Primary and secondary cell groups coexistence

Abstract

This application relates to primary and secondary cell group coexistence. Methods, systems, and devices for wireless communication are described. A wireless communication network can prioritize cell groups in dual connectivity. A higher priority cell group (e.g., a master cell group (MCG) or a secondary cell group (SCG)) can reserve time slots and indicate the reserved time slots to a lower priority cell group (e.g., a complementary SCG or MCG), for example, over a backhaul connection. The high priority cell group can also indicate additional, non-reserved time slots that the lower priority cell group can reserve or use for scheduling. One of the cell groups can transmit a slot format indication (SFI) to a user equipment (UE) in dual connectivity to indicate the time slot reservations. In some cases, a hybrid automatic repeat request (HARQ) timing parameter can be based on a number of reserved time slots. In some cases, power control can change based on whether the UE is capable of simultaneous uplink and downlink transmissions.

Description

[0001] This application is a divisional application of the invention patent application entitled "Coexistence of Primary Cell Cluster and Secondary Cell Cluster", filed on March 22, 2019, with application number 201980020820.8.

[0002] Cross-references

[0003] This patent application claims priority to U.S. Patent Application No. 16 / 360,450, filed March 21, 2019, entitled "Master Cell Group and Secondary Cell Group Coexistence"; U.S. Provisional Patent Application No. 62 / 674,824, filed May 22, 2018, entitled "Master Cell Group and Secondary Cell Group Coexistence"; and U.S. Provisional Patent Application No. 62 / 647,625, filed March 23, 2018, entitled "Master Cell Group and Secondary Cell Group Coexistence"; which have been assigned to the assignee of this application. Background Technology

[0004] The following generally refers to wireless communication, especially the coexistence of primary cell group (MCG) and secondary cell group (SCG).

[0005] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, video, packet data, message sending and receiving, broadcasting, and so on. These systems can 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, LTE-A Advanced (LTE-A) systems, or LTE-A Pro systems) and fifth-generation (5G) systems, which may be referred to as New Radio (NR) systems. These systems can employ 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 Extended OFDM (DFT-S-OFDM). A wireless multiple access communication system may include several base stations or network access nodes, each supporting communication from multiple communication devices simultaneously, which may also be referred to as User Equipment (UE).

[0006] Wireless communication systems can implement dual connectivity schemes, where a UE can simultaneously connect to a first base station for LTE communication and a second base station for NR communication. In dual connectivity, one of the base stations can be identified as an MCG. This base station (e.g., the MCG) provides an anchor carrier for communication with the UE. The anchor carrier can be associated with a RAT that uses the same radio access technology (RAT) as the MCG. A base station that is not an MCG in the dual connectivity scheme can be identified as an SCG. In some examples, the MCG is associated with LTE and controls the SCG associated with NR. In other examples, the MCG can be associated with NR, while the SCG can be associated with LTE. Dual connectivity schemes with an NR anchor can provide improved throughput for the UE. However, in either case, coexistence problems may arise if the MCG is associated with either NR or LTE, while the SCG is associated with a different RAT (either LTE or NR).

[0007] Overview

[0008] Wireless communication systems can implement dual connectivity schemes to improve the throughput of wireless devices. For example, a User Equipment (UE) can simultaneously connect to a first base station (e.g., an evolved B-node (eNB)) for LTE communications and a second base station (e.g., a next-generation B-node (gNB)) for new radio (NR) communications. One of the base stations can provide a primary cell group (MCG) controlling a secondary cell group (SCG). The core network can implement a prioritization scheme for each radio access technology (RAT) based on whether NR or LTE has higher priority. The higher-priority cell group can reserve time slots across cells in the dual connectivity scheme and indicate the reserved time slots to the lower-priority cell group (e.g., via backhaul). The higher-priority cell group can also indicate additional, non-reserved time slots, which the lower-priority cell group can reserve or use for scheduling. The higher-priority cell group can also independently schedule transmissions on non-reserved, additional time slots. The cell group can transmit a Slot Format Indication (SFI) to the UE to indicate time slot reservations. In some examples, wireless communication systems may utilize Hybrid Automatic Repeat Request (HARQ) timing offset indications based on the number of reserved time slots rather than the total number of time slots.

[0009] In some scenarios, the UE may be able to perform dual uplink transmissions on both NR and LTE carriers during non-reserved time slots. If the UE is capable of dynamic power control, the core network can prioritize uplink channels for the MCG and SCG. For example, the MCG uplink control channel may have a higher priority than the SCG uplink control channel, or the MCG uplink data channel may have the same priority as the SCG uplink data channel, or any MCG uplink channel may have a higher priority than its corresponding SCG uplink channel, among other configurations. The UE can be configured to reduce or decrease the transmit power of a channel based on its priority and the channel's transmission start time. In some other examples, time slots reserved for LTE and time slots reserved for NR may have different power configurations. For example, exclusive reserved time slots may have larger transmit power limits, while non-reserved time slots may have smaller transmit power limits. The UE may follow maximum power levels configured independently for the MCG and SCG.

[0010] A method for wireless communication at a UE is described. The method may include: identifying that the UE is operating with a primary cell group and a secondary cell group in dual connectivity; receiving from the primary cell group an indication of a reserved transmission time interval (TTI) reserved for priority uplink (UL) communication with the primary cell group; identifying an additional TTI that can be used for UL communication with either the primary or secondary cell group; transmitting one or more UL messages to the primary cell group using the reserved TTI; and transmitting one or more UL messages to either the primary or secondary cell group using the additional TTI.

[0011] 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. These instructions are executable by the processor to cause the apparatus to: identify that the UE is operating in dual connectivity with a primary cell group and a secondary cell group; receive from the primary cell group an indication of a reserved TTI reserved for priority UL communication with the primary cell group; identify an additional TTI that can be used for UL communication with the primary or secondary cell group; transmit one or more UL messages to the primary cell group using the reserved TTI; and transmit one or more UL messages to the primary or secondary cell group using the additional TTI.

[0012] Another apparatus for wireless communication at a UE is described. The apparatus may include: identifying that the UE is operating in dual connectivity with a primary cell group and a secondary cell group; receiving from the primary cell group an indication of a reserved TTI reserved for priority UL communication with the primary cell group; identifying an additional TTI that can be used for UL communication with either the primary or secondary cell group; transmitting one or more UL messages to the primary cell group using the reserved TTI; and transmitting one or more UL messages to either the primary or secondary cell group using the additional TTI.

[0013] A non-transient computer-readable medium is described, storing code for wireless communication at a UE. The code may include instructions executable by a processor for: identifying that the UE is operating in dual connectivity with a primary cell group and a secondary cell group; receiving from the primary cell group an indication of a reserved TTI reserved for priority UL communication with the primary cell group; identifying an additional TTI that can be used for UL communication with either the primary or secondary cell group; transmitting one or more UL messages to the primary cell group using the reserved TTI; and transmitting one or more UL messages to either the primary or secondary cell group using the additional TTI.

[0014] Some examples of the methods, apparatus (equipment), and non-transient computer-readable media described herein may further include operations, features, means, or instructions for: receiving from a secondary cell group an indication of an additional reserved TTI that may be reserved for UL communication with the secondary cell group, wherein the reserved TTI and the additional reserved TTI may be time-disjoint; and transmitting one or more UL messages to the secondary cell group using the additional reserved TTI. Some examples of the methods, apparatus (equipment), and non-transient computer-readable media described herein may further include operations, features, means, or instructions for: receiving a schedule for using one or more additional TTIs for UL communication with either the primary or secondary cell group, the schedule facilitating the avoidance of simultaneous UL transmissions to both the primary and secondary cell groups, wherein the transmission of one or more UL messages using the additional TTIs may be based on the schedule.

[0015] Some examples of the methods, apparatus (equipment), and non-transient computer-readable media described herein may further include operations, features, means, or instructions for: determining that UL messages destined for a primary cell group and UL messages destined for a secondary cell group can both be scheduled for the same TTI in an additional TTI; identifying the priority between the UL messages destined for the primary cell group and the UL messages destined for the secondary cell group; and transmitting one of the UL messages destined for the primary cell group or the UL messages destined for the secondary cell group during the TTI based on that priority. In some examples of the methods, apparatus (equipment), and non-transient computer-readable media described herein, receiving an indication of a reserved TTI may include operations, features, means, or instructions for: receiving a slot format indication (SFI) identifying a configuration for a UL TTI, a downlink (DL) TTI, an unknown TTI, or a combination thereof, wherein the reserved TTI includes the UL TTI.

[0016] In some examples of the methods, apparatus, and non-transient computer-readable media described herein, receiving an SFI may include operations, features, means, or instructions for receiving a cellular-specific configured SFI. In some examples of the methods, apparatus, and non-transient computer-readable media described herein, receiving an SFI may include operations, features, means, or instructions for receiving a UE-specific configured SFI, wherein the UE-specific configured SFI overrides any received cellular-specific configured SFI. In some examples of the methods, apparatus, and non-transient computer-readable media described herein, receiving an SFI may include operations, features, means, or instructions for receiving a dynamic SFI via a DCI, wherein the dynamic SFI may be specific to an upcoming TTI or a set of TTIs.

[0017] In some examples of the methods, apparatus (equipment), and non-transient computer-readable media described herein, the indication further indicates a DL TTI, an unknown TTI, or both that may be reserved for communication with the primary cellular group. In some examples of the methods, apparatus (equipment), and non-transient computer-readable media described herein, the primary cellular group may be configured for Time Division Duplex (TDD) operation, while the secondary cellular group may be configured for Frequency Division Duplex (FDD) operation. Some examples of the methods, apparatus (equipment), and non-transient computer-readable media described herein may further include operations, features, means, or instructions for actions where both the primary and secondary cellular groups can be configured for FDD operation. In some examples of the methods, apparatus (equipment), and non-transient computer-readable media described herein, the primary cellular group may be configured for TDD operation while the secondary cellular group may be configured for FDD operation, wherein UL transmissions to the secondary cellular group are time-division shared with Supplemental Uplink (SUL) transmissions to the primary cellular group.

[0018] Some examples of the methods, apparatus (equipment), and non-transient computer-readable media described herein may further include operations, features, means, or instructions for the following actions: both the primary cell group and the secondary cell group can be configured for TDD operations. Some examples of the methods, apparatus (equipment), and non-transient computer-readable media described herein may further include operations, features, means, or instructions for the following actions: identifying an FDD timing configuration for UL transmissions to the secondary cell group, the FDD timing configuration facilitating the avoidance of simultaneous UL transmissions to both the primary and secondary cell groups, wherein one or more UL messages can be transmitted using an additional TTI according to the FDD timing configuration.

[0019] In some examples of the methods, apparatus (equipment), and non-transient computer-readable media described herein, one or more UL messages transmitted using additional TTIs include LTE Physical Random Access Channel (PRACH) messages, Detection Reference Signal (SRS) messages, HARQ messages, or combinations thereof. Some examples of the methods, apparatus (equipment), and non-transient computer-readable media described herein may further include operations, features, means, or instructions for receiving a joint configuration that includes an indication of reserved TTIs that may be reserved for UL or DL ​​communication with a primary cell group, and an indication of which additional TTIs may be used for UL or DL ​​communication with a primary cell group and which additional TTIs may be used for UL or DL ​​communication with a secondary cell group.

[0020] Some examples of the methods, apparatus (equipment), and non-transient computer-readable media described herein may further include operations, features, means, or instructions for receiving a priority configuration that includes an indication of reserved TTIs that may be reserved for UL or DL ​​communication with a primary cellular group, and an indication of which additional TTIs may be used for UL or DL ​​communication with the primary cellular group. In some examples of the methods, apparatus (equipment), and non-transient computer-readable media described herein, transmitting one or more UL messages to a primary or secondary cellular group using additional TTIs may include operations, features, means, or instructions for transmitting one or more UL messages to a secondary cellular group during one of the additional TTIs indicated for DL ​​communication with the primary cellular group.

[0021] Some examples of the methods, apparatus (equipment), and non-transient computer-readable media described herein may further include operations, features, means, or instructions for identifying a parameter indicating a time offset for UL transmission of HARQ feedback after the reception of a data message, wherein the time offset may be transmitted according to the number of reserved TTIs and based on the parameter. In some examples of the methods, apparatus (equipment), and non-transient computer-readable media described herein, transmitting one or more UL messages to a primary or secondary cell group using an additional TTI may include operations, features, means, or instructions for transmitting UL messages to the primary and secondary cell groups during different TTIs. In some examples of the methods, apparatus (equipment), and non-transient computer-readable media described herein, transmitting one or more UL messages to a primary or secondary cell group using an additional TTI may include operations, features, means, or instructions for transmitting UL messages to the primary and secondary cell groups during the same TTI.

[0022] Some examples of the methods, apparatuses, and non-transient computer-readable media described herein may further include operations, features, means, or instructions for prioritizing power control for each UL message transmitted within the same TTI based on the type of the UL message. Some examples of the methods, apparatuses, and non-transient computer-readable media described herein may further include operations, features, means, or instructions for prioritizing power control for each UL message transmitted within the same TTI based on the start time of each UL message. In some examples of the methods, apparatuses, and non-transient computer-readable media described herein, the maximum power control for UL messages transmitted to the primary cell cluster and the maximum power control for UL messages transmitted to the secondary cell cluster within the same TTI may each be less than the corresponding power control for UL transmissions in different TTIs.

[0023] Some examples of the methods, apparatus (equipment), and non-transient computer-readable media described herein may further include operations, features, means, or instructions for: identifying a first TTI duration associated with a primary cell group, identifying a second TTI duration associated with a secondary cell group, and applying a transmit power control scheme at least in part based on the first TTI duration and the second TTI duration. In some examples of the methods, apparatus (equipment), and non-transient computer-readable media described herein, applying the transmit power control scheme further includes adjusting the transmit power for UL messages transmitted to the primary cell group and UL messages transmitted to the secondary cell group after a TTI duration of at least a TTI duration that is longer than the second TTI duration. In some examples of the methods, apparatus (equipment), and non-transient computer-readable media described herein, applying the transmit power control scheme further includes adjusting the transmit power for UL messages transmitted to the primary cell group and UL messages transmitted to the secondary cell group after a TTI duration of at least a TTI duration that is longer than the first TTI duration.

[0024] A method for wireless communication at a base station is described. The method may include: identifying that the base station is operating as a primary cellular group with a UE in dual connectivity; transmitting to the UE an indication of a reserved TTI (Time-of-Touch) reserved for priority UL (Ultra-Low) communication with the primary cellular group; indicating to a secondary cellular group the reserved TTI and additional TTIs that can be used for UL communication with either the primary or secondary cellular group; and receiving one or more UL messages from the UE using the reserved TTI.

[0025] 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. These instructions are executable by the processor to cause the apparatus to: identify that the base station is operating as a primary cellular group with a UE in dual connectivity; transmit to the UE an indication of a reserved TTI reserved for priority UL communication with the primary cellular group; indicate to a secondary cellular group the reserved TTI and additional TTIs that can be used for UL communication with either the primary or secondary cellular group; and receive one or more UL messages from the UE using the reserved TTIs.

[0026] Another apparatus for wireless communication at a base station is described. The apparatus may include: identifying that the base station is operating as a primary cellular group with a UE in dual connectivity; transmitting to the UE an indication of a reserved TTI reserved for priority UL communication with the primary cellular group; indicating to a secondary cellular group the reserved TTI and additional TTIs that can be used for UL communication with either the primary or secondary cellular group; and receiving one or more UL messages from the UE using the reserved TTI.

[0027] A non-transient computer-readable medium is described, storing code for wireless communication at a base station. The code may include instructions executable by a processor for: identifying that the base station is operating as a primary cellular group with a UE in dual connectivity; transmitting to the UE an indication of a reserved TTI reserved for priority UL communication with the primary cellular group; indicating to a secondary cellular group the reserved TTI and additional TTIs that can be used for UL communication with either the primary or secondary cellular group; and receiving one or more UL messages from the UE using the reserved TTIs.

[0028] Some examples of the methods, apparatus (equipment), and non-transient computer-readable media described herein may further include operations, features, means, or instructions for transmitting a schedule for using one or more additional TTIs for UL communication with a primary or secondary cell group, the scheduling facilitating the avoidance of simultaneous UL transmissions to both the primary and secondary cell groups. In some examples of the methods, apparatus (equipment), and non-transient computer-readable media described herein, transmitting an indication of a reserved TTI may include operations, features, means, or instructions for transmitting an SFI identifying a configuration for a UL TTI, DLTTI, unknown TTI, or a combination thereof, wherein the reserved TTI includes the UL TTI. In some examples of the methods, apparatus (equipment), and non-transient computer-readable media described herein, transmitting an SFI may include operations, features, means, or instructions for transmitting a configured SFI that varies depending on the cell.

[0029] In some examples of the methods, apparatuses, and non-transient computer-readable media described herein, transmitting an SFI may include operations, features, means, or instructions for: transmitting a UE-specific configured SFI, wherein the UE-specific configured SFI overrides any previously transmitted cell-specific configured SFI. In some examples of the methods, apparatuses, and non-transient computer-readable media described herein, transmitting an SFI may include operations, features, means, or instructions for: transmitting a dynamic SFI via a DCI, wherein the dynamic SFI may be specific to an upcoming TTI or set of TTIs. In some examples of the methods, apparatuses, and non-transient computer-readable media described herein, the indication further indicates a DL TTI, an unknown TTI, or both that may be reserved for communication with the primary cell group. In some examples of the methods, apparatuses, and non-transient computer-readable media described herein, the primary cell group may be configured for TDD operation, while the secondary cell group may be configured for FDD operation.

[0030] Some examples of the methods, apparatus (equipment), and non-transient computer-readable media described herein may further include operations, features, means, or instructions for actions where both the primary and secondary cell groups can be configured for FDD operations. In some examples of the methods, apparatus (equipment), and non-transient computer-readable media described herein, the primary cell group may be configured for TDD operations while the secondary cell group may be configured for FDD operations, wherein UL transmissions to the secondary cell group are time-division shared with SUL transmissions to the primary cell group. Some examples of the methods, apparatus (equipment), and non-transient computer-readable media described herein may further include operations, features, means, or instructions for actions where both the primary and secondary cell groups can be configured for TDD operations.

[0031] Examples of the methods, apparatuses, and non-transient computer-readable media described herein may further include operations, features, means, or instructions for: instructing the UE to an FDD timing configuration for UL transmission to a secondary cell group, the FDD timing configuration facilitating the avoidance of simultaneous UL transmission to both the primary and secondary cell groups. Examples of the methods, apparatuses, and non-transient computer-readable media described herein may further include operations, features, means, or instructions for: transmitting a joint configuration to the UE, the joint configuration including an indication of reserved TTIs that can be reserved for UL or DL ​​communication with the primary cell group, and an indication of which additional TTIs can be used for UL or DL ​​communication with the primary cell group and which additional TTIs can be used for UL or DL ​​communication with the secondary cell group.

[0032] Some examples of the methods, apparatus (equipment), and non-transient computer-readable media described herein may further include operations, features, means, or instructions for: transmitting a prioritization configuration to the UE, the prioritization configuration including an indication of reserved TTIs that can be reserved for UL or DL ​​communication with the primary cellular group, and an indication of which additional TTIs can be used for UL or DL ​​communication with the primary cellular group. Some examples of the methods, apparatus (equipment), and non-transient computer-readable media described herein may further include operations, features, means, or instructions for: transmitting to the UE a parameter indicating a time offset for UL transmission for HARQ feedback after the reception of a data message, wherein the time offset may be based on the number of reserved TTIs, and receiving HARQ feedback according to the parameter. Brief description of the attached diagram

[0033] Figure 1 Examples of wireless communication systems supporting the coexistence of primary cell groups (MCGs) and secondary cell groups (SCGs) according to various aspects of this disclosure are explained.

[0034] Figure 2 Examples of wireless communication systems supporting the coexistence of MCG and SCG according to various aspects of this disclosure are explained.

[0035] Figure 3 Examples of wireless communication systems supporting the coexistence of MCG and SCG according to various aspects of this disclosure are explained.

[0036] Figure 4 Examples of slot reservation distributions supporting the coexistence of MCG and SCG are explained according to various aspects of this disclosure.

[0037] Figure 5 An example of a dual-carrier configuration table supporting the coexistence of MCG and SCG according to various aspects of this disclosure is explained.

[0038] Figure 6A and 6B An example of a Hybrid Automatic Repeat Request (HARQ) timing offset configuration supporting the coexistence of MCG and SCG is explained according to various aspects of this disclosure.

[0039] Figure 7 Examples of process flows supporting the coexistence of MCG and SCG according to various aspects of this disclosure are explained.

[0040] Figure 8 Examples of power variations supporting the coexistence of MCG and SCG according to various aspects of this disclosure are explained.

[0041] Figure 9 and Figure 10A block diagram of an apparatus supporting the coexistence of MCG and SCG according to various aspects of this disclosure is shown.

[0042] Figure 11 A block diagram of an apparatus supporting the coexistence of MCG and SCG according to various aspects of this disclosure is shown.

[0043] Figure 12 A diagram of a system including a device supporting the coexistence of MCG and SCG is shown according to various aspects of this disclosure.

[0044] Figure 13 and Figure 14 A block diagram of an apparatus supporting the coexistence of MCG and SCG according to various aspects of this disclosure is shown.

[0045] Figure 15 A block diagram of an apparatus supporting the coexistence of MCG and SCG according to various aspects of this disclosure is shown.

[0046] Figure 16 A diagram of a system including a device supporting the coexistence of MCG and SCG is shown according to various aspects of this disclosure.

[0047] Figures 17 to 19 A flowchart illustrating methods for supporting the coexistence of MCG and SCG according to various aspects of this disclosure is shown. Detailed description

[0048] Wireless communication systems can implement dual connectivity schemes to improve the throughput of wireless devices. For example, a user equipment (UE) can simultaneously connect to a first base station (e.g., an evolved B-node (eNB)) for LTE communications and a second base station (e.g., a next-generation B-node (gNB)) for NR communications. One of the base stations can provide a primary cell group (MCG) that controls the secondary cell group (SCG). The MCG includes an anchor carrier associated with the same radio access technology (RAT) as the MCG.

[0049] Wireless communication systems can also implement various configurations for dual connectivity schemes. In many wireless communication systems, dual connectivity schemes include an LTE anchor, where the eNB is the MCG that connects the UE to the core network. Therefore, the SCG can connect the UE to the NR node in the core network either directly in the SCG bearer configuration or via a backhaul link with the MCG in a split bearer configuration. Dual connectivity schemes can also use an NR anchor, which can provide improved throughput for the UE. Therefore, in some scenarios, the NR node or gNB can be the MCG while the eNB can be the SCG. In both cases, coexistence issues can arise between NR and LTE communications.

[0050] For example, in a dual connectivity scheme, a UE may be restricted to using only one uplink carrier associated with a single RAT. If the UE connects to the NR network in a dual connectivity scheme using an NR anchor, the UE can transmit uplink information to the MCG on an NR carrier or to the SCG on an LTE carrier. In some cases, the UE can transmit on multiple carriers of the RAT for carrier aggregation. Furthermore, the scheduling for NR and LTE transmissions can be affected. The wireless communication system described herein enables techniques for improving NR and LTE coexistence.

[0051] To reduce LTE and NR scheduling conflicts, the serving cell can implement a prioritization scheme for each RAT. The core network can identify whether NR or LTE has higher priority. The UE can be the assigned resource first used for a higher-priority RAT, which is reserved across cells in a dual-connectivity scheme. In some cases, NR can be identified as a higher-priority RAT based on its association with the MCG or due to the higher potential throughput of NR. In some other examples, LTE can be identified as a higher-priority RAT based on the scheduling flexibility of NR and the relative scheduling rigidity of LTE. In some cases, for example, if the RAT is deployed in a lower frequency band, it can be identified as a higher-priority RAT based on higher reliability.

[0052] Cellular groups in a dual-connectivity scheme can implement techniques for coordinating NR and LTE scheduling based on priority. Higher-priority cell groups can reserve a set of Transmission Time Intervals (TTIs) (e.g., slots or subframes) and indicate the reserved slots to lower-priority cell groups (e.g., via backhaul connections). Lower-priority cell groups can schedule the remaining TTIs, provided that the reservations by lower-priority cell groups do not interfere with the reservations by higher-priority cells. For example, if LTE is higher priority, slots used for NR transmissions may not be scheduled to overlap with uplink subframes reserved for LTE. Similarly, if NR is higher priority, LTE transmissions may not be scheduled during subframes overlapping with uplink slots reserved for NR. Cellular groups can reserve TTIs to transmit or receive high-importance signals, such as Hybrid Automatic Repeat Request (HARQ) feedback or Physical Uplink Control Channel (PUCCH) messages. LTE and NR deployments can be based on different subcarrier intervals, and the slot duration for NR can be part of the subframe duration. In this scenario, if a TTI is reserved for a specific RAT, the time slot or subframe corresponding to that TTI cannot be used by another RAT.

[0053] Cellular clusters can reserve time slots for both Frequency Division Duplex (FDD) and Time Division Duplex (TDD) carriers. In some examples, an uplink or downlink carrier for a UE can be configured for FDD transmission, but the serving cell can schedule the UE based on the characteristics of the TDD configuration to reduce the complexity of reserving time slots and scheduling resources.

[0054] In some examples, the wireless communication system may utilize the HARQ timing offset indicator based on the number of reserved time slots rather than the total number of time slots. For example, the UE may receive downlink transmissions in the first reserved time slot and transmit HARQ feedback for the downlink time slot in the fourth reserved time slot. If the second and third time slots are not reserved, the UE may indicate a timing offset K1 = 1, and the HARQ feedback may be provided in the subsequent reserved time slots. In other configurations, the HARQ timing offset indicator may indicate the total number of time slots between data transmission and HARQ feedback, which may include non-reserved time slots. The MCG may instruct how to interpret the HARQ timing offset indicator via Radio Resource Control (RRC) signaling.

[0055] In some scenarios, the UE may be able to perform dual uplink transmissions on both NR and LTE carriers during non-reserved time slots. If the UE is capable of dynamic power control, the core network can prioritize uplink channels for the MCG and SCG. For example, the MCG PUCCH may have a higher priority than the SCG PUCCH, or the MCG PUSCH may have the same priority as the SCG PUSCH, or any MCG uplink channel may have a higher priority than its corresponding SCG uplink channel, among other configurations. If the aggregated transmit power exceeds the maximum transmit power and uplink channels start simultaneously, the UE can reduce or decrease the transmit power of the lower-priority channel. If the aggregated transmit power exceeds the maximum power limit and uplink channels start at different times, the UE can reduce or decrease the transmit power of the lower-priority channel, or decrease the power of the subsequently starting uplink channel or discard the subsequently starting uplink channel.

[0056] In some cases, time slots reserved for LTE and time slots reserved for NR can have different power configurations. For exclusive reserved time slots (e.g., other transmissions not allowed to have similar single uplink transmission limits), a larger transmit power limit can be configured individually for each RAT, e.g., for both LTE and NR transmissions. For non-reserved time slots, a smaller transmit power limit can be configured. The UE can follow power limits configured independently for MCG and SCG.

[0057] The aspects of this disclosure are initially described in the context of wireless communication systems. These aspects are further explained and described by way of, and with reference to, apparatus diagrams, system diagrams, and flowcharts relating to the coexistence of MCGs and SCGs.

[0058] Figure 1 Examples of a wireless communication system 100 supporting the coexistence of MCG and SCG according to various aspects of this disclosure are described. 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 a Long Term Evolution (LTE) network, an Advanced LTE (LTE-A) network, an LTE-A Pro network, or a New Radio (NR) network. In some cases, the wireless communication system 100 may support enhanced broadband communication, ultra-reliable (e.g., mission-critical) communication, low latency communication, or communication with low-cost and low-complexity devices.

[0059] Base station 105 can wirelessly communicate with UE 115 via one or more base station antennas. Base station 105 described herein may include, or may be referred to by those skilled in the art as, a base transceiver station, radio base station, access point, radio transceiver, B-node, evolved B-node (eNB), next-generation B-node, or gigabit B-node (any of which may be referred to as gNB), home B-node, home evolved B-node, or any other suitable term. Wireless communication system 100 may include different types of base station 105 (e.g., macro base station or small cell base station). UE 115 described herein may be able to communicate with various types of base station 105 and network equipment (including macro eNB, small cell eNB, gNB, relay base station, etc.).

[0060] Each base station 105 may be associated with a specific geographic coverage area 110, within which communication with various UEs 115 is supported. Each base station 105 may provide communication coverage to the corresponding geographic coverage area 110 via a communication link 125, and the communication link 125 between the base station 105 and the UE 115 may utilize one or more carriers. The communication link 125 shown in the wireless communication system 100 may include uplink transmission from the UE 115 to the base station 105, or downlink transmission from the base station 105 to the UE 115. Downlink transmission may also be referred to as forward link transmission, and uplink transmission may also be referred to as reverse link transmission.

[0061] The geographic coverage area 110 of base station 105 can be divided into sectors that constitute only a part of the geographic coverage area 110, and each sector can be associated with a cell. For example, each base station 105 can provide communication coverage to macrocells, small cells, hotspots, or other types of cells, or various combinations thereof. In some examples, base station 105 can be mobile and thus provide communication coverage to mobile geographic coverage areas 110. In some examples, different geographic coverage areas 110 associated with different technologies can overlap, and overlapping geographic coverage areas 110 associated with different technologies can be supported by the same base station 105 or different base stations 105. The wireless communication system 100 can include, for example, heterogeneous LTE / LTE-A / LTE-A Pro or NR networks, wherein different types of base stations 105 provide coverage to various geographic coverage areas 110.

[0062] The term "cell" refers to a logical communication entity used to communicate with base station 105 (e.g., on a carrier) and may be associated with identifiers 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 can provide access for 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 (e.g., a sector) of the geographical coverage area 110 on which the logical entity operates.

[0063] Each UE 115 may be distributed throughout the wireless communication system 100, and each UE 115 may be stationary or mobile. UE 115 may also be referred to as a mobile device, wireless device, remote device, handheld device, or subscriber device, or any other suitable term, wherein "device" may also be referred to as a unit, station, terminal, or client. UE 115 may also be a personal electronic device, such as a cellular phone, personal digital assistant (PDA), tablet computer, laptop computer, or personal computer. In some examples, UE 115 may also refer to a wireless local loop (WLL) station, Internet of Things (IoT) device, Internet of Everything (IoE) device, or MTC device, etc., which may be implemented in various items (such as appliances, vehicles, instruments, etc.).

[0064] Some UE 115 devices (such as MTC or IoT devices) can be low-cost or low-complexity devices and can provide automated machine-to-machine communication (e.g., via machine-to-machine (M2M) communication). M2M communication or MTC can refer to data communication technologies that allow devices to communicate with each other or with base station 105 without human intervention. In some examples, M2M communication or MTC may include communication from devices that have integrated sensors or meters to measure or capture information and relay that information to a central server or application that can utilize the information or present it to people interacting with the program or application. Some UE 115 devices may be designed to collect information or enable automated machine behavior. Examples of applications for MTC devices include: smart metering, inventory monitoring, water level monitoring, equipment monitoring, healthcare monitoring, wilderness survival monitoring, weather and geographic event monitoring, queue management and tracking, remote security sensing, physical access control, and transaction-based commercial charging.

[0065] Some UEs 115 can be configured to operate in reduced power consumption modes, 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 can be performed at a reduced peak rate. Other power-saving techniques for UE 115 include entering a power-saving “deep sleep” mode when not engaged in active communication, or operating on limited bandwidth (e.g., according to narrowband communication). In some cases, UE 115 can be designed to support critical functions (e.g., mission-critical functions), and the wireless communication system 100 can be configured to provide ultra-reliable communication for these functions.

[0066] In some scenarios, UE 115 may also be able to communicate directly with other UE 115s (e.g., using peer-to-peer (P2P) or device-to-device (D2D) protocols). One or more UEs in a group of UEs 115s utilizing D2D communication may be within the geographic coverage area 110 of base station 105. Other UEs 115s in such a group may be outside the geographic coverage area 110 of base station 105 or may be unable to receive transmissions from base station 105 for other reasons. In some scenarios, groups of UEs 115s communicating via D2D communication may utilize a one-to-many (1:M) system, where each UE 115 transmits to every other UE 115 in the group. In some scenarios, base station 105 facilitates the scheduling of resources for D2D communication. In other scenarios, D2D communication is performed between UEs 115 without involving base station 105.

[0067] Base station 105 can communicate with core network 130 and with each other. For example, base station 105 can interface with core network 130 via backhaul link 132 (e.g., via S1 or other interfaces). Base stations 105 can communicate with each other directly (e.g., directly between base stations 105) or indirectly (e.g., via core network 130) on backhaul link 134 (e.g., via X2 or other interfaces).

[0068] Core network 130 provides user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. 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 manages non-access stratum (e.g., control plane) functions, such as mobility, authentication, and bearer management of UE 115 served by base station 105 associated with the EPC. User IP packets can be delivered via the S-GW, which itself can connect to the P-GW. The P-GW provides IP address allocation and other functions. The P-GW can connect to network operator IP services. Operator IP services may include access to the Internet, intranets, IP Multimedia Subsystem (IMS), or packet-switched (PS) streaming services.

[0069] At least some network devices (such as base station 105) may include sub-components, 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 several other access network transport entities, which may be referred to as a radio headend, a smart radio headend, or a transmit / receive point (TRP). 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 headends and access network controllers) or combined into a single network device (e.g., base station 105).

[0070] Wireless communication system 100 can operate using one or more frequency bands typically in the range of 300 MHz to 300 GHz. Generally, the 300 MHz to 3 GHz region is referred to as the Ultra High Frequency (UHF) region or decimeter band because wavelengths range from approximately 1 decimeter to 1 meter. UHF waves can be blocked or redirected by buildings and environmental features. However, these waves can penetrate various structures sufficiently for macrocells to provide service to UE 115 located indoors. Compared to transmissions using smaller frequencies and longer waves in the High Frequency (HF) or Very High Frequency (VHF) portions of the spectrum below 300 MHz, UHF wave transmission can be associated with smaller antennas and shorter ranges (e.g., less than 100 km).

[0071] The wireless communication system 100 can also operate in the ultra-high frequency (SHF) region using a frequency band from 3 GHz to 30 GHz (also known as the centimeter band). The SHF region includes frequency bands that can be used opportunistically by devices capable of tolerating interference from other users (such as the 5 GHz Industrial, Scientific and Medical (ISM) band).

[0072] The wireless communication system 100 can also operate in the extremely high frequency (EHF) region of the spectrum (e.g., from 30 GHz to 300 GHz), also known as the millimeter band. In some examples, the wireless communication system 100 can support millimeter-wave (mmW) communication between the UE 115 and the base station 105, and the EHF antennas of the corresponding devices can be even smaller and more closely spaced than UHF antennas. In some cases, this can facilitate the use of antenna arrays within the UE 115. However, the propagation of EHF transmissions may suffer from even greater atmospheric attenuation and shorter range than SHF or UHF transmissions. The techniques disclosed herein can be employed across transmissions using one or more different frequency regions, and the frequency band usage specified across these frequency regions may vary by country or regulatory authority.

[0073] In some cases, wireless communication system 100 may utilize both licensed and unlicensed radio spectrum bands. For example, wireless communication system 100 may employ License-Assisted Access (LAA), LTE Unlicensed (LTE-U) radio access technology, or NR technology in unlicensed frequency bands (such as the 5 GHz ISM band). When operating in unlicensed radio spectrum bands, wireless devices (such as base station 105 and UE 115) may employ a Listen-Before-Talk (LBT) protocol to ensure the frequency channel is open before transmitting data. In some cases, operation in unlicensed frequency bands may be coordinated with CC operation in licensed frequency bands based on CA configuration (e.g., LAA). Operation in unlicensed spectrum may include downlink transmission, uplink transmission, peer-to-peer transmission, or a combination thereof. Duplexing in unlicensed spectrum may be based on FDD, TDD, or a combination of both.

[0074] In some examples, base station 105 or UE 115 may be equipped with multiple antennas, which can be used to employ techniques such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communication, or beamforming. For example, wireless communication system 100 may use a transmission scheme between a transmitting device (e.g., base station 105) and a receiving device (e.g., 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 combinations of antennas. Similarly, the receiving device may receive multiple signals via different antennas or different combinations of antennas. 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 used 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.

[0075] Beamforming (also known as spatial filtering, directional transmission, or directional reception) is a signal processing technique that can be used at a transmitting or receiving device (e.g., base station 105 or UE 115) to shape or guide an antenna beam (e.g., a transmit beam or a receive beam) along a spatial path between the transmitting and receiving devices. Beamforming can be achieved by combining signals transmitted via antenna elements of an antenna array, such that signals propagating relative to a particular orientation of the antenna array experience constructive interference, while other signals experience destructive interference. Adjustments to the signals transmitted via the antenna elements may include the transmitting or receiving device applying specific amplitude and phase shifts to the signals carried via each antenna element associated with that device. The adjustments associated with each antenna element may be defined by a beamforming weight set associated with a particular orientation (e.g., relative to the antenna array of the transmitting or receiving device, or relative to some other orientation).

[0076] In one example, base station 105 may use multiple antennas or antenna arrays to perform beamforming operations for directional communication with UE 115. For example, some signals (e.g., synchronization signals, reference signals, beam selection signals, or other control signals) may be transmitted multiple times by base station 105 in different directions. This may include a signal being transmitted according to different beamforming weight sets associated with different transmission directions. Transmissions in different beam directions can be used (e.g., by base station 105 or receiving device, such as UE 115) to identify the beam direction used by base station 105 for subsequent transmission and / or reception. Some signals (such as data signals associated with a particular receiving device) may be transmitted by base station 105 in a single beam direction (e.g., the direction associated with the receiving device, such as UE 115). In some examples, the beam direction associated with transmission along a single beam direction may be determined at least in part based on the signals transmitted in different beam directions. For example, UE 115 may receive one or more signals transmitted by base station 105 in different directions, and UE 115 may report to base station 105 an indication of the signals it received with the highest signal quality or other acceptable signal quality. Although these techniques are described with reference to signals transmitted by base station 105 in one or more directions, UE 115 may use similar techniques to transmit signals multiple times in different directions (e.g., to identify the beam direction used by UE 115 for subsequent transmission or reception) or to transmit signals in a single direction (e.g., to transmit data to a receiving device).

[0077] A receiver device (e.g., UE 115, which may be an example of an mmW receiver device) may attempt multiple receive beams when receiving various signals (such as synchronization signals, reference signals, beam selection signals, or other control signals) from base station 105. For example, the receiver device may attempt multiple reception directions by: receiving via different antenna subarrays; processing received signals according to different antenna subarrays; receiving according to different sets of receive beamforming weights applied to signals received at multiple antenna elements of the antenna array; or processing received signals according to different sets of receive beamforming weights applied to signals received at multiple antenna elements of the antenna array, any of which may be referred to as “listening” according to different receive beams or reception directions. In some examples, the receiver device may use a single receive beam to receive along a single beam direction (e.g., when receiving a data signal). A single receiving beam can be aligned on a beam direction determined at least in part based on listening to different receiving beam directions (e.g., a beam direction determined at least in part based on listening to multiple beam directions to have the highest signal strength, highest signal-to-noise ratio, or other acceptable signal quality).

[0078] In some cases, the antennas of base station 105 or UE 115 may be located within one or more antenna arrays that support MIMO operation or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays may coexist at an antenna assembly (such as an antenna tower). In some cases, the antennas or antenna arrays associated with base station 105 may be located in different geographical locations. Base station 105 may have an antenna array with several rows and columns of antenna ports that base station 105 can use to support beamforming for communication with UE 115. Similarly, UE 115 may have one or more antenna arrays that support various MIMO or beamforming operations.

[0079] In some scenarios, the wireless communication system 100 may be a packet-based network operating according to a layered protocol stack. In the user plane, communication at the bearer or Packet Data Convergence Protocol (PDCP) layer may be IP-based. In some scenarios, the Radio Link Control (RLC) layer may perform packet segmentation and reassembly for communication on logical channels. The Media Access Control (MAC) layer may perform priority handling and multiplexing of logical channels into transport channels. The MAC layer may also use HARQ to provide MAC layer retransmission, thereby improving link efficiency. In the control plane, the RRC protocol layer provides the establishment, configuration, and maintenance of RRC connections between the UE 115 and the base station 105 or core network 130 that support user plane data radio bearers. At the physical (PHY) layer, transport channels may be mapped to physical channels.

[0080] In some scenarios, UE 115 and base station 105 may support data retransmission to increase the likelihood of successful data reception. HARQ feedback is a technique to increase 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 throughput at the MAC layer in poor radio conditions (e.g., signal-to-noise ratio conditions). In some scenarios, the wireless device may support simultaneous time-slot HARQ feedback, where the device can provide HARQ feedback in a specific time slot for data received in previous symbols within that time slot. In other scenarios, the device can provide HARQ feedback in subsequent time slots or according to a different time interval.

[0081] In LTE or NR, time intervals can be expressed as multiples of a basic time unit (which may be, for example, a sampling period Ts = 1 / 30720000 seconds). Time intervals for communication resources can be organized according to radio frames, each with a duration of 10 milliseconds (ms), where the frame period can be expressed as T. f =307200T sRadio frames can be identified by System Frame Numbers (SFNs) 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. Subframes may be further divided into two time slots, each with a duration of 0.5 ms, and each time slot may contain 6 or 7 modulation symbol periods (e.g., depending on the length of the cyclic prefix added before each symbol period). Excluding the cyclic prefix, each symbol 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 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 shortened TTI (sTTI) or in a selected component carrier using sTTI).

[0082] In some wireless communication systems, time slots can be further divided into multiple mini-time slots containing one or more symbols. In some instances, the symbol or mini-time slot of a mini-time slot can be the smallest scheduling unit. For example, the duration of each symbol may vary depending on the subcarrier spacing or operating frequency band. Furthermore, some wireless communication systems can implement time slot aggregation, where multiple time slots or mini-time slots are aggregated together and used for communication between UE 115 and base station 105.

[0083] The term "carrier" refers to a set of radio frequency spectrum resources having a defined physical layer structure for supporting communications on communication link 125. For example, a carrier of communication link 125 may include a portion of a radio spectrum band operating according to physical layer channels for a given radio access technology. Each physical layer channel may carry user data, control information, or other signaling. Carriers may be associated with predefined frequency channels (e.g., E-UTRA Absolute Radio Channel Number (EARFCN)) and may be located according to a channel grid for discovery by UE 115. A carrier may be downlink or uplink (e.g., in FDD mode), or configured to carry both downlink and uplink communications (e.g., in TDD mode). In some examples, the signal waveform transmitted on a carrier may include multiple subcarriers (e.g., using multi-carrier modulation (MCM) techniques such as orthogonal frequency division multiplexing (OFDM) or DFT-s-OFDM).

[0084] The organization of a carrier can vary depending on the radio access technology (e.g., LTE, LTE-A, LTE-A Pro, NR, etc.). For example, communication on a carrier can be organized according to a TTI or time slot, each of which may include user data and control information or signaling that supports decoding the user data. A carrier may also include dedicated acquisition signaling (e.g., synchronization signals or system information) and control signaling that coordinates carrier operation. In some examples (e.g., in a carrier aggregation configuration), a carrier may also have acquisition signaling or control signaling that coordinates the operation of other carriers.

[0085] Physical channels can be multiplexed on a carrier using various techniques. Physical control channels and physical data channels can be multiplexed on a downlink carrier, for example, using time division multiplexing (TDM), frequency division multiplexing (FDM), or a hybrid TDM-FDM technique. In some examples, control information transmitted in the physical control channel can be distributed in a cascaded manner between different control regions (e.g., between a shared control region or shared search space and one or more UE-specific control regions or UE-specific search spaces).

[0086] A carrier may be associated with a specific bandwidth of the radio frequency spectrum, and in some examples, this carrier bandwidth may be referred to as the carrier or the “system bandwidth” of the 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 a portion 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 within the carrier (e.g., a set of subcarriers or RBs) (e.g., “in-band” deployment of a narrowband protocol type).

[0087] In systems employing 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 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). Therefore, the more resource elements UE 115 receives and the higher the order of the modulation scheme, the higher the data rate UE 115 can achieve. In MIMO systems, wireless communication resources can refer to a combination of radio frequency spectrum resources, temporal resources, and spatial resources (e.g., spatial layers), and using multiple spatial layers can further improve the data rate of communication with UE 115.

[0088] The devices of the wireless communication system 100 (e.g., base station 105 or UE 115) may have a hardware configuration that supports communication on a specific carrier bandwidth, or may be configurable to support communication on a single carrier bandwidth within a set of carrier bandwidths. In some examples, the wireless communication system 100 may include base station 105 and / or UE 115 that can support simultaneous communication via carriers associated with more than one different carrier bandwidth.

[0089] The wireless communication system 100 can support communication with the 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 depending on the carrier aggregation configuration. Carrier aggregation can be used in conjunction with both FDD and TDD component carriers.

[0090] In some scenarios, the wireless communication system 100 may utilize enhanced component carrier (eCC). eCC can be characterized by one or more features, including a wider carrier or frequency channel bandwidth, shorter symbol duration, shorter TTI duration, or a modified control channel configuration. In some scenarios, eCC may be associated with carrier aggregation configurations or dual connectivity configurations (e.g., when multiple serving cells have suboptimal or non-ideal backhaul links). eCC can also be configured for use in unlicensed or shared spectrum (e.g., where more than one operator is permitted to use the spectrum). eCC characterized by a wide carrier bandwidth may include one or more segments that can be utilized by a UE 115 that is unable to monitor the entire carrier bandwidth or is otherwise configured to use a limited carrier bandwidth (e.g., to save power).

[0091] In some cases, eCC may utilize symbol durations different from other CCs, which may include using a reduced symbol duration compared to other CCs. A shorter symbol duration may be associated with increased spacing between adjacent subcarriers. Devices utilizing eCC (such as UE 115 or base station 105) can transmit wideband signals (e.g., based on frequency channels or carrier bandwidths of 20, 40, 60, or 80 MHz) with a reduced symbol duration (e.g., 16.67 microseconds). The TTI in eCC may include one or more symbol periods. In some cases, the TTI duration (i.e., the number of symbol periods in the TTI) may be variable.

[0092] Wireless communication systems (such as NR systems) can utilize any combination of licensed, shared, and unlicensed spectrum bands. The flexibility of eCC symbol duration and subcarrier spacing allows eCC to be used across multiple spectrums. In some examples, NR spectrum sharing can improve spectrum utilization and frequency efficiency, particularly through dynamic vertical (e.g., across frequency domains) and horizontal (e.g., across time domains) sharing of resources.

[0093] The core network can implement prioritization schemes for each RAT and select whether NR or LTE has higher priority. Higher-priority cell groups can reserve time slots across cells in a dual connectivity scheme and indicate the reserved time slots to lower-priority cell groups (e.g., via backhaul connections). Higher-priority cell groups can also indicate additional, non-reserved time slots, which lower-priority cell groups can reserve or use for scheduling. Higher-priority cell groups can also independently schedule transmissions on non-reserved, additional time slots.

[0094] In dual connectivity, the cell group can transmit an SFI to the UE 115 to indicate slot reservation. The SFI can indicate whether the slot is downlink, uplink, or unknown. The SFI can indicate the direction of a configurable number of slots (e.g., one or more subframes). In some cases, if a slot is indicated as unknown, it can be scheduled by the SCG or MCG. The SFI can be a cell-specific SFI or a UE-specific SFI. A UE-specific SFI can override the slot format indicated by a cell-specific SFI.

[0095] Figure 2 Examples of a wireless communication system 200 supporting the coexistence of MCG and SCG according to various aspects of this disclosure are explained. In some examples, the wireless communication system 200 may implement aspects of the wireless communication system 100.

[0096] The wireless communication system 200 can implement a dual connectivity scheme to improve the throughput of UE 115-a. For example, UE 115-a can simultaneously connect to gNB 202 via NR link 205 for NR communication and to eNB 204 via LTE link 210 for LTE communication. gNB 202 and eNB 204 can each be examples of base station 105. gNB 202 can control the SCG provided by eNB 204. gNB 202 can provide an anchor carrier associated with the same RAT as the MCG.

[0097] The wireless communication system 200 can implement a split-bearer dual connectivity scheme. UE 115-a can connect to the control plane function (CPF) 220 of the next-generation core network (NGC) 215 via NG1 connection 230. gNB 202 can connect to the CPF 220 and user plane function (UPF) 225 of NGC 215 via NG2 connection 235 and NG3 connection 240 respectively. In the split-bearer configuration, eNB 204 can communicate with NGC 215 via gNB 202, and the two cell groups exchange information on backhaul link 134-a.

[0098] In some scenarios, UE 115-a may be limited to using only one uplink carrier associated with one RAT in a dual connectivity scheme. For example, UE 115-a may transmit uplink information to gNB 202 on an uplink carrier of NR link 205, or to eNB 204 on an uplink carrier of LTE link 210. In some scenarios, UE 115-a may transmit on multiple carriers of the RAT for carrier aggregation. For example, NR link 205 may include multiple uplink carriers, and UE 115-a may transmit on multiple NR uplink carriers according to carrier aggregation configuration. The wireless communication system 200 can implement techniques to improve NR and LTE coexistence when using NR anchor carriers in a dual connectivity scheme.

[0099] The NGC 215 and serving cell can assign priorities to LTE and NR. For example, the NGC 215 can select NR as a higher priority RAT, or the NGC 215 can select LTE as a higher priority RAT. In some cases, NR may be selected as a higher priority RAT based on its association with the MCG or based on the higher potential throughput of NR communications. In some other examples, LTE may be selected as a higher priority RAT based on the scheduling flexibility of NR and the relative scheduling rigidity of LTE.

[0100] gNB 202 and eNB 204 can coordinate NR and LTE scheduling based on a priority scheme. Cell groups corresponding to higher priority RATs can reserve uplink time slots, downlink time slots, or a combination of both. Higher priority cell groups can indicate the reserved time slots to lower priority cell groups (e.g., via backhaul link 134-a). Lower priority cell groups and higher priority cell groups can independently schedule resources for remaining time slots. In some examples, an uplink or downlink carrier for UE 115-a can be configured for FDD transmission, but the serving cell can implement a technique to schedule UE 115-a as if it were a TDD carrier. Figure 5 Further description is provided below. In some cases, such as... Figure 4 As described, after a higher-priority cell group reserves a time slot, a lower-priority cell group can also reserve a time slot.

[0101] In some scenarios, NR can support multiple subcarrier spacing configurations, allowing some NR slot durations to be part of a subframe in LTE. If an NR slot is reserved, the subframes overlapping with the reserved slots may not be used for LTE. Similarly, if a subframe is reserved for LTE, the slots overlapping with the reserved subframes may not be used by NR.

[0102] Cellular groups can reserve time slots and transmit SFIs to UE 115-a to indicate the reserved time slots. The SFI can indicate whether the time slot is downlink, uplink, or unknown. An SFI indicating a time slot as downlink or uplink can be used for time slot reservation. In some cases, if a time slot is indicated as unknown, it can be used for scheduling by the SCG or MCG. In some cases, unused time slots can be used for low-priority cell group reservations if the reservation of a low-priority cell group does not interfere with high-priority reservations. SFIs can be applied to both FDD and TDD carriers. In some cases, only a certain type of time slot can be reserved. For example, there can be configurations where only uplink time slots can be reserved. Therefore, an indication of an uplink time slot in the SFI can indicate that the corresponding time slot is reserved, but an indication of a downlink time slot may not indicate that the downlink time slot is reserved.

[0103] In some cases, the SFI can be a cell-specific SFI. The slot format indicated in a cell-specific SFI can be applied to any UE 115 receiving the cell-specific SFI. In another example, a cell group can transmit a UE-specific SFI. This UE-specific SFI can override the slot format indicated by the cell-specific SFI. In some cases, the MCG can transmit a dynamic SFI indicating reserved slots. For example, a slot may be indicated as uplink or downlink by a cell-specific SFI, but the MCG can transmit downlink control information using a dynamic SFI after the cell-specific SFI to reserve that slot.

[0104] Non-reserved time slots can be scheduled by either the MCG or SCG. The allocation of non-reserved time slots to the RAT can be determined based on the priority of the MCG and SCG, dynamic SFI, or scheduling. In dual connectivity schemes, NR and LTE scheduling can be independent. Therefore, eNB 204 or gNB 202 can independently schedule UE 115-a for one of the non-reserved time slots in downlink assignment or with uplink granting. Lower priority cell groups can be assigned resources, thus avoiding reserved time slots of higher priority cell groups.

[0105] In some scenarios, a lower-priority cell group may discard an assigned time slot at the request of a higher-priority cell group. For example, a time slot may be pre-scheduled for HARQ-ACK by a lower-priority cell group, but shortly before that time slot, a higher-priority cell group requests that time slot for uplink transmission. The lower-priority cell group may then discard the HARQ-ACK transmission so that the higher-priority cell group can use the resource. In some scenarios, NR and LTE cell groups may jointly determine resource allocation.

[0106] As an example, NR can be prioritized in wireless communication system 200. gNB 202 can transmit a cell-specific SFI indicating reserved uplink and downlink time slots to UE 115-a. The SFI can also indicate some unknown time slots. gNB 202 can reserve downlink time slots for downlink data transmission and uplink time slots for HARQ feedback for that data transmission. eNB 204 and gNB 202 can independently schedule remaining non-reserved time slots (e.g., including unknown time slots indicated in the SFI) for LTE and NR communications, respectively.

[0107] In some scenarios, UE 115-a may be able to perform dual uplink transmissions on NR and LTE carriers during non-reserved time slots. If UE 115-a is capable of dynamic power control, NGC 215 may prioritize uplink channels for MCG and SCG. For example, MCG PUCCH may have a higher priority than SCG PUCCH, or MCGPUSCH may have the same priority as SCG PUSCH, or any MCG uplink channel may have a higher priority than its corresponding SCG uplink channel, among other configurations. If the aggregated transmit power exceeds the maximum transmit power and uplink channels start simultaneously, UE 115-a may reduce or decrease the transmit power of the lower priority channel. If the aggregated transmit power exceeds the maximum power limit and uplink channels start at different times, UE 115-a may reduce or decrease the transmit power of the lower priority channel, or decrease the power of the subsequently starting uplink channel or discard the subsequently starting uplink channel.

[0108] In some cases, time slots reserved for LTE and time slots reserved for NR can have different power configurations. For exclusive reserved time slots (e.g., where other transmissions are not allowed), a larger transmit power limit can be configured for both LTE and NR transmissions. For non-reserved time slots, a smaller transmit power limit can be configured. UE 115-a can follow the maximum power level configured independently for MCG and SCG.

[0109] Although the above description describes a dual connectivity scheme in which gNB 202 provides an NR anchor carrier, the described techniques are also applicable to the case in which eNB 204 is an MCG and provides an LTE anchor carrier.

[0110] Figure 3 Examples of a wireless communication system 300 supporting the coexistence of MCG and SCG according to various aspects of this disclosure are explained. In some examples, the wireless communication system 300 may implement aspects of the wireless communication system 100.

[0111] The wireless communication system 300 can implement a dual connectivity scheme to improve the throughput of UE 115-b. UE 115-b can simultaneously connect to gNB 302 via NR link 305 for NR communication and to eNB 304 via LTE link 310 for LTE communication. gNB 302 can provide MCG and control SCG provided by eNB 304. gNB 302 can provide an anchor carrier associated with the same RAT as the MCG.

[0112] The wireless communication system 300 can implement a dual connectivity scheme for SCG bearers. UE 115-b can connect to CPF 320 of NGC 315 via NG1 connection 330. gNB 302 can connect to CPF320 and UPF325 of NGC 315 via NG2 connection 335 and NG3 connection 340-a, respectively. In the SCG bearer configuration, eNB 304 can have a direct link to UPF325 of NGC 315 via NG3 340-b, and the two cell groups exchange information on backhaul link 134-b.

[0113] UE 115-b can have the same Figure 2 Similar limitations to UE 115-a in this context can include a single uplink transmission. Therefore, the wireless communication system 300 can implement techniques to improve NR and LTE coexistence when using an NR anchor carrier in a dual connectivity scheme. For example... Figure 2 As described, NGC 315, MCG, and SCG implement a prioritization scheme for scheduling LTE and NR transmissions, and higher-priority cell groups can reserve uplink time slots, downlink time slots, or a combination of both. Lower-priority cell groups can schedule non-reserved time slots, or in some cases, reserve them after higher-priority cell groups. Cell groups (e.g., MCGs) can indicate reserved time slots and time slot formats in the SFI as described above.

[0114] Figure 4 Examples of a time slot reservation distribution 400 supporting the coexistence of MCG and SCG according to various aspects of this disclosure have been explained. In some examples, the time slot reservation distribution 400 can implement various aspects of the wireless communication system 100. The time slot reservation distribution 400 typically involves Figure 2 and 3The dual connectivity scheme described herein allows UE 115 to connect to both the eNB and gNB for LTE and NR communication. The time slot reservation distribution 400 may include time slots 405 reserved by the MCG, time slots 410 reserved by the SCG, and non-reserved time slots 415. Time slots 405 reserved by the MCG may represent time slots reserved by the MCG, while time slots 410 reserved by the SCG may represent time slots reserved by the SCG. Non-reserved time slots 415 can be used for communication with either the MCG or the SCG.

[0115] The total number of time slots available within the system bandwidth over a given time period. For example... Figure 2 As described, higher-priority cell groups can reserve some time slots for higher-priority RATs. Higher-priority cell groups can schedule high-priority signals, such as HARQ feedback or PUCCH, on these time slots. The time slots reserved for higher-priority cells can be assigned to lower-priority cell groups, which may then choose not to use the time slots reserved for higher-priority cells.

[0116] In some scenarios, NR can support multiple subcarrier spacing configurations, allowing some time slot durations in NR to be part of a subframe in LTE. If an NR time slot is reserved, the subframes overlapping with the reserved time slots may not be used for LTE. Similarly, if a subframe is reserved for LTE, the time slots overlapping with the reserved subframes may not be used by NR.

[0117] As an example, NR can be a higher priority RAT, while LTE can be a lower priority RAT. The MCG can correspond to the gNB 702 for NR communication, while the SCG can correspond to the eNB 704 for LTE communication. The MCG can reserve some time slots for NR and transmit an SFI indicating the time slot 405 reserved by the MCG. In some cases, the SCG can reserve subframes for LTE and transmit an SFI indicating the time slots overlapping with the subframes reserved by the SCG. The SCG can reserve time slots or subframes that do not overlap with any time slots reserved by the MCG 405. Unreserved time slots can be indicated as non-reserved time slot 415. The MCG and SCG can independently use non-reserved time slot 415 for scheduling equipment for either LTE or NR.

[0118] Figure 5 Examples of a dual-carrier configuration table 500 supporting the coexistence of MCG and SCG according to various aspects of this disclosure are explained. In some examples, the dual-carrier configuration 500 can implement various aspects of the wireless communication system 100. The dual-carrier configuration table 500 typically relates to (such as...) Figure 2 and 3 The dual-carrier configuration of the described wireless communication system.

[0119] Dual-carrier configuration table 500 includes four dual-carrier configurations 505. For each dual-carrier configuration 505, adjacent columns show multiplexing configurations for MCG 510 and SCG 515. Typically, dual-carrier configuration 505 is for a UE 115 with an NR anchor carrier connected to the NGC. Dual-carrier configuration 505 can have split bearers or SCG bearers.

[0120] For example, in scenario 1, the MCG 510 supports TDD communication while the SCG 515 supports FDD communication. The MCG 510 can perform time-division multiplexing for NR uplink and downlink transmissions, while the SCG 515 can perform frequency-division multiplexing for LTE uplink and downlink transmissions.

[0121] In some examples, Scenario 1 can be similar to TDD-FDD carrier aggregation with a TDD PCell. Downlink-reference uplink / downlink configuration for the LTE FDD SCG can be configured and used for scheduling and HARQ timing for the LTE FDD carrier. FDD timing configuration (e.g., periodicity and offset) can be applied to the LTE Physical Random Access Channel (PRACH) and Probe Reference Signal (SRS) on the LTE uplink carrier. The UE may not be configured to support LTE PRACH or SRS transmissions that do not overlap with the configured HARQ-ACK transmission timing. In some cases, UE-specific HARQ subframe offsets can be configured.

[0122] In scenario 2, the MCG 510 can support FDD NR communication while the SCG 515 can support FDD LTE communication. In some scenarios, the second configuration can be handled through scheduling. For example, the MCG 510 and SCG 515 can schedule uplink and downlink time slots to meet network constraints (e.g., single uplink, avoidance of self-interference, power limitations, etc.). In some other examples, in the scenario 2 configuration, the MCG 510 can implement time slot and subframe reservations for NR. The reserved time slots can be configured based on a semi-static SFI. For example, in a single uplink transmission constraint, certain uplink time slots can be reserved for NR transmission, and LTE uplink may not be allowed during the time slots reserved for NR. Similarly, NR uplink transmission may not be allowed during time slots that overlap with reserved subframes for LTE. LTE can be scheduled on subframes that do not overlap with reserved NR time slots. LTE can avoid using reserved time slots with appropriate downlink-reference uplink / downlink configurations. The described technique can effectively convert FDD carriers into TDD-like carriers to facilitate TDM, which reduces the complexity of reserving time slots. In some cases, such as scenario 2, the network can use dynamic SFI to reserve subframes.

[0123] In scenario 3, the MCG 510 can support TDD with supplemental uplink, while the SCG 515 can support FDD. In the supplemental uplink, the LTE uplink used for the SCG 515 can be time-division multiplexed with the NR uplink. Scenario 4 can be TDD for both the MCG 510 and the SCG 515.

[0124] Scenarios 3 and 4 may have a single uplink transmission restriction. In some scenarios, the LTE and NR uplink and downlink frame structures can be jointly determined by MCG 510 and SCG 515, which can improve LTE and NR coexistence. In some other examples, the NR downlink and uplink frame structures can be semi-statically configured to have higher priority. For example, UE 115 can transmit LTE uplink signals in subframes where UE 115 is not scheduled for NR uplink transmission (e.g., according to the frame structure). NR slots can be semi-statically configured or reserved as downlink, uplink, or unknown (e.g., uplink or downlink) within the frame structure. UE 115 can transmit LTE uplink signals in at least subframes where the corresponding NR slot is configured as downlink or unknown, or in any slot where the frame structure does not indicate that the slot is used for NR uplink.

[0125] Figure 6A and 6B Examples of HARQ timing offset configurations 600 and 601 supporting the coexistence of MCG and SCG according to various aspects of this disclosure are explained. In some examples, HARQ timing offset configurations 600 and 601 can implement various aspects of the wireless communication system 100. HARQ timing offset configurations typically involve transmission feedback in wireless communication systems supporting dual-carrier configurations.

[0126] As described herein, one RAT can be given priority over another RAT, and time slots can be classified as reserved or unreserved. For example, NR can be given priority over LTE. In this example, NR transmission and reception on reserved time slots can be highly reliable, while unreserved time slots are less reliable. Therefore, the serving cell can schedule high-importance signals for reserved time slots. For example, HARQ feedback can be transmitted on time slots reserved for carrying NR PUCCH. Offset K1 can be used to indicate the offset from the time slot used for data or physical downlink shared channel (PDSCH) transmission to the corresponding HARQ feedback time slot.

[0127] In HARQ timing offset configuration 600, K1 625-a and K1 630-a measure both reserved and non-reserved time slots. For example, UE 115 receives data transmission in reserved downlink time slot 605-a. After two non-reserved time slots (including non-reserved downlink time slot 610-a and non-reserved uplink / downlink time slot 615-a), UE 115 may transmit HARQ feedback for that data transmission on reserved uplink time slot 620-a, and in some examples, transmit HARQ feedback for data transmission received on non-reserved downlink time slot 610-a. HARQ feedback for reserved downlink time slot 605-a may be transmitted after three time slots, so K1 630-a can be set to 3. HARQ feedback for non-reserved downlink time slot 610-a may be transmitted after two time slots, so K1 625-a can be set to 2.

[0128] In HARQ timing offset configuration 601, K1 625-b and K1 630-b only measure reserved time slots. For example, UE 115 receives data transmission in reserved downlink time slot 605-b. After two non-reserved time slots (including non-reserved downlink time slot 610-b and non-reserved uplink / downlink time slot 615-b), UE 115 may transmit HARQ feedback for that data transmission on reserved uplink time slot 620-b, and in some examples, transmit HARQ feedback for data transmission received on non-reserved downlink time slot 610-b. HARQ feedback for reserved downlink time slot 605-b may be transmitted after one reserved time slot, so K1 630-b can be set to 1. HARQ feedback for non-reserved downlink time slot 610-b may also be transmitted after one reserved time slot, so K1 625-b can also be set to 1. In some cases, this can result in a lower value for K1, which can reduce the number of bits in the K1 bit field. The interpretation of K1 can be indicated via RRC signaling or another higher-level signaling.

[0129] Figure 7 Examples of a process flow 700 supporting the coexistence of MCG and SCG according to various aspects of this disclosure are explained. In some examples, process flow 700 may implement various aspects of wireless communication system 100. Process flow 700 may include UE 115-c, gNB 702, and eNB 704. UE 115-c may be an example of UE 115 as described herein. gNB 702 may be a reference to... Figure 2 and Figure 3 Examples of gNB 202 or 302 are described. eNB 704 may be a reference. Figure 2 and Figure 3Examples of eNB 204 or 304 described herein. gNB 702 and eNB 704 may each be examples of base station 105 as described herein.

[0130] At 705, UE 115-c can identify itself as operating with both the MCG and SCG in dual connectivity. The MCG can correspond to gNB 702, while the SCG can correspond to eNB 704. Similarly, at 705, gNB 702 can identify itself as operating as the MCG with UE 115-c in dual connectivity.

[0131] At 710, gNB 702 may transmit an indication of a reserved TTI reserved for priority uplink communication with the MCG. The TTI may be, for example, a time slot for NR or a subframe for LTE. At 715, gNB 702 may indicate the reserved TTI and additional TTIs that can be used for uplink communication with the MCG or SCG to the SCG (e.g., eNB 704). In some cases, at 720, UE 115-c may receive an indication of additional reserved TTIs reserved for uplink communication with the SCG, wherein the reserved TTI and the additional reserved TTIs are time-disjoint.

[0132] At 725, UE 115-c can use the reserved TTI to transmit one or more uplink messages to the MCG. At 730, UE 115-c can use an additional reserved TTI to transmit one or more uplink messages to the SCG.

[0133] In some scenarios, UE 115-c may receive scheduling for an additional TTI (e.g., from gNB 702 or eNB 704). This scheduling can facilitate avoiding uplink transmissions to both gNB 702 and eNB simultaneously. UE 115-c may use the additional TTI to transmit one or more uplink messages to the MCG or SCG.

[0134] Figure 8 Examples of power variation 800 supporting the coexistence of MCG and SCG according to various aspects of this disclosure are explained. In some examples, power variation 800 can implement various aspects of wireless communication system 100.

[0135] UE 115 (such as Figure 2UE 115 (as described in section 3) can be configured for a dual uplink configuration, thereby splitting uplink transmissions between NR and LTE. For example, the gNB can provide an MCG for NR communication, while the eNB can provide an SCG for LTE communication. UE 115 can implement power control techniques for the SCG and MCG. As described herein, one of the cell groups can have a higher priority. In this example, the MCG providing NR communication can be a higher priority cell group, and the SCG providing LTE communication can be a lower priority cell group. In another example, the MCG can be a lower priority cell group, or the MCG can provide LTE communication while the SCG can provide NR communication.

[0136] like Figure 2 As described, UE 115 can implement power control techniques. For example, if the aggregated transmit power exceeds the maximum transmit power allowed and uplink channels start simultaneously, UE 115 can reduce or decrease the transmit power of lower priority channels. In some other examples, if the aggregated transmit power exceeds the maximum power allowed and uplink channels start at different times, UE 115 can reduce or decrease the transmit power of lower priority channels, or UE 115 can reduce the power of uplink channels that start subsequently (e.g., after the TTI) or drop uplink channels that start subsequently (e.g., after the TTI).

[0137] Power control adjustments can be made at the end of the TTI. The time granularity used for power control can follow a RAT with a larger time granularity. For example, between LTE implementing a 1ms TTI (e.g., a subframe) and NR with a 30kHz subcarrier spacing (SCS) or higher (e.g., a 0.5ms slot), LTE has a larger time granularity because 1ms is greater than 0.5ms. Therefore, power control can be based on a 1ms TTI. Thus, even if there are multiple slots within a subframe, power control adjustments can be made after the subframe.

[0138] In another example, LTE can support shortened TTIs (sTTIs), where the duration of an sTTI can be 2 or 3 symbol periods long. For example, a UE can transmit 6 sTTIs in 1 ms in the format {3,2,2,2,2,3}, indicating a 3-symbol sTTI followed by 4 2-symbol sTTIs and ending with another 3-symbol sTTI. In this example, the 0.5 ms slot for NR will have a longer TTI than the LTE sTTI. Therefore, power control adaptation can occur after the 0.5 ms NR slot (e.g., after the first three sTTIs of lengths 3, 2, and 2 symbol periods). Therefore, there may be no power change within the NR slot. For example, if the NR slot is longer than the LTE sTTI, UE 115 may not change its transmit power after the LTE sTTI.

[0139] In some other examples, such as if LTE uses sTTI and NR uses a 0.25ms time slot, UE 115 can wait until a new subframe appears, a new uplink channel is established, or the end of the LTE sTTI aligns with the end of the NR time slot before making a power adjustment.

[0140] The illustrated example shows UE 115 adjusting transmit power distribution 810 after LTE TTI 805. Total transmit power is shared between NR power 815 and LTE power 820. For example, during the first LTE TTI 805-a, NR power 815-a can use 60% of the transmit power distribution, while LTE 820-a can use 40% of the transmit power distribution. After the first LTE TTI 805-a, UE 115 can adjust the transmit power distribution 810 such that NR power 815-b is 80% and LTE power 820-b is 20%. Even if NR communication uses a smaller TTI (e.g., a 0.5ms slot compared to a 1ms subframe in LTE), UE 115 can make power adjustments based on a larger time granularity (corresponding to LTE TTI 805). UE 115 can make transmit power adjustments in subsequent TTI 805, such that in the third TTI 805-c, NR power 815-c is 90% of the transmit power and LTE power 820-c is 10% of the transmit power. With the fourth TTI 805-d, power allocation 810 can be used entirely for NR communication, and NR power 815-d can use 100% of the transmit power.

[0141] Figure 9A block diagram 900 of an apparatus 905 supporting the coexistence of MCG and SCG according to various aspects of this disclosure is shown. Apparatus 905 may be an example of various aspects of UE 115 as described herein. Apparatus 905 may include a receiver 910, a communication manager 915, and a transmitter 920. Apparatus 905 may also include a processor. Each of these components may be in communication with each other (e.g., via one or more buses).

[0142] Receiver 910 can 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 the coexistence of MCG and SCG). This information can be transmitted to other components of device 905. Receiver 910 can be a reference... Figure 12 Examples of various aspects of the transceiver 1220 described. The receiver 910 may utilize a single antenna or an array of antennas.

[0143] The communication manager 915 can identify that the UE is operating in dual connectivity with the MCG and SCG; receive from the MCG an indication of a reserved TTI reserved for priority UL communication with the MCG; identify additional TTIs that can be used for UL communication with the MCG or SCG; transmit one or more UL messages to the MCG using the reserved TTIs; and transmit one or more UL messages to the MCG or SCG using the additional TTIs. The communication manager 915 can be a reference... Figure 12 Examples of various aspects of the described communication manager 1210.

[0144] The communication manager 915 or its sub-components may be implemented in hardware, code executed by a processor (e.g., software or firmware), or any combination thereof. If implemented in code executed by a processor, the functionality of the communication manager 915 or its sub-components may be performed by a general-purpose processor, DSP, application-specific integrated circuit (ASIC), field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof, designed to perform the functions described in this disclosure.

[0145] The communication manager 915 or its sub-components may be physically located at various locations, including being distributed such that portions of the functionality are implemented by one or more physical components at different physical locations. In some examples, according to various aspects of this disclosure, the communication manager 915 or its sub-components may be separate and distinct components. In some examples, according to various aspects of this disclosure, the communication manager 915 or its sub-components may be combined with one or more other hardware components (including, but not limited to, input / output (I / O) components, transceivers, network servers, other computing devices, one or more other components described in this disclosure, or combinations thereof).

[0146] Transmitter 920 can transmit signals generated by other components of device 905. In some examples, transmitter 920 may coexist with receiver 910 in a transceiver module. For example, transmitter 920 may be a reference... Figure 12 Examples of various aspects of the transceiver 1220 described. The transmitter 920 may utilize a single antenna or an array of antennas.

[0147] Figure 10 A block diagram 1000 of a device 1005 supporting the coexistence of MCG and SCG according to various aspects of this disclosure is shown. Device 1005 may be a reference... Figure 1 and Figure 9 Examples of various aspects of the described device 905 or UE 115. Device 1005 may include a receiver 1010, a communication manager 1015, and a transmitter 1045. 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).

[0148] Receiver 1010 can 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 the coexistence of MCG and SCG). The information can be transmitted to other components of device 1005. Receiver 1010 can be a reference... Figure 12 Examples of various aspects of the transceiver 1220 described herein. The receiver 1010 may utilize a single antenna or an array of antennas.

[0149] Communication Manager 1015 can be as follows: Figure 9 Examples of various aspects of the described communication manager 915. The communication manager 1015 may include a dual connectivity identifier 1020, a TTI reservation component 1025, an additional TTI identifier 1030, a reserved TTI transmission component 1035, and an additional TTI transmission component 1040. The communication manager 1015 may be a reference... Figure 12 Examples of various aspects of the described communication manager 1210.

[0150] Dual connectivity identifier 1020 identifies that the UE is operating with both the MCG and SCG in dual connectivity. TTI reservation component 1025 receives from the MCG an indication of reserved TTIs reserved for priority UL communication with the MCG. Additional TTI identifier 1030 identifies additional TTIs that can be used for UL communication with the MCG or SCG. Reserved TTI transmission component 1035 can use the reserved TTIs to transmit one or more UL messages to the MCG. Additional TTI transmission component 1040 can use the additional TTIs to transmit one or more UL messages to the MCG or SCG.

[0151] Transmitter 1045 can transmit signals generated by other components of device 1005. In some examples, transmitter 1045 may coexist with receiver 1010 in a transceiver module. For example, transmitter 1045 may be a reference... Figure 12 Examples of various aspects of the transceiver 1220 described. The transmitter 1045 may utilize a single antenna or an array of antennas.

[0152] Figure 11 A block diagram 1100 of a communication manager 1105 supporting the coexistence of MCG and SCG according to various aspects of this disclosure is shown. The communication manager 1105 may be a reference... Figure 9 , 10 Examples of aspects of the communication manager 915, communication manager 1015, or communication manager 1210 described in section 12. Communication manager 1105 may include a dual connectivity identifier 1110, a TTI reservation component 1115, an additional TTI identifier 1120, a reserved TTI transmission component 1125, an additional TTI transmission component 1130, a transmission priority component 1135, a priority configuration component 1140, a time offset component 1145, and a power control component 1150. Each of these modules may communicate directly or indirectly with each other (e.g., via one or more buses).

[0153] Dual connectivity identifier 1110 can identify whether the UE is operating with both MCG and SCG in dual connectivity. In some examples, dual connectivity identifier 1110 can configure both MCG and SCG for FDD operation. In some examples, dual connectivity identifier 1110 can configure both MCG and SCG for TDD operation. In some cases, MCG is configured for TDD operation, while SCG is configured for FDD operation. In some cases, MCG is configured for TDD operation and SCG is configured for FDD operation, wherein UL transmissions to SCG and Supplemental Uplink (SUL) transmissions to MCG are time-division shared.

[0154] TTI reservation component 1115 may receive from MCG an indication of a reserved TTI reserved for priority UL communication with MCG. In some examples, TTI reservation component 1115 may receive from SCG an indication of an additional reserved TTI reserved for UL communication with SCG, wherein the reserved TTI and the additional reserved TTI do not overlap in time.

[0155] In some examples, the TTI reservation component 1115 may receive an SFI identifying a configuration for a UL TTI, DLTTI, unknown TTI, or a combination thereof, wherein the reserved TTI includes the UL TTI. In some examples, the TTI reservation component 1115 may receive a cell-specific configured SFI. In some examples, the TTI reservation component 1115 may receive a UE-specific configured SFI, wherein the UE-specific configured SFI overrides any received cell-specific configured SFI. In some examples, the TTI reservation component 1115 may receive a dynamic SFI via DCI, wherein the dynamic SFI is specific to an upcoming TTI or set of TTIs.

[0156] In some examples, the TTI reservation component 1115 may receive a joint configuration that includes an indication of reserved TTIs reserved for UL or DL ​​communication with the MCG, and an indication of which additional TTIs are to be used for UL or DL ​​communication with the MCG and which additional TTIs are to be used for UL or DL ​​communication with the SCG. In some cases, the indication further indicates DL TTIs, unknown TTIs, or both reserved for communication with the MCG. An additional TTI identifier 1120 may identify additional TTIs that can be used for UL communication with the MCG or SCG. In some cases, one or more UL messages transmitted using additional TTIs include LTE PRACH messages, SRS messages, HARQ messages, or combinations thereof. The reserved TTI transmission component 1125 may use the reserved TTIs to transmit one or more UL messages to the MCG.

[0157] The additional TTI transmission component 1130 may use additional TTIs to transmit one or more UL messages to the MCG or SCG. In some examples, the additional TTI transmission component 1130 may use additional reserved TTIs to transmit one or more UL messages to the SCG. In some examples, the additional TTI transmission component 1130 may receive a schedule for using one or more additional TTIs for UL communication with the MCG or SCG, which facilitates avoiding simultaneous UL transmissions to both the MCG and SCG, wherein the transmission of one or more UL messages using additional TTIs is based on the schedule.

[0158] In some examples, the additional TTI transmission component 1130 may identify an FDD timing configuration for UL transmissions to the SCG, which facilitates avoiding simultaneous UL transmissions to both the MCG and SCG, wherein the transmission of one or more UL messages using the additional TTI is based on this FDD timing configuration. In some examples, the additional TTI transmission component 1130 may transmit UL messages to the MCG and SCG during different TTIs. In some examples, the additional TTI transmission component 1130 may transmit UL messages to the MCG and SCG during the same TTI.

[0159] Transmission prioritization component 1135 can determine that UL messages destined for the MCG and UL messages destined for the SCG are both scheduled for the same TTI in an additional TTI. In some examples, transmission prioritization component 1135 can identify the priority between UL messages destined for the MCG and UL messages destined for the subcell group. In some examples, transmission prioritization component 1135 can transmit either UL messages destined for the MCG or UL messages destined for the subcell group during a TTI based on this priority. Priority configuration component 1140 can receive priority configuration including an indication of reserved TTIs for UL or DL ​​communication with the MCG, and an indication of which additional TTIs should be used for UL or DL ​​communication with the MCG. In some examples, priority configuration component 1140 can transmit one or more UL messages to the SCG during one of the additional TTIs indicated for DL ​​communication with the MCG.

[0160] The time offset component 1145 may identify a parameter indicating the time offset of UL transmission for HARQ feedback after the reception of a data message, wherein the time offset is based on the number of reserved TTIs. In some examples, the time offset component 1145 may transmit HARQ feedback according to this parameter. The power control component 1150 may prioritize power control for each UL message transmitted within the same TTI based on the type of the UL message. In some examples, the power control component 1150 may prioritize power control for each UL message transmitted within the same TTI based on the start time of each UL message. In some cases, the maximum power control for UL messages transmitted to the MCG and the maximum power control for UL messages transmitted to the SCG within the same TTI may each be less than the corresponding power control for UL transmissions within different TTIs.

[0161] In some cases, the power control component 1150 may identify a first TTI duration associated with the MCG, identify a second TTI duration associated with the SCG, and apply a transmit power control scheme at least partially based on the first TTI duration and the second TTI duration. In some examples, applying the transmit power control scheme further includes adjusting the transmit power for UL messages transmitted to the MCG and UL messages transmitted to the SCG after the TTI duration of the first TTI duration, based at least partially on the fact that the first TTI duration is longer than the second TTI duration. In some examples, applying the transmit power control scheme further includes adjusting the transmit power for UL messages transmitted to the MCG and UL messages transmitted to the SCG after the TTI duration of the second TTI duration, based at least partially on the fact that the second TTI duration is longer than the first TTI duration.

[0162] Figure 12 A diagram is shown of a system 1200 including a device 1205 supporting the coexistence of MCG and SCG according to various aspects of this disclosure. Device 1205 may be, for example, as described above. Figure 1 , 9 Examples of components of the devices 905, 1005, or UE 115 described in 10, or including such components. Device 1205 may include components for bidirectional voice and data communication, including components for transmitting and receiving communications, including a communication manager 1210, an I / O controller 1215, a transceiver 1220, an antenna 1225, a memory 1230, and a processor 1240. These components may be in electronic communication via one or more buses (e.g., bus 1245).

[0163] The communication manager 1210 can identify that the UE is operating with the MCG and SCG in dual connectivity; receive from the MCG an indication of a reserved TTI reserved for priority UL communication with the MCG; identify additional TTIs that can be used for UL communication with the MCG or SCG; transmit one or more UL messages to the MCG using the reserved TTIs; and transmit one or more UL messages to the MCG or SCG using the additional TTIs.

[0164] I / O controller 1215 manages the input and output signals of device 1205. I / O controller 1215 can also manage peripheral devices not integrated into device 1205. In some cases, I / O controller 1215 may represent a physical connection or port to an external peripheral device. In some cases, I / O controller 1215 may utilize an operating system, such as... Or another known operating system. In other cases, I / O controller 1215 may represent or interact with a modem, keyboard, mouse, touchscreen, or similar device. In some cases, I / O controller 1215 may be implemented as part of a processor. In some cases, a user may interact with device 1205 via I / O controller 1215 or via hardware components controlled by I / O controller 1215.

[0165] Transceiver 1220 can communicate bidirectionally via one or more antennas, wired or wireless links, as described above. For example, transceiver 1220 can represent a wireless transceiver and can communicate bidirectionally with another wireless transceiver. Transceiver 1220 may also include a modem to modulate packets and provide the modulated packets to the antenna for transmission, and to demodulate packets received from the antenna.

[0166] In some cases, the wireless device may include a single antenna 1225. However, in other cases, the device may have more than one antenna 1225, which may be able to transmit or receive multiple wireless transmissions concurrently.

[0167] Memory 1230 may include random access memory (RAM) and read-only memory (ROM). Memory 1230 may store computer-readable, computer-executable code 1235, including instructions that, when executed, cause the processor to perform the various functions described herein. In some cases, memory 1230 may particularly include a basic input / output system (BIOS) that controls basic hardware or software operations, such as interaction with peripheral components or devices.

[0168] Processor 1240 may include intelligent hardware devices (e.g., general-purpose processors, DSPs, CPUs, microcontrollers, ASICs, FPGAs, programmable logic devices, discrete gate or transistor logic components, discrete hardware components, or any combination thereof). In some cases, processor 1240 may be configured to use a memory controller to operate a memory array. In other cases, the memory controller may be integrated into processor 1240. Processor 1240 may be configured to execute computer-readable instructions stored in memory (e.g., memory 1230) to cause device 1205 to perform various functions (e.g., functions or tasks supporting the coexistence of MCGs and SCGs).

[0169] Code 1235 may include instructions for implementing various aspects of this disclosure, including instructions for supporting wireless communication. Code 1235 may be stored in a non-transitory computer-readable medium, such as system memory or other types of memory. In some cases, code 1235 may not be directly executed by processor 1240, but may cause a computer (e.g., when compiled and executed) to perform the functions described herein.

[0170] Figure 13 A block diagram 1300 of an apparatus 1305 supporting the coexistence of MCG and SCG according to various aspects of this disclosure is shown. Apparatus 1305 may be an example of various aspects of base station 105 as described herein. Apparatus 1305 may include a receiver 1310, a communication manager 1315, and a transmitter 1320. Apparatus 1305 may also include a processor. Each of these components may be in communication with each other (e.g., via one or more buses).

[0171] Receiver 1310 can 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 the coexistence of MCG and SCG). The information can be transmitted to other components of device 1305. Receiver 1310 can be a reference... Figure 16 Examples of various aspects of the transceiver 1620 described. The receiver 1310 may utilize a single antenna or an array of antennas.

[0172] The communication manager 1315 can identify that the base station is operating as an MCG with the UE in dual connectivity; transmit to the UE an indication of reserved TTIs reserved for priority UL communication with the MCG; indicate to the SCG the reserved TTIs and additional TTIs that can be used for UL communication with the MCG or SCG; and receive one or more UL messages from the UE using the reserved TTIs. The communication manager 1315 can be a reference Figure 16 Examples of various aspects of the described communication manager 1610.

[0173] The communication manager 1315 or its sub-components may be implemented in hardware, processor-executable code (e.g., software or firmware), or any combination thereof. If implemented in processor-executable code, the functionality of the communication manager 1315 or its sub-components may be performed by a general-purpose processor, DSP, application-specific integrated circuit (ASIC), FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof, designed to perform the functions described in this disclosure.

[0174] The communication manager 1315 or its subcomponents may be physically located at various locations, including being distributed such that portions of the functionality are implemented by one or more physical components at different physical locations. In some examples, according to various aspects of this disclosure, the communication manager 1315 or its subcomponents may be separate and distinct components. In some examples, according to various aspects of this disclosure, the communication manager 1315 or its subcomponents may be combined with one or more other hardware components (including, but not limited to, input / output (I / O) components, transceivers, network servers, other computing devices, one or more other components described in this disclosure, or combinations thereof).

[0175] Transmitter 1320 can transmit signals generated by other components of device 1305. In some examples, transmitter 1320 may coexist with receiver 1310 in a transceiver module. For example, transmitter 1320 may be a reference... Figure 16 Examples of various aspects of the transceiver 1620 described. The transmitter 1320 may utilize a single antenna or an array of antennas.

[0176] Figure 14 A block diagram 1400 is shown of a device 1405 supporting the coexistence of MCG and SCG according to various aspects of this disclosure. Device 1405 may be as described in reference... Figure 1 and 13Examples of various aspects of the described device 1305 or base station 105. Device 1405 may include a receiver 1410, a communication manager 1415, and a transmitter 1440. Device 1405 may also include a processor. Each of these components may be in communication with each other (e.g., via one or more buses).

[0177] Receiver 1410 can 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 the coexistence of MCG and SCG). The information can be transmitted to other components of device 1405. Receiver 1410 can be a reference... Figure 16 Examples of various aspects of the transceiver 1620 are described. The receiver 1410 may utilize a single antenna or an array of antennas.

[0178] Communication Manager 1415 can be as follows: Figure 13 Examples of various aspects of the described communication manager 1315. The communication manager 1415 may include a dual connectivity identifier 1420, a reserved indication transmitter 1425, an additional TTI indicator 1430, and a reserved TTI receiver 1435. The communication manager 1415 may be a reference... Figure 16 Examples of various aspects of the described communication manager 1610.

[0179] Dual connectivity identifier 1420 identifies that the base station is operating as an MCG with the UE in dual connectivity. Reserved indication transmitter 1425 transmits to the UE an indication of a reserved TTI reserved for priority UL communication with the MCG. Additional TTI indicator 1430 indicates to the SCG the reserved TTI and additional TTIs that can be used for UL communication with the MCG or SCG. Reserved TTI receiver 1435 can use the reserved TTI to receive one or more UL messages from the UE.

[0180] Transmitter 1440 can transmit signals generated by other components of device 1405. In some examples, transmitter 1440 may coexist with receiver 1410 in a transceiver module. For example, transmitter 1440 may be a reference... Figure 16 Examples of various aspects of the transceiver 1620 are described. The transmitter 1440 may utilize a single antenna or an array of antennas.

[0181] Figure 15 A block diagram 1500 of a communication manager 1505 supporting the coexistence of MCG and SCG according to various aspects of this disclosure is shown. The communication manager 1505 may be a reference... Figure 13 , 14Examples of aspects of communication managers 1315, 1415, or 1610 as described in section 16. Communication manager 1505 may include a dual connectivity identifier 1510, a reservation indication transmitter 1515, an additional TTI indicator 1520, a reserved TTI receiver 1525, an additional TTI identifier 1530, and a time offset component 1535. Each of these modules may communicate directly or indirectly with each other (e.g., via one or more buses).

[0182] Dual connectivity identifier 1510 can identify whether the base station is operating with the UE as an MCG in dual connectivity. In some examples, dual connectivity identifier 1510 can configure both MCG and SCG for FDD operation. In some examples, dual connectivity identifier 1510 can configure both MCG and SCG for TDD operation.

[0183] In some examples, the dual connectivity identifier 1510 may indicate to the UE an FDD timing configuration for UL transmissions to the SCG, which facilitates avoiding simultaneous UL transmissions to both the MCG and SCG. In some cases, the MCG is configured for TDD operation, while the SCG is configured for FDD operation. In some cases, the MCG is configured for TDD operation and the SCG is configured for FDD operation, where UL transmissions to the SCG are time-division shared with SUL transmissions to the MCG.

[0184] The reservation indication transmitter 1515 may transmit to the UE an indication of a reserved TTI reserved for priority UL communication with the MCG. In some examples, the reservation indication transmitter 1515 may transmit a slot format indication (SFI) identifying the configuration for a UL TTI, DL TTI, unknown TTI, or a combination thereof, wherein the reserved TTI includes the UL TTI. In some examples, the reservation indication transmitter 1515 may transmit a cell-specific configured SFI. In some examples, the reservation indication transmitter 1515 may transmit a UE-specific configured SFI, wherein the UE-specific configured SFI overrides any previously transmitted cell-specific configured SFIs. In some examples, the reservation indication transmitter 1515 may transmit a dynamic SFI via DCI, wherein the dynamic SFI is specific to an upcoming TTI or set of TTIs.

[0185] In some examples, the reservation instruction transmitter 1515 may transmit a prioritization configuration to the UE, which includes an indication of reserved TTIs reserved for UL or DL ​​communication with the MCG, and an indication of which additional TTIs should be used for UL or DL ​​communication with the MCG. In some cases, the indication further indicates DL TTIs, unknown TTIs, or both reserved for communication with the MCG.

[0186] The additional TTI indicator 1520 can indicate to the SCG reserved TTIs and additional TTIs that can be used for UL communication with the MCG or SCG. In some examples, the additional TTI indicator 1520 can transmit a joint configuration to the UE, which includes an indication of reserved TTIs that can be reserved for UL or DL ​​communication with the MCG, and an indication of which additional TTIs are to be used for UL or DL ​​communication with the MCG and which additional TTIs are to be used for UL or DL ​​communication with the SCG.

[0187] The reserved TTI receiver 1525 can use the reserved TTIs to receive one or more UL messages from the UE. The additional TTI identifier 1530 can transmit a schedule for using one or more additional TTIs for UL communication with the MCG or SCG, which facilitates avoiding simultaneous UL transmissions to both the MCG and SCG. The time offset component 1535 can transmit to the UE a parameter indicating the time offset for UL transmissions for HARQ feedback after the reception of data messages, wherein the time offset is based on the number of reserved TTIs. In some examples, the time offset component 1535 can receive HARQ feedback based on this parameter.

[0188] Figure 16 A diagram is shown of a system 1600 including a device 1605 supporting the coexistence of MCG and SCG according to various aspects of this disclosure. Device 1605 may be, for example, as described above. Figure 1 , 13 Examples of components of device 1305, device 1405, or base station 105 described in section 14, or including such components. Device 1605 may include components for two-way voice and data communication, including components for transmitting and receiving communications, including a communication manager 1610, a network communication manager 1615, a transceiver 1620, an antenna 1625, a memory 1630, a processor 1640, and an inter-station communication manager 1645. These components may be in electronic communication via one or more buses (e.g., bus 1650).

[0189] The communication manager 1610 can identify that the base station is operating as an MCG with the UE in dual connectivity; transmit to the UE an indication of a reserved TTI reserved for priority UL communication with the MCG; indicate to the SCG the reserved TTI and additional TTIs that can be used for UL communication with the MCG or SCG; and receive one or more UL messages from the UE using the reserved TTI.

[0190] The network communication manager 1615 can manage communication with the core network (e.g., via one or more wired backhaul links). For example, the network communication manager 1615 can manage the delivery of data communication to client devices (such as one or more UEs 115).

[0191] Transceiver 1620 can communicate bidirectionally via one or more antennas, wired or wireless links, as described above. For example, transceiver 1620 can represent a wireless transceiver and can communicate bidirectionally with another wireless transceiver. Transceiver 1620 may also include a modem to modulate packets and provide the modulated packets to the antenna for transmission, and to demodulate packets received from the antenna.

[0192] In some cases, a wireless device may include a single antenna 1625. However, in other cases, the device may have more than one antenna 1625, which may be able to transmit or receive multiple wireless transmissions concurrently.

[0193] Memory 1630 may include RAM, ROM, or a combination thereof. Memory 1630 may store computer-readable code 1635 including instructions that, when executed by a processor (e.g., processor 1640), cause the device to perform the various functions described herein. In some cases, memory 1630 may, in particular, include a BIOS that controls basic hardware or software operations, such as interaction with peripheral components or devices.

[0194] Processor 1640 may include intelligent hardware devices (e.g., general-purpose processors, DSPs, CPUs, microcontrollers, ASICs, FPGAs, programmable logic devices, discrete gate or transistor logic components, discrete hardware components, or any combination thereof). In some cases, processor 1640 may be configured to use a memory controller to operate a memory array. In some cases, the memory controller may be integrated into processor 1640. Processor 1640 may be configured to execute computer-readable instructions stored in memory (e.g., memory 1630) to cause device 1605 to perform various functions (e.g., functions or tasks supporting the coexistence of MCGs and SCGs).

[0195] Inter-site communication manager 1645 manages communication with other base stations 105 and may include a controller or scheduler for cooperating with other base stations 105 to control communication with UE 115. For example, inter-site communication manager 1645 may coordinate the scheduling of transmissions to UE 115 for various interference mitigation techniques, such as beamforming or joint transmission. In some examples, inter-site communication manager 1645 may provide an X2 interface within LTE / LTE-A wireless communication network technology to facilitate communication between base stations 105.

[0196] Code 1635 may include instructions for implementing various aspects of this disclosure, including instructions for supporting wireless communication. Code 1635 may be stored in a non-transitory computer-readable medium, such as system memory or other types of memory. In some cases, code 1635 may not be directly executed by processor 1640, but may cause a computer (e.g., when compiled and executed) to perform the functions described herein.

[0197] Figure 17 A flowchart illustrating method 1700 for supporting the coexistence of MCG and SCG according to various aspects of this disclosure is shown. Operation of method 1700 may be implemented by UE 115 or its components as described herein. For example, operation of method 1700 may be implemented by referring to... Figures 9 to 12 The described communication manager is used to execute this. In some examples, the UE can execute a set of instructions to control the UE's functional elements to perform the functions described below. Additionally or alternatively, the UE can use dedicated hardware to perform aspects of the functions described below.

[0198] At 1705, UE 115 can identify that UE 115 is operating with MCG and SCG in dual connectivity. The operation at 1705 can be performed according to the methods described herein. In some examples, aspects of the operation at 1705 can be determined by referring to... Figures 9 to 12 The described biconnectivity identifier is used to perform this.

[0199] At 1710, UE 115 can receive from the MCG an indication of a reserved TTI reserved for priority UL communication with the MCG. Operation of 1710 can be performed according to the methods described herein. In some examples, aspects of the operation of 1710 can be determined by referring to... Figures 9 to 12 The TTI reserved components described are used for execution.

[0200] At 1715, UE 115 may identify additional TTIs that can be used for UL communication with the MCG or SCG. Operation of 1715 may be performed according to the methods described herein. In some examples, aspects of the operation of 1715 may be determined by reference to... Figures 9 to 12 The additional TTI identifier described is used to perform this.

[0201] At 1720, UE 115 can transmit one or more UL messages to the MCG using the reserved TTI. The operation of 1720 can be performed according to the methods described herein. In some examples, aspects of the operation of 1720 can be derived from, as referenced... Figures 9 to 12 The described reserved TTI transport components are used to perform this.

[0202] At 1725, UE 115 may use an additional TTI to transmit one or more UL messages to the MCG or SCG. Operation of 1725 can be performed according to the methods described herein. In some examples, aspects of operation of 1725 may be derived from, as referenced... Figures 9 to 12 The described additional TTI transport components are used to perform this.

[0203] Figure 18 A flowchart illustrating method 1800 for supporting the coexistence of MCG and SCG according to various aspects of this disclosure is shown. Operation of method 1800 may be implemented by UE 115 or its components as described herein. For example, operation of method 1800 may be implemented by referring to... Figures 9 to 12 The described communication manager is used to execute this. In some examples, the UE can execute a set of instructions to control the UE's functional elements to perform the functions described below. Additionally or alternatively, the UE can use dedicated hardware to perform aspects of the functions described below.

[0204] At point 1805, UE 115 can identify that UE 115 is operating with MCG and SCG in dual connectivity. The operation at point 1805 can be performed according to the methods described herein. In some examples, aspects of the operation at point 1805 can be determined by referring to... Figures 9 to 12 The described biconnectivity identifier is used to perform this.

[0205] At 1810, UE 115 can receive from the MCG an indication of the reserved TTI reserved for priority UL communication with the MCG. Operation of 1810 can be performed according to the method described herein. In some examples, aspects of the operation of 1810 can be determined by referring to... Figures 9 to 12 The TTI reserved components described are used for execution.

[0206] At 1815, UE 115 may receive from SCG an indication of an additional reserved TTI reserved for UL communication with SCG, wherein the reserved TTI and the additional reserved TTI are time-disjoint. Operation of 1815 may be performed according to the method described herein. In some examples, aspects of operation of 1815 may be determined by reference to... Figures 9 to 12 The TTI reserved components described are used for execution.

[0207] At 1820, UE 115 may identify additional TTIs that can be used for UL communication with the MCG or SCG. Operation of 1820 can be performed according to the methods described herein. In some examples, aspects of the operation of 1820 may be determined by reference to... Figures 9 to 12 The additional TTI identifier described is used to perform this.

[0208] At 1825, UE 115 may transmit one or more UL messages to the MCG using the reserved TTI. The operation of 1825 can be performed according to the methods described herein. In some examples, aspects of the operation of 1825 may be as described in reference... Figures 9 to 12 The described reserved TTI transport components are used to perform this.

[0209] At 1830, UE 115 may transmit one or more UL messages to the SCG using the additional reserved TTI. The operation at 1830 can be performed according to the methods described herein. In some examples, aspects of the operation at 1830 may be as described in reference... Figures 9 to 12 The described additional TTI transport components are used to perform this.

[0210] At 1835, UE 115 may use an additional TTI to transmit one or more UL messages to the MCG or SCG. Operation of 1835 can be performed according to the methods described herein. In some examples, aspects of operation of 1835 may be derived from, as referenced... Figures 9 to 12 The described additional TTI transport components are used to perform this.

[0211] Figure 19 A flowchart illustrating a method 1900 for supporting the coexistence of MCG and SCG according to various aspects of this disclosure is shown. Operation of method 1900 may be implemented by a base station 105 or components thereof as described herein. In some cases, base station 105 may be an example of gNB 202, 302, or 702 as described herein, particularly referring to... Figure 2 , 3 And 7. In some other examples, base station 105 may be an example of the eNB 204, 304 or 704 described herein, especially referring to Figure 2 , 3 And 7. For example, the operation of method 1900 can be performed by referring to Figures 13 to 16 The described communication manager is used to execute this. In some examples, the base station can execute a set of instructions 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 aspects of the functions described below.

[0212] At point 1905, base station 105 can identify that the base station is operating as an MCG with UE 115 in dual connectivity. The operation at point 1905 can be performed according to the methods described herein. In some examples, aspects of the operation at point 1905 can be determined by referring to... Figures 13 to 16 The described biconnectivity identifier is used to perform this.

[0213] At point 1910, base station 105 may transmit to UE 115 an indication of the reserved TTI reserved for priority UL communication with MCG. Operation of 1910 may be performed according to the method described herein. In some examples, aspects of operation of 1910 may be determined by reference to... Figures 13 to 16 The described reservation instruction is to be executed by the transmitter.

[0214] At point 1915, base station 105 may indicate to the SCG the reserved TTI and additional TTIs that can be used for UL communication with the MCG or SCG. Operation of point 1915 may be performed according to the method described herein. In some examples, aspects of operation of point 1915 may be determined by reference to... Figures 13 to 16 The described additional TTI indicator is used to perform this.

[0215] At point 1920, base station 105 can receive one or more UL messages from UE 115 using the reserved TTI. Operation at point 1920 can be performed according to the methods described herein. In some examples, aspects of operation at point 1920 can be determined by reference to... Figures 13 to 16 The reserved TTI receiver described is used to perform this.

[0216] It should be noted that the above methods describe possible implementations, and the operations and steps can be rearranged or otherwise modified, and other implementations are also possible. Furthermore, aspects from two or more methods can be combined.

[0217] The techniques described in this article 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 others. CDMA systems can implement radio technologies such as CDMA2000 and Universal Terrestrial Radio Access (UTRA). CDMA2000 encompasses the IS-2000, IS-95, and IS-856 standards. Versions of IS-2000 are often referred to as CDMA2000 1X, 1X, etc. IS-856 (TIA-856) is often 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).

[0218] OFDMA systems can implement radio technologies such as Ultra Mobile Broadband (UMB), Evolved UTRA (E-UTRA), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, and Flash-OFDM. UTRA and E-UTRA are part of the Universal Mobile Telecommunications System (UMTS). LTE, LTE-A, and LTE-A Pro are UMTS versions using E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, LTE-A Pro, NR, and GSM are described in documents from an organization called the 3rd Generation Partnership Project (3GPP). CDMA2000 and UMB are described in documents from an organization called 3rd Generation Partnership Project 2 (3GPP2). The technologies described herein can be used with the systems and radio technologies mentioned above, as well as with other systems and radio technologies. Although aspects of LTE, LTE-A, LTE-A Pro, or NR systems may be described for illustrative purposes, and the terms LTE, LTE-A, LTE-A Pro, or NR may be used in most of the descriptions, the techniques described herein may also be applied to applications beyond LTE, LTE-A, LTE-A Pro, or NR applications.

[0219] Macrocells typically cover a relatively large geographic area (e.g., an area with a radius of several kilometers) and allow unrestricted access by UE 115 with a service subscription to a network provider. Small cells may be associated with a lower-power base station 105 (compared to macrocells) and may operate in the same or different (e.g., licensed, unlicensed, etc.) frequency bands as macrocells. Depending on the examples, small cells may include picocells, femtocells, and microcells. Picocells may, for example, cover a smaller geographic area and allow unrestricted access by UE 115 with a service subscription to a network provider. Femtocells may also cover a smaller geographic area (e.g., a residential area) and provide restricted access by UE 115 associated with that femtocell (e.g., UE 115 in a closed subscriber group (CSG), UE 115 of a user in a residence, etc.). The eNB used for a macrocell may be referred to as a macro eNB. An eNB used for small cells may be referred to as a small cell eNB, pico eNB, femto eNB, or home eNB. An eNB may support one or more (e.g., two, three, four, etc.) cells and may also support communication using one or more component carriers.

[0220] One or more wireless communication systems 100 described herein can support synchronous or asynchronous operation. For synchronous operation, base stations 105 can have similar frame timing, and transmissions from different base stations 105 can be approximately time-aligned. For asynchronous operation, base stations 105 can have different frame timing, and transmissions from different base stations 105 may not be time-aligned. The techniques described herein can be used for both synchronous and asynchronous operation.

[0221] The information and signals described herein can be represented using any of a wide variety of different techniques and methods. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referred to throughout the above description can be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, light fields or light particles, or any combination thereof.

[0222] The various illustrative blocks and modules described herein can be implemented or executed using a general-purpose processor, digital signal processor (DSP), application-specific integrated circuit (ASIC), 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. The general-purpose processor may be a microprocessor, but in alternatives, the processor may be any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors working in conjunction with a DSP core, or any other such configuration).

[0223] The functions described herein can be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions can be stored or transmitted as one or more instructions or code on a computer-readable medium. Other examples and implementations fall within the scope of this disclosure and the appended claims. For example, due to the nature of software, the above functions can be implemented using software executed by a processor, hardware, firmware, hardwired, or any combination thereof. Features implementing the functions can also be physically located in various locations, including being distributed such that different parts of the function are implemented at different physical locations.

[0224] Computer-readable media includes both non-transient computer storage media and communication media, encompassing any medium that facilitates the transfer of a computer program from one location to another. Non-transient storage media can be any available medium accessible to a general-purpose or special-purpose computer. By way of example and not limitation, non-transient computer-readable media may include RAM, ROM, electrically erasable programmable read-only memory (EEPROM), flash memory, compact disc (CD) ROM or other optical disc storage, magnetic disk storage or other magnetic storage devices, or any other non-transient medium that can be used to carry or store desired program code in the form of instructions or data structures and is accessible to a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Any connection is also legitimately referred to as computer-readable media. For example, if software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then that coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of media. As used in this article, disk and disc include CDs, laser discs, optical discs, DVDs, floppy disks, and Blu-ray discs, where disks often magnetically reproduce data while discs optically reproduce data using lasers. Combinations of these media are also included within the scope of computer-readable media.

[0225] As used herein (including in the claims), the word "or" in an enumeration of items (e.g., an enumeration of items accompanied by phrases such as "at least one of" or "one or more of") indicates an inclusive enumeration, such that an enumeration of at least one of, for example, 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 construed as referencing 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 this disclosure. In other words, as used herein, the phrase "based on" should be interpreted in the same manner as the phrase "at least partially based on".

[0226] In the accompanying drawings, similar components or features may have the same reference numerals. Furthermore, components of the same type may be distinguished by a dash following the reference numeral and a second reference numeral used to differentiate between similar components. If only the first reference numeral is used in the description, the description may apply to any of the similar components having the same first reference numeral, regardless of the second reference numeral or other subsequent reference numerals.

[0227] This document, illustrated with reference to the accompanying drawings, describes exemplary configurations but does not represent all examples that can be implemented or fall within the scope of the claims. The term "exemplary" as used herein means "serving as an example, instance, or illustration" and does not mean "superior to" or "outperforms" 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.

[0228] The description provided herein is intended to enable those skilled in the art to make or use this disclosure. Various modifications to this disclosure will be apparent to those skilled in the art, and the universal principles defined herein can be applied to other variations without departing from the scope of this disclosure. Thus, this 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: identifying that the UE is operating in dual connectivity with a primary cell group and a secondary cell group; receiving, from the primary cell group, an indication of a reserved transmission time interval (TTI) reserved for priority uplink (UL) communications with the primary cell group; identifying an additional TTI available for UL communications with the primary cell group or the secondary cell group; and transmitting one or more UL messages to the primary cell group or the secondary cell group using the additional TTI, wherein transmitting one or more UL messages to the primary cell group or the secondary cell group using the additional TTI comprises: transmitting UL messages to the primary cell group and the secondary cell group during a same TTI.

2. The method of claim 1, further comprising: adjusting a transmit power for the UL messages transmitted to the primary cell group and the UL messages transmitted to the secondary cell group based on the aggregated transmit power.

3. The method of claim 2, wherein adjusting the transmit power comprises: reducing a transmit power of a lower priority channel.

4. The method of claim 1, further comprising: determining that UL messages to the primary cell group and UL messages to the secondary cell group are both scheduled for a same TTI in the additional TTI; identifying a priority between UL messages to the primary cell group and UL messages to the secondary cell group; and transmitting one of the UL messages to the primary cell group or the UL messages to the secondary cell group during the TTI based on the priority.

5. The method of claim 4, wherein a primary cell group uplink control channel has a higher priority than a secondary cell group uplink control channel.

6. The method of claim 5, wherein transmitting one of the UL messages to the primary cell group or the UL messages to the secondary cell group during the TTI based on the priority comprises: reducing or decreasing a transmit power of a channel based on a priority of the channel.

7. The method of claim 6, wherein reducing or decreasing the transmit power comprises: determining whether an aggregated transmit power exceeds a maximum transmit power; and reducing or decreasing the transmit power of a channel based on a priority of the channel in response to determining that the aggregated transmit power exceeds the maximum transmit power.

8. The method of claim 1, further comprising: identifying an FDD timing configuration for UL transmissions to the secondary cell group that facilitates avoiding UL transmissions to both the primary cell group and the secondary cell group at the same time, wherein transmitting one or more UL messages using the additional TTI is in accordance with the FDD timing configuration.

9. The method of claim 1, further comprising: ​ ​ ​ receiving a joint configuration, the joint configuration comprising an indication of reserved TTIs reserved for UL or downlink (DL) communications with the primary cell group and an indication of which of the additional TTIs are to be used for UL or DL communications with the primary cell group and which of the additional TTIs are to be used for UL or DL communications with the secondary cell group.

10. The method of claim 1, further comprising: receiving a prioritization configuration, the prioritization configuration comprising an indication of reserved TTIs reserved for UL or downlink (DL) communications with the primary cell group and an indication of which of the additional TTIs are to be used for UL or DL communications with the primary cell group.

11. The method of claim 1, further comprising: prioritizing power control for each of the UL messages transmitted during the same TTI based at least in part on a type of the UL messages.

12. The method of claim 1, further comprising: prioritizing power control for each of the UL messages transmitted during the same TTI based at least in part on a starting time of each of the UL messages.

13. The method of claim 1, wherein a maximum power control for UL messages transmitted to the primary cell group and a maximum power control for UL messages transmitted to the secondary cell group during the same TTI are each less than a respective power control for UL transmissions during different TTIs.

14. The method of claim 1, further comprising: identifying a first TTI duration associated with the primary cell group; identifying a second TTI duration associated with the secondary cell group; and applying a transmit power control scheme based at least in part on the first TTI duration and the second TTI duration.

15. The method of claim 14, wherein applying the transmit power control scheme further comprises: adjusting transmit power for UL messages transmitted to the primary cell group and UL messages transmitted to the secondary cell group after a TTI of the first TTI duration based at least in part on the first TTI duration being longer than the second TTI duration.

16. The method of claim 14, wherein applying the transmit power control scheme further comprises: adjusting transmit power for UL messages transmitted to the primary cell group and UL messages transmitted to the secondary cell group after a TTI of the second TTI duration based at least in part on the second TTI duration being longer than the first TTI duration.

17. A method for wireless communication at a network access node, comprising: identifying that the network access node is operating in dual connectivity as a primary cell group with a user equipment (UE); transmitting, to the UE, an indication of reserved transmission time intervals (TTIs) reserved for priority uplink (UL) communications with the primary cell group; indicating the reserved TTI and additional TTIs available for UL communication with the primary cell group or the secondary cell group to the secondary cell group; and receiving one or more UL messages from the UE during the same TTIs in the additional TTIs as the secondary cell group.

18. The method of claim 17, further comprising: transmitting a schedule of one or more of the additional TTIs for UL communication with the primary cell group or the secondary cell group, the schedule facilitating avoidance of UL transmissions to both the primary cell group and the secondary cell group at the same time.

19. The method of claim 17, wherein transmitting the indication of the reserved TTI comprises: transmitting a slot format indication (SFI) identifying a configuration for UL TTIs, downlink (DL) TTIs, unknown TTIs, or a combination thereof, wherein the reserved TTI comprises the UL TTIs.

20. The method of claim 17, wherein the indication further indicates downlink (DL) TTIs, unknown TTIs, or both, reserved for communication with the primary cell group.

21. The method of claim 17, wherein the primary cell group is configured for time division duplex (TDD) operation and the secondary cell group is configured for frequency division duplex (FDD) operation, wherein UL transmissions to the secondary cell group are time-shared with supplemental uplink (SUL) transmissions to the primary cell group.

22. The method of claim 17, further comprising: indicating to the UE an FDD timing configuration for UL transmissions to the secondary cell group, the FDD timing configuration facilitating avoidance of UL transmissions to both the primary cell group and the secondary cell group at the same time.

23. The method of claim 17, further comprising: transmitting a joint configuration to the UE, the joint configuration including an indication of reserved TTIs reserved for UL or downlink (DL) communication with the primary cell group and an indication of which of the additional TTIs are to be used for UL or DL communication with the primary cell group and which of the additional TTIs are to be used for UL or DL communication with the secondary cell group.

24. The method of claim 17, further comprising: transmitting a prioritization configuration to the UE, the prioritization configuration including an indication of reserved TTIs reserved for UL or downlink (DL) communication with the primary cell group and an indication of which of the additional TTIs are to be used for UL or DL communication with the primary cell group.

25. An apparatus for wireless communication at a user equipment (UE), comprising: means for identifying that the UE is operating in dual connectivity with a primary cell group and a secondary cell group; means for receiving an indication of a reserved transmission time interval (TTI) reserved for priority uplink (UL) communication with the primary cell group from the primary cell group; means for identifying an additional TTI available for UL communication with the primary cell group or the secondary cell group; and means for transmitting one or more UL messages to the primary cell group or the secondary cell group using the additional TTI, wherein the means for transmitting one or more UL messages to the primary cell group or the secondary cell group using the additional TTI comprises: means for transmitting UL messages to the primary cell group and the secondary cell group during the same TTI.

26. An apparatus for wireless communication at a user equipment (UE), comprising: means for performing the method of any of claims 2-16.

27. An apparatus for wireless communication at a network access node, comprising: means for identifying that the network access node is operating in dual connectivity as a primary cell group with a user equipment (UE); means for transmitting, to the UE, an indication of a reserved transmission time interval (TTI) reserved for priority uplink (UL) communication with the primary cell group; means for indicating, to a secondary cell group, the reserved TTI and an additional TTI available for UL communication with the primary cell group or the secondary cell group; and means for receiving one or more UL messages from the UE in the additional TTI during the same TTI as the secondary cell group.

28. An apparatus for wireless communication at a network access node, comprising: means for performing the method of any of claims 18-24.

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