Power-efficient way to operate user equipment (UE) in multi-radio access technology dual connectivity

Abstract

The present disclosure provides systems, methods, apparatus, and computer programs encoded on a computer-readable medium for providing the following operations: a user equipment (UE) receives a reference signal from a first base station, performs radio resource management (RRM) measurements based on the reference signal, and sends information about the RRM measurements to a second base station. In another aspect, the UE receives a reference signal from the first base station, performs channel quality indicator (CQI) measurements based on the reference signal, stores information about the CQI measurements, and sends the stored information to the first base station. In another aspect, the base station receives information associated with CQI measurements related to a second base station from the UE and sends the information to the second base station.

Description

Technical Field

[0001] In general, the technology discussed below relates to wireless communication systems or networks, and more particularly, to operating a user equipment (UE) in a dormant or deactivated power-efficient state relative to a secondary base station or node (SN) in a dual connectivity configuration with a primary base station or node (MN). Background Art

[0002] In many existing wireless communication systems, cellular networks are implemented by enabling wireless user equipment to communicate with each other through signaling with one or more nearby base stations or cells. As user equipment (UE) moves across a service area, handover occurs, allowing each UE to maintain communication with each other via its corresponding base station and associated one or more cells. In a dual connectivity configuration, a UE can be connected to two or more base stations, each of which can support a set of cells to provide radio resources for communicating with the UE. Summary of the Invention

[0003] The systems, methods and devices of the present disclosure each have several innovative aspects, no single one of which is solely responsible for the desirable attributes disclosed herein.

[0004] One innovative aspect of the subject matter described in the present disclosure relates to a method for wireless communication at an apparatus of a user equipment (UE), comprising: receiving one or more reference signals from a first base station; performing one or more radio resource management (RRM) measurements based on the one or more reference signals; and sending information about the one or more RRM measurements to a second base station.

[0005] Another innovative aspect of the subject matter described in this disclosure can be implemented in a user equipment comprising: a wireless transceiver; and a processor configured to: receive one or more reference signals from a first base station via the wireless transceiver; perform one or more radio resource management (RRM) measurements based on the one or more reference signals; and send information about the one or more RRM measurements to a second base station via the wireless transceiver.

[0006] Another innovative aspect of the subject matter described in this disclosure can be implemented in an apparatus comprising: means for receiving one or more reference signals from a first base station; means for performing one or more radio resource management (RRM) measurements based on the one or more reference signals; and means for sending information about the one or more RRM measurements to a second base station.

[0007] Another innovative aspect of the subject matter described in this disclosure relates to a non-transitory computer-readable medium storing computer-executable code, the computer-executable code including code for causing a processor in a user equipment to: receive one or more reference signals from a first base station; perform one or more radio resource management (RRM) measurements based on the one or more reference signals; and send information about the one or more RRM measurements to a second base station.

[0008] Another innovative aspect of the subject matter described in this disclosure can be implemented in a wireless communication system comprising: a first base station; a second base station; and a user equipment, the user equipment being configured to: receive one or more reference signals from the first base station; perform one or more radio resource management (RRM) measurements based on the one or more reference signals; and send information about the one or more RRM measurements to the second base station.

[0009] Another innovative aspect of the subject matter described in the present disclosure relates to a method for wireless communication at an apparatus of a user equipment (UE), comprising: receiving one or more reference signals from a first base station; performing one or more channel quality indicator (CQI) measurements based on the one or more reference signals; storing information about the one or more CQI measurements; and sending the stored information about the one or more CQI measurements to the first base station or a second base station.

[0010] Another innovative aspect of the subject matter described in the present disclosure can be implemented in a user device comprising: a memory; a wireless transceiver; and a processor configured to: receive one or more reference signals from a first base station via the wireless transceiver; perform one or more channel quality indicator (CQI) measurements based on the one or more reference signals; store information about the one or more CQI measurements in the memory; and send the stored information to the first base station or a second base station via the wireless transceiver.

[0011] Another innovative aspect of the subject matter described in the present disclosure can be implemented in an apparatus comprising: means for receiving one or more reference signals from a first base station; means for performing one or more channel quality indicator (CQI) measurements based on the one or more reference signals; means for storing information about the one or more CQI measurements; and means for sending the stored information about the one or more CQI measurements to the first base station or a second base station.

[0012] Another innovative aspect of the subject matter described in the present disclosure relates to a non-transitory computer-readable medium storing computer-executable code, the non-transitory computer-readable medium including code for causing a processor in a user equipment to: receive one or more reference signals from a first base station; perform one or more channel quality indicator (CQI) measurements based on the one or more reference signals; store information about the one or more CQI measurements; and send the stored information about the one or more CQI measurements to the first base station or a second base station.

[0013] Another innovative aspect of the subject matter described in the present disclosure can be implemented in a wireless communication system comprising: a first base station; a second base station; and a user equipment, the user equipment being configured to: receive one or more reference signals from the first base station; perform one or more channel quality indicator (CQI) measurements based on the one or more reference signals; store information about the one or more CQI measurements; and send the stored information about the one or more CQI measurements to the first base station or the second base station.

[0014] Another innovative aspect of the subject matter described in the present disclosure relates to a method for wireless communication at an apparatus of a first base station, comprising: receiving information associated with one or more channel quality indicator (CQI) measurements related to a second base station from a user equipment (UE); and sending the information to the second base station.

[0015] Another innovative aspect of the subject matter described in the present disclosure can be implemented in a base station comprising: a wireless transceiver; a backhaul interface; and a processor configured to: receive information associated with one or more channel quality indicator (CQI) measurements related to another base station from a user equipment (UE) via the wireless transceiver; and send the information to the second base station via the backhaul interface.

[0016] Another innovative aspect of the subject matter described in the present disclosure can be implemented in an apparatus comprising: means for receiving information associated with one or more channel quality indicator (CQI) measurements related to a second base station from a user equipment (UE); and means for sending the information to the second base station.

[0017] Another innovative aspect of the subject matter described in the present disclosure relates to a non-transitory computer-readable medium storing computer-executable code, the computer-executable code including code for causing a processor in a base station to: receive information associated with one or more channel quality indicator (CQI) measurements related to a second base station from a user equipment (UE); and send the information to the second base station.

[0018] Another innovative aspect of the subject matter described in the present disclosure can be implemented in a wireless communication system comprising: a user equipment; a first base station; a second base station, the second base station being configured to: receive information associated with one or more channel quality indicator (CQI) measurements related to the first base station from the user equipment; and send information to the first base station.

[0019] The details of one or more implementations of the subject matter described in this disclosure are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages will become apparent from the description, drawings, and claims. It should be noted that the relative dimensions of the following drawings may not be drawn to scale. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A diagram illustrating an example wireless radio access network is shown.

[0021] Figure 2 Diagram showing an example organization of wireless communication link resources in an air interface utilizing Orthogonal Frequency Division Multiplexing (OFDM).

[0022] Figure 3 An example cellular communication system is shown.

[0023] Figure 4 Shown for Figure 3 An example flow chart of a method for power-efficient handover operation of a cellular communication system.

[0024] Figure 5 Shown for Figure 3 An example flow chart of a method of power-efficient link adaptation operation for a cellular communication system.

[0025] Figure 6 Shown for Figure 3 An example flow chart of another method of power-efficient link adaptation operation for a cellular communication system.

[0026] Figure 7 A block diagram illustrating an example hardware implementation of a base station.

[0027] Figure 8 An example flow chart illustrating a method for reporting, by a primary base station to a secondary base station, information about channel quality indicator (CQI) measurements performed by a user equipment (UE) based on a reference signal received from the secondary base station for link adaptation purposes.

[0028] Figure 9 A block diagram illustrating an example hardware implementation of a user equipment (UE).

[0029] Figure 10An example flow chart of a method for reporting, by a user equipment (UE), to a primary base station, radio resource management (RRM) measurements performed by the UE based on a reference signal received from a secondary base station is shown.

[0030] Figure 11 An example flow chart of a method for reporting, by a user equipment (UE), to a primary base station, radio resource management (RRM) measurements performed by the UE based on a reference signal received from a secondary base station is shown.

[0031] Like reference numbers and designations in the various drawings indicate like elements. DETAILED DESCRIPTION

[0032] For the purpose of describing the innovative aspects of the present disclosure, the following description refers to certain implementations. However, those skilled in the art will readily recognize that the teachings herein can be applied in a variety of different ways. Some examples in the present disclosure are based on wireless and wired local area network (LAN) communications in accordance with the Institute of Electrical and Electronics Engineers (IEEE) 802.11 wireless standard, the IEEE 802.3 Ethernet standard, and the IEEE 1901 Power Line Communication (PLC) standard. The described implementations can be implemented in any device, system, or network capable of sending and receiving RF signals in accordance with any of the wireless communication standards, including any of the following: the IEEE 802.11 standard, the IEEE 802.3 Ethernet standard, and the IEEE 1901 Power Line Communication (PLC) standard. Standard, Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Global System for Mobile Communications (GSM), GSM or General Packet Radio Service (GPRS), Enhanced Data GSM Environment (EDGE), Terrestrial Trunked Radio (TETRA), Wideband-CDMA (W-CDMA), Evolution-Data Optimized (EV-DO), 1xEV-DO, EV-DO Rev A, EV-DO Rev B, High Speed ​​Packet Access (HSPA), High Speed ​​Downlink Packet Access (HSDPA), High Speed ​​Uplink Packet Access (HSUPA), Evolved High Speed ​​Packet Access (HSPA+), Long Term Evolution (LTE), AMPS, or other known signals used to communicate within a wireless, cellular or Internet of Things (IoT) network, such as a system utilizing 3G, 4G or 5G, or another implementation or technology thereof.

[0033] In one aspect, a user equipment (UE) connected to a master base station or master node (MN) and a secondary base station or secondary node (SN) can operate in a power-efficient state associated with a secondary cell group (SCG) of the SN, which may include a primary cell (PScell) and one or more secondary cells (SScells). For example, in the deactivated state, the UE does not perform data transmission with the SN, does not monitor the physical downlink control channel (PDCCH) associated with the SN, and does not perform channel quality indicator (CQI) measurements with respect to the SN. In the dormant state, the UE does not perform data transmission with the SN and does not monitor the physical downlink control channel (PDCCH) associated with the SN, but performs channel quality indicator (CQI) measurements with respect to the SN. These states are low power consumption states compared to the active state in which the UE monitors the PDCCH for data to be sent by the SN to the UE and receives data from the SN.

[0034] In another aspect, the UE operates in a manner to ensure coverage by the SN in a deactivated or dormant state. In this regard, the UE performs radio resource management (RRM) measurements associated with the SCG or SN while in the dormant or deactivated state and reports these measurements to the MN. The RRM measurements are used by the MN to determine whether to implement a handover with respect to the PSCell of the SN or SCG. Therefore, the purpose of the RRM measurements is to ensure continuous coverage of the SN. If the RRM measurements indicate that coverage is being lost, the MN can command the UE to perform a PSCell change or an SN change based on the RRM measurements.

[0035] In yet another aspect, the UE operates in a manner that reduces the delay between transitions from a dormant state to an active state. In this regard, the UE performs channel quality indicator (CQI) measurements with respect to an SCG or SN while in the dormant state, and stores the measurements for subsequent reporting to the SN (directly or via the MN) when the UE transitions to the active state. The CQI measurements are used by the SN to perform link adaptation (such as selecting a modulation and coding scheme (MCS)) for data radio bearers (DRBs) to the UE. Therefore, when the UE enters the active state, the delay may be relatively small because the SN already has the link adaptation information.

[0036] Specific implementations of the subject matter described in this disclosure may be implemented to achieve one or more of the following potential advantages. For example, when the UE is not receiving data from or sending data to the SN, the UE may be able to operate in a deactivated or dormant state, wherein the UE does not consume power to monitor the Physical Downlink Control Channel (PDDCH) for data sent by the SN, thereby saving power. Additionally, in the deactivated or dormant state, by having the UE report RRM measurements about the SN to the MN, the SN can ensure coverage when data is to be sent by the SN to the UE. Furthermore, in the dormant state, the UE may report CQI measurements to the SN directly or via the MN, so that the SN can perform link adaptation (such as selecting a modulation and coding scheme (MCS)) when data is to be sent to the UE after the UE transitions from the dormant state to the active state; thereby reducing the delay in the UE receiving data.

[0037] The various concepts presented throughout this disclosure may be implemented across a wide variety of telecommunication systems, network architectures, and communication standards.

[0038] Figure 1 A diagram of an example wireless radio access network 100 (e.g., a wireless communication system) is shown. The RAN 100 may implement any suitable wireless communication technology or technologies to provide radio access. As an example, the RAN 100 may operate in accordance with the Third Generation Partnership Project (3GPP) New Radio (NR) specifications (commonly referred to as 5G). As another example, the RAN 100 may operate in accordance with a hybrid of 5G NR and Evolved Universal Terrestrial Radio Access Network (eUTRAN) standards (commonly referred to as LTE). 3GPP refers to this hybrid RAN as the Next Generation RAN, or NG-RAN. Of course, many other examples may be utilized within the scope of the present disclosure.

[0039] The geographical area covered by the radio access network 100 may be divided into a plurality of cellular areas (cells) that can be uniquely identified by a user equipment (UE) based on an identity broadcast from an access point or base station within the geographical area. Figure 1 Macro cells 102, 104, and 106, and small cell 108 are shown, each of which may include one or more sectors (not shown). A sector is a sub-area of ​​a cell. All sectors within a cell are served by the same base station. Radio or communication links within a sector may be identified by a single logical identifier belonging to that sector. In a cell divided into sectors, multiple sectors within the cell may be formed by antenna groups, where each antenna is responsible for communicating with UEs in a portion of the cell.

[0040] Typically, a corresponding base station (BS) serves each cell. Broadly speaking, a base station is a network element in a radio access network that is responsible for radio transmission to and reception from UEs in one or more cells. A BS may also be referred to by those skilled in the art as a base transceiver station (BTS), a radio base station, a radio transceiver, a transceiver functional unit, a basic service set (BSS), an extended service set (ESS), an access point (AP), a Node B (NB), an evolved Node B (eNB), a gNode B (gNB), or some other appropriate terminology.

[0041] exist Figure 1 In the example, two base stations 110 and 112 are shown in cells 102 and 104, respectively; and a third base station 114 is shown controlling a remote radio head (RRH) 116 in cell 106. That is, the base stations may have integrated antennas or may be connected to antennas or RRHs via feeder cables. In the example shown, cells 102, 104, and 106 may be referred to as macro cells because base stations 110, 112, and 114 support cells with large sizes. Further, base station 118 is shown in a small cell 108 (such as a micro cell, pico cell, femto cell, home base station, home node B, home eNode B, etc.), which may overlap with one or more macro cells. In this example, cell 108 may be referred to as a small cell because base station 118 supports cells with relatively small sizes. Cell size setting may be done based on system design and component constraints. It is to be understood that the radio access network 100 may include any number of wireless base stations and cells. Further, relay nodes or UEs may be deployed to extend the size or coverage area of ​​a given cell, as well as to provide diverse or aggregated communication links between base stations and UEs.Base stations 110, 112, 114, and 118 provide wireless access points to the core network for any number of mobile devices.

[0042] Figure 1 Also included is a quadcopter or drone 120 that can be configured to act as a base station. That is, in some examples, the cell may not necessarily be stationary, and the geographic area of ​​the cell may move based on the location of a mobile base station such as the quadcopter 120.

[0043] Typically, a base station may include a backhaul interface for communicating with a backhaul portion of a network (not shown). The backhaul may provide a link between the base station and a core network (not shown), and in some examples, may provide interconnection between respective base stations. The core network may be part of a wireless communication system and may be independent of the radio access technology used in the radio access network. Various types of backhaul interfaces may be employed, such as a direct physical connection, a virtual network, or a similar interface using any suitable transport network.

[0044] RAN 100 is shown supporting wireless communications for multiple mobile devices. Mobile devices are generally referred to as user equipment (UE) in standards and specifications promulgated by the Third Generation Partnership Project (3GPP), but may also be referred to by those skilled in the art as mobile stations (MS), subscriber stations, mobile units, subscriber units, wireless units, remote units, mobile devices, wireless devices, wireless communication devices, remote devices, mobile subscriber stations, access terminals (ATs), mobile terminals, wireless terminals, remote terminals, handsets, terminals, user agents, mobile clients, clients, or some other appropriate terminology. A UE may be a device that provides a user with access to network services.

[0045] In this document, a "mobile" device does not necessarily need to have the ability to move and can be stationary. The term mobile device or mobile device broadly refers to a variety of devices and technologies. For example, some non-limiting examples of mobile devices include mobile stations, cellular (cell) phones, smart phones, session initiation protocol (SIP) phones, laptop computers, personal computers (PCs), notebook computers, netbooks, smart books, tablet devices, personal digital assistants (PDAs) and various embedded systems (such as corresponding to the "Internet of Things" (IoT)). A mobile device can also be a car or other vehicle, a remote sensor or actuator, a robot or robotic device, a satellite radio unit, a global positioning system (GPS) device, a target tracking device, an unmanned aerial vehicle, a multi-axis aircraft, a quadcopter, a remote control device, a consumer device or a wearable device (such as glasses, wearable cameras, virtual reality devices, smart watches, health or fitness trackers), a digital audio player (such as an MP3 player), a camera, a game console, etc.

[0046] Mobile devices may also be digital home or smart home devices, such as home audio, video or multimedia devices, appliances, vending machines, smart lighting, home security systems, smart meters, and the like. Mobile devices may also be smart energy devices, security devices, solar panels or solar arrays, municipal infrastructure (such as smart grids) that controls electricity, lighting, water, and the like; industrial automation and enterprise devices; logistics controllers; agricultural equipment; military defense equipment, vehicles, aircraft, ships, and weapons, and the like. Further, mobile devices may provide connected medical or telemedicine support (i.e., healthcare at a distance). Telemedicine devices may include telemedicine monitoring devices and telemedicine management devices, whose communications may be given priority treatment or priority access over other types of information, such as based on priority access for the transmission of critical service data or associated QoS for the transmission of critical service data.

[0047] Within RAN 100, cells may include UEs that may communicate with one or more sectors within each cell. For example, UEs 122 and 124 may communicate with base station 110; UEs 126 and 128 may communicate with base station 112; UEs 130 and 132 may communicate with base station 114 via RRH 116; UE 134 may communicate with base station 118; and UE 136 may communicate with mobile base station 120. Here, each base station 110, 112, 114, 118, and 120 may be configured to provide an access point to a core network (not shown) for all UEs in the corresponding cell. In another example, a mobile network node, such as quadcopter 120, may be configured to act as a UE. For example, quadcopter 120 may operate within cell 102 by communicating with base station 110.

[0048] Wireless communications between the RAN 100 and a UE (such as UE 122 or 124) may be described as utilizing an air interface. Transmissions from a base station (such as base station 110) to one or more UEs (such as UEs 122 and 124) over the air interface may be referred to as downlink (DL) transmissions. According to certain aspects of the present disclosure, the term downlink may refer to point-to-multipoint transmissions originating at a scheduling entity (described further below; such as base station 110). Another way to describe this approach may be to use the term broadcast channel multiplexing. Transmissions from a UE (such as UE 122) to a base station (such as base station 110) may be referred to as uplink (UL) transmissions. According to further aspects of the present disclosure, the term uplink may refer to point-to-point transmissions originating at a scheduled entity (described further below; such as UE 122).

[0049] For example, a DL transmission may include a unicast or broadcast transmission of control information or traffic information (such as user data traffic) from a base station (such as base station 110) to one or more UEs (such as UEs 122 and 124), while an UL transmission may include the transmission of control information and / or traffic information originating at a UE (such as UE 122). In addition, uplink or downlink control information and / or traffic information may be divided in time into frames, subframes, time slots, or symbols. As used herein, a symbol may refer to a time unit that carries one resource element (RE) per subcarrier in an orthogonal frequency division multiplexing (OFDM) waveform. A time slot may carry 7 or 14 OFDM symbols. A subframe may refer to a duration of 1 ms. Multiple subframes or time slots may be grouped together to form a single frame or radio frame. Of course, these definitions are not required, and any suitable scheme for organizing waveforms may be utilized, and the various time divisions of the waveforms may have any suitable duration.

[0050] The air interface in the RAN 100 may utilize one or more multiplexing and multiple access algorithms to enable simultaneous communication of various devices. For example, the 5G NR specification utilizes orthogonal frequency division multiplexing (OFDM) with a cyclic prefix (CP) to provide multiple access for UL or reverse link transmissions from UEs 122 and 124 to base station 110, and multiplexing for DL ​​or forward link transmissions from base station 110 to UEs 122 and 124. In addition, for UL transmissions, the 5G NR specification provides support for discrete Fourier transform spread OFDM (DFT-s-OFDM) with CP (also known as single carrier FDMA (SC-FDMA)). However, within the scope of the present disclosure, multiplexing and multiple access are not limited to the above schemes and may be provided using time division multiple access (TDMA), code division multiple access (CDMA), frequency division multiple access (FDMA), sparse code multiple access (SCMA), resource spread multiple access (RSMA), or other appropriate multiple access schemes. Further, multiplexing of DL transmissions from base station 110 to UEs 122 and 124 may be provided using time division multiplexing (TDM), code division multiplexing (CDM), frequency division multiplexing (FDM), orthogonal frequency division multiplexing (OFDM), sparse code multiplexing (SCM), or other suitable multiplexing schemes.

[0051] Furthermore, the air interface in the RAN 100 may utilize one or more duplexing algorithms. Duplexing refers to a point-to-point communication link in which two endpoints can communicate with each other in both directions. Full-duplexing means that two endpoints can communicate with each other simultaneously. Half-duplexing means that only one endpoint can send information to the other endpoint at a time. In wireless links, full-duplex channels typically rely on physical isolation of the transmitter and receiver and appropriate interference cancellation techniques. Full-duplex emulation for wireless links is often achieved by utilizing frequency division duplexing (FDD) or time division duplexing (TDD). In FDD, transmissions in different directions operate at different carrier frequencies. In TDD, transmissions in different directions on a given channel are separated from each other using time division multiplexing. That is, at some times, the channel is dedicated to transmission in one direction, while at other times, the channel is dedicated to transmission in the other direction, where the direction can change very quickly (e.g., several times per time slot).

[0052] In the RAN 100, the ability of a UE to communicate while moving (independent of its location) is called mobility. The various physical channels between the UE and the RAN are typically established, maintained, and released under the control of an Access and Mobility Management Function (AMF), which may include a Security Context Management Function (SCMF) that manages security context for both control plane and user plane functions, and a Security Anchor Function (SEAF) that performs authentication. In various aspects of the present disclosure, the RAN 100 may utilize either DL-based mobility or UL-based mobility to implement mobility and handover (i.e., the transfer of a UE's connection from one radio channel to another). In a network configured for DL-based mobility, during a call with a scheduling entity, or at any other time, a UE may monitor various parameters of a signal from its serving cell and various parameters of neighboring cells.

[0053] Depending on the quality of these parameters, the UE may maintain communication with one or more of the neighboring cells. During this time, if the UE moves from one cell to another, or if the signal quality from the neighboring cell exceeds the signal quality from the serving cell for a given amount of time, the UE may perform a handoff or handover from the serving cell to a neighboring (target) cell. For example, UE 124 may move from the geographic area corresponding to its serving cell 102 to the geographic area corresponding to neighboring cell 106. When the signal strength or quality from neighboring cell 106 exceeds the signal strength or quality of its serving cell 102 for a given amount of time, UE 124 may send a report message to its serving base station 110 indicating this condition. In response, UE 124 may receive a handover command, and the UE may undergo a handover to cell 106.

[0054] In a network configured for UL-based mobility, the UL reference signal from each UE can be used by the network to select a serving cell for each UE. In some examples, base stations 110, 112, and 114 / 116 can broadcast a unified synchronization signal (such as a unified primary synchronization signal (PSS), a unified secondary synchronization signal (SSS), and a unified physical broadcast channel (PBCH)). UEs 122, 124, 126, 128, 130, and 132 can receive the unified synchronization signal, derive the carrier frequency and radio frame timing based on the synchronization signal, and send an uplink pilot or reference signal in response to the derived timing. The uplink pilot signal sent by a UE (such as UE 124) can be received simultaneously by two or more cells in RAN 100 (such as base stations 110 and 114 / 116). Each of these cells may measure the strength of the pilot signal, and the RAN (e.g., one or more of base stations 110 and 114 / 116 and / or a central node in the core network) may determine a serving cell for UE 124. As UE 124 moves through RAN 100, the network may continue to monitor the uplink pilot signals sent by UE 124. When the signal strength or quality of the pilot signal measured by a neighbor cell exceeds the signal strength or quality measured by the serving cell, RAN 100 may handover UE 124 from the serving cell to a neighbor cell, with or without notifying UE 124.

[0055] Although the synchronization signals transmitted by base stations 110, 112, and 114 / 116 may be uniform, the synchronization signals may not identify a specific cell, but may identify a region of multiple cells operating on the same frequency or with the same timing. Using regions in 5G networks or other next-generation communication networks implements an uplink-based mobility framework and improves the efficiency of both the UE and the network because the number of mobility messages that need to be exchanged between the UE and the network can be reduced.

[0056] In various implementations, the air interface in the RAN 100 may utilize licensed spectrum, unlicensed spectrum, or shared spectrum. Licensed spectrum typically provides exclusive use of a portion of the spectrum by virtue of a mobile network operator purchasing a license from a government regulator. Unlicensed spectrum provides shared use of a portion of the spectrum without the need for a government-mandated license. While compliance with some technical regulations is typically still required to access unlicensed spectrum, generally speaking, any operator or device can gain access. Shared spectrum may fall between licensed and unlicensed spectrum; technical regulations or restrictions may be required to access the spectrum, but the spectrum can still be shared by multiple operators or multiple radio access technologies (RATs). For example, the holder of a license for a portion of the licensed spectrum may offer Licensed Shared Access (LSA) to share that spectrum with other parties (e.g., with appropriate licensee-determined conditions to gain access).

[0057] In some examples, access to the air interface may be scheduled, with a scheduling entity (e.g., a base station) allocating resources (e.g., time-frequency resources) for communication between some or all devices and apparatuses within its service area or cell. Within the present disclosure, as discussed further below, a scheduling entity may be responsible for scheduling, assigning, reconfiguring, and releasing resources for one or more scheduled entities. That is, for scheduled communications, a UE or scheduled entity utilizes resources allocated by the scheduling entity.

[0058] The base station is not the only entity that can act as a scheduling entity. That is, in some examples, the UE can act as a scheduling entity, scheduling resources for one or more scheduled entities (such as one or more other UEs). In this example, sidelink or other types of direct link signals can be transmitted directly between UEs without relying on scheduling or control information from another entity (e.g., a base station). For example, UE 138 is shown communicating with UEs 140 and 142. In some examples, UE 138 acts as a scheduling entity, while UEs 140 and 142 can act as scheduled entities. For example, UE 138 can act as a scheduling entity in a device-to-device (D2D), peer-to-peer (P2P), vehicle-to-everything (V2X), or mesh network. In the mesh network example, UEs 140 and 142 can optionally communicate directly with each other in addition to communicating with the scheduling entity 138.

[0059] In some other examples, two or more UEs (e.g., UEs 126 and 128) within the coverage area of ​​serving base station 112 can communicate with base station 112 using cellular signals and can communicate with each other using direct link (e.g., sidelink) signals 127 without relaying the communications through the base station. In the example of a V2X network within the coverage area of ​​base station 112, base station 112 or one or both of UEs 126 and 128 can act as a scheduling entity to schedule sidelink communications between UEs 126 and 128.

[0060] Sidelink communication 127 between UEs 126 and 128 or between UEs 138, 140, and 142 may occur via a proximity service (ProSe) PC5 interface. ProSe communication may support different operational scenarios, such as in-coverage, out-of-coverage, and partial coverage. Out-of-coverage refers to a scenario in which UEs (e.g., UEs 138, 140, and 142) are outside the coverage of a base station (e.g., base station 146), but each UE is still configured for ProSe communication. Partial coverage refers to a scenario in which a UE is outside the coverage area of ​​a base station while one or more other UEs communicating with the UE are within the coverage area of ​​the base station. In-coverage refers to a scenario in which UEs (e.g., UEs 126 and 128) communicate with a base station (e.g., base station 112) via a Uu (e.g., cellular interface) connection to receive ProSe service authorization and provisioning information to support ProSe operation.

[0061] Reference will be made to Figure 2Various aspects of the present disclosure are described using the OFDM waveforms schematically illustrated in FIG. It will be appreciated by those skilled in the art that various aspects of the present disclosure can be applied to SC-FDMA waveforms in substantially the same manner as described below herein. That is, while some examples of the present disclosure may focus on OFDM links for clarity, it will be appreciated that the same principles can also be applied to SC-FDMA waveforms.

[0062] Figure 2 A diagram illustrating an example organization of wireless communication link resources in an air interface utilizing orthogonal frequency division multiplexing (OFDM). An expanded view of an example subframe 202 is shown, illustrating the OFDM resource grid. However, as one skilled in the art will readily appreciate, the PHY transmission structure for any particular application may differ from the example described herein depending on any number of factors. Here, time is in the horizontal direction, in units of OFDM symbols; and frequency is in the vertical direction, in units of subcarriers.

[0063] Resource grid 204 can be used to schematically represent the time-frequency resources used for a given antenna port. That is, in a multiple-input, multiple-output (MIMO) implementation with multiple available antenna ports, a corresponding plurality of resource grids 204 can be available for communication. Resource grid 204 is divided into a plurality of resource elements (REs) 206. An RE (which is 1 carrier x 1 symbol) is the smallest discrete portion of the time-frequency grid and contains a single complex value representing data from a physical channel or signal. Depending on the modulation utilized in a particular implementation, each RE can represent one or more bits of information. In some examples, a block of REs can be referred to as a physical resource block (PRB), or more simply, a resource block (RB) 208, which contains any suitable number of consecutive subcarriers in the frequency domain. In one example, an RB can include 12 subcarriers, regardless of the digital scheme used. In some examples, depending on the digital scheme, an RB can include any suitable number of consecutive OFDM symbols in the time domain. Within this disclosure, it is assumed that a single RB (such as RB 208) corresponds entirely to a single communication direction (transmit or receive for a given device).

[0064] Scheduling a UE device for downlink, uplink, or sidelink transmission typically involves scheduling one or more resource elements 206 within one or more subbands. Thus, a UE device typically utilizes only a subset of the resource grid 204. In some examples, a RB can be the smallest unit of resources that can be allocated to a UE device. Thus, the more RBs scheduled for a UE device and the higher the modulation scheme selected for the air interface, the higher the data rate for the UE device. RBs can be scheduled by a base station (e.g., gNB, eNB, RSU, etc.) or can be self-scheduled by a UE implementing D2D sidelink communication.

[0065] In this diagram, RB 208 is shown as occupying less than the entire bandwidth of subframe 202, with some subcarriers shown above and below RB 208. In a given implementation, subframe 202 may have a bandwidth corresponding to any number of one or more RBs 208. Further, in this diagram, while RB 208 is shown as occupying less than the entire duration of subframe 202, this is merely one possible example.

[0066] Each 1 millisecond (ms) subframe 202 may be composed of one or more adjacent time slots. Figure 2 In the example shown in , a subframe 202 includes four time slots 210 as an illustrative example. In some examples, a time slot can be defined according to a specified number of OFDM symbols with a given cyclic prefix (CP) length. For example, a time slot can include 7 or 14 OFDM symbols with a nominal CP. Another example may include mini-slots with a shorter duration (e.g., one to three OFDM symbols). In some cases, these mini-slots may be sent to occupy resources scheduled for ongoing time slot transmissions for the same or different UEs. Any number of resource blocks within a subframe or time slot may be utilized.

[0067] The expanded view of one time slot 210 shows that the time slot 210 includes a control region 212 and a data region 214. In general, the control region 212 may carry control channels, and the data region 214 may carry data channels. Of course, a time slot may contain all DL, all UL, or at least one DL portion and at least one UL portion. Figure 2 The simple structure shown in is merely exemplary in nature, and different slot structures may be utilized, and may include one or more regions in each of the control region and the data region.

[0068] Despite Figure 2Although not shown, each RE 206 within an RB 208 may be scheduled to carry one or more physical channels, including a control channel, a shared channel, a data channel, etc. Other REs 206 within an RB 208 may also carry pilot or reference signals, including but not limited to a demodulation reference signal (DMRS), a control reference signal (CRS), or a sounding reference signal (SRS). These pilot or reference signals may be used to prepare a receiving device to perform channel estimation on the corresponding channel, which may enable coherent demodulation / detection of the control or data channel within the RB 208.

[0069] In some examples, time slot 210 may be used for broadcast or unicast communication. In a V2X or D2D network, broadcast communication may refer to point-to-multipoint transmission from one device (e.g., a vehicle, a base station (e.g., RSU, gNB, eNB, etc.), a UE, or other similar device) to other devices. Unicast communication may refer to point-to-point transmission from one device to a single other device.

[0070] In the example of cellular communication on a cellular carrier via a Uu interface, for DL ​​transmission, a scheduling entity (e.g., a base station) may allocate one or more REs 206 (e.g., within a control region 212 of a time slot 210) to carry DL control information including one or more DL control channels (e.g., SSBs, PDCCHs) destined for one or more scheduled entities (e.g., UEs) (which may include one or more sidelink devices (e.g., V2X / D2D devices)). The PDCCH carries downlink control information (DCI), which includes scheduling information such as grants and RE allocations for DL ​​and UL transmissions.

[0071] In UL transmissions over the Uu interface, a scheduled entity may utilize one or more REs 206 to carry UL control information (UCI) including one or more UL control channels (e.g., a physical uplink control channel (PUCCH)) destined for the scheduling entity. The UCI may include, for example, pilots, reference signals, and information used to enable or assist in decoding uplink data transmissions. In some examples, the UCI may include a scheduling request (SR), i.e., a request for the scheduling entity to schedule an uplink transmission.

[0072] In addition to control information, one or more REs 206 may be allocated for user data traffic (e.g., within data region 214). Such traffic may be carried on one or more traffic channels, such as the physical downlink shared channel (PDSCH) for DL ​​transmissions or the physical uplink shared channel (PUSCH) for UL transmissions. In some examples, one or more REs 206 may be configured to carry system information blocks (SIBs), which carry information that enables access to a given cell.

[0073] In the example of sidelink communication on a sidelink carrier via a PC5 interface, the control region 212 of a timeslot may include control information sent by the sidelink device on the sidelink channel, and the data region 214 of the timeslot 210 may include data sent by the sidelink device on the sidelink channel. In some examples, the control information may be sent within a sidelink control information (SCI) on a physical sidelink control channel (PSCCH), and the data may be sent within a physical sidelink shared channel (PSSCH). For in-coverage or partial coverage scenarios, the DCI sent by the base station on the Uu interface may include scheduling information indicating one or more resource blocks within the control region 212 or the data region 214 that are allocated to the sidelink device for sidelink communication.

[0074] These physical channels described above are typically multiplexed and mapped to transport channels for processing at the medium access control (MAC) layer. Transport channels carry information blocks called transport blocks (TBs). The transport block size (TBS), which may correspond to the number of information bits, may be a controlled parameter based on the modulation and coding scheme (MCS) and the number of RBs in a given transmission.

[0075] exist Figure 2 The channels or carriers shown in are not necessarily all channels or carriers that can be utilized between devices, and a person of ordinary skill in the art will recognize that other channels or carriers may be utilized in addition to the channels or carriers shown, such as other traffic, control, and feedback channels.

[0076] Figure 3 An example cellular communication system 300 is shown. As discussed in more detail herein, in a multi-radio access technology (RAT) dual connectivity configuration, a user equipment (UE) has simultaneous connections (signaling and data radio bearers) to both a primary base station (also referred to as a "master node (MN)") and a secondary base station (also referred to as a "secondary master node (SN)").

[0077] Dual connectivity provides many advantages, such as increased data rate because the UE uses radio resources from both the primary base station and the secondary base station; increased reliability because the secondary base station provides another data pipe that can be used to send data between the cellular network core and the UE; improved load balancing between different base stations in the cellular communication system; improved deployment of NR base stations and infrastructure using existing LTE cellular communication systems; and reuse of LTE cellular communication infrastructure to implement NR base stations and other infrastructure.

[0078] As discussed herein, a UE may operate in a power-efficient manner with respect to a secondary base station, particularly when no data is being transmitted between the secondary base station and the UE. For example, the UE may be in a "deactivated" operational state associated with the SCG of the secondary base station, characterized by: (1) no data transmission occurs between the secondary base station and the UE; (2) the UE does not monitor a physical downlink control channel (PDCCH) signal sent by the secondary base station; and (3) the UE does not perform channel quality indicator (CQI) measurements on the channel between the secondary base station and the UE. By not performing data transmission, not monitoring PDCCH signals, and not performing CQI measurements, the UE saves a significant amount of power, allowing the UE to operate in a power-efficient manner.

[0079] In another example, the UE may be in a "dormant" operating state associated with the SCG of the secondary base station, which is characterized by the following: (1) no data transmission occurs between the secondary base station and the UE; (2) the UE does not monitor the physical downlink control channel (PDCCH) signal sent by the secondary base station; and (3) the UE performs CQI measurements based on the reference signal received from the secondary base station. Although the UE consumes more power in the dormant operating state than when in the deactivated operating state (due to CQI measurements), the UE still operates in a power-efficient manner because it does not monitor the PDCCH signal and may not maintain uplink (UL) timing with the secondary base station.

[0080] When data is to be transmitted between the secondary base station and the UE, the UE transitions from a deactivated or dormant state to an "active" operating state associated with the SCG of the secondary base station. In the active state, the UE monitors the PDCCH signal to determine whether there is data to be sent from the secondary base station to the UE, in which resource block or blocks (RBs) the data is located, and link adaptation information (e.g., the modulation and coding scheme (MCS) used to transmit the data); and also maintains UL link timing when using some type of automatic repeat request (ARQ) message. Due to the additional tasks that the UE needs to perform in the active operating state, the UE consumes more power in the active state than in the deactivated or dormant state. Therefore, if no data is being transmitted between the secondary base station and the UE, the UE can operate in the deactivated or dormant state to save power. With respect to the primary base station, the UE operates in the active state to prevent delays in the exchange of data and signaling between the UE and the cellular core network via the primary base station.

[0081] In addition to the aforementioned operational states (deactivated, dormant, and active) of the secondary base station, the UE also performs operations to ensure coverage by the SN in the deactivated or dormant state. One operation is to perform one or more radio resource management (RRM) measurements based on one or more reference signals received from the secondary base station while the UE is in the deactivated or dormant state.

[0082] RRM measurements may include one or more of the following: reference signal received power (RSRP) measurement, reference signal received quality (RSRQ) measurement, carrier received signal strength indicator (RSSI), and signal to interference and noise ratio (SINR). If the secondary base station supports a cell set (also referred to as a secondary cell group (SCG)), the UE may perform RRM measurements based on reference signals generated by the cells of the SCG, respectively. The UE may also perform RRM measurements based on reference signals generated by candidate secondary base stations. As an example, from each secondary base station or a cell in an SCG supported by the base station, the reference signal may be a channel state information reference signal (CSI-RS) or a signal synchronization block (SSB) signal. RRM measurements are used to make handover decisions regarding the secondary base station, for example, changing the secondary base station assigned to the UE or changing the primary secondary cell (PSCell) of the SCG. The PSCell is the cell for which the UE performs an attach or reattach procedure. Other cells in the SCG may be used in conjunction with the PSCell for carrier aggregation (CA) to increase the data rate between the secondary base station and the UE.

[0083] Furthermore, in accordance with RRM measurement operations when the UE is in a deactivated or dormant operating state, the UE transmits information regarding RRM measurements to the primary base station. The primary base station can use this information to determine whether a change or handover is required regarding the secondary base station assigned to the UE or the PSCell assigned to the UE. If such a change or handover is required, the primary base station generates appropriate signaling to initiate the change or handover. Therefore, when the UE's operating state transitions from a deactivated or dormant state to an active state, the appropriate secondary base station and PSCell are used to transmit data between the secondary base station and the UE.

[0084] Another operation performed by the UE to reduce latency when transitioning from a dormant state to an active state in a power-efficient manner is to store or buffer CQI measurements based on reference signals received from the secondary base station and, after entering the active state, send the CQI measurements to the secondary base station. The CQI measurement, which is an indication of the signal-to-interference-plus-noise ratio (SINR), can be based on a CSI-RS reference signal transmitted by the secondary base station or a cell of the secondary base station's SCG. When data is to be transmitted between the secondary base station and the UE, the CQI measurement is useful in link adaptation (e.g., selecting an appropriate MCS based on channel conditions as indicated by the CQI measurement). Therefore, when the UE enters the active state and sends information about the CQI measurement to the secondary base station, the secondary base station can quickly perform link adaptation to transmit data to the UE.

[0085] Another operation performed by the primary base station to reduce the delay between the UE transitioning from the dormant operating state to the active operating state is that the primary base station forwards information about CQI measurements performed by the UE on the secondary base station while the UE was in the dormant state to the secondary base station via a signaling link. Having this information at hand when the UE enters the active state allows the secondary base station to quickly perform link adaptation (e.g., select an MCS for data) and send data to the UE based on the link adaptation. Figure 3 The above-described operating states and processes for reducing delays between a UE operating in a deactivated state or dormant state and changing to an active state are discussed in greater detail with reference to the cellular or wireless communication system 300 shown in FIG.

[0086] The cellular communication system 300 includes a user equipment (UE) 310, a master base station or MN 320, and a secondary base station or SN 330. The master base station 320 can support a set of cells 325-1 through 325-M (where M can be one or more), generally referred to as a master cell group (MCG). The cells of the MCGs 325-1 through 325-M can use different radio frequency (RF) carriers (e.g., in the case of carrier aggregation (CA)) to transmit and receive data and signaling to and from the UE 310. Similarly, the secondary base station 330 can support a set of cells 335-1 through 325-N (where N can be one or more), generally referred to as a secondary cell group (SCG). The cells of the SCGs 335-1 through 335-N can use different radio frequency (RF) carriers (e.g., in the case of carrier aggregation (CA)) to transmit and receive data and signaling to and from the UE 310.

[0087] Cellular communication system 300 also includes a mobility management equipment (MME) 340 and a serving gateway (SG) 350. While MME 340 performs many functions, it is responsible for tracking the location of UEs, paging, and authenticating UEs. SG 350 is responsible for forwarding data packets between packet gateways and base stations connected to the Internet or other networks. Although not shown, cellular communication system 300 may include additional infrastructure, such as a packet gateway, a home subscriber server (HSS), a billing server, and the like.

[0088] There are various control plane and user plane links between the various network components of the cellular communication system 300. Figure 3 As shown in FIG, control plane links are shown as dashed lines between network components, and user plane links are shown as solid lines between components. Control plane links are used to send control signals or signaling. User plane links are used to send data from or to a UE via one or more network components. For example, the cellular communication system 300 includes a control plane link 342 (e.g., S1-MME) between the MME 340 and the master base station 320; a control plane link 344 (e.g., S11) between the MME 340 and the SG 350; a control plane link 322 (e.g., Xn / X2) and a user plane link 324 (X2-U) between the master base station 320 and the secondary base station 330; a user plane link 352 (e.g., S1-U) between the SG 350 and the master base station 320; and may include a user plane link 358 (e.g., S1-U) between the SG 350 and the secondary base station 330, although in some implementations, the secondary base station receives user data via the user plane link 324.

[0089] In this example, UE 310 is connected to a primary base station 320 via a signaling radio bearer (SRB) 312 and a data radio bearer (DRB) 314. SRB 312 is used to transmit control signals from the primary base station 320 to UE 310 via downlink (DL) transmissions, and to transmit control signals from UE 310 to the primary base station 320 via uplink (UL) transmissions. Similarly, UE 310 is connected to a secondary base station 330 via a signaling radio bearer (SRB) 316 and a data radio bearer (DRB) 318. SRB 316 is used to transmit control signals from the secondary base station 330 to UE 310 via downlink (DL) transmissions, and to transmit control signals from UE 310 to the secondary base station 330 via uplink (UL) transmissions.

[0090] Since the UE 310 is connected to two base stations 320 and 330, the UE is said to be in a multi-RAT dual-connectivity configuration. As previously discussed, there are several advantages to the dual-connectivity configuration, including higher data rates, increased reliability, load balancing, and the rollout of NR over existing LTE networks. As indicated by the last advantage, the cellular communication system 300 can include a mix of LTE and NR infrastructures. For example, in the case of EUTRA-NR (EN-DC) dual connectivity, the primary base station 320 can be an LTE base station (e.g., a primary eNB (MeNB)), and the secondary base station can be an NR base station (e.g., an En-gNB). In some other implementations, the primary base station 320 can be an NR base station, and the secondary base station 330 can be an LTE base station. In other implementations, the primary base station 320 and the secondary base station 330 can be of the same type, both being LTE base stations or both being NR base stations.

[0091] Figure 4 Shown for Figure 3 The present invention provides an example flow chart of a method 400 for power-efficient handover operations in a cellular communication system. The method 400 is described with reference to the previously described cellular communication device 300. Regarding the method 400, the UE 310 is in a deactivated or dormant operating state. That is, in these two states, the UE 310 does not receive data from the secondary base station 330 and does not monitor any PDCCH signals transmitted by the secondary base station 330.

[0092] In the deactivated state, UE 310 does not perform CQI measurements based on reference signals transmitted by secondary base station 330. In the dormant state, UE 310 performs CQI measurements based on reference signals transmitted by secondary base station 330 and may report CQI measurements to secondary base station 330 after entering the active state (optionally via primary base station 320), or may report CQI measurements to primary base station 320 while UE 310 is operating in the dormant state. When operating in the deactivated or dormant state, UE 310 consumes less power than it would otherwise consume when operating in the active state. In addition, as discussed, UE 310 may be in a dual connectivity configuration, in which the UE is connected to both primary base station 320 and secondary base station 330.

[0093] Method 400 includes: the secondary base station 330 transmitting one or more reference signals (block 402). In some implementations, the one or more reference signals may each be a CSI-RS, an SSB, or other reference signal. In some implementations, if the secondary base station 330 supports SCG, the set of cells 335-1 through 335-N in the SCG each transmits a reference signal.

[0094] The method 400 also includes: the UE 310 receiving one or more reference signals (block 404), and performing one or more RRM measurements based on the one or more reference signals (block 406). In some implementations, the one or more RRM measurements are based on a configuration for RRM measurements received from the secondary base station 330. In some implementations, each RRM measurement can include a measurement of one or more of: RSRP, RSRQ, RSSI, and SINR. In another implementation, if the secondary base station 330 includes a set of cells 335-1 through 335-N in an SCG, then: in block 404, the UE 310 receives a set of reference signals from each of the sets of cells 335-1 through 335-N; and in block 406, the UE 310 performs a set of RRM measurements based on each of the sets of reference signals.

[0095] The method 400 also includes the UE 310 sending information about one or more RRMs to the primary base station 320 (block 408). In some implementations, the UE 310 sends the information to the primary base station 320 via a signaling radio bearer (SRB). In another implementation, the UE 310 sends the information to the primary base station 320 via SRB1 as defined in the LTE or NR specifications. In another implementation, when there is a second SRB for signaling from the UE 310 to the secondary base station 330, the UE 310 sends the information to the primary base station 320 via the first SRB. In yet another implementation, when there is an SRB3 for signaling from the UE 310 to the secondary base station 330, the UE 310 sends the information to the primary base station 320 via SRB1, where SRB1 and SRB3 are defined in the LTE or NR specifications. In another implementation, if the secondary base station 330 includes a set of cells 335 - 1 to 335 -N in the SCG, the UE 310 transmits information on the set of RRM measurements to the primary base station 320 .

[0096] The method 400 may also include the primary base station 320 deciding whether to change (handover) the current primary secondary cell (PSCell) or secondary base station assigned to the UE based on the RRM measurement information received from the UE (block 410). If the primary base station 320 decides to perform the change according to block 410, the primary base station 320 initiates the change of the PSCell or secondary base station (block 412). In some implementations, this may require the primary base station 320 to provide signaling to the secondary base station 330 via a control link 322, to provide signaling to the MME 340 via a control link 342, and to provide signaling to the new secondary base station via another control link (not shown).

[0097] Figure 5 Shown for Figure 3 The present invention provides an example flow chart of a method 500 for power-efficient link adaptation operation of a cellular communication system. The method 500 is described with reference to the previously described cellular communication device 300. Regarding the method 500, the UE 310 is in a dormant operating state. That is, the UE 310 does not receive data from the secondary base station 330, does not monitor the PDCCH signal transmitted by the secondary base station 330, and performs CQI measurements based on the reference signal transmitted by the secondary base station 330. When operating in the dormant state, the UE 310 consumes less power than it would otherwise consume when operating in an active state. Furthermore, as discussed, the UE 310 may be in a dual-connectivity configuration, wherein the UE is connected to both the primary base station 320 and the secondary base station 330.

[0098] Method 500 includes: the secondary base station 330 transmits one or more reference signals (block 502). In some implementations, the one or more reference signals may each be a CSI-RS, an SSB, or other reference signal. In some implementations, if the secondary base station 330 supports SCG, the set of cells 335-1 through 335-N in the SCG each transmits a reference signal.

[0099] The method 500 further includes: the UE 310 receiving one or more reference signals (block 504), and performing one or more CQI measurements based on the one or more reference signals (block 506). In some implementations, the one or more CQI measurements are based on a configuration for CQI measurements received from the secondary base station 330. In some implementations, each CQI measurement can be based on an SINR measurement. In another implementation, if the secondary base station 330 includes a set of cells 335-1 through 335-N in an SCG, then: in block 504, the UE 310 receives a set of reference signals from the set of cells 335-1 through 335-N, respectively; and in block 506, the UE 310 performs a set of CQI measurements based on the set of reference signals, respectively.

[0100] The method 500 also includes the UE 310 storing or buffering information about one or more CQIs in an internal memory (block 508). In one implementation, the UE 310 may store the information based on a parameter. For example, in one implementation, the parameter may specify the number of most recent CQI measurements to be stored or included for subsequent transmissions to the secondary base station 330. In another implementation, the parameter may specify the most recent CQI measurements taken within a defined time interval to be stored or included for subsequent transmissions to the secondary base station 330.

[0101] Method 500 also includes the UE 310 sending information regarding one or more CQI measurements to the secondary base station 330 (block 510). In some implementations, if the UE 310 determines that it is not aligned with the secondary base station 330 for uplink (UL) timing when transitioning from the dormant state to the active state, the UE 310 performs a random access channel (RACH) procedure with the secondary base station 330 to reacquire UL timing. In another implementation, the UE 310 sends the stored information to the secondary base station 330 after transitioning to the active state and completing the RACH procedure. In yet another implementation, the UE sends the information regarding the CQI measurements to the primary base station 320 for subsequent forwarding to the secondary base station 330. As discussed, in another implementation, only the most recent CQI measurement based on the parameters described above is sent to the secondary base station 330. In another implementation, the UE 310 sends the set of CQI measurements to the secondary base station 330 , where the set of CQI measurements is based on reference signals transmitted by the set of cells 335 - 1 to 335 -N of the SCG.

[0102] In some implementations, UE 310 transmits information to secondary base station 330 in response to UE 310 receiving a signal from primary base station 320 to operate in the active state. In another implementation, when UE 310 operates in the active state, UE 310 monitors the PDCCH channel for data transmitted by secondary base station 330. In yet another implementation, UE 310 receives data from secondary base station 330 via the PDSCH in the active state.

[0103] The method 500 may also include the secondary base station 330 performing link adaptation based on the one or more CQI measurements to transmit data to the UE 310 (block 512). In some implementations, the secondary base station 330 performs link adaptation by selecting a modulation and coding scheme (MCS) based on the one or more CQI measurements. The method 500 may also include the secondary base station 330 transmitting data to the UE 310 based on the link adaptation (block 514).

[0104] Figure 6 Shown for Figure 3 The method 600 is described with reference to the previously described cellular communication device 300. In this example, the primary base station 320 and the secondary base station 330 may be in a dual connectivity configuration with the UE 310.

[0105] Method 600 includes: UE 310 performing one or more CQI measurements based on one or more reference signals received from secondary base station 330 (block 602). In some implementations, the UE operates in a dormant state while performing the operations specified in block 602. In some implementations, each CQI measurement can be based on an SINR measurement. In another implementation, if secondary base station 330 includes a set of cells 335-1 through 335-N in an SCG, UE 310 performs a set of CQI measurements based on a set of reference signals received from the set of cells 335-1 through 335-N, respectively.

[0106] The method 600 also includes: the UE 310 sending information about one or more CQI measurements to the primary base station 320 (box 604). In some implementations, the UE 310 is in a dormant state associated with the SCG of the secondary base station 330. In another implementation, the UE 310 sends the information via a signaling radio bearer (SRB). In another implementation, the UE 310 sends the information via SRB1 as defined by the LTE or NR specifications. In yet another implementation, the UE 310 sends the information via a PUCCH channel. In yet another implementation, the UE 310 sends the information via a PUSCH channel. In another implementation, if the UE 310 receives a set of reference signals from the set of cells 335-1 to 335-N of the SCG, the UE 310 sends the information about the set of CQI measurements to the primary base station 320.

[0107] The method 600 further includes the primary base station 320 receiving information regarding one or more CQI measurements from the UE 310 (block 606). Again, in different implementations, the primary base station 320 may receive the information regarding the one or more CQI measurements via an SRB, SRB1, PUCCH, or PUSCH. In yet another implementation, the primary base station 320 may receive a set of CQI measurements associated with a set of cells 335-1 to 335-N of an SCG of the secondary base station 330.

[0108] The method 600 further includes the primary base station 320 sending information regarding one or more CQI measurements to the secondary base station 330 (block 608). In some implementations, the primary base station 320 sends the information to the secondary base station 330 via a control link or a backhaul communication link, e.g., a signaling link 322 (e.g., an Xn / X2 type link). In another implementation, the primary base station 320 sends the set of CQI measurements associated with the set of cells 335-1 through 335-N in the SCG to the secondary base station 330.

[0109] The method 600 may also include the secondary base station 330 performing link adaptation based on the one or more CQI measurements to transmit data to the UE 310 (block 610). In some implementations, the secondary base station 330 performs link adaptation by selecting a modulation and coding scheme (MCS) based on the one or more CQI measurements. The method 600 may also include the secondary base station 330 transmitting data to the UE 310 based on the link adaptation (block 612).

[0110] Figure 7 A block diagram illustrates an example hardware implementation of a base station 700. The base station 700 is depicted as employing a processing system 714. The base station 700 may correspond to any of the base stations previously discussed herein, such as the primary base station 320 and the secondary base station 330, for example.

[0111] The base station 700 can be implemented using a processing system 714 including one or more processors 704. Examples of the processor 704 include a microprocessor, a microcontroller, a digital signal processor (DSP), a field programmable gate array (FPGA), a programmable logic device (PLD), a state machine, gating logic, discrete hardware circuits, and other suitable hardware configured to perform the various functions described throughout this disclosure. In various examples, the base station device 700 can be configured to perform any one or more of the functions described herein. That is, the processor 704 as utilized in the base station 700 can be used to implement any one or more of the processes and procedures described below.

[0112] In this example, processing system 714 can be implemented using a bus architecture (generally represented by bus 702). Bus 702 can include any number of interconnecting buses and bridges depending on the specific application and overall design constraints of processing system 714. Bus 702 links together various circuits including one or more processors (generally represented by processor 704), memory 705, and computer-readable media (generally represented by computer-readable media 706). Bus 702 can also link various other circuits, such as timing sources, peripherals, voltage regulators, and power management circuits.

[0113] The bus interface 708 provides an interface between the bus 702 and the wireless transceiver 710 and the backhaul link interface 711. The wireless transceiver 710 allows the base station 700 to communicate with various other devices via a transmission medium (e.g., an air interface). The backhaul link interface 711 allows the base station 700 to communicate with various other devices via a backhaul communication link (e.g., a wired interface). Depending on the nature of the device, a user interface 712 (e.g., a keypad, display, touch screen, speaker, microphone, control knob, etc.) may also be provided. Of course, such a user interface 712 is optional and may be omitted in some examples.

[0114] The processor 704 is responsible for managing the bus 702 and general processing, including the execution of software stored on a computer-readable medium 706. Whether referred to as software, firmware, middleware, microcode, hardware description language, or other terms, software should be broadly interpreted to mean instructions, instruction sets, code, code segments, program code, programs, subroutines, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, threads of execution, procedures, functions, and the like. When executed by the processor 704, the software causes the processing system 714 to perform the various functions described below for any particular device. The computer-readable medium 706 and memory 705 may also be used to store data that is manipulated by the processor 704 when executing the software.

[0115] Computer-readable medium 706 may be a non-transitory computer-readable medium. For example, non-transitory computer-readable media include magnetic storage devices (e.g., hard disks, floppy disks, magnetic strips), optical disks (e.g., compact discs (CDs) or digital versatile discs (DVDs)), smart cards, flash memory devices (e.g., cards, sticks, or key drives), random access memory (RAM), read-only memory (ROM), programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), registers, removable disks, and any other suitable medium for storing software or instructions that can be accessed and read by a computer. Computer-readable medium 706 may reside in processing system 714, external to processing system 714, or distributed across multiple entities including processing system 714. Computer-readable medium 706 may be embodied in a computer program product. For example, a computer program product may include a computer-readable medium in packaging materials. In some examples, computer-readable medium 706 may be part of memory 705. Those skilled in the art will recognize how best to implement the described functionality presented throughout this disclosure depending on the particular application and the overall design constraints imposed on the overall system.

[0116] In some aspects of the present disclosure, the processor 704 may include circuits configured for various functions. For example, the processor 704 may include a resource assignment and scheduling circuit 742 configured to assign resources and schedule for signaling radio bearers (SRBs) and data radio bearers (DRBs) with the UE. The resource assignment and scheduling circuit 742 may also be configured to execute resource assignment and scheduling software 752 stored in the computer-readable medium 706 to implement one or more of the functions described herein.

[0117] The processor 704 also includes a DL traffic and control generation and transmission circuit 744 for transmitting DL signaling and data to the UE. For example, with respect to the wireless communication system 300, the DL traffic and control generation and transmission circuit 744 of the base station 320 or 330 will control the transmission of DL signaling and data to the UE 310 via one or more SRBs 312 or 316 and one or more DRBs 314 or 318. The DL traffic and control channel and transmission circuit 744 may also be configured to execute the DL traffic and control channel reception and processing software 754 stored in the computer-readable medium 706 to implement one or more of the functions described herein.

[0118] The processor 704 may also include an uplink (UL) traffic and control channel reception and processing circuit 746 configured to receive and process uplink control channels and uplink traffic channels from one or more UEs. For example, the UL traffic and control channel reception and processing circuit 746 may be configured to receive uplink control information (UCI) or uplink user data traffic from one or more UEs via one or more SRBs 312 or 316 and one or more DRBs 314 or 318. The UL traffic and control channel reception and processing circuit 746 may also be configured to execute UL traffic and control channel reception and processing software 756 stored in the computer-readable medium 706 to implement one or more of the functions described herein.

[0119] The processor 704 may further include a backhaul signaling management circuit 748 configured to perform backhaul signaling management for the base station 748. For example, the backhaul signaling management circuit 748 may be configured to send information about one or more CQI measurements for the primary base station 320 to the secondary base station 330 via the backhaul communication link 322. The backhaul signaling management circuit 748 may also be configured to execute backhaul signaling management software 758 stored in a computer-readable memory to implement one or more of the functions described herein.

[0120] Figure 8 An example flow chart illustrates a method 800 for reporting, by a primary base station, information about channel quality indicator (CQI) measurements performed by a user equipment (UE) based on a reference signal received from the secondary base station to a secondary base station for link adaptation purposes. The method 800 includes the processor 704 receiving, via the wireless transceiver 710, information associated with one or more channel quality indicator (CQI) measurements related to a second base station from the user equipment (UE) (block 802). The method 800 also includes the processor 704 sending the information to the second base station via the backhaul link interface 711 (block 804).

[0121] Figure 9A block diagram illustrates an example hardware implementation of a user equipment (UE) 900. The UE 900 is depicted as employing a processing system 914. The UE 900 may correspond to any of the UEs previously discussed herein, such as the UE 310, for example.

[0122] The UE 900 may be implemented using a processing system 914 including one or more processors 904. Examples of the processor 904 include a microprocessor, a microcontroller, a digital signal processor (DSP), a field programmable gate array (FPGA), a programmable logic device (PLD), a state machine, gated logic, a discrete hardware circuit, and other suitable hardware configured to perform the various functions described throughout this disclosure. In various examples, the UE 900 may be configured to perform any one or more of the functions described herein. That is, the processor 904 as utilized in the UE 900 may be used to implement any one or more of the processes and procedures described below.

[0123] In this example, processing system 914 can be implemented using a bus architecture (generally represented by bus 902). Depending on the specific application and overall design constraints of processing system 914, bus 902 can include any number of interconnecting buses and bridges. Bus 902 links together various circuits including one or more processors (generally represented by processor 904), memory 905, and computer-readable media (generally represented by computer-readable media 906). Bus 902 can also link various other circuits, such as timing sources, peripheral devices, voltage regulators, and power management circuits, which are well known in the art and therefore will not be described in any further detail.

[0124] The bus interface 908 provides an interface between the bus 902 and the wireless transceiver 910. The wireless transceiver 910 allows the UE 900 to communicate with various other devices via a transmission medium (e.g., an air interface). Depending on the nature of the device, a user interface 912 (e.g., a keypad, display, touch screen, speaker, microphone, control knob, etc.) may also be provided. Of course, such a user interface 912 is optional and may be omitted in some examples.

[0125] The processor 904 is responsible for managing the bus 902 and general processing, including the execution of software stored on the computer-readable medium 906. Whether referred to as software, firmware, middleware, microcode, hardware description language, or other terms, software should be broadly interpreted to mean instructions, instruction sets, code, code segments, program code, programs, subroutines, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, threads of execution, procedures, functions, etc. The software, when executed by the processor 904, causes the processing system 914 to perform the various functions described below for any particular device. The computer-readable medium 906 and memory 905 can also be used to store data manipulated by the processor 904 when executing the software.

[0126] Computer-readable medium 906 may be a non-transitory computer-readable medium. For example, non-transitory computer-readable media include magnetic storage devices (e.g., hard disks, floppy disks, magnetic strips), optical disks (e.g., compact discs (CDs) or digital versatile discs (DVDs)), smart cards, flash memory devices (e.g., cards, sticks, or key drives), random access memory (RAM), read-only memory (ROM), programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), registers, removable disks, and any other suitable medium for storing software or instructions that can be accessed and read by a computer. Computer-readable medium 906 may reside in processing system 914, external to processing system 914, or distributed across multiple entities including processing system 914. Computer-readable medium 906 may be embodied in a computer program product. For example, a computer program product may include a computer-readable medium in packaging materials. In some examples, computer-readable medium 906 may be part of memory 905. Those skilled in the art will recognize how best to implement the described functionality presented throughout this disclosure depending on the particular application and the overall design constraints imposed on the overall system.

[0127] In some aspects of the present disclosure, the processor 904 may include circuits configured for various functions. For example, the processor 904 may include a resource assignment and scheduling circuit 942 configured to assign resources and schedule for signaling radio bearers (SRBs) and data radio bearers (DRBs) with a base station. The resource assignment and scheduling circuit 942 may also be configured to execute resource assignment and scheduling software 952 stored in the computer-readable medium 906 to implement one or more of the functions described herein.

[0128] The processor 904 also includes a DL traffic and control generation and transmission circuit 944 for receiving DL signaling and data from a base station. For example, with respect to the wireless communication system 300, the DL traffic and control generation and transmission circuit 944 of the UE 310 controls the reception of DL signaling and data from the primary base station 320 via one or more SRBs 312 or 316, and controls the reception of DL signaling and data from the secondary base station 330 via one or more DRBs 314 or 318. The DL traffic and control channel and transmission circuit 944 can also be configured to execute DL traffic and control channel reception and processing software 954 stored in the computer-readable medium 906 to implement one or more of the functions described herein.

[0129] The processor 904 may also include an uplink (UL) traffic and control channel reception and processing circuit 946, which is configured to process uplink control channel signaling and uplink traffic data and send it to one or more base stations. For example, the UL traffic and control channel reception and processing circuit 946 may be configured to send uplink control information (UCI) or uplink user data traffic to the primary base station 320 via one or more SRBs 312 or 316, and to send uplink control information (UCI) or uplink user data traffic to the secondary base station 330 via one or more DRBs 314 or 318. The UL traffic and control channel reception and processing circuit 946 may also be configured to execute UL traffic and control channel reception and processing software 956 stored in the computer-readable medium 906 to implement one or more of the functions described herein.

[0130] Figure 10 An example flow chart illustrates a method 1000 for reporting, by a user equipment (UE), radio resource management (RRM) measurements performed by the UE based on reference signals received from a secondary base station to a primary base station. The method 1000 includes the processor 904 receiving one or more reference signals from a first base station via a wireless transceiver 910 (block 1002). The method 1000 also includes the processor 904 performing one or more radio resource management (RRM) measurements based on the one or more reference signals (block 1004). The method 1000 also includes the processor 904 sending information regarding the one or more RRM measurements to a second base station via the wireless transceiver 910 (block 1006).

[0131] Figure 11An example flow chart illustrates a method 1100 for reporting, by a user equipment (UE), radio resource management (RRM) measurements performed by the UE based on reference signals received from a secondary base station to a primary base station. The method 1100 includes the processor 904 receiving one or more reference signals from a first base station via the wireless transceiver 910 (block 1102). The method 1100 also includes the processor 904 performing one or more channel quality indicator (CQI) measurements based on the one or more reference signals (block 1104). The method 1100 also includes the processor 904 storing information regarding the one or more CQI measurements in the memory 905 (block 1106). The method 1100 also includes the processor 904 transmitting the stored information regarding the one or more CQI measurements to the first base station or the second base station via the wireless transceiver 910 (block 1108).

[0132] Several aspects of wireless communication networks have been presented with reference to example implementations. As those skilled in the art will readily appreciate, various aspects described throughout this disclosure may be extended to other telecommunication systems, network architectures, and communication standards.

[0133] For example, various aspects may be implemented in other systems defined by 3GPP, such as Long Term Evolution (LTE), Evolved Packet System (EPS), Universal Mobile Telecommunications System (UMTS), or Global System for Mobile Communications (GSM). Various aspects may also be extended to systems defined by the 3rd Generation Partnership Project 2 (3GPP2), such as CDMA2000 or Evolution-Data Optimized (EV-DO). Other examples may be implemented in systems employing IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Ultra-Wideband (UWB), Bluetooth, or other suitable systems. The actual telecommunication standard, network architecture, or communication standard used will depend on the specific application and the overall design constraints imposed on the system.

[0134] As used herein, a phrase referring to "at least one of" a list of items refers to any combination of those items, including single members. As an example, "at least one of a, b, or c" is intended to encompass: a, b, c, ab, ac, bc, and abc.

[0135] The various illustrative logics, logic blocks, modules, circuits, and algorithmic processes described in conjunction with the implementations disclosed herein can be implemented as electronic hardware, computer software, or a combination of both. The interchangeability of hardware and software has been generally described with respect to functionality and illustrated in the various illustrative components, blocks, modules, circuits, and processes described above. Whether such functionality is implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system.

[0136] The hardware and data processing apparatus for implementing the various illustrative logics, logic blocks, modules, and circuits described in conjunction with the various aspects disclosed herein may be implemented or performed using a general-purpose single-chip or multi-chip processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic devices, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor or any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, a plurality of microprocessors, a combination of one or more microprocessors and a DSP core, or any other such configuration. In some implementations, a particular process or method may be performed by circuits specific to a given function.

[0137] In one or more aspects, the functions described may be implemented in hardware, digital electronic circuitry, computer software, firmware (including the structures disclosed in this specification and their structural equivalents), or any combination thereof. Implementations of the subject matter described in this specification may also be implemented as one or more computer programs, i.e., one or more modules of computer program instructions, encoded on computer storage media for execution by, or to control the operation of, data processing apparatus.

[0138] If implemented in software, the functions may be stored as one or more instructions or codes in a computer-readable medium or transmitted via a computer-readable medium. The processes of the methods or algorithms disclosed herein may be implemented in a processor-executable software module that may reside on a computer-readable medium. Computer-readable media include both computer storage media and communication media, and communication media include any medium that can enable the transfer of a computer program from one place to another. The storage medium may be any available medium that can be accessed by a computer. By way of example and not limitation, such computer-readable media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired program code in the form of instructions or data structures and that can be accessed by a computer. In addition, any connection may be appropriately referred to as a computer-readable medium. As used herein, "disk" and "optical disk" include compact discs (CDs), laser discs, optical discs, digital versatile discs (DVDs), floppy disks, and Blu-ray discs, where disks typically reproduce data magnetically, while optical discs typically reproduce data optically using lasers. Combinations of the above should also be included within the scope of computer-readable media. Additionally, the operations of a method or algorithm may reside as any one or any combination or set of codes and instructions on a machine-readable medium or computer-readable medium, which may be incorporated into a computer program product.

[0139] Various modifications to the implementations described in this disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other implementations without departing from the spirit or scope of this disclosure. Accordingly, the present claims are not intended to be limited to the implementations shown herein, but are to be accorded the widest scope consistent with this disclosure, the principles, and the novel features disclosed herein.

[0140] In addition, those skilled in the art will readily recognize that the terms "upper" and "lower" are sometimes used for convenience in describing the drawings and indicate relative positions corresponding to the orientation of the drawings on a correctly oriented page and may not reflect the correct orientation of any device as implemented.

[0141] Certain features described in this specification in the context of separate implementations may also be implemented in combination in a single implementation. Conversely, various features described in the context of a single implementation may also be implemented in multiple implementations individually or in any suitable subcombination. Furthermore, while features may be described above as functioning in certain combinations and even initially claimed as such, in some cases one or more features from a claimed combination may be removed from that combination, and a claimed combination may involve subcombinations or variations of subcombinations.

[0142] Similarly, although operations are depicted in a particular order in the accompanying drawings, this should not be understood as requiring that such operations be performed in the particular order shown or in a sequential order, or that all illustrated operations be performed, in order to achieve the desired result. Further, the accompanying drawings may graphically depict one or more example processes in the form of flow charts. However, other operations not depicted may be incorporated into the illustrated example processes. For example, one or more additional operations may be performed before, after, simultaneously with, or between any of the illustrated operations. In some cases, multitasking and parallel processing may be advantageous. In addition, the separation of the various system components in the implementations described above should not be understood as requiring such separation in all implementations, and it should be understood that the described program components and systems can generally be integrated together in a single software product, or packaged as multiple software products. In addition, other implementations are within the scope of the appended claims. In some cases, the actions recited in the claims can be performed in different orders and still achieve the desired result.

Claims

1. A method for wireless communication at a user equipment (UE) device, comprising: receiving one or more reference signals from a secondary cell group (SCG) of a secondary base station; performing one or more radio resource management (RRM) measurements based on the one or more reference signals; as well as sending information about the one or more RRM measurements to a primary base station, The UE is in a deactivated operation state associated with the SCG of the secondary base station during the period of receiving the one or more reference signals, performing the one or more RRM measurements, and sending the information.

2. The method according to claim 1, wherein Performing the one or more RRM measurements is based on a configuration for the one or more RRM measurements received from the secondary base station.

3. The method according to claim 1, wherein When the UE is in the dormant operating state or the deactivated operating state, no data transmission occurs between the UE and the secondary base station.

4. The method according to claim 1, wherein When the UE is in the dormant operating state or the deactivated operating state, the UE does not monitor a physical downlink control channel (PDCCH) signal sent by the secondary base station.

5. The method according to claim 1, wherein When the UE is in the deactivated operation state, the UE does not perform a channel quality indicator (CQI) measurement associated with the secondary base station.

6. The method according to claim 1, further comprising: When the UE is in a dormant operation state, one or more channel quality indicator (CQI) measurements associated with the secondary base station are performed, and information of the one or more CQI measurements is sent to the secondary base station or the primary base station.

7. The method according to claim 1, wherein Sending the information about the one or more RRM measurements to the primary base station occurs via a signaling radio bearer (SRB).

8. The method according to claim 1, wherein Sending the information about the one or more RRM measurements to the primary base station occurs via Signaling Radio Bearer 1 (SRB1 ) as defined in Long Term Evolution (LTE) or New Radio (NR) specifications.

9. The method according to claim 1, wherein When there is a second signaling radio bearer (SRB) for sending signaling from the UE to the secondary base station, sending the information about the one or more RRM measurements to the primary base station occurs via a first SRB.

10. The method according to claim 1, wherein When there is a signaling radio bearer 3 (SRB3) for sending signaling from the UE to the secondary base station, sending the information about the one or more RRM measurements to the primary base station occurs via SRB1, wherein the SRB1 and the SRB3 are defined in the LTE or NR specifications.

11. The method according to claim 1, wherein The primary base station and the secondary base station are in a multi-radio access technology (RAT) dual connectivity configuration.

12. The method according to claim 1, wherein The secondary base station includes a cell set, wherein receiving the one or more reference signals from the secondary base station includes: receiving reference signal sets from the cell set respectively, wherein performing the one or more RRM measurements includes: performing the RRM measurement set based on the reference signal set based on a configuration for the RRM measurement set received from the secondary base station, and wherein sending the information about the one or more RRM measurements to the primary base station includes: sending information about the RRM measurement set to the primary base station.

13. A user equipment, comprising: wireless transceiver; as well as A processor configured to: receiving, via the wireless transceiver, one or more reference signals from a secondary cell group (SCG) of a secondary base station; performing one or more radio resource management (RRM) measurements based on the one or more reference signals; as well as sending, via the wireless transceiver, information regarding the one or more RRM measurements to a primary base station; The processor is configured to be in a deactivated operation state associated with the SCG of the secondary base station during receiving the one or more reference signals, performing the one or more RRM measurements, and sending the information.

14. The user equipment according to claim 13, wherein: The processor is configured to perform the one or more RRM measurements based on a configuration for the one or more RRM measurements received from the secondary base station.

15. The user equipment according to claim 13, wherein: The processor is configured to: when the processor is in the sleep operation state or the deactivated operation state, not receive data from the secondary base station.

16. The user equipment according to claim 13, wherein: The processor is configured to: when the processor is in a sleep operation state or the deactivated operation state, not monitor a physical downlink control channel (PDCCH) signal sent by the secondary base station.

17. The user equipment according to claim 13, wherein: The processor is configured to: when the processor is in the deactivated operation state, not perform a channel quality indicator (CQI) measurement on the secondary base station.

18. The user equipment according to claim 13, wherein: The processor is configured to: when the processor is in a sleep operating state, perform one or more channel quality indicator (CQI) measurements associated with the secondary base station and send information about the one or more CQI measurements to the secondary base station or the primary base station via the wireless transceiver.

19. The user equipment according to claim 13, wherein: The processor is configured to send the information about the one or more RRM measurements to the primary base station via a signaling radio bearer (SRB).

20. The user equipment according to claim 13, wherein: The processor is configured to send the information about the one or more RRM measurements to the primary base station via a Signaling Radio Bearer 1 (SRB1) as defined in Long Term Evolution (LTE) or New Radio (NR) specifications.

21. The user equipment according to claim 13, wherein: The processor is configured to, when there is a second signaling radio bearer (SRB) for the processor to send signaling to the secondary base station, send the information about the one or more RRM measurements to the primary base station via a first SRB.

22. The user equipment according to claim 13, wherein: The processor is configured to: when there is a signaling radio bearer 3 (SRB3) for the processor to send signaling to the secondary base station, send the information about the one or more RRM measurements to the primary base station via SRB1, wherein the SRB1 and the SRB3 are defined in the LTE or NR specification.

23. An apparatus for wireless communication, comprising: means for receiving one or more reference signals from a secondary cell group (SCG) of a secondary base station; means for performing one or more radio resource management (RRM) measurements based on the one or more reference signals; as well as means for sending information about the one or more RRM measurements to a primary base station, The apparatus is in a deactivated operation state associated with the SCG of the secondary base station during the period of receiving the one or more reference signals, performing the one or more RRM measurements, and sending the information.

24. A non-transitory computer-readable medium storing computer-executable code, comprising code for causing a processor in a user equipment (UE) to: receiving one or more reference signals from a secondary cell group (SCG) of a secondary base station; performing one or more radio resource management (RRM) measurements based on the one or more reference signals; and sending information about the one or more RRM measurements to a primary base station, in, The UE is in a deactivated operation state associated with the SCG of the secondary base station during receiving the one or more reference signals, performing the one or more RRM measurements, and sending the information.

25. A wireless communication system comprising: Secondary base station; Main base station; as well as A user equipment (UE) configured to: receiving one or more reference signals from a secondary cell group (SCG) of the secondary base station; performing one or more radio resource management (RRM) measurements based on the one or more reference signals; as well as sending information about the one or more RRM measurements to the primary base station, The UE is in a deactivated operation state associated with the SCG of the secondary base station during the period of receiving the one or more reference signals, performing the one or more RRM measurements, and sending the information.

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