WO2021232397A1

WO2021232397A1 - Secondary cell group assignment

Info

Publication number: WO2021232397A1
Application number: PCT/CN2020/091723
Authority: WO
Inventors: Chaofeng HUI; Yuankun ZHU; Fojian ZHANG; Hao Zhang; Jian Li
Original assignee: Qualcomm Incorporated
Priority date: 2020-05-22
Filing date: 2020-05-22
Publication date: 2021-11-25

Abstract

Methods, systems, and devices for wireless communications are described. The methods may include a base station receiving, from one or more UEs associated with a first secondary cell of the base station, one or more failure messages indicating a failure associated with communications with the first secondary cell, determining that a number of the received one or more failure messages for the first secondary cell exceeds a failure message threshold, and transmitting, to the UE based on the determined number of failure messages exceeding the failure message threshold, a reconfiguration message that indicates for the UE to measure a signal quality and a receive power for the first secondary cell and for a second secondary cell associated with the base station.

Description

SECONDARY CELL GROUP ASSIGNMENT

FIELD OF TECHNOLOGY

The following relates generally to wireless communications and more specifically to secondary cell group assignment.

BACKGROUND

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

A UE may have multiple subscriptions to provide different network connections to different radio access technologies. Some techniques for establishing these network connections may be improved.

SUMMARY

The described techniques relate to improved methods, systems, devices, and apparatuses that support secondary cell group (SCG) assignment. Generally, the described techniques provide for an anchor cell configuring a user equipment (UE) with an SCG. In some examples, the anchor cell may select an SCG with which to configure the UE and indicate the selected SCG to the UE. The anchor cell may select the SCG based on a first metric associated with the SCG reported by the UE (e.g., a reference signal receive power (RSRP) ) . In some cases, the UE may repeatedly fail to add the selected SCG due to one or more poor second metrics such as a poor reference signal received quality (RSRQ) or a poor a signal to noise ratio (SNR) . Here, the UE may indicate the SCG failure to the anchor cell. Thus, in some examples, a base station (e.g., anchor cell) may receive, from one or more UEs associated with a first secondary cell of the base station, one or more failure messages indicating a failure associated with communications with the first secondary cell (e.g., failures associated with communications between the one or more UEs and the first secondary cell) . The base station may determine that a number of the received one or more failure messages for the first secondary cell exceeds a failure message threshold. The base station may transmit, to a UE of the one or more UEs based at least in part on the determined number of failure messages exceeding the failure message threshold, a reconfiguration message that indicates for the UE to measure a signal quality in addition to the receive power for the first secondary cell and for a second secondary cell associated with the base station. In some examples, the base station may receive a measurement report from the UE that indicates the signal quality and the receive power. In some examples, the base station may select the secondary cell with the highest signal quality measurement and may indicate the selected secondary cell to the UE.

A method of wireless communications at a base station is described. The method may include receiving, from one or more UEs associated with a first secondary cell of the base station, one or more failure messages indicating a failure associated with communications with the first secondary cell, determining that a number of the received one or more failure messages for the first secondary cell exceeds a failure message threshold, and transmitting, to a UE of the one or more UEs based on the determined number of failure messages exceeding the failure message threshold, a reconfiguration message that indicates for the UE to measure a signal quality and a receive power for the first secondary cell and for a second secondary cell associated with the base station.

An apparatus for wireless communications at a base station is described. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to receive, from one or more UEs associated with a first secondary cell of the base station, one or more failure messages indicating a failure associated with communications with the first secondary cell, determine that a number of the received one or more failure messages for the first secondary cell exceeds a failure message threshold, and transmit, to a UE of the one or more UEs based on the determined number of failure messages exceeding the failure message threshold, a reconfiguration message that indicates for the UE to measure a signal quality and a receive power for the first secondary cell and for a second secondary cell associated with the base station.

Another apparatus for wireless communications at a base station is described. The apparatus may include means for receiving, from one or more UEs associated with a first secondary cell of the base station, one or more failure messages indicating a failure associated with communications with the first secondary cell, determining that a number of the received one or more failure messages for the first secondary cell exceeds a failure message threshold, and transmitting, to a UE of the one or more UEs based on the determined number of failure messages exceeding the failure message threshold, a reconfiguration message that indicates for the UE to measure a signal quality and a receive power for the first secondary cell and for a second secondary cell associated with the base station.

A non-transitory computer-readable medium storing code for wireless communications at a base station is described. The code may include instructions executable by a processor to receive, from one or more UEs associated with a first secondary cell of the base station, one or more failure messages indicating a failure associated with communications with the first secondary cell, determine that a number of the received one or more failure messages for the first secondary cell exceeds a failure message threshold, and transmit, to a UE of the one or more UEs based on the determined number of failure messages exceeding the failure message threshold, a reconfiguration message that indicates for the UE to measure a signal quality and a receive power for the first secondary cell and for a second secondary cell associated with the base station.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving a measurement report based on transmitting the reconfiguration message to the UE, where the measurement report includes the signal quality and the receive power for the first secondary cell and the second secondary cell.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining a signal quality of the second secondary cell exceeds a signal quality of the first secondary cell, and transmitting, based on determining that the signal quality of the second secondary cell exceeds the signal quality of the first secondary cell, a second reconfiguration message to the UE that indicates to use the second secondary cell.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the reconfiguration message or the second reconfiguration message, or both, include a radio resource control reconfiguration message.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving a reconfiguration complete message from the UE responsive at least in part to the transmitted second reconfiguration message.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for initiating a cell selection timer based on the determined number of failure messages exceeding the failure message threshold.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the reconfiguration message may be transmitted after initiating the cell selection timer.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the reconfiguration message may include operations, features, means, or instructions for transmitting, after the cell selection timer may be initiated and before the cell section timer expires, the reconfiguration message including a first bit field and a second bit field, the first bit field indicating that the UE may be to measure the signal quality of each secondary cell of the secondary cell group, and the second bit field indicating that the UE may be to measure the receive power of each secondary cell of the secondary cell group.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting, after the cell selection timer expires, a third reconfiguration message including a first bit field and a second bit field, the first bit field indicating that the UE may be to not measure the signal quality of each secondary cell of the secondary cell group, and the second bit field indicating that the UE may be to measure the receive power of each secondary cell of the secondary cell group.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving, from the UE based on transmitting the reconfiguration message to the UE, a set of measurement reports for a set of secondary cells associated with the base station, the set of measurement reports indicating the signal strength associated with each secondary cell of the set of secondary cells, where the set of secondary cells include at least the first secondary cell and the second secondary cell, sorting, based on the received set of measurement reports, the set of secondary cells according to signal quality, selecting the second secondary cell of the set of secondary cells based on the second secondary cell associated with a highest signal quality among the sorted set of secondary cell, transmitting, to the UE, a message indicating that the UE may be to perform a random access procedure to establish a wireless connection with the second secondary cell, and communicating with the UE using a primary cell of the base station and the second secondary cell associated with the base station following the random access procedure.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the receive power includes a reference signal received power.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the signal quality includes a signal to noise ratio, or a signal-to-noise and interference ratio, or a reference signal received quality, or received signal strength indicator, or any combination thereof.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, a primary cell of the base station may be configured to operate according to a release of a first wireless communications standard, and the first secondary cell and the second secondary cell associated with the base station may be configured to operate according to a release of a second wireless communications standard.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the first wireless communications standard includes LTE, and the second wireless communications standard includes New Radio (NR) .

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the failure associated with the communications with the first secondary cell includes a failure to decode signals broadcast by the first secondary cell.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the failure associated with the communications with the first secondary cell includes a failure associated with performing a random access procedure with the first secondary cell.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the signals broadcast by the first secondary cell associated with the base station include a master information block broadcast from the first secondary cell using a physical broadcast channel.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example of a system for wireless communications that supports secondary cell group assignment in accordance with aspects of the present disclosure.

FIG. 2 illustrates an example of a wireless communications system that supports secondary cell group assignment in accordance with aspects of the present disclosure.

FIG. 3 illustrates an example of a process flow that supports secondary cell group assignment in accordance with aspects of the present disclosure.

FIGs. 4 and 5 show block diagrams of devices that support secondary cell group assignment in accordance with aspects of the present disclosure.

FIG. 6 shows a block diagram of a communications manager that supports secondary cell group assignment in accordance with aspects of the present disclosure.

FIG. 7 shows a diagram of a system including a device that supports secondary cell group assignment in accordance with aspects of the present disclosure.

FIGs. 8 and 9 show flowcharts illustrating methods that support secondary cell group assignment in accordance with aspects of the present disclosure.

DETAILED DESCRIPTION

In some wireless communications systems, an anchor cell may configure a user equipment (UE) with a secondary cell group (SCG) . The anchor cell may select an SCG with which to configure the UE and indicate the selected SCG to the UE. The anchor cell may select the SCG based on a first metric associated with the SCG reported by the UE (e.g., a reference signal receive power (RSRP) ) . In some cases, the UE may repeatedly fail to add the selected SCG due to one or more poor second metrics such as a poor reference signal received quality (RSRQ) or a poor a signal to noise ratio (SNR) . Here, the UE may indicate the SCG failure to the anchor cell. In some wireless communications systems, the anchor cell may continue to select a same SCG and the UE may continue to indicate SCG failures associated with the selected SCG to the anchor cell.

In some other wireless communications systems, the anchor cell may track a quantity of SCG failures associated with each cell of an SCG and refrain from selecting an SCG cell associated with repeated failures. In some examples, the anchor cell may increment a counter indicating a quantity of SCG failures associated with each SCG cell each time the anchor cell receives an SCG failure indication associated with the SCG cell. The anchor cell may then compare the quantity of SCG failures associated with the SCG (e.g., indicated by the counter) to a threshold quantity. In a case that the quantity of SCG failures associated with an SCG cell does not satisfy the threshold quantity (e.g., less than the threshold quantity, or equal to or less than the threshold quality) , the anchor cell may reconfigure the associated UE with the same SCG cell. In a case that the quantity of SCG failures associated with an SCG cell satisfies the threshold quantity (e.g., exceeds the threshold quantity, or equal to or greater than the threshold quality) , the anchor cell may reconfigure the associated UE with a different SCG cell. In some examples, the anchor cell may start a timer upon determining that the quantity of SCG failures satisfies the threshold. In some examples, the timer may be associated with a time period (e.g., a cell selection time period) . After starting the timer (e.g., during the time period of the timer) the anchor cell may send a reconfiguration message to the UE that indicates to the UE to measure a signal quality parameter (e.g., RSRQ, SNR, SINR, etc. ) in addition to measuring RSRP. In some examples, the UE may perform RSRP measurements as well as signal quality measurements of cells in the SCG. The UE may send a measurement report (e.g., during the timer period of the timer) to the anchor cell that indicates the RSRP measurements and the signal quality measurements of the cells in the SCG. The anchor cell may analyze the measurement report (e.g., during the timer period of the timer) and determine the SCG cell with the highest signal quality measurement. The anchor cell may send a reconfiguration message to the UE (e.g., during the timer period of the timer) that indicates the SCG cell with the highest signal quality measurement. Thus, the anchor cell may configure a UE (e.g., during the timer period of the timer) with another cell of the same SCG or with a cell of a different SCG based on the anchor cell selecting the SCG cell with the best measured value of signal quality (e.g., SNR, SINR, or RSRQ) . After the time period expires, the anchor cell may send a reconfiguration message to the UE that indicates to the UE to measure RSRP (e.g., to measure RSRP and not measure the signal quality parameter) .

The described techniques include several advantages over other wireless communications systems. The described techniques enable a network (e.g., an LTE network, a New Radio (NR) network, evolved universal terrestrial radio access network NR –dual connectivity (ENDC) ) to determine a best quality cell of an SCG for UEs associated with the network. The described techniques improve UE data throughput. The described techniques provide an improved data throughput by configuring a UE to connect to the SCG cell determined to have the highest signal quality measurement instead of the SCG cell determined to have the highest received power measurement.

Aspects of the disclosure are initially described in the context of wireless communications systems. Aspects of the disclosure are further illustrated by and described with reference to process flow diagrams. Aspects of the disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flowcharts that relate to secondary cell group assignment.

FIG. 1 illustrates an example of a wireless communications system 100 that supports secondary cell group assignment in accordance with aspects of the present disclosure. The wireless communications system 100 may include one or more base stations 105, one or more UEs 115, and a core network 130. In some examples, the wireless communications system 100 may be a Long Term Evolution (LTE) network, an LTE- Advanced (LTE-A) network, an LTE-A Pro network, or a New Radio (NR) network. In some examples, the wireless communications system 100 may support enhanced broadband communications, ultra-reliable (e.g., mission critical) communications, low latency communications, communications with low-cost and low-complexity devices, or any combination thereof.

The base stations 105 may be dispersed throughout a geographic area to form the wireless communications system 100 and may be devices in different forms or having different capabilities. The base stations 105 and the UEs 115 may wirelessly communicate via one or more communication links 125. Each base station 105 may provide a coverage area 110 over which the UEs 115 and the base station 105 may establish one or more communication links 125. The coverage area 110 may be an example of a geographic area over which a base station 105 and a UE 115 may support the communication of signals according to one or more radio access technologies.

The UEs 115 may be dispersed throughout a coverage area 110 of the wireless communications system 100, and each UE 115 may be stationary, or mobile, or both at different times. The UEs 115 may be devices in different forms or having different capabilities. Some example UEs 115 are illustrated in FIG. 1. The UEs 115 described herein may be able to communicate with various types of devices, such as other UEs 115, the base stations 105, or network equipment (e.g., core network nodes, relay devices, integrated access and backhaul (IAB) nodes, or other network equipment) , as shown in FIG. 1.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

In wireless communications system 100, an anchor cell may configure a UE 115 with an SCG. The anchor cell may select an SCG with which to configure the UE 115 and indicate the selected SCG to the UE 115. The anchor cell may select the SCG based on a first metric associated with the SCG reported by the UE (e.g., an RSRP) . In some cases, the UE 115 may repeatedly fail to add the selected SCG due to one or more poor second metrics such as a poor RSRQ or a poor a SNR. Here, the UE 115 may indicate the SCG failure to the anchor cell. In some other wireless communications systems, the anchor cell may continue to select a same SCG and the UE 115 may continue to indicate SCG failures associated with the selected SCG to the anchor cell.

In some examples of wireless communications system 100, the anchor cell may track a quantity of SCG failures associated with each SCG and based on an SCG associated with repeated failures may instruct the UE 115 to perform new SCG measurements. In some examples, the anchor cell may increment a counter indicating a quantity of SCG failures associated with each SCG each time the anchor cell receives an SCG failure indication associated with the SCG. The anchor cell may then compare the quantity of SCG failures associated with the SCG (e.g., indicated by the counter) to a threshold quantity. In a case that the quantity of SCG failures associated with an SCG exceeds the threshold quantity, the anchor cell may reconfigure UE 115 to perform signal quality measurements in addition to the RSRP measurements. In some examples, the anchor cell may initiate a timer (e.g., a timer of a cell selection time period) upon determining that the quantity of SCG failures exceeds the threshold. During the cell selection time period, the anchor cell may instruct the UE 115 to perform signal quality measurements of the SCG or one or more other SCGs, or both. Thus, the anchor cell may configure UE 115 to measure the signal quality of each cell of one or more SCGs. The UE 115 may transmit a measurement report to the anchor cell and the anchor cell may determine the SCG cell with the highest signal quality measurement. The anchor cell may send a message to UE 115 (e.g., a radio resource control (RRC) message) indicating the SCG cell with the highest signal quality measurement. In some examples, the anchor cell may configure the UE 115 to establish a connection with the SCG cell that has the highest signal quality measurement. After the timer expires (e.g., after the lapsing of the cell selection time period) the anchor cell may instruct UE 115 to measure RSRP (e.g., measure RSRP without measuring the signal quality) .

FIG. 2 illustrates an example of a wireless communications system 200 that supports secondary cell group assignment in accordance with aspects of the present disclosure. In some examples, wireless communications system 200 may implement aspects of wireless communication system 100. The wireless communications system 200 may include a UE 115-a, which may be an example of a UE 115 as described with reference to FIG. 1. Additionally, the wireless communications system 200 may include an anchor cell 205 and SCG cells 210, which may be examples of anchor cells and SCG cells as described with reference to FIG. 1. In some cases, the anchor cell 205 and SCG cells 210 may be associated with a same base station. Additionally or alternatively, one or more of the anchor cell 205 and the SCG cells 210 may be associated with different base stations.

The UE 115-a may communicate with a first wireless network (e.g., an LTE network, a New Radio (NR) network) by a communication link 215 with the anchor cell 205. Here, the anchor cell 205 may provide the UE 115-a with a standalone connection to the first network. The UE 115-a may be configured to additionally connect to a second wireless network (e.g., the UE 115-a may be configured for evolved universal terrestrial radio access network NR –dual connectivity (ENDC) ) . In some examples, the UE 115-a may be an example of a dual-subscriber identity module (SIM) , or multi-SIM UE 115. In some examples, the UE 115-a may include a first SIM and a second SIM. The first SIM may provide a first subscription and the second SIM may provide a second subscription. The UE 115-a may communicate with the first wireless network via the first subscription and may simultaneously communicate with the second wireless network via the second subscription.

The anchor cell 205 may configure the UE 115-a with an additional non-standalone connection to the second wireless network by a communication link 220 with an SCG cell 210. In some examples, the anchor cell 205 may transmit a radio resource control (RRC) reconfiguration measurement requesting a measurement report from the UE 115-a. In response, the UE 115-a may measure and report one or more metrics associated with each of the SCG cells 210. In some instances, the UE 115-a may detect and report (e.g., to the anchor cell 205) a received power measurements (e.g., RSRP) for each of the SCG cells 210. The anchor cell 205 may receive the measurement report and select one of the SCG cells 210 to be used by the UE 115-a based on the values of the received power measurements. In some examples, the anchor cell 205 may select first SCG cell 210-a based on first SCG cell 210-a having a highest reported RSRP (e.g., from the RSRPs reported within the measurement report) . The anchor cell 205 may indicate the selected first SCG cell 210-a to the UE 115-a in an RRC reconfiguration message. The UE 115-a may thus attempt to add the first SCG cell 210-a. In some examples, the UE 115-a may monitor for a physical broadcast channel (PBCH) transmission from the first SCG cell 210-a via communication link 220-a. In some cases, the UE 115-a may fail to decode the PBCH transmission from the first SCG cell 210-a and fail to add the first SCG cell 210-a. The UE 115-a may fail to add the first SCG cell 210-a due one or more metrics associated with the communication link 220-a being unsatisfactory. In some examples, the communication link 220-a may experience interference and may thus be associated with a low signal quality (e.g., SNR, SINR, RSRQ, etc. ) . The UE 115-a may indicate the SCG failure associated with the first SCG cell 210-a to the anchor cell 205.

The anchor cell 205 may receive the indication of the SCG failure from the UE 115-a and increment a counter associated with such failure messages associated with the first SCG cell 210-a. In some cases, each time the anchor cell 205 receives an indication of an SCG failure associated with the first SCG cell 210-a (e.g., from the UE 115-a or another UE 115) , the anchor cell 205 may increment the counter. Additionally, each time the anchor cell 205 receives an indication of an SCG failure associated with the second SCG cell 210-b (e.g., from the UE 115-a or another UE 115) , the anchor cell 205 may increment a different counter associated with the second SCG cell 210-b. In some cases, the counter may indicate a quantity of SCG failures associated with the first SCG cell 210-a within a predetermined period of time. That is, the anchor cell 205 may periodically refresh the counter. Additionally or alternatively, the anchor cell 205 may adjust the counter based on the predetermined period of time.

After incrementing the counter associated with the first SCG cell 210-a, the anchor cell 205 may compare the quantity of SCG failures indicated by the counter to a threshold quantity. If the quantity of SCG failures indicated by the counter associated with the first SCG cell 210-a is less than the threshold quantity, the anchor cell 205 may continue to indicate, to the UE 115-a, the SCG cell 210 associated with a highest RSRP. Alternatively, if the quantity of SCG failures indicated by the counter associated with the first SCG cell 210-a is greater than, or equal to or greater than, the threshold quantity, the anchor cell 205 may refrain from configuring the UE 115-a and other UEs 115 with the first SCG cell 210-a. The anchor cell 205 may refrain from configuring UEs 115 with the first SCG cell 210-a for a defined period of time. In some examples, the anchor cell 205 may initiate a timer (e.g., a timer of a cell selection time period) upon determining that the quantity of SCG failures associated with the first SCG cell 210-a exceeds the threshold quantity.

During the cell selection time period, anchor cell 205 may send an updated reconfiguration message (e.g., RRC reconfiguration message) to UE 115-a. In some examples, the anchor cell 205 may update a field of the reconfiguration message to indicate signal quality measurements in addition to the RSRP measurements. In some examples, the reconfiguration message may include a first bit of a field that indicates whether to perform RSRP measurements. In some examples, a binary 0 in the first bit may indicate RSRP measurements are not to be performed, while a binary 1 in the first bit may indicate RSRP measurements are to be performed. In some instances, a binary 1 in the first bit may indicate RSRP measurements are not to be performed, while a binary 0 in the first bit may indicate RSRP measurements are to be performed. In some examples, the reconfiguration message may include a second bit of a field that indicates whether to perform signal quality measurements. In some examples, a binary 0 in the second bit may indicate signal quality measurements are not to be performed, while a binary 1 in the second bit may indicate signal quality measurements are to be performed. In some instances, a binary 1 in the second bit may indicate signal quality measurements are not to be performed, while a binary 0 in the second bit may indicate signal quality measurements are to be performed.

In some examples, the UE 115-a may perform signal quality measurements and RSRP measurements of SCG cells 210 based on the updated reconfiguration message. The UE 115-a may generate a measurement report based on the signal quality measurements and RSRP measurements and transmit the measurement report to anchor cell 205. In some examples, anchor cell 205 may determine that the signal quality measurement of the second SCG cell 210-b is higher than the signal quality measurement of the first SCG cell 210-a. In some examples, anchor cell 205 may select of the second SCG cell 210-b based on the higher signal quality measurement of the second SCG cell 210-b. In some instances, anchor cell 205 may send a reconfiguration message (e.g., RRC reconfiguration message) that configures UE 115-a to establish a connection with the second SCG cell 210-b (e.g., communication link 220-b) .

In some examples, although an RSRP associated with the communication link 220-a with the first SCG cell 210-a may be greater than an RSRP associated with the communication link 220-b with the second SCG cell 210-b, the anchor cell 205 may select the second SCG cell 210-b and indicate the second SCG cell 210-b to the UE 115-a based on the second SCG cell 210-b having the highest signal quality. Thus, the communication link 220-b may be associated with a better RSRQ or SNR (e.g., when compared to the communication link 220-a) and the UE 115-a may thus be enabled to add the second SCG cell 210-b.

FIG. 3 illustrates an example of a process flow 300 that supports secondary cell group assignment in accordance with aspects of the present disclosure. In some examples, process flow 300 may implement aspects of

wireless communications systems

100 and 200. The process flow 300 includes UE 115-b (e.g., of one or more UEs) , anchor cell 205-b, and SCG cells 210. UE 115-a may be an example of UEs 115 as described with reference to FIGs. 1 and 2. Additionally, the anchor cell 205-b and SCG cells 210 may be examples of anchor cells and SCG cells, respectively, described with reference to FIGs. 1 and 2. In some cases, the anchor cell 205-b may be an LTE cell configured to connect the UE 115-b to an LTE network. Additionally, the SCG cells 210 may be 5G SCG cells 210 configured to connect the UE 115-b to an NR network. Alternative examples of the following may be implemented, where some steps are performed in a different order than described or are not performed at all. In some cases, steps may include additional features not mentioned herein, or further steps may be added.

At 305, the UE 115-b and anchor cell 205-b may perform an attach procedure. After performing the attach procedure, the UE 115-b may be attached to the anchor cell 205-b and may be connected to a first wireless network by the anchor cell 205-b.

In some cases, the UE 115-b may be configured to additionally connect to a second wireless network (e.g., the UE 115-a may be configured for ENDC) . Thus, the anchor cell 205-b may perform Procedure 1 to enable the UE 115-b to add one of the SCG cells 210 and connect to the second wireless network. To initiate Procedure 1, the anchor cell 205-b may transmit a measurement report request to the UE 115-b at 310. The measurement report request may be an RRC reconfiguration message (e.g., an RRC reconfiguration message that includes a measObjectNR information element) . Based on receiving the measurement report request, the UE 115-b may transmit the measurement report to the anchor cell 205-b. In some examples, the UE 115-b may detect a received power (e.g., RSRP) for each of the SCG cells 210. The UE 115-b may include the detected power measurements in the measurement report.

At 320, the anchor cell 205-b may transmit an SCG indication to the UE 115-b. The SCG indication may be an RRC reconfiguration message indicating one of the SCG cells 210. In some examples, the anchor cell 205-b may select one of the SCG cells 210 based on the SCG cell 210 with a highest reported RSRP. In some examples, the measurement report may include an RSRP associated with the first SCG cell 210-c and an RSRP associated with the second SCG cell 210-d. In a case that the RSRP associated with the first SCG cell 210-c is higher than the RSRP associated with the second SCG cell 210-d, the anchor cell 205-b may indicate the first SCG cell 210-c by the SCG indication.

Based on receiving the SCG indication, the UE 115-b may attempt to add the indicated SCG cell 210. In some examples, if the SCG indication indicates first SCG cell 210-c, the UE 115-b may attempt to decode a PBCH transmission from first SCG cell 210-c. In some cases, however, a communication link between UE 115-b and first SCG cell 210-c may be associated with interference such that the UE 115-b is unable to decode a PBCH transmission from the first SCG cell 210-c. In some examples, when the SCG indication indicates first SCG cell 210-c, the UE 115-b may attempt to perform a random access procedure. In some cases, however, a failure associated with the communications with the first secondary cell may include a failure associated with performing the random access procedure with the first secondary cell. Thus, the UE 115-b may detect an SCG failure associated with first SCG cell 210-c based on an inability to decode a PBCH transmission or based on a failed random access procedure, or both.

Based on detecting the SCG failure associated with the first SCG cell 210-c, the UE 115-b may transmit an SCG failure indication to the anchor cell 205-b at 330. The anchor cell 205-b may increment a counter associated with the first SCG cell 210-c based on receiving the SCG failure indication. In some cases, the counter may indicate a quantity of SCG failures associated with the first SCG cell 210-a. That is, the anchor cell 205-b may receive, from the UE 115-b or one or more other UEs 115, an SCG failure indication associated with the first SCG cell 210-c at a time different than 330 (e.g., prior to 330, after 330) and may increment the counter based on receiving that SCG failure indication (e.g., and each SCG failure indication received from the one or more UEs 115) .

At 335, the anchor cell 205-b may compare the quantity of SCG failures indicated by the counter to a threshold quantity. If the anchor cell 205-b determines that the quantity of SCG failures does not satisfy the threshold quantity (e.g., the quantity of SCG failures is less than the threshold quantity, or less than or equal to the threshold quantity) , the anchor cell 205-b may proceed to 340 and loop Procedure 1. That is, the anchor cell 205-b may transmit another measurement report request, receive another measurement report from the UE 115-b, and indicate the SCG cell 210 with the highest reported RSRP.

In some instances, when the anchor cell 205-b determines that the quantity of SCG failures satisfies the threshold quantity (e.g., the quantity of SCG failures is greater than the threshold quantity, or greater than or equal to the threshold quantity) , the anchor cell 205-b exits Procedure 1. In some examples, the anchor cell 205-b may initiate a timer and may request UE 115-b to perform a new measurement of SCG cells 210 or cells of one or more other SCGs, or both, based on RSRP measurements as well as signal quality measurements.

At 345, anchor cell 205-b may initiate a timer (e.g., a timer of a cell selection time period) . In some examples, during the cell selection time period the anchor cell 205-b may request UE 115-b to perform a new measurement of SCG cells 210 or cells of one or more other SCGs, or both, based on RSRP measurements as well as signal quality measurements.

At 350, the anchor cell 205-b may transmit a measurement report request to the UE 115-b. In some examples, the measurement report request at 350 may include an updated measurement report request. In some examples, the measurement report request at 310 may indicate to perform received power measurements (e.g., RSRP measurements) , but not signal quality measurements. On the other hand, the updated measurement report request at 350 may indicate to perform received power measurements (e.g., RSRP measurements) as well as signal quality measurements (e.g., SNR, SINR, RSRQ, etc. ) .

At 355, based on receiving the updated measurement report request at 350, UE 115-b may transmit the generated measurement report to the anchor cell 205-b. In some examples, the UE 115-b may perform both received power measurements as well as signal quality measurements for SCG cells 210, or for cells of one or more other SCGs, or both, based on receiving the updated measurement report request at 350. UE 115-b may generate a measurement report based on performing the received power measurements and signal quality measurements and then transmit the generated measurement report at 355. In some examples, the measurement report may indicate that the first SCG cell 210-c has a higher reported RSRP than the second SCG cell 210-d, but that the second SCG cell 210-d has a higher reported signal quality measurement (e.g., SNR, SINR, RSRQ, etc. ) than the first SCG cell 210-c.

At 360, anchor cell 205-b may sort the cells by the signal quality measurement (e.g., SNR, SINR, RSRQ, etc. ) . In some examples, the anchor cell 205-b may determine the second SCG cell 210-d has the highest signal quality measurement. In some examples, , the anchor cell 205-b may select the second SCG cell 210-d based on the second SCG cell 210-d having the highest signal quality measurement.

At 365 the anchor cell 205-b may transmit an SCG indication to the UE 115-b indicating the second SCG cell 210-d to the UE 115-b based on the anchor cell 205-b determining that the second SCG cell 210-d has the highest signal quality measurement.

At 370, the UE 115-b may transmit an RRC reconfiguration complete indication to the anchor cell 205-b. In some examples, the UE 115-b may attempt and successfully decode a PBCH transmission from the second SCG cell 210-d and may transmit the RRC reconfiguration complete indication based on successfully decoding the PBCH transmission.

At 375, the UE 115-b may perform a random access procedure with the second SCG cell 210-d. In some examples, the UE 115-b and the second SCG cell 210-d may exchange message 1, message 2, message 3, and message 4 during the random access procedure.

At 380, the UE 115-b and the second SCG cell 210-d may have successfully set of the RRC connection. Thus, the UE 115-b may be connected to the second wireless network (e.g., an NR network) by the second SCG cell 210-d.

FIG. 4 shows a block diagram 400 of a device 405 that supports secondary cell group assignment in accordance with aspects of the present disclosure. The device 405 may be an example of aspects of a base station 105 as described herein. The device 405 may include a receiver 410, a communications manager 415, and a transmitter 420. The device 405 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses) .

The receiver 410 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to secondary cell group assignment, etc. ) . Information may be passed on to other components of the device 405. The receiver 410 may be an example of aspects of the transceiver 720 described with reference to FIG. 7. The receiver 410 may utilize a single antenna or a set of antennas.

The communications manager 415 may receive, from one or more UEs associated with a first secondary cell of the base station, one or more failure messages indicating a failure associated with communications with the first secondary cell, determine that a number of the received one or more failure messages for the first secondary cell exceeds a failure message threshold, and transmit, to the UE based on the determined number of failure messages exceeding the failure message threshold, a reconfiguration message that indicates for the UE to measure a signal quality and a receive power for the first secondary cell and for a second secondary cell associated with the base station. The communications manager 415 may be an example of aspects of the communications manager 710 described herein.

The communications manager 415, or its sub-components, may be implemented in hardware, code (e.g., software or firmware) executed by a processor, or any combination thereof. If implemented in code executed by a processor, the functions of the communications manager 415, or its sub-components may be executed by a general-purpose processor, a DSP, an application-specific integrated circuit (ASIC) , a FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in the present disclosure.

The communications manager 415, or its sub-components, may be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations by one or more physical components. In some examples, the communications manager 415, or its sub-components, may be a separate and distinct component in accordance with various aspects of the present disclosure. In some examples, the communications manager 415, or its sub-components, may be combined with one or more other hardware components, including but not limited to an input/output (I/O) component, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof in accordance with various aspects of the present disclosure.

The transmitter 420 may transmit signals generated by other components of the device 405. In some examples, the transmitter 420 may be collocated with a receiver 410 in a transceiver module. For example, the transmitter 420 may be an example of aspects of the transceiver 720 described with reference to FIG. 7. The transmitter 420 may utilize a single antenna or a set of antennas.

FIG. 5 shows a block diagram 500 of a device 505 that supports secondary cell group assignment in accordance with aspects of the present disclosure. The device 505 may be an example of aspects of a device 405, or a base station 105 as described herein. The device 505 may include a receiver 510, a communications manager 515, and a transmitter 535. The device 505 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses) .

The receiver 510 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to secondary cell group assignment, etc. ) . Information may be passed on to other components of the device 505. The receiver 510 may be an example of aspects of the transceiver 720 described with reference to FIG. 7. The receiver 510 may utilize a single antenna or a set of antennas.

The communications manager 515 may be an example of aspects of the communications manager 415 as described herein. The communications manager 515 may include a connection manager 520, an enumeration manager 525, and a configuration manager 530. The communications manager 515 may be an example of aspects of the communications manager 710 described herein.

The connection manager 520 may receive, from one or more UEs associated with a first secondary cell of the base station, one or more failure messages indicating a failure associated with communications with the first secondary cell.

The enumeration manager 525 may determine that a number of the received one or more failure messages for the first secondary cell exceeds a failure message threshold.

The configuration manager 530 may transmit, to the UE based on the determined number of failure messages exceeding the failure message threshold, a reconfiguration message that indicates for the UE to measure a signal quality and a receive power for the first secondary cell and for a second secondary cell associated with the base station.

The transmitter 535 may transmit signals generated by other components of the device 505. In some examples, the transmitter 535 may be collocated with a receiver 510 in a transceiver module. For example, the transmitter 535 may be an example of aspects of the transceiver 720 described with reference to FIG. 7. The transmitter 535 may utilize a single antenna or a set of antennas.

FIG. 6 shows a block diagram 600 of a communications manager 605 that supports secondary cell group assignment in accordance with aspects of the present disclosure. The communications manager 605 may be an example of aspects of a communications manager 415, a communications manager 515, or a communications manager 710 described herein. The communications manager 605 may include a connection manager 610, an enumeration manager 615, a configuration manager 620, an evaluation manager 625, and a timer manager 630. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses) .

The connection manager 610 may receive, from one or more UEs associated with a first secondary cell of the base station, one or more failure messages indicating a failure associated with communications with the first secondary cell.

The enumeration manager 615 may determine that a number of the received one or more failure messages for the first secondary cell exceeds a failure message threshold.

The configuration manager 620 may transmit, to the UE based on the determined number of failure messages exceeding the failure message threshold, a reconfiguration message that indicates for the UE to measure a signal quality and a receive power for the first secondary cell and for a second secondary cell associated with the base station. In some examples, the failure associated with the communications with the first secondary cell includes a failure (e.g., by the one or more UEs) to decode signals broadcast by the first secondary cell. In some examples, the failure associated with the communications with the first secondary cell includes a failure associated with performing a random access procedure with the first secondary cell. In some examples, the signals broadcast by the first secondary cell associated with the base station include a master information block broadcast from the first secondary cell using a physical broadcast channel.

In some examples, the configuration manager 620 may determine a signal quality of the second secondary cell exceeds a signal quality of the first secondary cell.

In some examples, the configuration manager 620 may transmit, based on determining that the signal quality of the second secondary cell exceeds the signal quality of the first secondary cell, a second reconfiguration message to the UE that indicates to use the second secondary cell.

In some examples, the configuration manager 620 may receive a reconfiguration complete message from the UE responsive at least in part to the transmitted second reconfiguration message.

In some cases, the reconfiguration message or the second reconfiguration message, or both, include a radio resource control reconfiguration message. In some cases, the receive power includes a reference signal received power. In some cases, the signal quality includes a signal to noise ratio, or a signal-to-noise and interference ratio, or a reference signal received quality, or received signal strength indicator, or any combination thereof.

In some cases, a primary cell of the base station is configured to operate according to a release of a first wireless communications standard, and the first secondary cell and the second secondary cell associated with the base station are configured to operate according to a release of a second wireless communications standard. In some cases, the first wireless communications standard includes LTE, and the second wireless communications standard includes New Radio (NR) .

The evaluation manager 625 may receive a measurement report based on transmitting the reconfiguration message to the UE, where the measurement report includes the signal quality and the receive power for the first secondary cell and the second secondary cell.

In some examples, the evaluation manager 625 may receive, from the UE based on transmitting the reconfiguration message to the UE, a set of measurement reports for a set of secondary cells associated with the base station, the set of measurement reports indicating the signal strength associated with each secondary cell of the set of secondary cells, where the set of secondary cells include at least the first secondary cell and the second secondary cell.

In some examples, the evaluation manager 625 may sort, based on the received set of measurement reports, the set of secondary cells according to signal quality.

In some examples, the evaluation manager 625 may select the second secondary cell of the set of secondary cells based on the second secondary cell associated with a highest signal quality among the sorted set of secondary cell.

In some examples, the configuration manager 620 may transmit, to the UE, a message indicating that the UE is to perform a random access procedure to establish a wireless connection with the second secondary cell.

In some examples, the configuration manager 620 may communicate with the UE using a primary cell of the base station and the second secondary cell associated with the base station following the random access procedure.

The timer manager 630 may initiate a cell selection timer based on the determined number of failure messages exceeding the failure message threshold. In some cases, the reconfiguration message is transmitted after initiating the cell selection timer.

In some examples, the configuration manager 620 may transmit, after the cell selection timer is initiated and before the cell section timer expires, the reconfiguration message including a first bit field and a second bit field, the first bit field indicating that the UE is to measure the signal quality of each secondary cell of the secondary cell group, and the second bit field indicating that the UE is to measure the receive power of each secondary cell of the secondary cell group.

In some examples, the configuration manager 620 may transmit, after the cell selection timer expires, a third reconfiguration message including a first bit field and a second bit field, the first bit field indicating that the UE is to not measure the signal quality of each secondary cell of the secondary cell group, and the second bit field indicating that the UE is to measure the receive power of each secondary cell of the secondary cell group.

FIG. 7 shows a diagram of a system 700 including a device 705 that supports secondary cell group assignment in accordance with aspects of the present disclosure. The device 705 may be an example of or include the components of device 405, device 505, or a base station 105 as described herein. The device 705 may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including a communications manager 710, a network communications manager 715, a transceiver 720, an antenna 725, memory 730, a processor 740, and an inter-station communications manager 745. These components may be in electronic communication via one or more buses (e.g., bus 750) .

The communications manager 710 may receive, from one or more UEs associated with a first secondary cell of the base station, one or more failure messages indicating a failure associated with communications with the first secondary cell, determine that a number of the received one or more failure messages for the first secondary cell exceeds a failure message threshold, and transmit, to the UE based on the determined number of failure messages exceeding the failure message threshold, a reconfiguration message that indicates for the UE to measure a signal quality and a receive power for the first secondary cell and for a second secondary cell associated with the base station.

The network communications manager 715 may manage communications with the core network (e.g., via one or more wired backhaul links) . For example, the network communications manager 715 may manage the transfer of data communications for client devices, such as one or more UEs 115.

The transceiver 720 may communicate bi-directionally, via one or more antennas, wired, or wireless links as described herein. For example, the transceiver 720 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 720 may also include a modem to modulate the packets and provide the modulated packets to the antennas for transmission, and to demodulate packets received from the antennas.

In some cases, the wireless device may include a single antenna 725. However, in some cases the device may have more than one antenna 725, which may be capable of concurrently transmitting or receiving multiple wireless transmissions.

The memory 730 may include RAM, ROM, or a combination thereof. The memory 730 may store computer-readable code 735 including instructions that, when executed by a processor (e.g., the processor 740) cause the device to perform various functions described herein. In some cases, the memory 730 may contain, among other things, a BIOS which may control basic hardware or software operation such as the interaction with peripheral components or devices.

The processor 740 may include an intelligent hardware device, (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof) . In some cases, the processor 740 may be configured to operate a memory array using a memory controller. In some cases, a memory controller may be integrated into processor 740. The processor 740 may be configured to execute computer-readable instructions stored in a memory (e.g., the memory 730) to cause the device 705 to perform various functions (e.g., functions or tasks supporting secondary cell group assignment) .

The inter-station communications manager 745 may manage communications with other base station 105, and may include a controller or scheduler for controlling communications with UEs 115 in cooperation with other base stations 105. For example, the inter-station communications manager 745 may coordinate scheduling for transmissions to UEs 115 for various interference mitigation techniques such as beamforming or joint transmission. In some examples, the inter-station communications manager 745 may provide an X2 interface within an LTE/LTE-A wireless communication network technology to provide communication between base stations 105.

The code 735 may include instructions to implement aspects of the present disclosure, including instructions to support wireless communications. The code 735 may be stored in a non-transitory computer-readable medium such as system memory or other type of memory. In some cases, the code 735 may not be directly executable by the processor 740 but may cause a computer (e.g., when compiled and executed) to perform functions described herein.

FIG. 8 shows a flowchart illustrating a method 800 that supports secondary cell group assignment in accordance with aspects of the present disclosure. The operations of method 800 may be implemented by a base station 105 or its components as described herein. For example, the operations of method 800 may be performed by a communications manager as described with reference to FIGs. 4 through 7. In some examples, a base station may execute a set of instructions to control the functional elements of the base station to perform the functions described herein. Additionally or alternatively, a base station may perform aspects of the functions described herein using special-purpose hardware.

At 805, the base station may receive, from one or more UEs associated with a first secondary cell of the base station, one or more failure messages indicating a failure associated with communications with the first secondary cell. The operations of 805 may be performed according to the methods described herein. In some examples, aspects of the operations of 805 may be performed by a connection manager as described with reference to FIGs. 4 through 7.

At 810, the base station may determine that a number of the received one or more failure messages for the first secondary cell exceeds a failure message threshold. The operations of 810 may be performed according to the methods described herein. In some examples, aspects of the operations of 810 may be performed by an enumeration manager as described with reference to FIGs. 4 through 7.

At 815, the base station may transmit, to the UE based on the determined number of failure messages exceeding the failure message threshold, a reconfiguration message that indicates for the UE to measure a signal quality and a receive power for the first secondary cell and for a second secondary cell associated with the base station. The operations of 815 may be performed according to the methods described herein. In some examples, aspects of the operations of 815 may be performed by a configuration manager as described with reference to FIGs. 4 through 7.

FIG. 9 shows a flowchart illustrating a method 900 that supports secondary cell group assignment in accordance with aspects of the present disclosure. The operations of method 900 may be implemented by a base station 105 or its components as described herein. For example, the operations of method 900 may be performed by a communications manager as described with reference to FIGs. 4 through 7. In some examples, a base station may execute a set of instructions to control the functional elements of the base station to perform the functions described herein. Additionally or alternatively, a base station may perform aspects of the functions described herein using special-purpose hardware.

At 905, the base station may receive, from one or more UEs associated with a first secondary cell of the base station, one or more failure messages indicating a failure associated with communications with the first secondary cell. The operations of 905 may be performed according to the methods described herein. In some examples, aspects of the operations of 905 may be performed by a connection manager as described with reference to FIGs. 4 through 7.

At 910, the base station may determine that a number of the received one or more failure messages for the first secondary cell exceeds a failure message threshold. The operations of 910 may be performed according to the methods described herein. In some examples, aspects of the operations of 910 may be performed by an enumeration manager as described with reference to FIGs. 4 through 7.

At 915, the base station may transmit, to the UE based on the determined number of failure messages exceeding the failure message threshold, a reconfiguration message that indicates for the UE to measure a signal quality and a receive power for the first secondary cell and for a second secondary cell associated with the base station. The operations of 915 may be performed according to the methods described herein. In some examples, aspects of the operations of 915 may be performed by a configuration manager as described with reference to FIGs. 4 through 7.

At 920, the base station may receive a measurement report based on transmitting the reconfiguration message to the UE, where the measurement report includes the signal quality and the receive power for the first secondary cell and the second secondary cell. The operations of 920 may be performed according to the methods described herein. In some examples, aspects of the operations of 920 may be performed by an evaluation manager as described with reference to FIGs. 4 through 7.

At 925, the base station may determine a signal quality of the second secondary cell exceeds a signal quality of the first secondary cell. The operations of 925 may be performed according to the methods described herein. In some examples, aspects of the operations of 925 may be performed by a configuration manager as described with reference to FIGs. 4 through 7.

At 930, the base station may transmit, based on determining that the signal quality of the second secondary cell exceeds the signal quality of the first secondary cell, a second reconfiguration message to the UE that indicates to use the second secondary cell. The operations of 930 may be performed according to the methods described herein. In some examples, aspects of the operations of 930 may be performed by a configuration manager as described with reference to FIGs. 4 through 7.

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

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

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

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

The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope of the disclosure and appended claims. For example, due to the nature of software, functions described herein may be implemented using software executed by a processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations.

Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A non-transitory storage medium may be any available medium that may be accessed by a general-purpose or special purpose computer. By way of example, and not limitation, non-transitory computer-readable media may include random-access memory (RAM) , read-only memory (ROM) , electrically erasable programmable ROM (EEPROM) , flash memory, compact disk (CD) ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that may be used to carry or store desired program code means in the form of instructions or data structures and that may be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) , or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of computer-readable medium. Disk and disc, as used herein, include CD, laser disc, optical disc, digital versatile disc (DVD) , floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media.

As used herein, including in the claims, “or” as used in a list of items (e.g., a list of items prefaced by a phrase such as “at least one of” or “one or more of” ) indicates an inclusive list such that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C) . Also, as used herein, the phrase “based on” shall not be construed as a reference to a closed set of conditions. For example, an example step that is described as “based on condition A” may be based on both a condition A and a condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase “based on” shall be construed in the same manner as the phrase “based at least in part on. ”

In the appended figures, similar components or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label by a dash and a second label that distinguishes among the similar components. If just the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label, or other subsequent reference label.

The description set forth herein, in connection with the appended drawings, describes example configurations and does not represent all the examples that may be implemented or that are within the scope of the claims. The term “example” used herein means “serving as an example, instance, or illustration, ” and not “preferred” or “advantageous over other examples. ” The detailed description includes specific details for the purpose of providing an understanding of the described techniques. These techniques, however, may be practiced without these specific details. In some instances, known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the described examples.

The description herein is provided to enable a person having ordinary skill in the art to make or use the disclosure. Various modifications to the disclosure will be apparent to a person having ordinary skill in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not limited to the examples and designs described herein, but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein.

Claims

A method for wireless communications at a base station, comprising:

receiving, from one or more user equipments (UEs) associated with a first secondary cell of the base station, one or more failure messages indicating a failure associated with communications with the first secondary cell;

determining that a number of the received one or more failure messages for the first secondary cell exceeds a failure message threshold; and

transmitting, to a UE of the one or more UEs based at least in part on the determined number of failure messages exceeding the failure message threshold, a reconfiguration message that indicates for the UE to measure a signal quality and a receive power for the first secondary cell and for a second secondary cell associated with the base station.
The method of claim 1, further comprising:

receiving a measurement report based at least in part on transmitting the reconfiguration message to the UE, wherein the measurement report comprises the signal quality and the receive power for the first secondary cell and the second secondary cell.
The method of claim 1, further comprising:

determining a signal quality of the second secondary cell exceeds a signal quality of the first secondary cell; and

transmitting, based at least in part on determining that the signal quality of the second secondary cell exceeds the signal quality of the first secondary cell, a second reconfiguration message to the UE that indicates to use the second secondary cell.
The method of claim 3, wherein the reconfiguration message or the second reconfiguration message, or both, comprise a radio resource control reconfiguration message.
The method of claim 3, further comprising:

receiving a reconfiguration complete message from the UE responsive at least in part to the transmitted second reconfiguration message.
The method of claim 1, further comprising:

initiating a cell selection timer based at least in part on the determined number of failure messages exceeding the failure message threshold.
The method of claim 6, wherein the reconfiguration message is transmitted after initiating the cell selection timer.
The method of claim 6, wherein transmitting the reconfiguration message comprises:

transmitting, after the cell selection timer is initiated and before the cell section timer expires, the reconfiguration message comprising a first bit field and a second bit field, the first bit field indicating that the UE is to measure the signal quality of each secondary cell of the secondary cell group, and the second bit field indicating that the UE is to measure the receive power of each secondary cell of the secondary cell group.
The method of claim 6, further comprising:

transmitting, after the cell selection timer expires, a third reconfiguration message comprising a first bit field and a second bit field, the first bit field indicating that the UE is to not measure the signal quality of each secondary cell of the secondary cell group, and the second bit field indicating that the UE is to measure the receive power of each secondary cell of the secondary cell group.
The method of claim 1, further comprising:

receiving, from the UE based at least in part on transmitting the reconfiguration message to the UE, a plurality of measurement reports for a plurality of secondary cells associated with the base station, the plurality of measurement reports indicating the signal strength associated with each secondary cell of the plurality of secondary cells, wherein the plurality of secondary cells comprise at least the first secondary cell and the second secondary cell;

sorting, based at least in part on the received plurality of measurement reports, the plurality of secondary cells according to signal quality;

selecting the second secondary cell of the plurality of secondary cells based at least in part on the second secondary cell associated with a highest signal quality among the sorted plurality of secondary cell;

transmitting, to the UE, a message indicating that the UE is to perform a random access procedure to establish a wireless connection with the second secondary cell; and

communicating with the UE using a primary cell of the base station and the second secondary cell associated with the base station following the random access procedure.
The method of claim 1, wherein the receive power comprises a reference signal received power.
The method of claim 1, wherein the signal quality comprises a signal to noise ratio, or a signal-to-noise and interference ratio, or a reference signal received quality, or received signal strength indicator, or any combination thereof.
The method of claim 1, wherein a primary cell of the base station is configured to operate according to a release of a first wireless communications standard, and the first secondary cell and the second secondary cell associated with the base station are configured to operate according to a release of a second wireless communications standard.
The method of claim 13, wherein the first wireless communications standard comprises Long Term Evolution (LTE) , and the second wireless communications standard comprises New Radio (NR) .
The method of claim 1, wherein the failure associated with the communications with the first secondary cell comprises a failure to decode signals broadcast by the first secondary cell.
The method of claim 1, wherein the failure associated with the communications with the first secondary cell comprises a failure associated with performing a random access procedure with the first secondary cell.
The method of claim 1, wherein the signals broadcast by the first secondary cell associated with the base station comprise a master information block broadcast from the first secondary cell using a physical broadcast channel.
An apparatus for wireless communications at a base station, comprising:

a processor,

memory coupled with the processor; and

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

receive, from one or more user equipments (UEs) associated with a first secondary cell of the base station, one or more failure messages indicating a failure associated with communications with the first secondary cell;

determine that a number of the received one or more failure messages for the first secondary cell exceeds a failure message threshold; and

transmit, to a UE of the one or more UEs based at least in part on the determined number of failure messages exceeding the failure message threshold, a reconfiguration message that indicates for the UE to measure a signal quality and a receive power for the first secondary cell and for a second secondary cell associated with the base station.
The apparatus of claim 18, wherein the instructions are further executable by the processor to cause the apparatus to:

receive a measurement report based at least in part on transmitting the reconfiguration message to the UE, wherein the measurement report comprises the signal quality and the receive power for the first secondary cell and the second secondary cell.
The apparatus of claim 18, wherein the instructions are further executable by the processor to cause the apparatus to:

determine a signal quality of the second secondary cell exceeds a signal quality of the first secondary cell; and

transmit, based at least in part on determining that the signal quality of the second secondary cell exceeds the signal quality of the first secondary cell, a second reconfiguration message to the UE that indicates to use the second secondary cell.
The apparatus of claim 20, wherein the reconfiguration message or the second reconfiguration message, or both, comprise a radio resource control reconfiguration message.
The apparatus of claim 20, wherein the instructions are further executable by the processor to cause the apparatus to:

receive a reconfiguration complete message from the UE responsive at least in part to the transmitted second reconfiguration message.
The apparatus of claim 18, wherein the instructions are further executable by the processor to cause the apparatus to:

initiate a cell selection timer based at least in part on the determined number of failure messages exceeding the failure message threshold.
The apparatus of claim 23, wherein the reconfiguration message is transmitted after initiating the cell selection timer.
The apparatus of claim 23, wherein the instructions to transmit the reconfiguration message are executable by the processor to cause the apparatus to:

transmit, after the cell selection timer is initiated and before the cell section timer expires, the reconfiguration message comprising a first bit field and a second bit field, the first bit field indicating that the UE is to measure the signal quality of each secondary cell of the secondary cell group, and the second bit field indicating that the UE is to measure the receive power of each secondary cell of the secondary cell group.
The apparatus of claim 23, wherein the instructions are further executable by the processor to cause the apparatus to:

transmit, after the cell selection timer expires, a third reconfiguration message comprising a first bit field and a second bit field, the first bit field indicating that the UE is to not measure the signal quality of each secondary cell of the secondary cell group, and the second bit field indicating that the UE is to measure the receive power of each secondary cell of the secondary cell group.
The apparatus of claim 18, wherein the instructions are further executable by the processor to cause the apparatus to:

receive, from the UE based at least in part on transmitting the reconfiguration message to the UE, a plurality of measurement reports for a plurality of secondary cells associated with the base station, the plurality of measurement reports indicating the signal strength associated with each secondary cell of the plurality of secondary cells, wherein the plurality of secondary cells comprise at least the first secondary cell and the second secondary cell;

sort, based at least in part on the received plurality of measurement reports, the plurality of secondary cells according to signal quality;

select the second secondary cell of the plurality of secondary cells based at least in part on the second secondary cell associated with a highest signal quality among the sorted plurality of secondary cell;

transmit, to the UE, a message indicating that the UE is to perform a random access procedure to establish a wireless connection with the second secondary cell; and

communicate with the UE using a primary cell of the base station and the second secondary cell associated with the base station following the random access procedure.
The apparatus of claim 18, wherein the receive power comprises a reference signal received power.
The apparatus of claim 18, wherein the signal quality comprises a signal to noise ratio, or a signal-to-noise and interference ratio, or a reference signal received quality, or received signal strength indicator, or any combination thereof.
The apparatus of claim 18, wherein a primary cell of the base station is configured to operate according to a release of a first wireless communications standard, and the first secondary cell and the second secondary cell associated with the base station are configured to operate according to a release of a second wireless communications standard.
The apparatus of claim 30, wherein the first wireless communications standard comprises Long Term Evolution (LTE) , and the second wireless communications standard comprises New Radio (NR) .
The apparatus of claim 18, wherein the failure associated with the communications with the first secondary cell comprises a failure to decode signals broadcast by the first secondary cell.
The apparatus of claim 18, wherein the failure associated with the communications with the first secondary cell comprises a failure associated with performing a random access procedure with the first secondary cell.
The apparatus of claim 18, wherein the signals broadcast by the first secondary cell associated with the base station comprise a master information block broadcast from the first secondary cell using a physical broadcast channel.
An apparatus for wireless communications at a base station, comprising:

means for receiving, from one or more user equipments (UEs) associated with a first secondary cell of the base station, one or more failure messages indicating a failure associated with communications with the first secondary cell;

means for determining that a number of the received one or more failure messages for the first secondary cell exceeds a failure message threshold; and

means for transmitting, to a UE of the one or more UEs based at least in part on the determined number of failure messages exceeding the failure message threshold, a reconfiguration message that indicates for the UE to measure a signal quality and a receive power for the first secondary cell and for a second secondary cell associated with the base station.
The apparatus of claim 35, further comprising:

means for receiving a measurement report based at least in part on transmitting the reconfiguration message to the UE, wherein the measurement report comprises the signal quality and the receive power for the first secondary cell and the second secondary cell.
The apparatus of claim 35, further comprising:

means for determining a signal quality of the second secondary cell exceeds a signal quality of the first secondary cell; and

means for transmitting, based at least in part on determining that the signal quality of the second secondary cell exceeds the signal quality of the first secondary cell, a second reconfiguration message to the UE that indicates to use the second secondary cell.
The apparatus of claim 37, wherein the reconfiguration message or the second reconfiguration message, or both, comprise a radio resource control reconfiguration message.
The apparatus of claim 37, further comprising:

means for receiving a reconfiguration complete message from the UE responsive at least in part to the transmitted second reconfiguration message.
The apparatus of claim 35, further comprising:

means for initiating a cell selection timer based at least in part on the determined number of failure messages exceeding the failure message threshold.
The apparatus of claim 40, wherein the reconfiguration message is transmitted after initiating the cell selection timer.
The apparatus of claim 40, wherein the means for transmitting the reconfiguration message comprises:

means for transmitting, after the cell selection timer is initiated and before the cell section timer expires, the reconfiguration message comprising a first bit field and a second bit field, the first bit field indicating that the UE is to measure the signal quality of each secondary cell of the secondary cell group, and the second bit field indicating that the UE is to measure the receive power of each secondary cell of the secondary cell group.
The apparatus of claim 40, further comprising:

means for transmitting, after the cell selection timer expires, a third reconfiguration message comprising a first bit field and a second bit field, the first bit field indicating that the UE is to not measure the signal quality of each secondary cell of the secondary cell group, and the second bit field indicating that the UE is to measure the receive power of each secondary cell of the secondary cell group.
The apparatus of claim 35, further comprising:

means for receiving, from the UE based at least in part on transmitting the reconfiguration message to the UE, a plurality of measurement reports for a plurality of secondary cells associated with the base station, the plurality of measurement reports indicating the signal strength associated with each secondary cell of the plurality of secondary cells, wherein the plurality of secondary cells comprise at least the first secondary cell and the second secondary cell;

means for sorting, based at least in part on the received plurality of measurement reports, the plurality of secondary cells according to signal quality;

means for selecting the second secondary cell of the plurality of secondary cells based at least in part on the second secondary cell associated with a highest signal quality among the sorted plurality of secondary cell;

means for transmitting, to the UE, a message indicating that the UE is to perform a random access procedure to establish a wireless connection with the second secondary cell; and

means for communicating with the UE using a primary cell of the base station and the second secondary cell associated with the base station following the random access procedure.
The apparatus of claim 35, wherein the receive power comprises a reference signal received power.
The apparatus of claim 35, wherein the signal quality comprises a signal to noise ratio, or a signal-to-noise and interference ratio, or a reference signal received quality, or received signal strength indicator, or any combination thereof.
The apparatus of claim 35, wherein a primary cell of the base station is configured to operate according to a release of a first wireless communications standard, and the first secondary cell and the second secondary cell associated with the base station are configured to operate according to a release of a second wireless communications standard.
The apparatus of claim 47, wherein the first wireless communications standard comprises Long Term Evolution (LTE) , and the second wireless communications standard comprises New Radio (NR) .
The apparatus of claim 35, wherein the failure associated with the communications with the first secondary cell comprises a failure to decode signals broadcast by the first secondary cell.
The apparatus of claim 35, wherein the failure associated with the communications with the first secondary cell comprises a failure associated with performing a random access procedure with the first secondary cell.
The apparatus of claim 35, wherein the signals broadcast by the first secondary cell associated with the base station comprise a master information block broadcast from the first secondary cell using a physical broadcast channel.
A non-transitory computer-readable medium storing code for wireless communications at a base station, the code comprising instructions executable by a processor to:

receive, from one or more user equipments (UEs) associated with a first secondary cell of the base station, one or more failure messages indicating a failure associated with communications with the first secondary cell;

determine that a number of the received one or more failure messages for the first secondary cell exceeds a failure message threshold; and

transmit, to a UE of the one or more UEs based at least in part on the determined number of failure messages exceeding the failure message threshold, a reconfiguration message that indicates for the UE to measure a signal quality and a receive power for the first secondary cell and for a second secondary cell associated with the base station.
The non-transitory computer-readable medium of claim 52, wherein the instructions are further executable to:

receive a measurement report based at least in part on transmitting the reconfiguration message to the UE, wherein the measurement report comprises the signal quality and the receive power for the first secondary cell and the second secondary cell.
The non-transitory computer-readable medium of claim 52, wherein the instructions are further executable to:

determine a signal quality of the second secondary cell exceeds a signal quality of the first secondary cell; and

transmit, based at least in part on determining that the signal quality of the second secondary cell exceeds the signal quality of the first secondary cell, a second reconfiguration message to the UE that indicates to use the second secondary cell.
The non-transitory computer-readable medium of claim 54, wherein the reconfiguration message or the second reconfiguration message, or both, comprise a radio resource control reconfiguration message.
The non-transitory computer-readable medium of claim 54, wherein the instructions are further executable to:

receive a reconfiguration complete message from the UE responsive at least in part to the transmitted second reconfiguration message.
The non-transitory computer-readable medium of claim 52, wherein the instructions are further executable to:

initiate a cell selection timer based at least in part on the determined number of failure messages exceeding the failure message threshold.
The non-transitory computer-readable medium of claim 57, wherein the reconfiguration message is transmitted after initiating the cell selection timer.
The non-transitory computer-readable medium of claim 57, wherein the instructions to transmit the reconfiguration message are executable to:

transmit, after the cell selection timer is initiated and before the cell section timer expires, the reconfiguration message comprising a first bit field and a second bit field, the first bit field indicating that the UE is to measure the signal quality of each secondary cell of the secondary cell group, and the second bit field indicating that the UE is to measure the receive power of each secondary cell of the secondary cell group.
The non-transitory computer-readable medium of claim 57, wherein the instructions are further executable to:

transmit, after the cell selection timer expires, a third reconfiguration message comprising a first bit field and a second bit field, the first bit field indicating that the UE is to not measure the signal quality of each secondary cell of the secondary cell group, and the second bit field indicating that the UE is to measure the receive power of each secondary cell of the secondary cell group.
The non-transitory computer-readable medium of claim 52, wherein the instructions are further executable to:

receive, from the UE based at least in part on transmitting the reconfiguration message to the UE, a plurality of measurement reports for a plurality of secondary cells associated with the base station, the plurality of measurement reports indicating the signal strength associated with each secondary cell of the plurality of secondary cells, wherein the plurality of secondary cells comprise at least the first secondary cell and the second secondary cell;

sort, based at least in part on the received plurality of measurement reports, the plurality of secondary cells according to signal quality;

select the second secondary cell of the plurality of secondary cells based at least in part on the second secondary cell associated with a highest signal quality among the sorted plurality of secondary cell;

transmit, to the UE, a message indicating that the UE is to perform a random access procedure to establish a wireless connection with the second secondary cell; and

communicate with the UE using a primary cell of the base station and the second secondary cell associated with the base station following the random access procedure.
The non-transitory computer-readable medium of claim 52, wherein the receive power comprises a reference signal received power.
The non-transitory computer-readable medium of claim 52, wherein the signal quality comprises a signal to noise ratio, or a signal-to-noise and interference ratio, or a reference signal received quality, or received signal strength indicator, or any combination thereof.
The non-transitory computer-readable medium of claim 52, wherein a primary cell of the base station is configured to operate according to a release of a first wireless communications standard, and the first secondary cell and the second secondary cell associated with the base station are configured to operate according to a release of a second wireless communications standard.
The non-transitory computer-readable medium of claim 64, wherein the first wireless communications standard comprises Long Term Evolution (LTE) , and the second wireless communications standard comprises New Radio (NR) .
The non-transitory computer-readable medium of claim 52, wherein the failure associated with the communications with the first secondary cell comprises a failure to decode signals broadcast by the first secondary cell.
The non-transitory computer-readable medium of claim 52, wherein the failure associated with the communications with the first secondary cell comprises a failure associated with performing a random access procedure with the first secondary cell.
The non-transitory computer-readable medium of claim 52, wherein the signals broadcast by the first secondary cell associated with the base station comprise a master information block broadcast from the first secondary cell using a physical broadcast channel.