The communication manager 1115 may be an example of aspects of the communication manager 1015 as described herein. The communication manager 1115 may include a DC manager 1120, a TDD configuration component 1125, a downlink transmission component 1130, and an uplink transmission component 1135. The communication manager 1115 may be an example of aspects of the communication manager 1310 described herein.

[0130] The DC manager 1120 may establish a first connection with a UE using a first RAN, and wherein a second connection is established at the UE using a second RAN.

[0131] The TDD configuration component 1125 may identify a reference TDD configuration for the first connection and a designated TDD configuration for both the first connection and the second connection, wherein the designated TDD configuration has a first uplink subframe set and the reference TDD configuration has a second uplink subframe set that is a subset of the first uplink subframe set.

[0132] Downlink transmission component 1130 can transmit a downlink transmission to the UE via the first RAN according to the reference TDD configuration.

[0133] The uplink transmission component 1135 can receive an uplink transmission from the UE via the first RAN in accordance with a specified TDD configuration, and wherein the UE transmits the uplink transmission via the second RAN in accordance with the specified TDD configuration.

[0134] The transmitter 1140 may transmit signals generated by other components of the device 1105. In some examples, the transmitter 1140 may be co-located with the receiver 1110 in a transceiver module. For example, the transmitter 1140 may be a reference Fig.13 Examples of various aspects of the transceiver 1320 are described. The transmitter 1140 may utilize a single antenna or a collection of antennas.

[0135] Fig.12 A block diagram 1200 of a communication manager 1205 supporting time division duplex technology for dual connectivity to different radio access networks in accordance with aspects of the present disclosure is shown. The communication manager 1205 can be an example of aspects of the communication manager 1015, the communication manager 1115, or the communication manager 1310 described herein. The communication manager 1205 can include a DC manager 1210, a TDD configuration component 1215, a downlink transmission component 1220, an uplink transmission component 1225, a HARQ manager 1230, and a scheduling component 1235. Each of these modules can communicate directly or indirectly with each other (e.g., via one or more buses).

[0136] The DC manager 1210 may establish a first connection with a UE using a first RAN, and wherein a second connection is established at the UE using a second RAN. In some examples, the DC manager 1210 may receive a dynamic sharing capability of the UE and a single transmission capability or a dual transmission capability of the UE from the UE before identifying a reference TDD configuration, and wherein the reference TDD configuration is identified based on the dynamic sharing capability and the single transmission capability or the dual transmission capability. In some cases, the first RAN is a fourth generation (4G) or LTE RAN, and the second RAN is a fifth generation (5G) or NR RAN. In some cases, under the DC configuration, a first connection using the first RAN is established as an MCG connection, and a second connection using the second RAN is established as an SCG connection.

[0137] The TDD configuration component 1215 may identify a reference TDD configuration for the first connection and a designated TDD configuration for both the first connection and the second connection, wherein the designated TDD configuration has a first uplink subframe set and the reference TDD configuration has a second uplink subframe set that is a subset of the first uplink subframe set.

[0138] Downlink transmitting component 1220 can transmit a downlink transmission to the UE via the first RAN according to the reference TDD configuration.

[0139] The uplink transmission component 1225 can receive an uplink transmission from the UE via the first RAN according to a specified TDD configuration, and wherein the UE transmits the uplink transmission via the second RAN according to the specified TDD configuration. In some examples, uplink shared channel transmissions of the first RAN are transmitted according to the specified TDD configuration. In some examples, uplink ACK / NACK feedback information, uplink shared channel data, uplink control channel data, uplink reference signals, and downlink ACK / NACK feedback of the second RAN are transmitted according to the specified TDD configuration.

[0140] The HARQ manager 1230 may manage ACK / NACK feedback corresponding to a downlink HARQ process of the first RAN according to a reference TDD configuration. In some examples, the HARQ manager 1230 may manage ACK / NACK feedback corresponding to an uplink HARQ process of the first RAN according to a specified TDD configuration.

[0141] The scheduling component 1235 may schedule the UE for uplink transmission via the first RAN and the second RAN, wherein the uplink transmission of the first RAN is scheduled in an uplink subframe different from the uplink transmission of the second RAN of the specified TDD configuration. In some examples, the scheduling component 1235 may receive the uplink transmission from the UE according to the schedule. In some examples, the scheduling component 1235 may receive the first uplink transmission of the first RAN in the first TDD uplink subframe when both the first uplink transmission of the first RAN and the second uplink transmission of the second RAN are scheduled in the first TDD uplink subframe, and wherein the UE discards the second uplink transmission of the second RAN. In some cases, the UE is configured to: identify an error condition when both the first uplink transmission of the first RAN and the second uplink transmission of the second RAN are scheduled in the same first TDD uplink subframe.

[0142] Fig.13 A diagram of a system 1300 including a device 1305 supporting time division duplex technology for dual connectivity to different radio access networks according to aspects of the present disclosure is shown. The device 1305 may be an example of or include components of the device 1005, device 1105, or base station 105 as described herein. The device 1305 may include components for two-way voice and data communications, including components for transmitting and receiving communications, including a communication manager 1310, a network communication manager 1315, a transceiver 1320, an antenna 1325, a memory 1330, a processor 1340, and an inter-station communication manager 1345. These components may be in electronic communication via one or more buses (e.g., bus 1350).

[0143] The communication manager 1310 may: establish a first connection with a UE using a first RAN, and wherein a second connection is established at the UE using a second RAN; identify a reference TDD configuration for the first connection and a specified TDD configuration for both the first connection and the second connection, wherein the specified TDD configuration has a first uplink subframe set, and the reference TDD configuration has a second uplink subframe set that is a subset of the first uplink subframe set; transmit a downlink transmission to the UE via the first RAN according to the reference TDD configuration; and receive an uplink transmission from the UE via the first RAN according to the specified TDD configuration, and wherein the UE transmits the uplink transmission via the second RAN according to the specified TDD configuration.

[0144] The network communications manager 1315 may manage communications with the core network (eg, via one or more wired backhaul links). For example, the network communications manager 1315 may manage the delivery of data communications for client devices, such as one or more UEs 115.

[0145] The transceiver 1320 can communicate bidirectionally via one or more antennas, wired or wireless links, as described above. For example, the transceiver 1320 may represent a wireless transceiver and can communicate bidirectionally with another wireless transceiver. The transceiver 1320 may also include a modem to modulate packets and provide the modulated packets to an antenna for transmission, and demodulate packets received from an antenna.

[0146] In some cases, a 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 transmitting or receiving multiple wireless transmissions concurrently.

[0147] Memory 1330 may include RAM, ROM, or a combination thereof. Memory 1330 may store computer readable code 1335 including instructions that, when executed by a processor (e.g., processor 1340), cause the device to perform various functions described herein. In some cases, memory 1330 may include, among other things, a BIOS that may control basic hardware or software operations, such as interaction with peripheral components or devices.

[0148] 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, the memory controller may be integrated into the processor 1340. The processor 1340 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 1330) to cause the device to perform various functions (e.g., functions or tasks of supporting TDD technology for DC to different RANs).

[0149] The inter-site communication manager 1345 may manage communications with other base stations 105 and may include a controller or scheduler for controlling communications with UE 115 in cooperation with other base stations 105. For example, the inter-site communication manager 1345 may coordinate scheduling of transmissions to UE 115 for various interference mitigation techniques such as beamforming or joint transmission. In some examples, the inter-site communication manager 1345 may provide an X2 interface within an LTE / LTE-A wireless communication network technology to provide communications between base stations 105.

[0150] The code 1335 may include instructions for implementing various aspects of the present disclosure, including instructions for supporting wireless communications. The code 1335 may be stored in a non-transitory computer-readable medium, such as a system memory or other type of memory. In some cases, the code 1335 may not be directly executed by the processor 1340, but may cause a computer (e.g., when compiled and executed) to perform the functions described herein.

[0151] Fig.14 1 is a flow chart illustrating a method 1400 for supporting a time division duplexing technique for dual connectivity to different radio access networks according to aspects of the present disclosure. The operations of the method 1400 may be implemented by a UE 115 or components thereof as described herein. For example, the operations of the method 1400 may be implemented by a UE 115 or components thereof as described herein. Figures 6 to 9 In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described below.

[0152] At 1405, the UE may establish a first connection using the first RAN and a second connection using the second RAN. 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 as described with reference to Figures 6 to 9 In some cases, the UE may determine the dynamic sharing capability of the UE and the single transmission capability or dual transmission capability of the UE before identifying the reference TDD configuration, and wherein the reference TDD configuration is identified based on the dynamic sharing capability and the single transmission capability or dual transmission capability.

[0153] At 1410, the UE may identify a reference TDD configuration for a first connection and a designated TDD configuration for both the first connection and the second connection, wherein the designated TDD configuration has a first uplink subframe set and the reference TDD configuration has a second uplink subframe set that is a subset of the first uplink subframe set. 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 as described with reference to Figures 6 to 9 The described TDD configuration components are performed.

[0154] At 1420, the UE may receive a downlink transmission via the first RAN according to the reference TDD configuration. The operations of 1420 may be performed according to the methods described herein. In some examples, aspects of the operations of 1420 may be performed as described with reference to Figures 6 to 9 The described downlink transmission components are performed.

[0155] At 1425, the UE may transmit uplink transmissions via the first RAN and the second RAN according to the specified TDD configuration. The operations of 1425 may be performed according to the methods described herein. In some examples, aspects of the operations of 1425 may be performed as described with reference to Figures 6 to 9 In some cases, ACK / NACK feedback corresponding to a downlink HARQ process of the first RAN is transmitted according to a reference TDD configuration. In some cases, ACK / NACK feedback corresponding to an uplink HARQ process of the first RAN is transmitted according to a specified TDD configuration. In some cases, uplink shared channel transmissions of the first RAN are transmitted according to a specified TDD configuration. In some cases, uplink ACK / NACK feedback information, uplink shared channel data, uplink control channel data, uplink reference signals, and downlink ACK / NACK feedback of the second RAN are transmitted according to a specified TDD configuration.

[0156] Fig.15 1 is a flow chart illustrating a method 1500 for supporting a time division duplexing technique for dual connectivity to different radio access networks according to aspects of the present disclosure. The operations of the method 1500 may be implemented by a UE 115 or a component thereof as described herein. For example, the operations of the method 1500 may be implemented by a UE 115 or a component thereof as described herein. Figures 6 to 9 In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described below.

[0157] At 1505, the UE may establish a first connection using a first RAN and a second connection using a second RAN. 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 as described with reference to Figures 6 to 9 The DC Manager described above is used to perform

[0158] At 1510, the UE may identify a reference TDD configuration for a first connection and a designated TDD configuration for both the first connection and the second connection, wherein the designated TDD configuration has a first uplink subframe set and the reference TDD configuration has a second uplink subframe set that is a subset of the first uplink subframe set. 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 as described with reference to Figures 6 to 9 In some cases,

[0159] At 1515, the UE may receive scheduling information for transmitting uplink transmissions of the first RAN and the second RAN, wherein the uplink transmissions of the first RAN are scheduled in uplink subframes different from the uplink transmissions of the second RAN in a specified TDD configuration. 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 as described with reference to Figures 6 to 9 The described scheduling component is executed.

[0160] At 1520, the UE may determine that both the first uplink transmission of the first RAN and the second uplink transmission of the second RAN are scheduled in the same first TDD uplink subframe. The operations of 1520 may be performed according to the methods described herein. In some examples, aspects of the operations of 1520 may be performed as described with reference to Figures 6 to 9 The described scheduling component is executed.

[0161] At 1525, the UE may identify the first TDD uplink subframe as an error condition. The operations of 1525 may be performed according to the methods described herein. In some examples, aspects of the operations of 1525 may be as described with reference to Figures 6 to 9 The UE may transmit uplink transmissions of the first RAN and the second RAN according to the scheduling information.

[0162] Fig.16 1 is a flow chart illustrating a method 1600 for supporting a time division duplexing technique for dual connectivity to different radio access networks according to aspects of the present disclosure. The operations of the method 1600 may be implemented by a UE 115 or a component thereof as described herein. For example, the operations of the method 1600 may be implemented by a UE 115 or a component thereof as described herein. Figures 6 to 9 In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described below.

[0163] At 1605, the UE may establish a first connection using the first RAN and a second connection using the second RAN. 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 as described with reference to Figures 6 to 9 The DC Manager described above is used to perform

[0164] At 1610, the UE may identify a reference TDD configuration for a first connection and a designated TDD configuration for both the first connection and the second connection, wherein the designated TDD configuration has a first uplink subframe set and the reference TDD configuration has a second uplink subframe set that is a subset of the first uplink subframe set. 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 as described with reference to Figures 6 to 9 The described TDD configuration components are performed.

[0165] At 1615, the UE may receive scheduling information for transmitting uplink transmissions of the first RAN and the second RAN, wherein the uplink transmissions of the first RAN are scheduled in uplink subframes different from the uplink transmissions of the second RAN in a specified TDD configuration. 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 as described with reference to Figures 6 to 9 The described scheduling component is executed.

[0166] At 1620, the UE may determine that both the first uplink transmission of the first RAN and the second uplink transmission of the second RAN are scheduled in the same first TDD uplink subframe. 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 as described with reference to Figures 6 to 9 The described scheduling component is executed.

[0167] At 1625, the UE may discard the second uplink transmission of the second RAN. The operations of 1625 may be performed according to the methods described herein. In some examples, aspects of the operations of 1625 may be performed as described with reference to Figures 6 to 9 The described scheduling component is executed.

[0168] At 1630, the UE may transmit a first uplink transmission of the first RAN in a first TDD uplink subframe. The operations of 1630 may be performed according to the methods described herein. In some examples, aspects of the operations of 1630 may be performed as described with reference to Figures 6 to 9 The described scheduling component is executed.

[0169] Fig.17 1 is a flow chart illustrating a method 1700 for supporting a time division duplexing technique for dual connectivity to different radio access networks according to aspects of the present disclosure. The operations of the method 1700 may be implemented by a base station 105 or components thereof as described herein. For example, the operations of the method 1700 may be implemented by a base station 105 or components thereof as described herein. Figures 10 to 13In some examples, the base station may execute an instruction set to control the functional elements of the base station to perform the functions described below. Additionally or alternatively, the base station may use dedicated hardware to perform various aspects of the functions described below.

[0170] At 1705, the base station may establish a first connection with the UE using the first RAN, and wherein a second connection is established at the UE using the second RAN. The operations of 1705 may be performed according to the methods described herein. In some examples, aspects of the operations of 1705 may be as described with reference to Figures 10 to 13 The DC Manager described above is used to perform

[0171] At 1710, the base station may identify a reference TDD configuration for a first connection and a designated TDD configuration for both the first connection and the second connection, wherein the designated TDD configuration has a first uplink subframe set and the reference TDD configuration has a second uplink subframe set that is a subset of the first uplink subframe set. 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 as described with reference to Figures 10 to 13 The described TDD configuration components are performed.

[0172] At 1715, the base station may transmit a downlink transmission to the UE via the first RAN according to the reference TDD configuration. 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 as described with reference to Figures 10 to 13 The described downlink transmission components are performed.

[0173] At 1720, the base station may receive an uplink transmission from the UE via the first RAN according to the specified TDD configuration, and wherein the UE transmits the uplink transmission via the second RAN according to the specified TDD configuration. 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 as described with reference to Figures 10 to 13 The described uplink transmission component is performed.

[0174] Fig.18 1 is a flow chart illustrating a method 1800 for supporting a time division duplexing technique for dual connectivity to different radio access networks according to aspects of the present disclosure. The operations of the method 1800 may be implemented by a base station 105 or components thereof as described herein. For example, the operations of the method 1800 may be implemented by a base station 105 or components thereof as described herein. Figures 10 to 13 In some examples, the base station may execute an instruction set to control the functional elements of the base station to perform the functions described below. Additionally or alternatively, the base station may use dedicated hardware to perform various aspects of the functions described below.

[0175] At 1805, the base station may establish a first connection with the UE using the first RAN, and wherein a second connection is established at the UE using the second RAN. The operations of 1805 may be performed according to the methods described herein. In some examples, aspects of the operations of 1805 may be as described with reference to Figures 10 to 13 The DC Manager described above is used to perform

[0176] At 1810, the base station may identify a reference TDD configuration for a first connection and a designated TDD configuration for both the first connection and the second connection, wherein the designated TDD configuration has a first uplink subframe set and the reference TDD configuration has a second uplink subframe set that is a subset of the first uplink subframe set. The operations of 1810 may be performed according to the methods described herein. In some examples, aspects of the operations of 1810 may be performed as described with reference to Figures 10 to 13 The described TDD configuration components are performed.

[0177] At 1815, the base station may schedule the UE to perform uplink transmissions via the first RAN and the second RAN, wherein the uplink transmissions of the first RAN are scheduled in uplink subframes of a specified TDD configuration that are different from the uplink transmissions of the second RAN. The operations of 1815 may be performed according to the methods described herein. In some examples, aspects of the operations of 1815 may be performed as described with reference to Figures 10 to 13 The described scheduling component is executed.

[0178] At 1820, the base station may receive a first uplink transmission of the first RAN in a first TDD uplink subframe when both the first uplink transmission of the first RAN and the second uplink transmission of the second RAN are scheduled in the first TDD uplink subframe, and wherein the UE discards the second uplink transmission of the second RAN. The operations of 1820 may be performed according to the methods described herein. In some examples, aspects of the operations of 1820 may be performed as described with reference to Figures 10 to 13 The described scheduling component is executed.

[0179] It should be noted that the above methods describe possible implementations, and that the operations and steps may be rearranged or otherwise modified and other implementations are possible. Furthermore, aspects from two or more methods may be combined.

[0180] The technology described herein can be used in various wireless communication systems, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access (SC-FDMA) and other systems. CDMA systems can implement radio technologies such as CDMA2000, Universal Terrestrial Radio Access (UTRA). CDMA2000 covers IS-2000, IS-95 and IS-856 standards. IS-2000 versions are generally referred to as CDMA2000 1X, 1X, etc. IS-856 (TIA-856) is generally referred to as CDMA2000 1xEV-DO, High Rate Packet Data (HRPD), etc. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. TDMA systems can implement radio technologies such as Global System for Mobile Communications (GSM).

[0181] OFDMA systems can implement radio technologies such as Ultra Mobile Broadband (UMB), Evolved UTRA (E-UTRA), Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, etc. UTRA and E-UTRA are part of Universal Mobile Telecommunications System (UMTS). LTE, LTE-A, and LTE-A Pro are versions of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, LTE-A Pro, NR, and GSM are described in documents from an organization called "3rd Generation Partnership Project" (3GPP). CDMA2000 and UMB are described in documents from an organization called "3rd Generation Partnership Project 2" (3GPP2). The technology described herein can be used for the systems and radio technologies mentioned above as well as for other systems and radio technologies. Although aspects of LTE, LTE-A, LTE-A Pro, or NR systems may be described for example purposes and LTE, LTE-A, LTE-A Pro, or NR terminology may be used in much of the description, the techniques described herein may also be applicable to applications other than LTE, LTE-A, LTE-A Pro, or NR applications.

[0182] A macro cell generally covers a relatively large geographic area (e.g., an area of ​​several kilometers in radius) and may allow unrestricted access by UEs 115 that have service subscriptions with a network provider. A small cell may be associated with a lower power base station 105 (compared to a macro cell), and the small cell may operate in the same or different (e.g., licensed, unlicensed, etc.) frequency band as the macro cell. According to various examples, a small cell may include a pico cell, a femto cell, and a micro cell. A pico cell, for example, may cover a smaller geographic area and may allow unrestricted access by UEs 115 that have service subscriptions with a network provider. A femto cell may also cover a smaller geographic area (e.g., a residence) and may provide restricted access by UEs 115 associated with the femto cell (e.g., UEs 115 in a closed subscriber group (CSG), UEs 115 of users in a residence, etc.). An eNB for a macro cell may be referred to as a macro eNB. An eNB for a small cell may be referred to as a small cell eNB, a pico eNB, a femto eNB, or a home eNB. An eNB may support one or more (eg, two, three, four, etc.) cells and may also support communication using one or more component carriers.

[0183] One or more wireless communication systems 100 described herein may support synchronous or asynchronous operation. For synchronous operation, the base stations 105 may have similar frame timing, and transmissions from different base stations 105 may be approximately aligned in time. For asynchronous operation, the base stations 105 may have different frame timing, and transmissions from different base stations 105 may not be aligned in time. The techniques described herein may be used for synchronous or asynchronous operation.

[0184] The information and signals described herein may be represented using any of a variety of different techniques and technologies. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be mentioned throughout the above description may be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or optical particles, or any combination thereof.

[0185] The various illustrative blocks and modules described in conjunction with the disclosure herein may be implemented or executed with 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 (PLD), 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 conventional processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration).

[0186] 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 by a computer-readable medium as one or more instructions or codes. Other examples and implementations fall within the scope of this disclosure and the appended claims. For example, due to the nature of software, the functions described above may be implemented using software executed by a processor, hardware, firmware, hardwiring, or any combination thereof. Features that implement the functions may also be physically located in various locations, including being distributed so that parts of the functions are implemented at different physical locations.

[0187] Computer readable medium includes both non-transient computer storage medium and communication medium, and it includes any medium that facilitates computer program to transfer from one place to another place.Non-transient storage medium can be any available medium that can be accessed by general or special-purpose computer.As an example and not limitation, non-transient computer readable medium can include random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory, compact disk (CD) ROM or other optical disk storage, disk storage or other magnetic storage device, or can be used to carry or store instruction or data structure form of desired program code means and can be accessed by general or special-purpose computer or general or special-purpose processor any other non-transient medium.Any connection is also properly referred to as computer readable medium.For example, if software is transmitted from website, server or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) or wireless technology such as infrared, radio and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL or wireless technology such as infrared, radio and microwave are just included in the definition of medium. Disk and disc as used herein include CDs, laser discs, optical discs, digital versatile discs (DVDs), floppy disks, and Blu-ray discs, 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.

[0188] As used herein (including in the claims), "or" used in a list of items (e.g., a list of items with a phrase such as "at least one of" or "one or more of") indicates an inclusive list, so 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). Similarly, as used herein, the phrase "based on" should not be interpreted as referring to a closed set of conditions. For example, an exemplary step described as "based on condition A" may be based on both condition A and condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase "based on" should be interpreted in the same manner as the phrase "based at least in part on."

[0189] In the accompanying drawings, similar components or features may have the same reference number. In addition, various components of the same type may be distinguished by following the reference number with a dash and a second reference number that distinguishes between similar components. If only the first reference number is used in the specification, the description may apply to any of the similar components having the same first reference number regardless of the second reference number, or other subsequent reference numbers.

[0190] The descriptions set forth herein in conjunction with the accompanying drawings describe example configurations and do not represent all examples that may be implemented or that fall within the scope of the claims. The term "exemplary" as used herein means "used as an example, instance, or illustration" and does not mean "better than" or "better than other examples." This detailed description includes specific details to provide an understanding of the described techniques. However, these techniques may be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form to avoid obscuring the concepts of the described examples.

[0191] The description herein is provided to enable those skilled in the art to make or use the present disclosure. Various modifications to the present disclosure will be apparent to those skilled in the art, and the universal principles defined herein may be applied to other variations without departing from the scope of the present disclosure. Thus, the present disclosure is not limited to the examples and designs described herein, but should be granted the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for wireless communication at a user equipment (UE), comprising: establishing, at the UE, a first connection using a first radio access network (RAN) and a second connection using a second RAN; identifying a reference time division duplex (TDD) configuration for the first connection and a designated TDD configuration for both the first connection and the second connection, wherein the designated TDD configuration has a first set of uplink subframes and the reference TDD configuration has a second set of uplink subframes that is a subset of the first set of uplink subframes; receiving a downlink transmission via the first RAN according to the reference TDD configuration; as well as Uplink transmissions are transmitted via the first RAN and the second RAN according to the same designated TDD configuration, wherein the uplink subframes of the designated TDD configuration are usable for uplink transmissions via the first RAN and the second RAN.

2. The method of claim 1, wherein: Acknowledgement / negative acknowledgement (ACK / NACK) feedback corresponding to a downlink hybrid acknowledgment repeat request (HARQ) process of the first RAN is transmitted according to the reference TDD configuration.

3. The method of claim 2, wherein: ACK / NACK feedback corresponding to an uplink HARQ process of the first RAN is transmitted according to the specified TDD configuration.

4. The method of claim 3, wherein: An uplink shared channel transmission of the first RAN is transmitted according to the specified TDD configuration.

5. The method of claim 2, wherein: Uplink ACK / NACK feedback information, uplink shared channel data, uplink control channel data, uplink reference signal, and downlink ACK / NACK feedback of the second RAN are transmitted according to the specified TDD configuration.

6. The method of claim 1, further comprising: receiving scheduling information for transmitting uplink transmissions of the first RAN and the second RAN, wherein the uplink transmissions of the first RAN are scheduled in a different uplink subframe of the specified TDD configuration than the uplink transmissions of the second RAN; as well as Uplink transmissions of the first RAN and the second RAN are transmitted according to the scheduling information.

7. The method of claim 6, further comprising: determining that a first uplink transmission of the first RAN and a second uplink transmission of the second RAN are both scheduled in a same first TDD uplink subframe; as well as The first TDD uplink subframe is identified as an error condition.

8. The method of claim 6, further comprising: determining that a first uplink transmission of the first RAN and a second uplink transmission of the second RAN are both scheduled in a same first TDD uplink subframe; discarding the second uplink transmission of the second RAN; and The first uplink transmission of the first RAN is transmitted in the first TDD uplink subframe.

9. The method of claim 1, wherein the first RAN is a fourth generation (4G) or long term evolution (LTE) RAN, and the second RAN is a fifth generation (5G) or new radio (NR) RAN.

10. The method of claim 9, wherein in a dual connectivity (DC) configuration, the first connection using the first RAN is established as a primary cell group (MCG) connection, and the second connection using the second RAN is established as a secondary cell group (SCG) connection.

11. The method of claim 1, further comprising: A dynamic sharing capability of the UE and a single transmission capability or a dual transmission capability of the UE are determined prior to identifying the reference TDD configuration, and wherein the reference TDD configuration is identified based at least in part on the dynamic sharing capability and the single transmission capability or the dual transmission capability.

12. A method for wireless communication at a base station, comprising: establishing a first connection with a user equipment (UE) using a first radio access network (RAN), and wherein a second connection is established at the UE using a second RAN; identifying a reference time division duplex (TDD) configuration for the first connection and a designated TDD configuration for both the first connection and the second connection, wherein the designated TDD configuration has a first set of uplink subframes and the reference TDD configuration has a second set of uplink subframes that is a subset of the first set of uplink subframes; transmitting a downlink transmission to the UE via the first RAN according to the reference TDD configuration; as well as An uplink transmission is received from the UE via the first RAN according to the specified TDD configuration, and wherein the UE transmits an uplink transmission via the second RAN according to the specified TDD configuration, and wherein the uplink subframe of the specified TDD configuration can be used for uplink transmission via the first RAN and the second RAN.

13. The method of claim 12, wherein: Acknowledgement / negative acknowledgement (ACK / NACK) feedback corresponding to a downlink hybrid acknowledgment repeat request (HARQ) process of the first RAN is transmitted according to the reference TDD configuration.

14. The method of claim 13, wherein: ACK / NACK feedback corresponding to an uplink HARQ process of the first RAN is transmitted according to the specified TDD configuration.

15. The method of claim 14, wherein: An uplink shared channel transmission of the first RAN is transmitted according to the specified TDD configuration.

16. The method of claim 13, wherein: Uplink ACK / NACK feedback information, uplink shared channel data, uplink control channel data, uplink reference signal, and downlink ACK / NACK feedback of the second RAN are transmitted according to the specified TDD configuration.

17. The method of claim 12, further comprising: scheduling the UE for uplink transmission via the first RAN and the second RAN, wherein the uplink transmission of the first RAN is scheduled in a different uplink subframe of the specified TDD configuration than the uplink transmission of the second RAN; as well as An uplink transmission is received from the UE according to the schedule.

18. The method of claim 17, wherein the UE is configured to identify an error condition when a first uplink transmission of the first RAN and a second uplink transmission of the second RAN are both scheduled in the same first TDD uplink subframe.

19. The method of claim 17, further comprising: When a first uplink transmission of the first RAN and a second uplink transmission of the second RAN are both scheduled in a first TDD uplink subframe, the first uplink transmission of the first RAN is received in the first TDD uplink subframe, and wherein the UE discards the second uplink transmission of the second RAN.

20. The method of claim 12, wherein the first RAN is a fourth generation (4G) or long term evolution (LTE) RAN, and the second RAN is a fifth generation (5G) or new radio (NR) RAN.

21. The method of claim 20, wherein in a dual connectivity (DC) configuration, the first connection using the first RAN is established as a primary cell group (MCG) connection, and the second connection using the second RAN is established as a secondary cell group (SCG) connection.

22. The method of claim 12, further comprising: A dynamic shared capability of the UE and a single transmission capability or a dual transmission capability of the UE are received from the UE before identifying the reference TDD configuration, and wherein the reference TDD configuration is identified based at least in part on the dynamic shared capability and the single transmission capability or the dual transmission capability.

23. An apparatus for wireless communication at a user equipment (UE), comprising: processor, a memory in electronic communication with the processor; as well as instructions stored in the memory and executable by the processor to cause the apparatus to: establishing, at the UE, a first connection using a first radio access network (RAN) and a second connection using a second RAN; identifying a reference time division duplex (TDD) configuration for the first connection and a designated TDD configuration for both the first connection and the second connection, wherein the designated TDD configuration has a first set of uplink subframes and the reference TDD configuration has a second set of uplink subframes that is a subset of the first set of uplink subframes; receiving a downlink transmission via the first RAN according to the reference TDD configuration; as well as Uplink transmissions are transmitted via the first RAN and the second RAN according to the same designated TDD configuration, wherein the uplink subframes of the designated TDD configuration are usable for uplink transmissions via the first RAN and the second RAN.

24. The apparatus of claim 23, wherein an acknowledgement / negative acknowledgement (ACK / NACK) feedback corresponding to a downlink hybrid acknowledgment repeat request (HARQ) process of the first RAN is transmitted according to the reference TDD configuration.

25. The apparatus of claim 24, wherein ACK / NACK feedback corresponding to an uplink HARQ process of the first RAN is transmitted according to the specified TDD configuration.

26. The apparatus of claim 25, wherein uplink shared channel transmissions of the first RAN are transmitted according to the specified TDD configuration.

27. The apparatus of claim 24, wherein uplink ACK / NACK feedback information, uplink shared channel data, uplink control channel data, uplink reference signal, and downlink ACK / NACK feedback of the second RAN are transmitted according to the specified TDD configuration.

28. The apparatus of claim 23, wherein the instructions are further executable by the processor to cause the apparatus to: receiving scheduling information for transmitting uplink transmissions of the first RAN and the second RAN, wherein the uplink transmissions of the first RAN are scheduled in a different uplink subframe of the specified TDD configuration than the uplink transmissions of the second RAN; and Uplink transmissions of the first RAN and the second RAN are transmitted according to the scheduling information.

29. The apparatus of claim 28, wherein the instructions are further executable by the processor to cause the apparatus to: determining that a first uplink transmission of the first RAN and a second uplink transmission of the second RAN are both scheduled in a same first TDD uplink subframe; and The first TDD uplink subframe is identified as an error condition.

30. The apparatus of claim 28, wherein the instructions are further executable by the processor to cause the apparatus to: determining that a first uplink transmission of the first RAN and a second uplink transmission of the second RAN are both scheduled in a same first TDD uplink subframe; discarding the second uplink transmission of the second RAN; and The first uplink transmission of the first RAN is transmitted in the first TDD uplink subframe.

31. The apparatus of claim 23, wherein the first RAN is a fourth generation (4G) or long term evolution (LTE) RAN, and the second RAN is a fifth generation (5G) or new radio (NR) RAN.

32. The apparatus of claim 31 , wherein in a dual connectivity (DC) configuration, the first connection using the first RAN is established as a primary cell group (MCG) connection, and the second connection using the second RAN is established as a secondary cell group (SCG) connection.

33. The apparatus of claim 23, wherein the instructions are further executable by the processor to cause the apparatus to: A dynamic sharing capability of the UE and a single transmission capability or a dual transmission capability of the UE are determined prior to identifying the reference TDD configuration, and wherein the reference TDD configuration is identified based at least in part on the dynamic sharing capability and the single transmission capability or the dual transmission capability.

34. An apparatus for wireless communication at a base station, comprising: processor, a memory in electronic communication with the processor; as well as instructions stored in the memory and executable by the processor to cause the apparatus to: establishing a first connection with a user equipment (UE) using a first radio access network (RAN), and wherein a second connection is established at the UE using a second RAN; identifying a reference time division duplex (TDD) configuration for the first connection and a designated TDD configuration for both the first connection and the second connection, wherein the designated TDD configuration has a first set of uplink subframes and the reference TDD configuration has a second set of uplink subframes that is a subset of the first set of uplink subframes; transmitting a downlink transmission to the UE via the first RAN according to the reference TDD configuration; as well as An uplink transmission is received from the UE via the first RAN according to the specified TDD configuration, and wherein the UE transmits an uplink transmission via the second RAN according to the specified TDD configuration, and wherein the uplink subframe of the specified TDD configuration can be used for uplink transmission via the first RAN and the second RAN.

35. The apparatus of claim 34, wherein an acknowledgement / negative acknowledgement (ACK / NACK) feedback corresponding to a downlink hybrid acknowledgment repeat request (HARQ) process of the first RAN is transmitted according to the reference TDD configuration.

36. The apparatus of claim 35, wherein ACK / NACK feedback corresponding to an uplink HARQ process of the first RAN is transmitted according to the specified TDD configuration.

37. The apparatus of claim 36, wherein uplink shared channel transmissions of the first RAN are transmitted according to the specified TDD configuration.

38. The apparatus of claim 35, wherein uplink ACK / NACK feedback information, uplink shared channel data, uplink control channel data, uplink reference signal, and downlink ACK / NACK feedback of the second RAN are transmitted according to the specified TDD configuration.

39. The apparatus of claim 34, wherein the instructions are further executable by the processor to cause the apparatus to: scheduling the UE for uplink transmission via the first RAN and the second RAN, wherein the uplink transmission of the first RAN is scheduled in a different uplink subframe of the specified TDD configuration than the uplink transmission of the second RAN; and An uplink transmission is received from the UE according to the schedule.

40. The apparatus of claim 39, wherein the UE is configured to identify an error condition when a first uplink transmission of the first RAN and a second uplink transmission of the second RAN are both scheduled in a same first TDD uplink subframe.

41. The apparatus of claim 39, wherein the instructions are further executable by the processor to cause the apparatus to: When a first uplink transmission of the first RAN and a second uplink transmission of the second RAN are both scheduled in a first TDD uplink subframe, the first uplink transmission of the first RAN is received in the first TDD uplink subframe, and wherein the UE discards the second uplink transmission of the second RAN.

42. The apparatus of claim 34, wherein the first RAN is a fourth generation (4G) or long term evolution (LTE) RAN, and the second RAN is a fifth generation (5G) or new radio (NR) RAN.

43. The apparatus of claim 42, wherein in a dual connectivity (DC) configuration, the first connection using the first RAN is established as a primary cell group (MCG) connection, and the second connection using the second RAN is established as a secondary cell group (SCG) connection.

44. The apparatus of claim 34, wherein the instructions are further executable by the processor to cause the apparatus to: A dynamic shared capability of the UE and a single transmission capability or a dual transmission capability of the UE are received from the UE before identifying the reference TDD configuration, and wherein the reference TDD configuration is identified based at least in part on the dynamic shared capability and the single transmission capability or the dual transmission capability.

45. An apparatus for wireless communication at a user equipment (UE), comprising: means for establishing, at the UE, a first connection using a first radio access network (RAN) and a second connection using a second RAN; means for identifying a reference time division duplex (TDD) configuration for the first connection and a designated TDD configuration for both the first connection and the second connection, wherein the designated TDD configuration has a first set of uplink subframes and the reference TDD configuration has a second set of uplink subframes that is a subset of the first set of uplink subframes; means for receiving a downlink transmission via the first RAN according to the reference TDD configuration; as well as Means for transmitting uplink transmissions via the first RAN and the second RAN according to the same designated TDD configuration, wherein the uplink subframes of the designated TDD configuration can be used for uplink transmissions via the first RAN and the second RAN.

46. ​​An apparatus for wireless communication at a base station, comprising: means for establishing a first connection with a user equipment (UE) using a first radio access network (RAN), and wherein a second connection is established at the UE using a second RAN; means for identifying a reference time division duplex (TDD) configuration for the first connection and a designated TDD configuration for both the first connection and the second connection, wherein the designated TDD configuration has a first set of uplink subframes and the reference TDD configuration has a second set of uplink subframes that is a subset of the first set of uplink subframes; means for transmitting a downlink transmission to the UE via the first RAN according to the reference TDD configuration; as well as means for receiving an uplink transmission from the UE via the first RAN according to the specified TDD configuration, and wherein the UE transmits an uplink transmission via the second RAN according to the specified TDD configuration, wherein the uplink subframe of the specified TDD configuration can be used for uplink transmission via the first RAN and the second RAN.

47. A non-transitory computer-readable medium storing code for wireless communication at a user equipment (UE), the code comprising instructions executable by a processor to: establishing, at the UE, a first connection using a first radio access network (RAN) and a second connection using a second RAN; identifying a reference time division duplex (TDD) configuration for the first connection and a designated TDD configuration for both the first connection and the second connection, wherein the designated TDD configuration has a first set of uplink subframes and the reference TDD configuration has a second set of uplink subframes that is a subset of the first set of uplink subframes; receiving a downlink transmission via the first RAN according to the reference TDD configuration; as well as Uplink transmissions are transmitted via the first RAN and the second RAN according to the same designated TDD configuration, wherein the uplink subframes of the designated TDD configuration are usable for uplink transmissions via the first RAN and the second RAN.

48. A non-transitory computer-readable medium storing code for wireless communication at a base station, the code comprising instructions executable by a processor to: establishing a first connection with a user equipment (UE) using a first radio access network (RAN), and wherein a second connection is established at the UE using a second RAN; identifying a reference time division duplex (TDD) configuration for the first connection and a designated TDD configuration for both the first connection and the second connection, wherein the designated TDD configuration has a first set of uplink subframes and the reference TDD configuration has a second set of uplink subframes that is a subset of the first set of uplink subframes; transmitting a downlink transmission to the UE via the first RAN according to the reference TDD configuration; as well as An uplink transmission is received from the UE via the first RAN according to the specified TDD configuration, and wherein the UE transmits an uplink transmission via the second RAN according to the specified TDD configuration, wherein the uplink subframe of the specified TDD configuration can be used for uplink transmission via the first RAN and the second RAN.

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