WO2021223135A1

WO2021223135A1 - Sharing bar cell information in dual new radio user equipment

Info

Publication number: WO2021223135A1
Application number: PCT/CN2020/088891
Authority: WO
Inventors: Hao Zhang; Fojian ZHANG; Jian Li; Chaofeng HUI; Yi Liu; Jing Zhou; Tianya LIN
Original assignee: Qualcomm Incorporated
Priority date: 2020-05-07
Filing date: 2020-05-07
Publication date: 2021-11-11

Abstract

Methods, systems, and devices for wireless communications are described. A user equipment (UE) may establish a connection with a first cell associated with a radio access technology and in a non-standalone mode of operation. The UE may receive, from a base station supporting the first cell, a connection release message after establishing the connection, and may modify a list of cells associated with a first subscription of the UE based on receiving the connection release message. In some examples, the UE may send, for a second subscription of the UE, a synchronization message on modifying the list of cells. The UE may then perform, for the second subscription and based on the synchronization message, a reselection procedure to establish a connection with a second cell associated with the radio access technology.

Description

SHARING BAR CELL INFORMATION IN DUAL NEW RADIO USER EQUIPMENT

FIELD OF TECHNOLOGY

The following relates generally to wireless communications and more specifically to sharing bar cell information in dual new radio (NR) user equipment (UE) .

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 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 UE.

A UE may support multiple subscriptions to connect with multiple networks simultaneously. Additionally, a UE may support a non-standalone architecture to connect with multiple networks. In some cases, communications in a non-standalone architecture may be unstable and may adversely impact the performance of the UE.

SUMMARY

The described techniques relate to improved methods, systems, devices, and apparatuses that support sharing bar cell information in dual new radio (NR) user equipment (UE) . Generally, the described techniques provide for improvements in communications systems by sharing cell information among multiple subscriptions of a user equipment (UE) . A UE may support multiple subscriptions, where both subscriptions may be associated with the same cell. Each subscription of the UE may also support a non-standalone architecture, where different radio access technologies are utilized concurrently (e.g., at least partially overlapping) or simultaneously. In some examples, a first subscription and a second subscription of the UE may establish connection with a first cell associated with a radio access technology and in a non-standalone mode of operation. The first subscription may transmit a service request to a base station supporting the first cell, and may receive a connection release message. Upon receiving the connection release message, the first subscription may add information associated with the first cell to a list of cells. For example, the first subscription may refrain from communicating with the first cell based on the list of cells. The first subscription may then indicate information associated with the first cell to a second subscription on the UE. For instance, the first subscription may send a synchronization message for the second subscription of the UE. The UE may then perform, for the second subscription and based on the synchronization message, a reselection procedure to establish a connection with a second cell associated with the radio access technology.

A method of wireless communication at a UE is described. The method may include establishing a connection with a first cell associated with a radio access technology and in a non-standalone mode of operation, receiving, from a base station supporting the first cell, a connection release message after establishing the connection, modifying a list of cells associated with a first subscription of the UE based on receiving the connection release message, sending, for a second subscription of the UE, a synchronization message based on modifying the list of cells, and performing, for the second subscription and based on the synchronization message, a reselection procedure to establish a connection with a second cell associated with the radio access technology.

An apparatus for wireless communication at a UE is described. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to establish a connection with a first cell associated with a radio access technology and in a non-standalone mode of operation, receive, from a base station supporting the first cell, a connection release message after establishing the connection, modify a list of cells associated with a first subscription of the UE based on receiving the connection release message, send, for a second subscription of the UE, a synchronization message based on modifying the list of cells, and perform, for the second subscription and based on the synchronization message, a reselection procedure to establish a connection with a second cell associated with the radio access technology.

Another apparatus for wireless communication at a UE is described. The apparatus may include means for establishing a connection with a first cell associated with a radio access technology and in a non-standalone mode of operation, receiving, from a base station supporting the first cell, a connection release message after establishing the connection, modifying a list of cells associated with a first subscription of the UE based on receiving the connection release message, sending, for a second subscription of the UE, a synchronization message based on modifying the list of cells, and performing, for the second subscription and based on the synchronization message, a reselection procedure to establish a connection with a second cell associated with the radio access technology.

A non-transitory computer-readable medium storing code for wireless communication at a UE is described. The code may include instructions executable by a processor to establish a connection with a first cell associated with a radio access technology and in a non-standalone mode of operation, receive, from a base station supporting the first cell, a connection release message after establishing the connection, modify a list of cells associated with a first subscription of the UE based on receiving the connection release message, send, for a second subscription of the UE, a synchronization message based on modifying the list of cells, and perform, for the second subscription and based on the synchronization message, a reselection procedure to establish a connection with a second cell associated with the radio access technology.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for performing, for the first subscription and based on modifying the list of cells associated with the first subscription, a second reselection procedure to establish a connection with the second cell associated with the radio access technology.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting, to the base station supporting the first cell, a service request, where the connection release message may be received within a determined duration after transmitting the service request.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, modifying the list of cells further may include operations, features, means, or instructions for adding information associated with the first cell to the list of cells associated with the first subscription. 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 back-off timer upon modifying the list of cells associated with the first subscription, where sending the synchronization message may be based on the back-off timer.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for re-enabling connectivity for the first subscription with the first cell upon expiration of the back-off timer. Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting, to the base station supporting the first cell, a service request based on the synchronization message, and receiving, from the base station supporting the first cell, a second connection release message based on transmitting the service request, where performing the reselection procedure may be based on receiving the second connection release message.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for modifying a second list of cells associated with the second subscription based on receiving the second connection release message. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, modifying the second list of cells further may include operations, features, means, or instructions for adding information associated with the first cell to the second list of cells associated with the second subscription.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining that the connection release message may be received within a determined duration after transmitting the service request, where performing the reselection procedure may be based on determining that the connection release message may be received within the determined duration.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the service request includes a radio resource control connection establishment request. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the service request and the second connection release message may be associated with the second subscription.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for updating a counter for each connection release message received within a determined duration after transmitting a service request, where modifying the list of cells may be based on the counter satisfying a threshold value.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, establishing the connection with the first cell further may include operations, features, means, or instructions for transmitting, to the base station supporting the first cell, an attach request message, and receiving, from the base station supporting the first cell, an attach accept message in response to transmitting the attach request message.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the connection with the first cell may be associated with the first subscription, the second subscription, or both. Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting, to a second base station supporting the second cell, a first attach request message, receiving, from the second base station supporting the second cell, a first attach accept message in response to transmitting the first attach request message, transmitting, to the second base station supporting the second cell, a second attach request message, and receiving, from the second base station supporting the second cell, a second attach accept message in response to transmitting the second attach request message.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the first attach request message and the first attach accept message may be associated with the first subscription. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the second attach request message and the second attach accept message may be associated with the second subscription.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the first attach request message and the second attach request message include an indication of a capability to support dual connectivity with new radio technology. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the synchronization message includes an indication of the first cell.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the first subscription and the second subscription may be associated with a common operator. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the first cell may have a higher priority than the second cell.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the radio access technology includes at least one of a long term evolution technology, a fourth generation (4G) technology, a new radio technology, a fifth generation (5G) technology, or a combination thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example of a wireless communications system that supports sharing bar cell information in dual new radio (NR) user equipment (UE) in accordance with aspects of the present disclosure.

FIG. 2 illustrates an example of a wireless communications system in accordance with aspects of the present disclosure.

FIG. 3 illustrates an example of a process flow in accordance with aspects of the present disclosure.

FIG. 4 illustrates an example of a process flow in accordance with aspects of the present disclosure.

FIGs. 5 and 6 show block diagrams of devices in accordance with aspects of the present disclosure.

FIG. 7 shows a block diagram of a communications manager in accordance with aspects of the present disclosure.

FIG. 8 shows a diagram of a system including a device in accordance with aspects of the present disclosure.

FIGs. 9 through 11 show flowcharts illustrating methods in accordance with aspects of the present disclosure.

DETAILED DESCRIPTION

A user equipment (UE) may support a dual (e.g., non-standalone) architecture, where different radio access technologies can be use concurrently or simultaneously. For example, a non-standalone UE may anchor on or connect to a cell associated with a first radio access technology (e.g., Long-Term Evolution (LTE) ) , while facilitating communications with a cell associated with a second radio access technology (e.g., New Radio (NR) ) . In some cases, the cells associated with each radio access technology may be related to a single base station or may be related to separate base stations.

As described herein, some wireless networks may be configured to operate in a dual-connectivity configuration. For example, a wireless network may be configured to operate in an evolved universal terrestrial radio access network (E-UTRAN) in NR, which may be referred to as EN-DC, as 5G EN-DC, or as a 5G NR dual-connectivity configuration or system, or some combination thereof. Broadly, the dual-connectivity configuration may support the UE being connected to two cells or two devices, such as base stations, (or nodes) at the same time. In some examples, one node (e.g., a master node) may be a 5G (e.g., an NR) node and a second node (e.g., a secondary node) may be an LTE node. In other examples, the master node may be an LTE node and the secondary node may be a 5G (e.g., NR) node. In some examples, the master node and the secondary node may be 5G (e.g., NR) nodes or they may both be LTE nodes. The dual-connectivity configuration may be supported when inter-connectivity has been established between the master node and secondary node, via one or more backhaul links, core network functions, or the like. Some examples of dual-connectivity may include the UE being concurrently or simultaneously connected to the LTE and 5G NR node or the UE utilizing the LTE node for control plane information and the 5G NR node for user plane traffic, or any combination thereof. In some aspects, the dual-connectivity configuration may support direct or split signaling radio bearers (or both) .

In some wireless communications systems, a UE may be configured with a dual-subscriber identity module (SIM) . Each SIM may be associated with a subscription that allows the UE to connect to a network. In some cases, each SIM may connect to a different network. For example, the UE may have a first SIM with a first subscription providing access to a first network (e.g., 5G network) , and a second SIM with a second subscription providing access to a second network (e.g., 4G network) . Alternatively, the first SIM with the first subscription and the second SIM with the second subscription may provide access to the same network. In some examples, the first SIM with the first subscription and the second SIM with the second subscription may be configured to support NR technology and may be configured to concurrently or simultaneously operate in a non-standalone mode of operation.

According to one or more aspects of the present disclosure, the UE may establish a connection with a cell of a radio access technology using a first subscription and a second subscription. While operating in a non-standalone mode of operation, a first subscription of the UE may establish a connection with a base station supporting a first cell. The first subscription of the UE may receive a release message from the base station after the UE sends a service request for data transfer. In some cases, the first subscription of the UE may re-establish a connection with the first cell in response to receiving the release message. The UE, however, may frequently receive release messages or may receive a release message within a threshold time period after sending the service request.

If the first subscription of the UE receives one or more release messages from the first cell, the first subscription may include the first cell in a list of barred cells and may refrain from communicating with the first cell for a duration, such as a predetermined duration. However, the second subscription of the UE may be unaware of the list of barred cells and may attempt to establish a connection with the first cell. The second subscription may also receive a connection release message, thus unnecessarily adversely impacting the efficiency and the user experience at the second subscription of the UE.

To mitigate the communications interruptions between a UE in a non-standalone mode of operation and a cell, a first subscription of the UE may be configured to send an indication of a barred cell to a second subscription of the UE. In some examples, a first subscription of the UE may be configured to detect when connectivity with a first cell meets a condition, such as being unstable. For example, the first subscription may receive a connection release message after establishing the connection with the first cell. Upon receiving the connection release message, the first subscription may modify a list of cells to add information associated with the first cell to the list of cells. In some examples, the first subscription may send, for a second subscription of the UE, a synchronization message based on modifying the list of cells. For example, upon barring the first cell at the first subscription, the UE may support sending an indication of the barred cell to the second subscription. The UE may then perform, for the second subscription and based on the synchronization message, a reselection procedure to establish a connection with a second cell associated with the radio access technology.

UEs capable of supporting sharing bar cell information between multiple subscriptions may utilize the techniques described herein to experience power saving, such as reduced power consumption and extended battery life while ensuring reliable and efficient communications between UEs and base stations, among other benefits. Particular aspects of the subject matter described in this disclosure may be implemented to realize one or more of the following potential advantages. The techniques employed by the described UEs may provide benefits and enhancements to the operation of the UEs. For example, operations performed by the UEs may provide improvements to wireless operations. Additionally or alternatively, the techniques employed by the described UEs may provide time and power savings for multiple subscriptions. In some examples, the UEs may support high reliability and low latency communications, among other examples, in accordance with aspects of the present disclosure. The described techniques may thus include features for improvements to power consumption, spectral efficiency, higher data rates and, in some examples, may promote enhanced efficiency for high reliability and low latency operations, among other benefits.

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 wireless communications systems and process flows. Aspects of the disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flowcharts that relate to sharing bar cell information in dual NR UE.

FIG. 1 illustrates an example of a wireless communications system 100 that supports sharing bar cell information in dual NR UE 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 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.

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

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

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

Signal waveforms transmitted over a carrier may be made up of multiple subcarriers (e.g., using multi-carrier modulation (MCM) techniques such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT- S-OFDM) ) . In a system employing MCM techniques, a resource element may 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.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

The wireless communications system 100 may be a packet-based network that operates according to a layered protocol stack. In the user plane, communications at the bearer or 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.

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

A UE may support operations to manage unstable communications that may allow the UE to establish connections with multiple subscriptions. In some wireless communications systems, a UE may establish a connection with a cell of a radio access technology using a first subscription and a second subscription. A first subscription of the UE may establish a connection with a base station supporting a first cell. The first subscription of the UE may transmit a service request to the base station associated with the first cell and may receive a release message from the base station after the UE sends a service request. Upon receiving one or more release messages from the first cell, the first subscription may include the first cell in a list of barred cells and may refrain from communicating with the first cell for a duration, such as a predetermined duration. However, the second subscription of the UE may be unaware of the list of barred cells and may attempt to establish a connection with the first cell, thus adversely affecting the efficiency and the user experience at the second subscription of the UE.

According to one or more aspects of the present disclosure, a first subscription and a second subscription of a UE 115 may establish a connection with a first cell associated with a radio access technology and in a non-standalone mode of operation. In some examples, a first subscription of the UE 115 may receive a connection release message after establishing the connection with the first cell. Upon receiving the connection release message, the first subscription may modify a list of cells to add information associated with the first cell to the list of cells. In some examples, the first subscription may send, for a second subscription of the UE 115, a synchronization message based on modifying the list of cells. The UE 115 may then perform, for the second subscription and based on the synchronization message, a reselection procedure to establish a connection with a second cell associated with the radio access technology.

FIG. 2 illustrates an example of a wireless communications system 200 that supports sharing bar cell information in dual NR UE in accordance with aspects of the present disclosure. In some examples, the wireless communications system 200 may implement aspects of the wireless communications system 100. The wireless communications system 200 may include base stations 105-a and 105-b, and UE 115-a, which may be examples of base stations 105 and a UE 115 as described with reference to FIG. 1. Each base station 105 may serve a geographic coverage area. In some cases, one or more of the geographic coverage areas served by base stations 105-a and 105-b may overlap. In some cases, the UE 115-a may be configured with multiple SIM functionality and may be configured to support improved multiple subscription communications by sharing bar cell information. For example, when the UE 115-a limits communications for a first subscription with a barred cell served by one base station 105, the UE 115-a may provide an indication of the barred cell to a second subscription to improve communications.

In the example of FIG. 2, the UE 115-a may operate in a non-standalone mode. That is, the UE 115-a may support a non-standalone architecture, where different radio access technologies may be utilized concurrently or simultaneously by different serving base stations. For example, a non-standalone UE may anchor on or connect to a first cell while facilitating communications with a second cell. Additionally or alternatively, a non-standalone UE may anchor on or connect to a cell associated with a first radio access technology (e.g., LTE) , while facilitating communications with a cell associated with a second radio access technology (e.g., NR) . In some cases, the cells associated with each radio access technology may be contained at a single base station or may be located on separate base stations.

In some examples, the UE 115-a may support multiple subscriptions. In some cases, the UE 115-a may be an example of a dual-SIM, or multi-SIM, UE 115. For example, UE 115-a may include a first SIM 205 and a second SIM 210. The first SIM 205 may provide a first subscription, and the second SIM 210 may provide a second subscription. In some cases, both subscriptions (e.g., the first SIM 205 and the second SIM 210) may be configured to support a non-standalone architecture. In some instances, the first SIM 205 and the second SIM 210 may be camped on a first cell. That is, the UE 115-a may communicate with a first cell via the first subscription and may concurrently or simultaneously communicate with the first cell via the second subscription. In some cases, the first cell may be supported by a different base station 105, or the first cell may be supported by the same base station 105, or any combination thereof. In some cases, the first cell may be associated with a radio access technology. In some cases, each network may be supported by a different base station 105, or each network may be supported by the same base station 105, or any combination thereof. In one example, the base station 105-a and 105-b may support a non-standalone 5G network. In some cases, a network may refer to a cell.

Because the UE 115-a is configured with two subscriptions, the UE 115-a may support communications with two base stations 105 at a time. As depicted herein, the UE 115-a may be configured to support dual-connectivity. In one example, the UE 115-a may communicate with base station 105-a associated with a first cell (e.g., an anchor cell) associated with a radio access technology (e.g., a 5G network, an LTE network, or a 4G network) via communication link 215. For example, UE 115-a may establish a connection with the base station 105-a for a first subscription and a second subscription via communication link 215. As depicted herein, the UE 115-a may establish a connection with the base station 105-b over communication link 220. Additionally or alternatively, as the UE 115-a is configured to support dual-connectivity, the UE 115-a may support communications with two base stations 105 (e.g., two networks) at a time.

In some cases, the UE 115-a may be configured to support improved communications by managing unstable radio resource control connections while operating in a non-standalone architecture (or non-standalone mode) . For example, the UE 115-a may limit communications on an abnormal network served by one base station 105 associated with a radio access technology to improve efficiency and reduce latency. As described herein, upon detecting abnormal network behavior while operating in a non-standalone mode, the UE 115-a may be configured to disable the connection with the anchor cell of the non-standalone mode, and may refrain from communicating with the cell (e.g., add the cell to a barred cell list) for a duration, such as a predetermined duration. In some examples, if the UE 115-a determines that a cell is added to a barred cell list for a first subscription, then the UE 115-a may provide an indication of the barred cell to a second subscription. Additionally or alternatively, other wireless devices, such as base stations 105-a and 105-b, or some combination of these base stations 105, may implement procedures to improve multiple subscription communications by sharing bar cell information.

As described herein, some wireless communications systems provide for non-standalone connections. The UE 115-a may establish a connection with the base station 105-a and transmit and receive signals to base station 105-a over communication link 215. For example, both subscriptions of the UE 115-a may establish a connection with the base station 105-a. In some cases, the UE 115-a may experience unstable connections. While operating in a non-standalone mode of operation, a first subscription of the UE 115-a may establish a connection with a base station supporting a first cell (e.g., base station 105-a) . The first subscription of the UE 115-a may receive a release message from the base station after the UE 115-a sends a service request for data transfer. If the UE 115-a frequently receives release messages from the first cell, the UE 115-a may refrain from communicating with the first cell for a duration, such as a predetermined duration. In one example, the first subscription (e.g., first SIM 205) at the UE 115-a may add the first cell to a list of cells barred from communication. However, a second subscription at the UE 115-a may not be aware of the list of cells barred by the first subscription. The second subscription may try to establish a connection with a cell included in the list of cells barred by the first subscription (e.g., the first cell) , which may impact efficiency related to the second subscription that could otherwise be avoided based on the list of cells barred by the first subscription.

To mitigate the communications interruptions between a UE (such as UE 115-a) in a non-standalone mode of operation and a cell, a first subscription of the UE 115-a may be configured to send an indication of a barred cell to a second subscription of the UE 115-a. In some cases, the first subscription and the second subscription may be associated with a common operator. In some examples, to decrease latency and improve resource efficiency, a first subscription of the UE 115-a may be configured to detect when connectivity with a first cell is unstable for that subscription. Upon detecting an unstable connection with the first cell, the first subscription of the UE 115-a may modify a list of cells to include information associated with the first cell. Specifically, the first subscription of the UE 115-a may be configured to include the first cell in a list of cells to be barred for a threshold duration. In the example of FIG. 2, the base station 105-a may be associated with the first cell.

The first subscription may trigger a reselection procedure to connect to a second cell served by the base station 105-b. In some examples, the first subscription of the UE 115-a may send an indication of the barred cell (i.e., the first cell associated with the base station 105-a) to a second subscription of the UE 115-a. According to one or more aspects of the present disclosure, each time a cell is added to a list of cells barred from communication, both subscriptions (e.g., the first SIM 205 and the second SIM 210) at the UE 115-a may trigger cell reselection to camp on another cell. For example, after receiving an indication of barred cell, the second subscription may perform a reselection procedure to establish a connection with the second cell (i.e., the second cell served by the base station 105-b) . In some examples, the first cell and the second cell may be associated with the same radio access technology.

According to one or more aspects of the present disclosure, the second SIM 210 may receive a synchronization message including an indication of a cell (e.g., the first cell associated with the base station 105-a) barred at the first SIM 205. Upon receiving the indication of the barred cell (e.g., “bar_cell_list_sync_req” synchronization message) , the second SIM 210 may transmit another service request to the first cell. If the second SIM 210 receives a release message, the second SIM 210 and may trigger a cell re-selection upon receiving the release message (instead of waiting to receive a threshold number of release messages) from the first cell. In some case, the second SIM 210 may trigger a cell reselection process to switch a connection to the base station 105-b associated with the second cell.

FIG. 3 illustrates an example of a process flow 300 that supports sharing bar cell information in dual NR UE in accordance with aspects of the present disclosure. In some examples, the process flow 300 may implement or may be implemented by aspects of wireless communications system 100 as described in FIG. 1 and wireless communications system 200 as described in FIG. 2. The process flow 300 may illustrate an example of sharing information of a barred cell between multiple subscriptions for improved communications.

For example, a UE, such as a UE described with reference to FIGs. 1 and 2, may support dual-connectivity. For instance, the UE may support a non-standalone mode of communication. In one example, the UE may support a first subscription 305-a and a second subscription 305-b which may be used for communications with a first cell 310-a (LTE Cell_1) , or a second cell 310-b (LTE Cell_2) , or any combination thereof. In some examples, the first subscription 305-a and the second subscription 305-b may switch between cells 310 based on a previously enabled cell demonstrating a network issue. In some cases, the cells 310 may each be served by a different base station, or multiple cells 310 may be served by the same base station 105, where the one or more base stations may be examples of the corresponding wireless devices described with reference to FIG. 1 and FIG. 2. In some cases, a cell may refer to a network as described with reference to FIG. 2. In some cases, instead of a UE implementing procedures to improve unstable communications, another device, such as a base station may implement the procedures.

In the following description of the process flow 300, the operations between the first subscription 305-a, the second subscription 305-b, the first cell 310-a (LTE Cell_1) , and the second cell 310-b (LTE Cell_2) may be transmitted in a different order than the example order shown, or the operations performed by the first subscription 305-a, the second subscription 305-b the first cell 310-a (LTE Cell_1) , and the second cell 310-b (LTE Cell_2) may be performed in different orders or at different times. Some operations may also be omitted from the process flow 300, and other operations may be added to the process flow 300.

At 312, the second subscription 305-b (or the UE supporting the second subscription 305-b) may establish a connection with the first cell 310-a (LTE Cell_1) associated with a radio access technology and in a non-standalone mode of operation. For example, the second subscription 305-b may transmit, to a base station supporting the first cell 310-a, an attach request message. In some cases, the attach request message may include or otherwise indicate a tracking area update request message.

At 314, the second subscription 305-b may receive, from the base station supporting the first cell 310-a (LTE Cell_1) , an attach accept message in response to transmitting the attach request message. In some examples, the attach receipt message may be or include a tracking area update accept message. Although not shown in the example of FIG. 3, it may be understood that the first subscription 305-a may also establish a connection with the first cell 310-a (LTE Cell_1) associated with the radio access technology and in the non- standalone mode of operation. Thus, the first subscription 305-a and the second subscription 305-b may be connected to the same cell (e.g., the first cell 310-a) .

In some cases, one subscription or both subscriptions (e.g., the first subscription 305-a and the second subscription 305-b) may enable dual connectivity with NR. The UE supporting the subscriptions (e.g., the first subscription 305-a and the second subscription 305-b) may use the attach request message to provide an indication of a capability to support dual connectivity with NR.

At 316, the first subscription 305-a may transmit, to a base station supporting the first cell 310-a (LTE Cell_1) , a service request. In some examples, the service request may include a radio resource control connection establishment request.

At 318, the first subscription 305-a may receive, from the base station supporting the first cell 310-a (LTE Cell_1) , a connection release message after establishing the connection and transmitting the service request. In some cases, the connection release message may include a resource control connection release message. For example, the first cell 310-a may send a connection release message within a determined duration after receiving the service request.

At 320, the UE supporting the first subscription 305-a may modify a list of cells associated with the first subscription 305-a based on receiving the connection release message. For example, the first subscription 305-a may add information associated with the first cell 310-a to the list of cells associated with the first subscription. In some cases, the first subscription 305-a may determine that the connection release message (at 318) is received within a determined duration after transmitting the service request (at 316) . Additionally or alternatively, the first subscription 305-a may update a counter for each connection release message received within a determined duration after transmitting a service request (not shown) . In some cases, the first subscription 305-a may modify the list of cells based on the counter satisfying a threshold value. As described in the example of FIG. 3, the first subscription 305-a may add information identify the LTE Cell_1 to a list of cells associated with the first subscription 305-a (e.g., a list of barred cells) .

At 322, the first subscription 305-a (i.e., the UE supporting the first subscription 305-a) may initiate a back-off timer upon modifying the list of cells associated with the first subscription 305-a. At 324, the UE may perform, for the first subscription 305-a and based on modifying the list of cells associated with the first subscription, a reselection procedure to establish a connection with the second cell 310-b associated with the radio access technology.

At 326, the first subscription 305-a of the UE may send, to the second subscription 305-b of the UE, a synchronization message based on modifying the list of cells. For example, upon identifying the first cell 310-a (e.g., a cell associated with an unstable connection) , the first subscription 305-a may transmit an indication of the first cell 310-a to the second subscription 305-b.

At 328, the UE may perform, for the second subscription 305-b of the UE and based on the synchronization message, a reselection procedure to establish a connection with the second cell 310-b associated with the radio access technology. For example, the second subscription 305-b may switch its connection to camp on the second cell 310-b (LTE Cell_2) after receiving an indication that the first cell 310-a is barred at the first subscription 305-a. In some cases, after performing the reselection procedure for the first subscription 305-a and the second subscription 305-b, the UE may perform procedure 1.

At 330, the first subscription 305-a (or the UE supporting the first subscription 305-a) may transmit, to a second base station supporting the second cell 310-b (LTE Cell_2) , an attach request message. The attach request message may include or otherwise indicate a tracking area update request message. The UE, for the first subscription 305-a, may provide an indication of a capability to support dual connectivity with NR via the attach request message. At 332, the first subscription 305-a may receive, from the base station supporting the second cell 310-b (LTE Cell_2) , an attach accept message in response to transmitting the attach request message (at 330) .

At 334, the second subscription 305-b (or the UE supporting the second subscription 305-b) may transmit, to the second base station supporting the second cell 310-b (LTE Cell_2, ) an attach request message. As depicted herein, the attach request message may include a tracking area update request message and an indication of a capability of the UE to support dual connectivity with NR. At 336, the second subscription 305-b may receive, from the base station supporting the second cell 310-b (LTE Cell_2) , an attach accept message in response to transmitting the attach request message (at 334) .

FIG. 4 illustrates an example of a process flow 400 that supports sharing bar cell information in dual NR UE in accordance with aspects of the present disclosure. In some examples, the process flow 400 may implement or may be implemented by aspects of wireless communications system 100 as described in FIG. 1 and wireless communications system 200 as described in FIG. 2. The process flow 400 may illustrate an example of sharing information of a barred cell between multiple subscriptions for improved communications.

For example, a UE, such as a UE described with reference to FIGs. 1 and 2, may support dual-connectivity. For instance, the UE may support a non-standalone mode of communication. As described herein, the UE may support a first subscription 405-a and a second subscription 405-b which may be used for communications with a first cell 410-a (LTE Cell_1) , or a second cell 410-b (LTE Cell_2) , or any combination thereof. In some examples, the cells 410 may each be served by a different base station, or multiple cells 410 may be served by the same base station 105, where the one or more base stations may be examples of the corresponding wireless devices described with reference to FIG. 1 and FIG. 2. In some cases, a cell 410 may refer to a network as described with reference to FIG. 2. In some cases, instead of a UE implementing procedures to improve unstable communications, another device, such as a base station may implement the procedures.

In the following description of the process flow 400, the operations between the first subscription 405-a, the second subscription 405-b, the first cell 410-a (LTE Cell_1) , and the second cell 410-b (LTE Cell_2) may be transmitted in a different order than the example order shown, or the operations performed by the first subscription 405-a, the second subscription 405-b the first cell 410-a (LTE Cell_1) , and the second cell 410-b (LTE Cell_2) may be performed in different orders or at different times. Some operations may also be omitted from the process flow 400, and other operations may be added to the process flow 400.

At 412, the second subscription 405-b (or the UE supporting the second subscription 405-b) may establish a connection with the first cell 410-a (LTE Cell_1) associated with a radio access technology and in a non-standalone mode of operation. As depicted herein, the radio access technology may include at least one of an LTE technology, a 4G technology, an NR technology, a 5G technology, or any combination thereof. The second subscription 405-b may transmit, to a base station supporting the first cell 410-a, an attach request message. In some cases, the attach request message may include or otherwise indicate a tracking area update request message. The attach request message may further include an indication of a capability of the UE to support dual connectivity with NR.

At 414, the second subscription 405-b may receive, from the base station supporting the first cell 410-a (LTE Cell_1) , an attach accept message in response to transmitting the attach request message. In some examples, the attach receipt message may be or include a tracking area update accept message. Although not shown in the example of FIG. 4, it may be understood that the first subscription 405-a may also establish a connection with the first cell 410-a (LTE Cell_1) either prior to or after the second subscription 405-b. An attach request message transmitted by the UE for the first subscription 405-a may also include an indication of a capability of the UE to support dual connectivity with NR. In some cases, the first subscription 405-a and the second subscription 405-b may be associated with a common operator.

At 416, the first subscription 405-a (or the UE supporting the first subscription 405-a) may transmit, to a base station supporting the first cell 410-a (LTE Cell_1) , a service request. In some examples, the service request may include a radio resource control connection establishment request. At 418, the first subscription 405-a may receive, from the base station supporting the first cell 410-a (LTE Cell_1) , a connection release message after transmitting the service request.

At 420, the UE may modify a list of cells associated with the first subscription 405-a based on receiving the connection release message. For example, modifying the list of cells may include adding information associated with the first cell 410-a to the list of cells associated with the first subscription 405-a.

At 422, the first subscription 405-a (i.e., the UE supporting the first subscription 405-a) may initiate a back-off timer upon modifying the list of cells associated with the first subscription 405-a. At 424, the UE may perform, for the first subscription 405-a and based on modifying the list of cells associated with the first subscription, a reselection procedure to establish a connection with the second cell 410-b associated with the radio access technology. In some cases, the first cell 410-a may have a higher priority than the second cell 410-b.

At 426, the first subscription 405-a may send, to the second subscription 405-b, a synchronization message based on modifying the list of cells. The first subscription 405-amay indicate that the first cell 410-a (LTE Cell_1) has been added to a list of barred cells.

At 428, the second subscription 405-b may provisionally update a list of cells associated with the second subscription 405-b. At 430, the second subscription 405-b may transmit, to the base station supporting the first cell 410-a (LTE Cell_1) , a service request based on the synchronization message received at 426.

At 434, the second subscription 405-b may receive, from the base station supporting the first cell 410-a, a second connection release message based on transmitting the service request. In some cases, the second subscription 405-b may determine that the connection release message is received within a determined duration after transmitting the service request. In some cases, the service request may include a resource control connection establishment request.

Although not depicted with reference to FIG. 4, upon receiving the second connection release message, the second subscription 405-b (or the UE supporting the second subscription 405-b) may modify a second list of cells associated with the second subscription 405-b. In some cases, modifying the second list of cells associated with the second subscription 405-b may include adding information associated with the first cell 410-a to the second list of cells associated with the second subscription 405-b.

At 436, the UE may perform, for the second subscription 405-b of the UE and based on the synchronization message, a reselection procedure to establish a connection with the second cell 410-b associated with the radio access technology. In some cases, after performing the reselection procedure for the first subscription 405-a and the second subscription 405-b, the UE may perform procedure 1.

At 438, the first subscription 405-a (or the UE supporting the first subscription 405-a) may transmit, to a second base station supporting the second cell 410-b (LTE Cell_2) , an attach request message. At 440, the first subscription 405-a may receive, from the base station supporting the second cell 410-b (LTE Cell_2) , an attach accept message in response to transmitting the attach request message (at 438) .

At 442, the second subscription 405-b (or the UE supporting the second subscription 405-b) may transmit, to the second base station supporting the second cell 410-b (LTE Cell_2, ) an attach request message. At 444, the second subscription 405-b may receive, from the base station supporting the second cell 410-b (LTE Cell_2) , an attach accept message in response to transmitting the attach request message (at 442) . As depicted herein, the attach request messages may include or otherwise indicate a tracking area update request message and an indication of a capability of the UE to support dual connectivity with NR. Additionally or alternatively, the attach accept messages as depicted herein may include or otherwise indicate a tracking area update accept message.

FIG. 5 shows a block diagram 500 of a device 505 that supports sharing bar cell information in dual NR UE in accordance with aspects of the present disclosure. The device 505 may be an example of aspects of a UE 115 as described herein. The device 505 may include a receiver 510, a communications manager 515, and a transmitter 520. 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 sharing bar cell information in dual NR UE, 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 820 described with reference to FIG. 8. The receiver 510 may utilize a single antenna or a set of antennas.

The communications manager 515 may establish a connection with a first cell associated with a radio access technology and in a non-standalone mode of operation, receive, from a base station supporting the first cell, a connection release message after establishing the connection, modify a list of cells associated with a first subscription of the UE based on receiving the connection release message, send, for a second subscription of the UE, a synchronization message based on modifying the list of cells, and perform, for the second subscription and based on the synchronization message, a reselection procedure to establish a connection with a second cell associated with the radio access technology. The communications manager 515 may be an example of aspects of the communications manager 810 described herein.

The communications manager 515, 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 515, 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 515, 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 515, 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 515, 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 any combination thereof in accordance with various aspects of the present disclosure.

The transmitter 520 may transmit signals generated by other components of the device 505. In some examples, the transmitter 520 may be collocated with a receiver 510 in a transceiver module. For example, the transmitter 520 may be an example of aspects of the transceiver 820 described with reference to FIG. 8. The transmitter 520 may utilize a single antenna or a set of antennas.

FIG. 6 shows a block diagram 600 of a device 605 that supports sharing bar cell information in dual NR UE in accordance with aspects of the present disclosure. The device 605 may be an example of aspects of a device 505, or a UE 115 as described herein. The device 605 may include a receiver 610, a communications manager 615, and a transmitter 645. The device 605 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses) .

The receiver 610 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to sharing bar cell information in dual NR UE, etc. ) . Information may be passed on to other components of the device 605. The receiver 610 may be an example of aspects of the transceiver 820 described with reference to FIG. 8. The receiver 610 may utilize a single antenna or a set of antennas.

The communications manager 615 may be an example of aspects of the communications manager 515 as described herein. The communications manager 615 may include a connection establishment component 620, a release message component 625, a cell list modification component 630, a synchronization component 635, and a reselection component 640. The communications manager 615 may be an example of aspects of the communications manager 810 described herein.

The connection establishment component 620 may establish a connection with a first cell associated with a radio access technology and in a non-standalone mode of operation. The release message component 625 may receive, from a base station supporting the first cell, a connection release message after establishing the connection.

The cell list modification component 630 may modify a list of cells associated with a first subscription of the UE based on receiving the connection release message. The synchronization component 635 may send, for a second subscription of the UE, a synchronization message based on modifying the list of cells. The reselection component 640 may perform, for the second subscription and based on the synchronization message, a reselection procedure to establish a connection with a second cell associated with the radio access technology.

The transmitter 645 may transmit signals generated by other components of the device 605. In some examples, the transmitter 645 may be collocated with a receiver 610 in a transceiver module. For example, the transmitter 645 may be an example of aspects of the transceiver 820 described with reference to FIG. 8. The transmitter 645 may utilize a single antenna or a set of antennas.

FIG. 7 shows a block diagram 700 of a communications manager 705 that supports sharing bar cell information in dual NR UE in accordance with aspects of the present disclosure. The communications manager 705 may be an example of aspects of a communications manager 515, a communications manager 615, or a communications manager 810 described herein. The communications manager 705 may include a connection establishment component 710, a release message component 715, a cell list modification component 720, a synchronization component 725, a reselection component 730, a service request component 735, a timer component 740, a counter component 745, and an attach component 750. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses) .

The connection establishment component 710 may establish a connection with a first cell associated with a radio access technology and in a non-standalone mode of operation. In some cases, the radio access technology includes at least one of an LTE technology, a 4G technology, an NR technology, a 5G technology, or any combination thereof.

The release message component 715 may receive, from a base station supporting the first cell, a connection release message after establishing the connection. The cell list modification component 720 may modify a list of cells associated with a first subscription of the UE based on receiving the connection release message.

The synchronization component 725 may send, for a second subscription of the UE, a synchronization message based on modifying the list of cells. In some cases, the synchronization message includes an indication of the first cell. In some cases, the first subscription and the second subscription are associated with a common operator.

The reselection component 730 may perform, for the second subscription and based on the synchronization message, a reselection procedure to establish a connection with a second cell associated with the radio access technology. In some cases, the first cell has a higher priority than the second cell.

In some examples, the reselection component 730 may perform, for the first subscription and based on modifying the list of cells associated with the first subscription, a second reselection procedure to establish a connection with the second cell associated with the radio access technology.

The service request component 735 may transmit, to the base station supporting the first cell, a service request, where the connection release message is received within a determined duration after transmitting the service request. In some examples, the cell list modification component 720 may add information associated with the first cell to the list of cells associated with the first subscription.

The timer component 740 may initiate a back-off timer upon modifying the list of cells associated with the first subscription, where sending the synchronization message is based on the back-off timer. In some examples, the connection establishment component 710 may re-enable connectivity for the first subscription with the first cell upon expiration of the back-off timer.

In some examples, the service request component 735 may transmit, to the base station supporting the first cell, a service request based on the synchronization message. In some examples, the release message component 715 may receive, from the base station supporting the first cell, a second connection release message based on transmitting the service request, where performing the reselection procedure is based on receiving the second connection release message.

In some examples, the cell list modification component 720 may modify a second list of cells associated with the second subscription based on receiving the second connection release message. In some examples, the cell list modification component 720 may add information associated with the first cell to the second list of cells associated with the second subscription.

In some examples, the release message component 715 may determine that the connection release message is received within a determined duration after transmitting the service request, where performing the reselection procedure is based on determining that the connection release message is received within the determined duration. In some cases, the service request includes a radio resource control connection establishment request. In some cases, the service request and the second connection release message are associated with the second subscription.

The counter component 745 may update a counter for each connection release message received within a determined duration after transmitting a service request, where modifying the list of cells is based on the counter satisfying a threshold value.

The attach component 750 may transmit, to the base station supporting the first cell, an attach request message. In some examples, the attach component 750 may receive, from the base station supporting the first cell, an attach accept message in response to transmitting the attach request message.

In some examples, the attach component 750 may transmit, to a second base station supporting the second cell, a first attach request message. In some examples, the attach component 750 may receive, from the second base station supporting the second cell, a first attach accept message in response to transmitting the first attach request message.

In some examples, the attach component 750 may transmit, to the second base station supporting the second cell, a second attach request message. In some examples, the attach component 750 may receive, from the second base station supporting the second cell, a second attach accept message in response to transmitting the second attach request message.

In some cases, the connection with the first cell is associated with the first subscription, the second subscription, or both. In some cases, the first attach request message and the first attach accept message are associated with the first subscription. In some cases, the second attach request message and the second attach accept message are associated with the second subscription. In some cases, the first attach request message and the second attach request message include an indication of a capability to support dual connectivity with NR technology.

FIG. 8 shows a diagram of a system 800 including a device 805 that supports sharing bar cell information in dual NR UE in accordance with aspects of the present disclosure. The device 805 may be an example of or include the components of device 505, device 605, or a UE 115 as described herein. The device 805 may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including a communications manager 810, an I/O controller 815, a transceiver 820, an antenna 825, memory 830, and a processor 840. These components may be in electronic communication via one or more buses (e.g., bus 845) .

The communications manager 810 may establish a connection with a first cell associated with a radio access technology and in a non-standalone mode of operation, receive, from a base station supporting the first cell, a connection release message after establishing the connection, modify a list of cells associated with a first subscription of the UE based on receiving the connection release message, send, for a second subscription of the UE, a synchronization message based on modifying the list of cells, and perform, for the second subscription and based on the synchronization message, a reselection procedure to establish a connection with a second cell associated with the radio access technology.

The I/O controller 815 may manage input and output signals for the device 805. The I/O controller 815 may also manage peripherals not integrated into the device 805. In some cases, the I/O controller 815 may represent a physical connection or port to an external peripheral. In some cases, the I/O controller 815 may utilize an operating system such as

or another known operating system. In other cases, the I/O controller 815 may represent or interact with a modem, a keyboard, a mouse, a touchscreen, or a similar device. In some cases, the I/O controller 815 may be implemented as part of a processor. In some cases, a user may interact with the device 805 via the I/O controller 815 or via hardware components controlled by the I/O controller 815.

The transceiver 820 may communicate bi-directionally, via one or more antennas, wired, or wireless links as described above. For example, the transceiver 820 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 820 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 825. However, in some cases the device may have more than one antenna 825, which may be capable of concurrently transmitting or receiving multiple wireless transmissions.

The memory 830 may include RAM and ROM. The memory 830 may store computer-readable, computer-executable code 835 including instructions that, when executed, cause the processor to perform various functions described herein. In some cases, the memory 830 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 840 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 840 may be configured to operate a memory array using a memory controller. In other cases, a memory controller may be integrated into the processor 840. The processor 840 may be configured to execute computer-readable instructions stored in a memory (e.g., the memory 830) to cause the device 805 to perform various functions (e.g., functions or tasks supporting sharing bar cell information in dual NR UE) .

The code 835 may include instructions to implement aspects of the present disclosure, including instructions to support wireless communications. The code 835 may be stored in a non-transitory computer-readable medium such as system memory or other type of memory. In some cases, the code 835 may not be directly executable by the processor 840 but may cause a computer (e.g., when compiled and executed) to perform functions described herein.

FIG. 9 shows a flowchart illustrating a method 900 that supports sharing bar cell information in dual NR UE in accordance with aspects of the present disclosure. The operations of method 900 may be implemented by a UE 115 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. 5 through 8. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, a UE may perform aspects of the functions described below using special-purpose hardware.

At 905, the UE may establish a connection with a first cell associated with a radio access technology and in a non-standalone mode of operation. 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 establishment component as described with reference to FIGs. 5 through 8.

At 910, the UE may receive, from a base station supporting the first cell, a connection release message after establishing the connection. 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 a release message component as described with reference to FIGs. 5 through 8.

At 915, the UE may modify a list of cells associated with a first subscription of the UE based on receiving the connection release message. 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 cell list modification component as described with reference to FIGs. 5 through 8.

At 920, the UE may send, for a second subscription of the UE, a synchronization message based on modifying the list of cells. 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 a synchronization component as described with reference to FIGs. 5 through 8.

At 925, the UE may perform, for the second subscription and based on the synchronization message, a reselection procedure to establish a connection with a second cell associated with the radio access technology. 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 reselection component as described with reference to FIGs. 5 through 8.

FIG. 10 shows a flowchart illustrating a method 1000 that supports sharing bar cell information in dual NR UE in accordance with aspects of the present disclosure. The operations of method 1000 may be implemented by a UE 115 or its components as described herein. For example, the operations of method 1000 may be performed by a communications manager as described with reference to FIGs. 5 through 8. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, a UE may perform aspects of the functions described below using special-purpose hardware.

At 1005, the UE may establish a connection with a first cell associated with a radio access technology and in a non-standalone mode of operation. The operations of 1005 may be performed according to the methods described herein. In some examples, aspects of the operations of 1005 may be performed by a connection establishment component as described with reference to FIGs. 5 through 8.

At 1010, the UE may transmit, to the base station supporting the first cell, a service request, where the connection release message is received within a determined duration after transmitting the service request. The operations of 1010 may be performed according to the methods described herein. In some examples, aspects of the operations of 1010 may be performed by a service request component as described with reference to FIGs. 5 through 8.

At 1015, the UE may receive, from a base station supporting the first cell, a connection release message after establishing the connection. The operations of 1015 may be performed according to the methods described herein. In some examples, aspects of the operations of 1015 may be performed by a release message component as described with reference to FIGs. 5 through 8.

At 1020, the UE may add information associated with the first cell to the list of cells associated with the first subscription. The operations of 1020 may be performed according to the methods described herein. In some examples, aspects of the operations of 1020 may be performed by a cell list modification component as described with reference to FIGs. 5 through 8.

At 1025, the UE may modify a list of cells associated with a first subscription of the UE. The operations of 1025 may be performed according to the methods described herein. In some examples, aspects of the operations of 1025 may be performed by a cell list modification component as described with reference to FIGs. 5 through 8.

At 1030, the UE may send, for a second subscription of the UE, a synchronization message based on modifying the list of cells. The operations of 1030 may be performed according to the methods described herein. In some examples, aspects of the operations of 1030 may be performed by a synchronization component as described with reference to FIGs. 5 through 8.

At 1035, the UE may perform, for the second subscription and based on the synchronization message, a reselection procedure to establish a connection with a second cell associated with the radio access technology. The operations of 1035 may be performed according to the methods described herein. In some examples, aspects of the operations of 1035 may be performed by a reselection component as described with reference to FIGs. 5 through 8.

FIG. 11 shows a flowchart illustrating a method 1100 that supports sharing bar cell information in dual NR UE in accordance with aspects of the present disclosure. The operations of method 1100 may be implemented by a UE 115 or its components as described herein. For example, the operations of method 1100 may be performed by a communications manager as described with reference to FIGs. 5 through 8. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, a UE may perform aspects of the functions described below using special-purpose hardware.

At 1105, the UE may establish a connection with a first cell associated with a radio access technology and in a non-standalone mode of operation. The operations of 1105 may be performed according to the methods described herein. In some examples, aspects of the operations of 1105 may be performed by a connection establishment component as described with reference to FIGs. 5 through 8.

At 1110, the UE may receive, from a base station supporting the first cell, a connection release message after establishing the connection. The operations of 1110 may be performed according to the methods described herein. In some examples, aspects of the operations of 1110 may be performed by a release message component as described with reference to FIGs. 5 through 8.

At 1115, the UE may modify a list of cells associated with a first subscription of the UE based on receiving the connection release message. The operations of 1115 may be performed according to the methods described herein. In some examples, aspects of the operations of 1115 may be performed by a cell list modification component as described with reference to FIGs. 5 through 8.

At 1120, the UE may send, for a second subscription of the UE, a synchronization message based on modifying the list of cells. The operations of 1120 may be performed according to the methods described herein. In some examples, aspects of the operations of 1120 may be performed by a synchronization component as described with reference to FIGs. 5 through 8.

At 1125, the UE may perform, for the second subscription and based on the synchronization message, a reselection procedure to establish a connection with a second cell associated with the radio access technology. The operations of 1125 may be performed according to the methods described herein. In some examples, aspects of the operations of 1125 may be performed by a reselection component as described with reference to FIGs. 5 through 8.

At 1130, the UE may transmit, to the base station supporting the first cell, a service request based on the synchronization message. The operations of 1130 may be performed according to the methods described herein. In some examples, aspects of the operations of 1130 may be performed by a service request component as described with reference to FIGs. 5 through 8.

At 1135, the UE may receive, from the base station supporting the first cell, a second connection release message based on transmitting the service request, where performing the reselection procedure is based on receiving the second connection release message. The operations of 1135 may be performed according to the methods described herein. In some examples, aspects of the operations of 1135 may be performed by a release message component as described with reference to FIGs. 5 through 8.

At 1140, the UE may modify a second list of cells associated with the second subscription based on receiving the second connection release message. The operations of 1140 may be performed according to the methods described herein. In some examples, aspects of the operations of 1140 may be performed by a cell list modification component as described with reference to FIGs. 5 through 8.

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 communication at a user equipment (UE) , comprising:

establishing a connection with a first cell associated with a radio access technology and in a non-standalone mode of operation;

receiving, from a base station supporting the first cell, a connection release message after establishing the connection;

modifying a list of cells associated with a first subscription of the UE based at least in part on receiving the connection release message;

sending, for a second subscription of the UE, a synchronization message based at least in part on modifying the list of cells; and

performing, for the second subscription and based at least in part on the synchronization message, a reselection procedure to establish a connection with a second cell associated with the radio access technology.
The method of claim 1, further comprising:

performing, for the first subscription and based at least in part on modifying the list of cells associated with the first subscription, a second reselection procedure to establish a connection with the second cell associated with the radio access technology.
The method of claim 1, further comprising:

transmitting, to the base station supporting the first cell, a service request, wherein the connection release message is received within a determined duration after transmitting the service request.
The method of claim 1, wherein modifying the list of cells further comprises:

adding information associated with the first cell to the list of cells associated with the first subscription.
The method of claim 1, further comprising:

initiating a back-off timer upon modifying the list of cells associated with the first subscription, wherein sending the synchronization message is based at least in part on the back-off timer.
The method of claim 5, further comprising:

re-enabling connectivity for the first subscription with the first cell upon expiration of the back-off timer.
The method of claim 1, further comprising:

transmitting, to the base station supporting the first cell, a service request based at least in part on the synchronization message; and

receiving, from the base station supporting the first cell, a second connection release message based at least in part on transmitting the service request, wherein performing the reselection procedure is based at least in part on receiving the second connection release message.
The method of claim 7, further comprising:

modifying a second list of cells associated with the second subscription based at least in part on receiving the second connection release message.
The method of claim 8, wherein modifying the second list of cells further comprises:

adding information associated with the first cell to the second list of cells associated with the second subscription.
The method of claim 7, further comprising:

determining that the connection release message is received within a determined duration after transmitting the service request, wherein performing the reselection procedure is based at least in part on determining that the connection release message is received within the determined duration.
The method of claim 7, wherein the service request comprises a radio resource control connection establishment request.
The method of claim 7, wherein the service request and the second connection release message are associated with the second subscription.
The method of claim 1, further comprising:

updating a counter for each connection release message received within a determined duration after transmitting a service request, wherein modifying the list of cells is based at least in part on the counter satisfying a threshold value.
The method of claim 1, wherein establishing the connection with the first cell further comprises:

transmitting, to the base station supporting the first cell, an attach request message; and

receiving, from the base station supporting the first cell, an attach accept message in response to transmitting the attach request message.
The method of claim 14, wherein the connection with the first cell is associated with the first subscription, the second subscription, or both.
The method of claim 1, further comprising:

transmitting, to a second base station supporting the second cell, a first attach request message;

receiving, from the second base station supporting the second cell, a first attach accept message in response to transmitting the first attach request message;

transmitting, to the second base station supporting the second cell, a second attach request message; and

receiving, from the second base station supporting the second cell, a second attach accept message in response to transmitting the second attach request message.
The method of claim 16, wherein the first attach request message and the first attach accept message are associated with the first subscription.
The method of claim 16, wherein the second attach request message and the second attach accept message are associated with the second subscription.
The method of claim 16, wherein the first attach request message and the second attach request message comprise an indication of a capability to support dual connectivity with new radio technology.
The method of claim 1, wherein the synchronization message comprises an indication of the first cell.
The method of claim 1, wherein the first subscription and the second subscription are associated with a common operator.
The method of claim 1, wherein the first cell has a higher priority than the second cell.
The method of claim 1, wherein the radio access technology comprises at least one of a long term evolution technology, a fourth generation (4G) technology, a new radio technology, a fifth generation (5G) technology, or any combination thereof.
An apparatus for wireless communication at a user equipment (UE) , comprising:

a processor,

memory coupled with the processor; and

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

establish a connection with a first cell associated with a radio access technology and in a non-standalone mode of operation;

receive, from a base station supporting the first cell, a connection release message after establishing the connection;

modify a list of cells associated with a first subscription of the UE based at least in part on receiving the connection release message;

send, for a second subscription of the UE, a synchronization message based at least in part on modifying the list of cells; and

perform, for the second subscription and based at least in part on the synchronization message, a reselection procedure to establish a connection with a second cell associated with the radio access technology.
The apparatus of claim 24, wherein the instructions are further executable by the processor to cause the apparatus to:

perform, for the first subscription and based at least in part on modifying the list of cells associated with the first subscription, a second reselection procedure to establish a connection with the second cell associated with the radio access technology.
The apparatus of claim 24, wherein the instructions are further executable by the processor to cause the apparatus to:

transmit, to the base station supporting the first cell, a service request, wherein the connection release message is received within a determined duration after transmitting the service request.
The apparatus of claim 24, wherein the instructions to modify the list of cells further are executable by the processor to cause the apparatus to:

add information associated with the first cell to the list of cells associated with the first subscription.
The apparatus of claim 24, wherein the instructions are further executable by the processor to cause the apparatus to:

initiate a back-off timer upon modifying the list of cells associated with the first subscription, wherein sending the synchronization message is based at least in part on the back-off timer.
The apparatus of claim 28, wherein the instructions are further executable by the processor to cause the apparatus to:

re-enable connectivity for the first subscription with the first cell upon expiration of the back-off timer.
The apparatus of claim 24, wherein the instructions are further executable by the processor to cause the apparatus to:

transmit, to the base station supporting the first cell, a service request based at least in part on the synchronization message; and

receive, from the base station supporting the first cell, a second connection release message based at least in part on transmitting the service request, wherein performing the reselection procedure is based at least in part on receiving the second connection release message.
The apparatus of claim 30, wherein the instructions are further executable by the processor to cause the apparatus to:

modify a second list of cells associated with the second subscription based at least in part on receiving the second connection release message.
The apparatus of claim 31, wherein the instructions to modify the second list of cells further are executable by the processor to cause the apparatus to:

add information associated with the first cell to the second list of cells associated with the second subscription.
The apparatus of claim 30, wherein the instructions are further executable by the processor to cause the apparatus to:

determine that the connection release message is received within a determined duration after transmitting the service request, wherein performing the reselection procedure is based at least in part on determining that the connection release message is received within the determined duration.
The apparatus of claim 30, wherein the service request comprises a radio resource control connection establishment request.
The apparatus of claim 30, wherein the service request and the second connection release message are associated with the second subscription.
The apparatus of claim 24, wherein the instructions are further executable by the processor to cause the apparatus to:

update a counter for each connection release message received within a determined duration after transmitting a service request, wherein modifying the list of cells is based at least in part on the counter satisfying a threshold value.
The apparatus of claim 24, wherein the instructions to establish the connection with the first cell further are executable by the processor to cause the apparatus to:

transmit, to the base station supporting the first cell, an attach request message; and

receive, from the base station supporting the first cell, an attach accept message in response to transmitting the attach request message.
The apparatus of claim 37, wherein the connection with the first cell is associated with the first subscription, the second subscription, or both.
The apparatus of claim 24, wherein the instructions are further executable by the processor to cause the apparatus to:

transmit, to a second base station supporting the second cell, a first attach request message;

receive, from the second base station supporting the second cell, a first attach accept message in response to transmitting the first attach request message;

transmit, to the second base station supporting the second cell, a second attach request message; and

receive, from the second base station supporting the second cell, a second attach accept message in response to transmitting the second attach request message.
The apparatus of claim 39, wherein the first attach request message and the first attach accept message are associated with the first subscription.
The apparatus of claim 39, wherein the second attach request message and the second attach accept message are associated with the second subscription.
The apparatus of claim 39, wherein the first attach request message and the second attach request message comprise an indication of a capability to support dual connectivity with new radio technology.
The apparatus of claim 24, wherein the synchronization message comprises an indication of the first cell.
The apparatus of claim 24, wherein the first subscription and the second subscription are associated with a common operator.
The apparatus of claim 24, wherein the first cell has a higher priority than the second cell.
The apparatus of claim 24, wherein the radio access technology comprises at least one of a long term evolution technology, a fourth generation (4G) technology, a new radio technology, a fifth generation (5G) technology, or any combination thereof.
An apparatus for wireless communication at a user equipment (UE) , comprising:

means for establishing a connection with a first cell associated with a radio access technology and in a non-standalone mode of operation;

means for receiving, from a base station supporting the first cell, a connection release message after establishing the connection;

means for modifying a list of cells associated with a first subscription of the UE based at least in part on receiving the connection release message;

means for sending, for a second subscription of the UE, a synchronization message based at least in part on modifying the list of cells; and

means for performing, for the second subscription and based at least in part on the synchronization message, a reselection procedure to establish a connection with a second cell associated with the radio access technology.
The apparatus of claim 47, further comprising:

means for performing, for the first subscription and based at least in part on modifying the list of cells associated with the first subscription, a second reselection procedure to establish a connection with the second cell associated with the radio access technology.
The apparatus of claim 47, further comprising:

means for transmitting, to the base station supporting the first cell, a service request, wherein the connection release message is received within a determined duration after transmitting the service request.
The apparatus of claim 47, wherein the means for modifying the list of cells further comprises:

means for adding information associated with the first cell to the list of cells associated with the first subscription.
The apparatus of claim 47, further comprising:

means for initiating a back-off timer upon modifying the list of cells associated with the first subscription, wherein sending the synchronization message is based at least in part on the back-off timer.
The apparatus of claim 51, further comprising:

means for re-enabling connectivity for the first subscription with the first cell upon expiration of the back-off timer.
The apparatus of claim 47, further comprising:

means for transmitting, to the base station supporting the first cell, a service request based at least in part on the synchronization message; and

means for receiving, from the base station supporting the first cell, a second connection release message based at least in part on transmitting the service request, wherein performing the reselection procedure is based at least in part on receiving the second connection release message.
The apparatus of claim 53, further comprising:

means for modifying a second list of cells associated with the second subscription based at least in part on receiving the second connection release message.
The apparatus of claim 54, wherein the means for modifying the second list of cells further comprises:

means for adding information associated with the first cell to the second list of cells associated with the second subscription.
The apparatus of claim 53, further comprising:

means for determining that the connection release message is received within a determined duration after transmitting the service request, wherein performing the reselection procedure is based at least in part on determining that the connection release message is received within the determined duration.
The apparatus of claim 53, wherein the service request comprises a radio resource control connection establishment request.
The apparatus of claim 53, wherein the service request and the second connection release message are associated with the second subscription.
The apparatus of claim 47, further comprising:

means for updating a counter for each connection release message received within a determined duration after transmitting a service request, wherein modifying the list of cells is based at least in part on the counter satisfying a threshold value.
The apparatus of claim 47, wherein the means for establishing the connection with the first cell further comprises:

means for transmitting, to the base station supporting the first cell, an attach request message; and

means for receiving, from the base station supporting the first cell, an attach accept message in response to transmitting the attach request message.
The apparatus of claim 60, wherein the connection with the first cell is associated with the first subscription, the second subscription, or both.
The apparatus of claim 47, further comprising:

means for transmitting, to a second base station supporting the second cell, a first attach request message;

means for receiving, from the second base station supporting the second cell, a first attach accept message in response to transmitting the first attach request message;

means for transmitting, to the second base station supporting the second cell, a second attach request message; and

means for receiving, from the second base station supporting the second cell, a second attach accept message in response to transmitting the second attach request message.
The apparatus of claim 62, wherein the first attach request message and the first attach accept message are associated with the first subscription.
The apparatus of claim 62, wherein the second attach request message and the second attach accept message are associated with the second subscription.
The apparatus of claim 62, wherein the first attach request message and the second attach request message comprise an indication of a capability to support dual connectivity with new radio technology.
The apparatus of claim 47, wherein the synchronization message comprises an indication of the first cell.
The apparatus of claim 47, wherein the first subscription and the second subscription are associated with a common operator.
The apparatus of claim 47, wherein the first cell has a higher priority than the second cell.
The apparatus of claim 47, wherein the radio access technology comprises at least one of a long term evolution technology, a fourth generation (4G) technology, a new radio technology, a fifth generation (5G) technology, or any combination thereof.
A non-transitory computer-readable medium storing code for wireless communication at a user equipment (UE) , the code comprising instructions executable by a processor to:

establish a connection with a first cell associated with a radio access technology and in a non-standalone mode of operation;

receive, from a base station supporting the first cell, a connection release message after establishing the connection;

modify a list of cells associated with a first subscription of the UE based at least in part on receiving the connection release message;

send, for a second subscription of the UE, a synchronization message based at least in part on modifying the list of cells; and

perform, for the second subscription and based at least in part on the synchronization message, a reselection procedure to establish a connection with a second cell associated with the radio access technology.
The non-transitory computer-readable medium of claim 70, wherein the instructions are further executable to:

perform, for the first subscription and based at least in part on modifying the list of cells associated with the first subscription, a second reselection procedure to establish a connection with the second cell associated with the radio access technology.
The non-transitory computer-readable medium of claim 70, wherein the instructions are further executable to:

transmit, to the base station supporting the first cell, a service request, wherein the connection release message is received within a determined duration after transmitting the service request.
The non-transitory computer-readable medium of claim 70, wherein the instructions to modify the list of cells further are executable to:

add information associated with the first cell to the list of cells associated with the first subscription.
The non-transitory computer-readable medium of claim 70, wherein the instructions are further executable to:

initiate a back-off timer upon modifying the list of cells associated with the first subscription, wherein sending the synchronization message is based at least in part on the back-off timer.
The non-transitory computer-readable medium of claim 74, wherein the instructions are further executable to:

re-enable connectivity for the first subscription with the first cell upon expiration of the back-off timer.
The non-transitory computer-readable medium of claim 70, wherein the instructions are further executable to:

transmit, to the base station supporting the first cell, a service request based at least in part on the synchronization message; and

receive, from the base station supporting the first cell, a second connection release message based at least in part on transmitting the service request, wherein performing the reselection procedure is based at least in part on receiving the second connection release message.
The non-transitory computer-readable medium of claim 76, wherein the instructions are further executable to:

modify a second list of cells associated with the second subscription based at least in part on receiving the second connection release message.
The non-transitory computer-readable medium of claim 77, wherein the instructions to modify the second list of cells further are executable to:

add information associated with the first cell to the second list of cells associated with the second subscription.
The non-transitory computer-readable medium of claim 76, wherein the instructions are further executable to:

determine that the connection release message is received within a determined duration after transmitting the service request, wherein performing the reselection procedure is based at least in part on determining that the connection release message is received within the determined duration.
The non-transitory computer-readable medium of claim 76, wherein the service request comprises a radio resource control connection establishment request.
The non-transitory computer-readable medium of claim 76, wherein the service request and the second connection release message are associated with the second subscription.
The non-transitory computer-readable medium of claim 70, wherein the instructions are further executable to:

update a counter for each connection release message received within a determined duration after transmitting a service request, wherein modifying the list of cells is based at least in part on the counter satisfying a threshold value.
The non-transitory computer-readable medium of claim 70, wherein the instructions to establish the connection with the first cell further are executable to:

transmit, to the base station supporting the first cell, an attach request message; and

receive, from the base station supporting the first cell, an attach accept message in response to transmitting the attach request message.
The non-transitory computer-readable medium of claim 83, wherein the connection with the first cell is associated with the first subscription, the second subscription, or both.
The non-transitory computer-readable medium of claim 70, wherein the instructions are further executable to:

transmit, to a second base station supporting the second cell, a first attach request message;

receive, from the second base station supporting the second cell, a first attach accept message in response to transmitting the first attach request message;

transmit, to the second base station supporting the second cell, a second attach request message; and

receive, from the second base station supporting the second cell, a second attach accept message in response to transmitting the second attach request message.
The non-transitory computer-readable medium of claim 85, wherein the first attach request message and the first attach accept message are associated with the first subscription.
The non-transitory computer-readable medium of claim 85, wherein the second attach request message and the second attach accept message are associated with the second subscription.
The non-transitory computer-readable medium of claim 85, wherein the first attach request message and the second attach request message comprise an indication of a capability to support dual connectivity with new radio technology.
The non-transitory computer-readable medium of claim 70, wherein the synchronization message comprises an indication of the first cell.
The non-transitory computer-readable medium of claim 70, wherein the first subscription and the second subscription are associated with a common operator.
The non-transitory computer-readable medium of claim 70, wherein the first cell has a higher priority than the second cell.
The non-transitory computer-readable medium of claim 70, wherein the radio access technology comprises at least one of a long term evolution technology, a fourth generation (4G) technology, a new radio technology, a fifth generation (5G) technology, or any combination thereof.