WO2021212453A1

WO2021212453A1 - Service recovery techniques for wireless communications systems

Info

Publication number: WO2021212453A1
Application number: PCT/CN2020/086613
Authority: WO
Inventors: Chaofeng HUI; Fojian ZHANG; Hao Zhang; Yuankun ZHU; Jian Li; Pan JIANG; Quanling ZHANG; Ying Wang; Bo Yu
Original assignee: Qualcomm Incorporated
Priority date: 2020-04-24
Filing date: 2020-04-24
Publication date: 2021-10-28

Abstract

Methods, systems, and devices for wireless communications are described. A user equipment (UE) and a base station may communicate using a first radio access technology. The UE may transmit, via the first radio access technology, a first control message indicating a capability to communicate data using a second radio access technology. The base station may transmit, to the UE, a configuration message based on receiving the first control message. The configuration message may indicate a network configuration associated with the second radio access technology. The UE may transmit, to the base station, a second control message indicating a capability to communicate data using the first radio access technology based on the network configuration associated with the second radio access technology being unsupported by the UE.

Description

SERVICE RECOVERY TECHNIQUES FOR WIRELESS COMMUNICATIONS SYSTEMS

FIELD OF TECHNOLOGY

The following relates generally to wireless communications and more specifically to service recovery techniques for wireless communications systems.

BACKGROUND

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

SUMMARY

The described techniques relate to improved methods, systems, devices, and apparatuses that support service recovery techniques for wireless communications systems. Generally, the described techniques enable a user equipment (UE) and/or a base station to implement one or more service recovery schemes as described herein. For example, a UE may communicate with a base station using a first radio access technology (RAT) . The UE may transmit a control message indicating a capability to communicate using a second RAT (e.g., in addition to or alternative to communicating using the first RAT) . The base station may receive the control message and may transmit a configuration message associated with the second RAT in response to the control message. The configuration message may indicate one or more feature information elements (IEs) associated with a network configuration for communications using the second RAT. In some examples, the UE may determine that the network configuration is not supported by the UE (e.g., one or more of the feature IEs may be unsupported by the UE) . In such examples, the UE may implement a fallback procedure as described herein.

For example, the UE may transmit a second control message based on the network configuration being unsupported by the UE. The second control message may indicate a capability of the UE to communicate using the first RAT (e.g., the UE may indicate a request to communicate using the first RAT in response to determining that the network configuration of the second RAT is unsupported at the UE) . In some examples, the second control message may be a tracking area update request. In some examples, the second control message may be an attach request associated with the first RAT. The base station and the UE may communicate using the first RAT based on the second control message. As an example, the UE may initiate a timer associated with the fallback procedure and communicate using the first RAT until an expiration of the timer. Upon expiration of the timer, the UE may attempt to communicate using the second RAT. For example, the UE may switch from a single RAT, such as the first RAT, to both the first RAT and the second RAT (e.g., the first RAT and the second RAT may be connected simultaneously, for example, in accordance with a dual connection mode, a non-standalone (NSA) mode, or both) .

A method of wireless communications at a UE is described. The method may include transmitting, to a base station via a first RAT, a first control message indicating a capability to communicate data using a second RAT, receiving a configuration message based on the first control message, the configuration message indicating a network configuration associated with the second RAT, and transmitting a second control message indicating a capability to communicate data using the first RAT based on the network configuration associated with the second RAT being unsupported by the UE.

An apparatus for wireless communications 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 transmit, to a base station via a first RAT, a first control message indicating a capability to communicate data using a second RAT, receive a configuration message based on the first control message, the configuration message indicating a network configuration associated with the second RAT, and transmit a second control message indicating a capability to communicate data using the first RAT based on the network configuration associated with the second RAT being unsupported by the UE.

Another apparatus for wireless communications at a UE is described. The apparatus may include means for transmitting, to a base station via a first RAT, a first control message indicating a capability to communicate data using a second RAT, receiving a configuration message based on the first control message, the configuration message indicating a network configuration associated with the second RAT, and transmitting a second control message indicating a capability to communicate data using the first RAT based on the network configuration associated with the second RAT being unsupported by the UE.

A non-transitory computer-readable medium storing code for wireless communications at a UE is described. The code may include instructions executable by a processor to transmit, to a base station via a first RAT, a first control message indicating a capability to communicate data using a second RAT, receive a configuration message based on the first control message, the configuration message indicating a network configuration associated with the second RAT, and transmit a second control message indicating a capability to communicate data using the first RAT based on the network configuration associated with the second RAT being unsupported by the UE.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the second control message may include operations, features, means, or instructions for transmitting the second control message that may be a tracking area update request message indicating the capability to communicate data using the first RAT.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the tracking area update request message may include operations, features, means, or instructions for transmitting the tracking area update request message based on a determination that the network configuration may be unsupported.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving a tracking area update accept message based on the tracking area update request message, transmitting a service request message associated with the first RAT based on the tracking area update accept message, and communicating with the base station via a data service path associated with the first RAT established based on the service request message.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting a detach request message to the base station based at least in part the network configuration associated with the second RAT being unsupported.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the detach request message further may include operations, features, means, or instructions for transmitting the detach request message to the base station based on a determination that the network configuration may be unsupported.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving a detach accept message based on the detach request message.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the second control message may include operations, features, means, or instructions for transmitting the second control message that may be an attach request message associated with the first RAT based on receiving the detach accept message.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving an attach accept message associated with the first RAT based on the attach request message, and communicating with the base station via a data service path associated with the first RAT established based on the attach request message.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the first control message indicates a first value for a dual connectivity new radio (DCNR) parameter and the second control message indicates a second value for the DCNR parameter that differs from the first value.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the configuration message may include operations, features, means, or instructions for receiving the configuration message that indicates to add a secondary cell group for a data service path.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving a second configuration message configuring a data service path associated with the first RAT based on transmitting the second control message, and communicating with the base station via the data service path.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the second control message indicates the capability to communicate data using the first RAT instead of the second RAT.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the first control message may include operations, features, means, or instructions for transmitting the first control message that may be an attach request message associated with the second RAT.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving an attach accept message associated with the second RAT based on the attach request message, and transmitting a service request message associated with the second RAT based on receiving the attach accept message, where receiving the configuration message may be based on transmitting the service request message.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the first RAT may be a LTE RAT and the second RAT may be a New Radio (NR) RAT.

A method of wireless communications at a base station is described. The method may include receiving, from a UE via a first RAT, a first control message indicating a capability to communicate data using a second RAT, transmitting a configuration message based on the first control message, the configuration message indicating a network configuration associated with the second RAT, and receiving a second control message indicating a capability to communicate data using the first RAT based on the network configuration associated with the second RAT being unsupported by the UE.

An apparatus for wireless communications at a base station is described. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to receive, from a UE via a first RAT, a first control message indicating a capability to communicate data using a second RAT, transmit a configuration message based on the first control message, the configuration message indicating a network configuration associated with the second RAT, and receive a second control message indicating a capability to communicate data using the first RAT based on the network configuration associated with the second RAT being unsupported by the UE.

Another apparatus for wireless communications at a base station is described. The apparatus may include means for receiving, from a UE via a first RAT, a first control message indicating a capability to communicate data using a second RAT, transmitting a configuration message based on the first control message, the configuration message indicating a network configuration associated with the second RAT, and receiving a second control message indicating a capability to communicate data using the first RAT based on the network configuration associated with the second RAT being unsupported by the UE.

A non-transitory computer-readable medium storing code for wireless communications at a base station is described. The code may include instructions executable by a processor to receive, from a UE via a first RAT, a first control message indicating a capability to communicate data using a second RAT, transmit a configuration message based on the first control message, the configuration message indicating a network configuration associated with the second RAT, and receive a second control message indicating a capability to communicate data using the first RAT based on the network configuration associated with the second RAT being unsupported by the UE.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the second control message may include operations, features, means, or instructions for receiving the second control message that may be a tracking area update request message indicating the capability to communicate data using the first RAT.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the tracking area update request message may include operations, features, means, or instructions for receiving the tracking area update request message based on a determination that the network configuration may be unsupported.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting a tracking area update accept message based on the tracking area update request message, receiving a service request message associated with the first RAT based on the tracking area update accept message, and communicating with the UE via a data service path associated with the first RAT established based on the service request message.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving a detach request message from the UE based on the network configuration associated with the second RAT being unsupported.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the detach request message further may include operations, features, means, or instructions for receiving the detach request message to the base station based on a determination that the network configuration may be unsupported.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting a detach accept message based on the detach request message.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the second control message may include operations, features, means, or instructions for receiving the second control message that may be an attach request message associated with the first RAT based on the detach accept message.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting an attach accept message associated with the first RAT based on the attach request message, and communicating with the UE via a data service path associated with the first RAT established based on the attach request message.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the first control message indicates a first value for a DCNR parameter and the second control message indicates a second value for the DCNR parameter that differs from the first value.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the configuration message may include operations, features, means, or instructions for transmitting the configuration message that indicates to add a secondary cell group for a data service path.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting a second configuration message configuring a data service path associated with the first RAT based on the second control message, and communicating with the UE via the data service path.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the first control message may include operations, features, means, or instructions for receiving the first control message that may be an attach request message associated with the second RAT.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting an attach accept message associated with the second RAT based on the attach request message, and receiving a service request message associated with the second RAT based on the attach accept message, where transmitting the configuration message may be based on receiving the service request message.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the first RAT may be an LTE RAT and the second RAT may be an NR RAT.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example of a system for wireless communications 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.

FIG. 5 illustrates an example of a process flow in accordance with aspects of the present disclosure.

FIGs. 6 and 7 show block diagrams of devices in accordance with aspects of the present disclosure.

FIG. 8 shows a block diagram of a communications manager in accordance with aspects of the present disclosure.

FIG. 9 shows a diagram of a system including a device in accordance with aspects of the present disclosure.

FIGs. 10 and 11 show block diagrams of devices that support service recovery techniques for wireless communications systems in accordance with aspects of the present disclosure.

FIG. 12 shows a block diagram of a communications manager in accordance with aspects of the present disclosure.

FIG. 13 shows a diagram of a system including a device in accordance with aspects of the present disclosure.

FIGs. 14 through 17 show flowcharts illustrating methods in accordance with aspects of the present disclosure.

DETAILED DESCRIPTION

In some wireless communications systems, wireless devices may communicate using one or more radio access technologies (RATs) . For example, a user equipment (UE) and a base station may communicate using a first RAT (e.g., Long Term Evolution (LTE) ) , a second RAT (e.g., New Radio (NR) ) , or both. The UE may establish communications with the base station using the first RAT. Additionally or alternatively, the UE may be capable of communications using the second RAT. The UE may indicate the capability to communicate using the second RAT to the base station. For example, the UE may transmit a control message indicating the capability (e.g., an attach request message with a dual-connectivity NR (DCNR) parameter indicating that the UE is capable of NR communications, for example, in a dual connection mode for communications using both NR and LTE) ) . The base station may transmit a configuration message associated with the second RAT based on receiving the control message. The configuration message may indicate a network configuration for communications using the second RAT (e.g., the configuration message may be an example of a radio resource control (RRC) reconfiguration message for the addition of a secondary cell group (SCG) for NR) . The configuration message may include one or more feature information elements (IEs) for communications using the second RAT.

However, in some cases the network configuration may not be supported by the UE (e.g., one or more indicated feature IEs may be unsupported by the UE) . In such cases, the UE may experience connectivity issues with the base station, such as a loss of data service (e.g., user plane data service associated with NR may be lost due to an invalid network configuration, while a control plane over LTE may be maintained for communications between the UE and the base station) . For example, the UE may be unable to communicate with the base station via the second RAT due to the unsupported network configuration (e.g., the UE may drop the SCG if one or more feature IEs are not supported by the UE) . Such connectivity issues may result in relatively poor user experience and relatively inefficient communications in the system.

According to the techniques described herein, the UE and the base station may be enabled to perform one or more fallback procedures for recovering service. For example, the UE may transmit a second control message based on the network configuration being unsupported by the UE. The second control message may indicate a capability of the UE to communicate using the first RAT. For example, the UE may transmit a request message or an attach message to communicate using the first RAT in response to determining that the network configuration of the second RAT is unsupported at the UE. In some examples, the second control message may be a tracking area update request (e.g., the tracking area update request may include a DCNR parameter indicating communications via the first RAT) . In some examples, the second control message may be an attach request associated with the first RAT (e.g., the UE may perform a detach procedure and transmit the attach request with a DCNR parameter indicating communications via the first RAT) . The base station and the UE may communicate using the first RAT based on the second control message. As an example, the UE may initiate a timer associated with the fallback procedure and communicate using the first RAT until an expiration of the timer. Upon expiration of the timer, the UE may attempt to communicate using the second RAT (e.g., the UE may communicate using both the first RAT and the second RAT in a dual connection mode) . For example, the UE may transmit an attach request with a DCNR parameter indicating communications via the second RAT at a subsequent time period.

Aspects of the disclosure are initially described in the context of wireless communications systems. Aspects of the disclosure are then described in the context of process flows. Aspects of the disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flowcharts that relate to service recovery techniques for wireless communications systems.

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

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

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

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

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

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

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

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

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 (NSA) mode where a connection is anchored using a different carrier (e.g., of the same or a different RAT) . For example, a UE 115 may operate in the NSA mode and communicate in a dual connection (e.g., dual connectivity) mode using a first RAT (e.g., LTE) and a second RAT (e.g., NR) .

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

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

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

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

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

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

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

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

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

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

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

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

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

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 UE 115 and a base station 105 may communicate using one or more networks and/or RATs. For example, a UE 115 and a base station 105 may communicate using LTE, NR, or both, among other examples of RATs and networks. The UE 115 may establish communications with the base station 105 using a first RAT (e.g., LTE) . Additionally or alternatively, the UE 115 may be capable of communications using a second RAT (e.g., NR) . The UE 115 may indicate the capability to communicate using the second RAT to the base station 105. For example, the UE 115 may transmit a control message indicating the capability (e.g., an attach request message with a DCNR parameter indicating that the UE is capable of NR communications) . The base station 105 may transmit a configuration message associated with the second RAT based on receiving the control message. The configuration message may indicate a network configuration for communications using the second RAT (e.g., the configuration message may be an example of a RRC reconfiguration message for the addition of a SCG for NR) . The configuration message may include one or more feature IEs for communications using the second RAT.

However, in some cases the network configuration may not be supported by the UE 115 (e.g., one or more indicated feature IEs may be unsupported by the UE 115) . In such cases, the UE 115 may experience connectivity issues with the base station 105, such as a loss of data service associated with the second RAT (e.g., the UE 115 may communicate via a control plane over LTE and may lose user plane data service associated with NR due to an unsupported network configuration) . For example, the UE 115 may be unable to communicate with the base station 105 via the second RAT (e.g., NR) due to the unsupported network configuration (e.g., the UE 115 may drop the SCG if one or more feature IEs are not supported by the UE 115) . Such connectivity issues may result in relatively poor user experience and relatively inefficient communications in the wireless communications system 100.

According to the techniques described herein, the UE 115 and the base station 105 may be enabled to perform one or more fallback procedures for recovering data service (e.g., maintaining user plane communications) . For example, the UE 115 may transmit a second control message based on the network configuration being unsupported by the UE 115. The second control message may indicate a capability of the UE 115 to communicate using the first RAT. For example, the UE 115 may transmit a request message or an attach message to communicate using the first RAT in response to determining that the network configuration of the second RAT is unsupported at the UE 115. In some examples, the second control message may be a tracking area update request (e.g., the tracking area update request may include a DCNR parameter requesting communications via the first RAT) . In some examples, the second control message may be an attach request associated with the first RAT (e.g., the UE 115 may perform a detach procedure and transmit the attach request with a DCNR parameter indicating communications via the first RAT) . The base station 105 and the UE 115 may communicate using the first RAT based on the second control message. As an example, the UE 115 may initiate a timer associated with a fallback procedure and communicate using the first RAT (e.g., via user plane data configured through LTE) until an expiration of the timer. Upon expiration of the timer, the UE 115 may attempt to communicate using the second RAT (e.g., the UE may switch from using a single RAT to using both the first RAT and the second RAT in a dual connection mode) . For example, the UE 115 may transmit an attach request with a DCNR parameter indicating communications via the second RAT, in addition or alternative to the first RAT, at a subsequent time period.

FIG. 2 illustrates an example of a wireless communications system 200 in accordance with aspects of the present disclosure. In some examples, the wireless communications system 200 may implement aspects of wireless communications system 100. The wireless communications system 200 may include UE 115-a and base station 105-a, which may be examples of a UE 115 and a base station 105 as described with reference to FIG. 1.

The UE 115-a and the base station 105-a may communicate using one or more RATs (e.g., LTE, LTE-A, LTE-A Pro, Wi-Fi, NR, etc. ) within the coverage area 110-a. For example, the UE 115-a may transmit uplink communications 210 to the base station 105-a via one or more RATs and the base station 105-a may transmit downlink communications 205 to the UE 115-a via one or more RATs. In some examples, the base station 105-a may be an example of an LTE anchor cell. The base station 105-a may offer non-standalone (NS) service to the UE 115-a.

The UE 115-a and the base station 105-a may establish communications via a first RAT (e.g., LTE) . In some examples, the UE 115-a and the base station 105-a may be capable of communications via a second RAT (e.g., NR) . For example, the UE 115-a may include dual connectivity capabilities (e.g., the UE 115-a may be an example of a multiple reception/transmission capable UE configured to utilize resources of multiple nodes of one or more base stations 105, such as a master node and a secondary node) . In such examples, the UE 115-a may communicate using an identifier associated with a master cell group (MCG) (e.g., via the first RAT) and the UE 115-a may communicate using an identifier associated with a SCG (e.g., via the second RAT) .

The UE 115-a may indicate the capability of the UE 115-a to communicate via the second RAT. For example, the UE 115-a may have established communications via the first RAT (e.g., LTE) and may transmit a control message (e.g., an attach request message) associated with the second RAT. Such a control message may include one or more parameters indicating the capability of the UE to communicate via the second RAT (e.g., the control message may include a DCNR parameter with a value of 1, among other examples) . The base station 105-a may transmit a configuration message associated with the second RAT based on receiving the control message. The configuration message may indicate a network configuration for communications using the second RAT (e.g., the configuration message may be an example of a RRC reconfiguration message for the addition of a SCG for NR communications) . The configuration message may include one or more feature IEs for communications using the second RAT.

In some examples, the indicated network configuration may not be supported by the UE 115-a, which may result in a loss of communications between the UE 115-a and the base station 105-a. Accordingly, the UE 115-a and the base station 105-a may be enabled to perform one or more fallback procedures as described herein. For example, the UE 115-a may transmit a second control message based on the network configuration being unsupported by the UE 115-a. The second control message may indicate a capability of the UE 115-a to communicate using the first RAT. For example, the UE 115-a may transmit a request message or an attach message to communicate using the first RAT in response to determining that the network configuration of the second RAT is unsupported at the UE 115-a. In some examples, the second control message may be a tracking area update request (e.g., the tracking area update request may include a DCNR parameter requesting communications via the first RAT, such as a DCNR parameter with a value of 0, among other examples) . In some examples, the second control message may be an attach request associated with the first RAT (e.g., the UE 115-a may perform a detach procedure prior to transmitting the attach request with a DCNR parameter indicating communications via the first RAT) . The base station 105-a and the UE 115-a may communicate using the first RAT based on the second control message. As an example, the UE 115-a may initiate a timer (e.g., a 5G back off timer) associated with the fallback procedure and communicate using the first RAT until an expiration of the timer. Upon expiration of the timer, the UE 115-a may attempt to communicate using the second RAT (e.g., the UE 115-a may communicate using both the first RAT and the second RAT in a dual connection mode) . For example, the UE 115-a may transmit an attach request with a DCNR parameter of 1 indicating communications via the second RAT at a time period subsequent or upon the expiration of the timer.

FIG. 3 illustrates an example of a process flow 300 in accordance with aspects of the present disclosure. In some examples, the process flow 300 may implement aspects of wireless communications system 100 or wireless communications system 200. The UE 115-b and the base station 105-b may be examples of a UE 115 and a base station 105 as described with reference to FIGs. 1 and 2. Generally, the process flow 300 may illustrate a first fallback procedure for service recovery in wireless communications systems.

In some examples, the UE 115-b may establish communications with the base station 105-b via a first RAT (e.g., LTE) using an attach procedure. For example, the UE 115-b may transmit an attach request associated with the first RAT (in addition or alternative to a second RAT, such as NR, if the UE is capable of dual connectivity operation) at 305. In some examples, the UE 115-b may perform an RRC connection establishment procedure (e.g., a random access channel (RACH) procedure) , a bearer setup procedure (e.g., configuration of a default LTE bearer for data communications) , or any combination thereof.

At 305, the UE 115-b may transmit an attach request message (e.g., a first control message) to the base station 105-b. For example, the UE 115-b may transmit the attach request message associated with the first RAT (e.g., in addition to or alternative to a second RAT, such as NR, if the UE is capable of dual connectivity operation) . As an example, the UE 115-b may be capable of communications using a second RAT (e.g., NR) and may initiate an attach procedure for dual connection with the first RAT and the second RAT. The attach request associated with the second RAT may include one or more parameters indicating the capability of the UE to communicate using the second RAT. For example, the attach request may include a DCNR parameter with a value indicating the UE capability (e.g., a DCNR parameter may be set to true, such as a field with a value of 1, and the DCNR parameter may indicate that the UE attach request is associated with a SCG for NR communications and LTE communications, among other examples of RAT communications) .

At 310, the base station 105-b may transmit an attach accept message to the UE 115-b based on receiving the attach request message. The attach accept message may indicate that the attach request message was successfully received at the base station 105-b and that the attach procedure was successful. At 315, the UE 115-b may transmit a service request message to the base station 105-b based on receiving the attach accept message. The service request message may be an example of a request for communications associated with the second RAT (e.g., a request for NR resources for communications between the UE 115-b and the base station 105-b) . In some examples, the service request may be a request for a packet switch (PS) data transfer procedure.

At 320, the base station 105-b may transmit a configuration message to the UE 115-b in response to the service request. The configuration message may indicate a network configuration associated with the second RAT (e.g., NR) . For example, the base station 105-b may transmit an RRC reconfiguration message (e.g., RRC_RECONFIG) indicating the addition of a SCG associated with the second RAT (e.g., NR) . The configuration message may include one or more parameters associated with the second RAT. For example, the configuration message may include one or more feature IEs for configuration of the SCG for communications via the second RAT. As an illustrative example, the configuration message may configure the UE 115-b with a data service path for the SCG for NR communications (e.g., a context may be established for a data bearer indicating the path over which data service may be provided from the network to the UE 115-b) .

At 325, the UE 115-b may determine whether the network configuration indicated by the configuration message is supported. In some examples, the UE 115-b may determine that the network configuration is supported at the UE 115-b (e.g., the configuration message does not include unsupported feature IEs associated with the second RAT) . In such examples, the UE 115-b may transmit a configuration response message indicating that the addition of the SCG and an associated bearer for communications via the second RAT is complete. In some cases, the procedure described with reference to operations 315–325 may be repeated. For example, the UE 115-b may gain service using the second RAT (e.g., when the network configuration is supported by the UE 115-b) at a first time period. The UE 115-b may transmit another service request at a second time period upon the service using the second RAT expiring (e.g., the UE 115-b may request service for the second RAT, request service using a different RAT, etc. ) .

In some other examples, the UE 115-b may determine that the network configuration is not supported at the UE 115-b (e.g., the configuration message may include unsupported feature IEs associated with the second RAT due to an invalid network configuration) . In such examples, the UE 115-b may implement the fallback procedure 330 based on the determination that the network configuration is not supported by the UE 115-b. For example, the fallback procedure 330 may enable the UE 115-b to maintain service with the base station 105-b via the first RAT (e.g., instead of dropping the SCG due to the unsupported network configuration and losing data service for the second RAT) , which may result in more efficient communications, an enhanced user experience, among other benefits.

In some examples, at 335 the UE 115-b may start a timer associated with the fallback procedure 330. For example, the UE 115-b may initiate a fallback timer (e.g., t_backoff_5G) associated with communicating via the first RAT. Such a timer may enable the UE 115-b to maintain service with the base station 105-b via the first RAT for a configured time period before attempting to communicate via the second RAT. For example, the UE may restart the process flow 300 (e.g., transmitting an attach request message at 305) to initiate the configuration of a SCG associated with the second RAT based on an expiration of the timer.

At 340, the UE 115-b may transmit a tracking area update request message to the base station 105-b. In some examples, the tracking area update request message may be referred to as a second control message. The tracking area update request message may indicate a capability of the UE 115-b to communicate via the first RAT (e.g., LTE) . For example, the tracking area update request message may include a DCNR parameter (e.g., with a value of 0) indicating that the tracking area update request message is associated with communications via the first RAT (e.g., instead of the second RAT) . At 345, the base station 105-b may transmit a tracking area update accept message based on receiving the tracking area update request message. The tracking area update accept message may indicate that the tracking area update request message was successfully received.

At 350, the UE 115-b may transmit a service request associated with the first RAT based on receiving the tracking area update accept message. At 355, the base station 105-b may transmit a configuration message (e.g., a second configuration message associated with the first RAT) based on receiving the service request at 350. For example, the configuration message may indicate a network configuration for communications via the first RAT. In some examples, the configuration message may activate a data bearer for communications via the first RAT (e.g., an evolved packet system (EPS) bearer for LTE service) . For example, the configuration message may establish a context for a data bearer indicating the path over which data service may be provided from the network to the UE 115-b. At 360, the base station 105-b and the UE 115-b may communicate via the activated data bearer (e.g., the UE 115-b and the base station 105-b may communicate using a data service path associated with a MCG for LTE) , for example, until an expiration of the timer initiated at 335.

FIG. 4 illustrates an example of a process flow 400 in accordance with aspects of the present disclosure. In some examples, the process flow 400 may implement aspects of

wireless communications system

100 or 200, or the process flow 300. The UE 115-c and the base station 105-c may be examples of a UE 115 and a base station 105 as described with reference to FIGs. 1 through 3. Generally, the process flow 400 may illustrate a second fallback procedure for service recovery in wireless communications systems.

In some examples, the UE 115-c may establish communications with the base station 105-c via a first RAT (e.g., LTE) using an attach procedure. For example, the UE 115-b may transmit an attach request associated with the first RAT (e.g., in addition or alternative to a second RAT, such as NR, in a dual connectivity operation mode) at 405. In some examples, the UE 115-c may perform an RRC connection establishment procedure (e.g., a random access channel (RACH) procedure) , a bearer setup procedure (e.g., configuration of a default LTE bearer for data communications) , or any combination thereof.

At 405, the UE 115-c may transmit an attach request message (e.g., a first control message) to the base station 105-c. For example, the UE 115-b may transmit the attach request message associated with the first RAT (e.g., in addition to or alternative to a second RAT, such as NR, if the UE is capable of dual connectivity operation) . As an example, the UE 115-c may be capable of communications using a second RAT (e.g., NR) and may initiate an attach procedure for dual connection with the first RAT and the second RAT. The attach request associated with the second RAT may include one or more parameters indicating the capability of the UE to communicate using the second RAT. For example, the attach request may include a DCNR parameter with a value indicating the UE capability (e.g., a DCNR parameter with a value of 1 may indicate that the UE attach request is associated with a SCG for NR communications, in addition to LTE communications in a dual connection mode, among other examples of RAT communications) .

At 410, the base station 105-c may transmit an attach accept message to the UE 115-c based on receiving the attach request message. The attach accept message may indicate that the attach request message was successfully received at the base station 105-c and that the attach procedure was successful. At 415, the UE 115-c may transmit a service request message to the base station 105-c based on receiving the attach accept message. The service request message may be an example of a request for communications associated with the second RAT (e.g., a request for NR resources for communications between the UE 115-c and the base station 105-c) .

At 420, the base station 105-c may transmit a configuration message to the UE 115-c in response to the service request. The configuration message may indicate a network configuration associated with the second RAT (e.g., NR) . For example, the base station 105-c may transmit an RRC reconfiguration message (e.g., RRC_RECONFIG) indicating the addition of a SCG associated with the second RAT (e.g., NR) . The configuration message may include one or more parameters associated with the second RAT. For example, the configuration message may include one or more feature IEs for configuration of the SCG for communications via the second RAT (e.g., the configuration message may configure the UE 115-c with a data service path for the SCG for NR communications) .

At 425, the UE 115-c may determine whether the network configuration indicated by the configuration message is supported. In some examples, the UE 115-c may determine that the network configuration is supported at the UE 115-c (e.g., the configuration message does not include unsupported feature IEs associated with the second RAT) . In some examples, at 465 the UE 115-c may transmit a configuration response message indicating that the addition of the SCG and an associated bearer for communications via the second RAT is complete. For example, the UE 115-c may transmit an RRC_RECONFIG_COMPLETE message to the base station 105-c upon successful configuration of the SCG (e.g., when the network configuration indicated at 420 is supported by the UE 115-c) . In some cases, the procedure described with reference to operations 415–425 and 465 may be repeated. For example, the UE 115-c may gain service using the second RAT (e.g., when the network configuration is supported by the UE 115-c) at a first time period. The UE 115-c may transmit another service request at a second time period upon the service using the second RAT expiring (e.g., the UE 115-c may request service for the second RAT, request service using a different RAT, etc. ) .

In some other examples, the UE 115-c may determine that the network configuration is not supported at the UE 115-c (e.g., the configuration message may include unsupported feature IEs associated with the second RAT due to an invalid network configuration) . In such examples, the UE 115-c may implement the fallback procedure 430 based on the determination that the network configuration is not supported by the UE 115-c. For example, the fallback procedure 430 may enable the UE 115-c to maintain service with the base station 105-c via the first RAT (e.g., instead of dropping the SCG due to the unsupported network configuration and losing data service via the second RAT) , which may result in more efficient communications, an enhanced user experience, among other benefits.

In some examples, at 435 the UE 115-c may start a timer associated with the fallback procedure 430. For example, the UE 115-c may initiate a fallback timer (e.g., t_backoff_5G) associated with communicating via the first RAT. Such a timer may enable the UE 115-c to maintain service with the base station 105-c via the first RAT for a configured time period before attempting to communicate via the second RAT. For example, the UE may restart the process flow 400 (e.g., transmitting an attach request message at 405) to initiate the configuration of a SCG associated with the second RAT based on an expiration of the timer.

At 440, the UE 115-c may initiate a detach procedure . For example, the UE 115-c may transmit a detach request message to the base station 105-c. At 445, the base station 105-c may transmit a detach accept message indicating that the detach procedure was successful.

At 450, the UE 115-c may initiate an attach procedure associated with the first RAT based on receiving the detach accept message. For example, the UE 115-c may transmit an attach request message associated with the first RAT. In some examples, the attach request message may be referred to as a second control message. The attach request message may indicate a capability of the UE 115-c to communicate via the first RAT (e.g., LTE) . For example, the attach request message may include a DCNR parameter (e.g., with a value of 0) indicating that the attach request message is associated with communications via the first RAT (e.g., instead of the second RAT) . At 445, the base station 105-c may transmit an attach accept message based on receiving the attach request message. The attach accept message may indicate that the attach procedure was successful.

At 460, the base station 105-c and the UE 115-c may communicate via the first RAT. For example, the UE 115-c and the base station 105-c may establish a data service path for the first RAT (e.g., the UE 115-c and the base station 105-c may activate an EPS bearer for LTE communications) , for example, until an expiration of the timer initiated at 435.

FIG. 5 illustrates an example of a process flow 500 in accordance with aspects of the present disclosure. In some examples, the process flow 500 may implement aspects of

wireless communications system

100 or 200, or the process flows 300 or 400. The UE 115-d and the base station 105-d may be examples of a UE 115 and a base station 105 as described with reference to FIGs. 1 through 4.

At 505, the UE 115-d may transmit, via a first RAT (e.g., LTE) , a first control message associated with at least a second RAT (e.g., NR, both NR and LTE in a dual connection mode, etc. ) to the base station 105-d. The first control message may be an example of an attach request message as described with reference to FIGs. 3 and 4.

At 510, the base station 105-d may transmit, to the UE 115-d, a first configuration message associated with the second RAT. The first configuration message may be an example of a configuration message as described with reference to FIGs. 3 and 4. For example, the first configuration message may indicate a network configuration for communications via the second RAT (e.g., the network configuration may configure the UE 115-d to add a SCG bearer for an NR service data path) .

At 515, the UE 115-d may determine whether the network configuration is supported by the UE 115-d. For example, the UE 115-d may identify one or more feature IEs that are unsupported by the UE 115-d as described with reference to FIGs. 3 and 4. In some examples, the UE 115-d may determine that the network configuration is supported and communicate via the second RAT with the base station 105-d. In some other examples, the UE 115-d may determine that the network configuration is unsupported by the UE 115-d and the UE 115-d may initiate one or more fallback procedures as described herein (e.g., based on the network configuration being unsupported by the UE 115-d) .

In some examples, at 520 the UE 115-d may start a timer associated with the one or more fallback procedures as described herein with reference to FIGs. 3 and 4. At 525, the UE 115-d may transmit a second control message to the base station 105-d as described herein with reference to FIGs. 3 and 4. For example, the second control message may indicate a capability of the UE 115-d to communicate via the first RAT. In some examples, the second control message may be an example of a tracking area update request message associated with the first RAT. In some examples, the second control message may be an example of an attach request message associated with the first RAT.

In some examples, at 530 the base station 105-d may transmit a second configuration message to the UE 115-d. For example, the base station 105-d may transmit an RRC reconfiguration message associated with the first RAT (e.g., in response to the second control message) .

At 535, the UE 115-d and the base station 105-d may communicate via the first RAT (e.g., via a data service path for an LTE bearer) . In some examples, the UE 115-d and the base station 105-d may communicate for a duration of the timer initiated at 520. For example, the UE 115-d and the base station 105-d may maintain communications via the first RAT upon detection that the network configuration is unsupported by the UE 115-d at a first time period. The timer may expire at a second time period, and the UE 115-d may attempt to establish communications via the second RAT (e.g., a SCG bearer for NR communications and/or LTE communications) , in addition or alternative to communications via the first RAT (e.g., communications via the first RAT and the second RAT in a dual connection mode) based on the expiration of the timer.

FIG. 6 shows a block diagram 600 of a device 605 in accordance with aspects of the present disclosure. The device 605 may be an example of aspects of a UE 115 as described herein. The device 605 may include a receiver 610, a communications manager 615, and a transmitter 620. 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 service recovery techniques for wireless communications systems, 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 920 described with reference to FIG. 9. The receiver 610 may utilize a single antenna or a set of antennas.

The communications manager 615 may transmit, to a base station via a first radio access technology, a first control message indicating a capability to communicate data using a second radio access technology, receive a configuration message based on the first control message, the configuration message indicating a network configuration associated with the second radio access technology, and transmit a second control message indicating a capability to communicate data using the first radio access technology based on the network configuration associated with the second radio access technology being unsupported by the UE. The communications manager 615 may be an example of aspects of the communications manager 910 described herein.

The communications manager 615, 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 615, or its sub-components may be executed by a general-purpose processor, a digital signal processor (DSP) , an application-specific integrated circuit (ASIC) , a field programmable gate array (FPGA) or other programmable logic device, 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 615, 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 615, 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 615, or its sub-components, may be combined with one or more other hardware components, including but not limited to an input/output (I/O) component, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof in accordance with various aspects of the present disclosure.

The actions performed by the communications manager 615 as described herein may be implemented to realize one or more potential advantages. For example, the communications manager 615 may implement one or more fallback procedures as described herein, which may enable a UE and a base station to recover service (e.g., maintain communications) , for example, if the base station attempts to configure the UE with a network configuration unsupported by the UE. Such procedures may result in more efficient communications and improved user experience, among other benefits.

The transmitter 620 may transmit signals generated by other components of the device 605. In some examples, the transmitter 620 may be collocated with a receiver 610 in a transceiver module. For example, the transmitter 620 may be an example of aspects of the transceiver 920 described with reference to FIG. 9. The transmitter 620 may utilize a single antenna or a set of antennas.

FIG. 7 shows a block diagram 700 of a device 705 in accordance with aspects of the present disclosure. The device 705 may be an example of aspects of a device 605, or a UE 115 as described herein. The device 705 may include a receiver 710, a communications manager 715, and a transmitter 735. The device 705 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 710 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to service recovery techniques for wireless communications systems, etc. ) . Information may be passed on to other components of the device 705. The receiver 710 may be an example of aspects of the transceiver 920 described with reference to FIG. 9. The receiver 710 may utilize a single antenna or a set of antennas.

The communications manager 715 may be an example of aspects of the communications manager 615 as described herein. The communications manager 715 may include a first message component 720, a configuration component 725, and a second message component 730. The communications manager 715 may be an example of aspects of the communications manager 910 described herein.

The first message component 720 may transmit, to a base station via a first radio access technology, a first control message indicating a capability to communicate data using a second radio access technology.

The configuration component 725 may receive a configuration message based on the first control message, the configuration message indicating a network configuration associated with the second radio access technology.

The second message component 730 may transmit a second control message indicating a capability to communicate data using the first radio access technology based on the network configuration associated with the second radio access technology being unsupported by the UE.

The transmitter 735 may transmit signals generated by other components of the device 705. In some examples, the transmitter 735 may be collocated with a receiver 710 in a transceiver module. For example, the transmitter 735 may be an example of aspects of the transceiver 920 described with reference to FIG. 9. The transmitter 735 may utilize a single antenna or a set of antennas.

FIG. 8 shows a block diagram 800 of a communications manager 805 in accordance with aspects of the present disclosure. The communications manager 805 may be an example of aspects of a communications manager 615, a communications manager 715, or a communications manager 910 described herein. The communications manager 805 may include a first message component 810, a configuration component 815, a second message component 820, a tracking area component 825, a request component 830, a data component 835, a detach component 840, and an attach component 845. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses) .

The first message component 810 may transmit, to a base station via a first radio access technology, a first control message indicating a capability to communicate data using a second radio access technology. In some examples, the first message component 810 may transmit the first control message that is an attach request message associated with the second radio access technology. In some cases, the first control message indicates a first value for a dual connectivity new radio (DCNR) parameter and the second control message indicates a second value for the DCNR parameter that differs from the first value. In some cases, the first radio access technology is an LTE radio access technology and the second radio access technology is a NR radio access technology.

The configuration component 815 may receive a configuration message based on the first control message, the configuration message indicating a network configuration associated with the second radio access technology. In some examples, the configuration component 815 may receive the configuration message that indicates to add a secondary cell group for a data service path. In some examples, the configuration component 815 may receive a second configuration message configuring a data service path associated with the first radio access technology based on transmitting the second control message.

The second message component 820 may transmit a second control message indicating a capability to communicate data using the first radio access technology based on the network configuration associated with the second radio access technology being unsupported by the UE. In some examples, the second message component 820 may transmit the second control message that is a tracking area update request message indicating the capability to communicate data using the first radio access technology. In some examples, the second message component 820 may transmit a detach request message to the base station based at least in part the network configuration associated with the second radio access technology being unsupported. In some examples, the second message component 820 may transmit the detach request message to the base station based on a determination that the network configuration is unsupported. In some examples, the second message component 820 may transmit the second control message that is an attach request message associated with the first radio access technology based on receiving the detach accept message. In some cases, the second control message indicates the capability to communicate data using the first radio access technology instead of the second radio access technology.

The tracking area component 825 may transmit the tracking area update request message based on a determination that the network configuration is unsupported. In some examples, the tracking area component 825 may receive a tracking area update accept message based on the tracking area update request message.

The request component 830 may transmit a service request message associated with the first radio access technology based on the tracking area update accept message. In some examples, the request component 830 may transmit a service request message associated with the second radio access technology based on receiving the attach accept message, where receiving the configuration message is based on transmitting the service request message.

The data component 835 may communicate with the base station via a data service path associated with the first radio access technology established based on the service request message. In some examples, the data component 835 may communicate with the base station via a data service path associated with the first radio access technology established based on the attach request message. In some examples, the data component 835 may communicate with the base station via the data service path.

The detach component 840 may receive a detach accept message based on the detach request message.

The attach component 845 may receive an attach accept message associated with the first radio access technology based on the attach request message. In some examples, the attach component 845 may receive an attach accept message associated with the second radio access technology based on the attach request message.

FIG. 9 shows a diagram of a system 900 including a device 905 in accordance with aspects of the present disclosure. The device 905 may be an example of or include the components of device 605, device 705, or a UE 115 as described herein. The device 905 may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including a communications manager 910, an I/O controller 915, a transceiver 920, an antenna 925, memory 930, and a processor 940. These components may be in electronic communication via one or more buses (e.g., bus 945) .

The communications manager 910 may transmit, to a base station via a first radio access technology, a first control message indicating a capability to communicate data using a second radio access technology, receive a configuration message based on the first control message, the configuration message indicating a network configuration associated with the second radio access technology, and transmit a second control message indicating a capability to communicate data using the first radio access technology based on the network configuration associated with the second radio access technology being unsupported by the UE.

The I/O controller 915 may manage input and output signals for the device 905. The I/O controller 915 may also manage peripherals not integrated into the device 905. In some cases, the I/O controller 915 may represent a physical connection or port to an external peripheral. In some cases, the I/O controller 915 may utilize an operating system such as

or another known operating system. In other cases, the I/O controller 915 may represent or interact with a modem, a keyboard, a mouse, a touchscreen, or a similar device. In some cases, the I/O controller 915 may be implemented as part of a processor. In some cases, a user may interact with the device 905 via the I/O controller 915 or via hardware components controlled by the I/O controller 915.

The transceiver 920 may communicate bi-directionally, via one or more antennas, wired, or wireless links as described above. For example, the transceiver 920 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 920 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 925. However, in some cases the device may have more than one antenna 925, which may be capable of concurrently transmitting or receiving multiple wireless transmissions.

The memory 930 may include random-access memory (RAM) and read-only memory (ROM) . The memory 930 may store computer-readable, computer-executable code 935 including instructions that, when executed, cause the processor to perform various functions described herein. In some cases, the memory 930 may contain, among other things, a basic input/output system (BIOS) which may control basic hardware or software operation such as the interaction with peripheral components or devices.

The processor 940 may include an intelligent hardware device, (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof) . In some cases, the processor 940 may be configured to operate a memory array using a memory controller. In other cases, a memory controller may be integrated into the processor 940. The processor 940 may be configured to execute computer-readable instructions stored in a memory (e.g., the memory 930) to cause the device 905 to perform various functions (e.g., functions or tasks supporting service recovery techniques for wireless communications systems) .

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

FIG. 10 shows a block diagram 1000 of a device 1005 in accordance with aspects of the present disclosure. The device 1005 may be an example of aspects of a base station 105 as described herein. The device 1005 may include a receiver 1010, a communications manager 1015, and a transmitter 1020. The device 1005 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 1010 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to service recovery techniques for wireless communications systems, etc. ) . Information may be passed on to other components of the device 1005. The receiver 1010 may be an example of aspects of the transceiver 1320 described with reference to FIG. 13. The receiver 1010 may utilize a single antenna or a set of antennas.

The communications manager 1015 may receive, from a UE via a first radio access technology, a first control message indicating a capability to communicate data using a second radio access technology, transmit a configuration message based on the first control message, the configuration message indicating a network configuration associated with the second radio access technology, and receive a second control message indicating a capability to communicate data using the first radio access technology based on the network configuration associated with the second radio access technology being unsupported by the UE. The communications manager 1015 may be an example of aspects of the communications manager 1310 described herein.

The communications manager 1015, 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 1015, 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 1015, 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 1015, 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 1015, or its sub-components, may be combined with one or more other hardware components, including but not limited to an input/output (I/O) component, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof in accordance with various aspects of the present disclosure.

The transmitter 1020 may transmit signals generated by other components of the device 1005. In some examples, the transmitter 1020 may be collocated with a receiver 1010 in a transceiver module. For example, the transmitter 1020 may be an example of aspects of the transceiver 1320 described with reference to FIG. 13. The transmitter 1020 may utilize a single antenna or a set of antennas.

FIG. 11 shows a block diagram 1100 of a device 1105 in accordance with aspects of the present disclosure. The device 1105 may be an example of aspects of a device 1005, or a base station 105 as described herein. The device 1105 may include a receiver 1110, a communications manager 1115, and a transmitter 1135. The device 1105 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 1110 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to service recovery techniques for wireless communications systems, etc. ) . Information may be passed on to other components of the device 1105. The receiver 1110 may be an example of aspects of the transceiver 1320 described with reference to FIG. 13. The receiver 1110 may utilize a single antenna or a set of antennas.

The communications manager 1115 may be an example of aspects of the communications manager 1015 as described herein. The communications manager 1115 may include a first message module 1120, a configuration module 1125, and a second message module 1130. The communications manager 1115 may be an example of aspects of the communications manager 1310 described herein.

The first message module 1120 may receive, from a UE via a first radio access technology, a first control message indicating a capability to communicate data using a second radio access technology.

The configuration module 1125 may transmit a configuration message based on the first control message, the configuration message indicating a network configuration associated with the second radio access technology.

The second message module 1130 may receive a second control message indicating a capability to communicate data using the first radio access technology based on the network configuration associated with the second radio access technology being unsupported by the UE.

The transmitter 1135 may transmit signals generated by other components of the device 1105. In some examples, the transmitter 1135 may be collocated with a receiver 1110 in a transceiver module. For example, the transmitter 1135 may be an example of aspects of the transceiver 1320 described with reference to FIG. 13. The transmitter 1135 may utilize a single antenna or a set of antennas.

FIG. 12 shows a block diagram 1200 of a communications manager 1205 in accordance with aspects of the present disclosure. The communications manager 1205 may be an example of aspects of a communications manager 1015, a communications manager 1115, or a communications manager 1310 described herein. The communications manager 1205 may include a first message module 1210, a configuration module 1215, a second message module 1220, a tracking area module 1225, a request module 1230, a data module 1235, a detach module 1240, and an attach module 1245. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses) .

The first message module 1210 may receive, from a UE via a first radio access technology, a first control message indicating a capability to communicate data using a second radio access technology. In some examples, the first message module 1210 may receive the first control message that is an attach request message associated with the second radio access technology. In some cases, the first control message indicates a first value for a dual connectivity new radio (DCNR) parameter and the second control message indicates a second value for the DCNR parameter that differs from the first value. In some cases, the first radio access technology is an LTE radio access technology and the second radio access technology is a NR radio access technology.

The configuration module 1215 may transmit a configuration message based on the first control message, the configuration message indicating a network configuration associated with the second radio access technology. In some examples, the configuration module 1215 may transmit the configuration message that indicates to add a secondary cell group for a data service path. In some examples, the configuration module 1215 may transmit a second configuration message configuring a data service path associated with the first radio access technology based on the second control message.

The second message module 1220 may receive a second control message indicating a capability to communicate data using the first radio access technology based on the network configuration associated with the second radio access technology being unsupported by the UE. In some examples, the second message module 1220 may receive the second control message that is a tracking area update request message indicating the capability to communicate data using the first radio access technology. In some cases, the second control message indicates the capability to communicate data using the first radio access technology instead of the second radio access technology.

The tracking area module 1225 may receive the tracking area update request message based on a determination that the network configuration is unsupported. In some examples, the tracking area module 1225 may transmit a tracking area update accept message based on the tracking area update request message.

The request module 1230 may receive a service request message associated with the first radio access technology based on the tracking area update accept message. In some examples, the request module 1230 may receive a service request message associated with the second radio access technology based on the attach accept message, where transmitting the configuration message is based on receiving the service request message.

The data module 1235 may communicate with the UE via a data service path associated with the first radio access technology established based on the service request message. In some examples, the data module 1235 may communicate with the UE via a data service path associated with the first radio access technology established based on the attach request message. In some examples, the data module 1235 may communicate with the UE via the data service path.

The detach module 1240 may receive a detach request message from the UE based on the network configuration associated with the second radio access technology being unsupported. In some examples, the detach module 1240 may receive the detach request message to the base station based on a determination that the network configuration is unsupported. In some examples, the detach module 1240 may transmit a detach accept message based on the detach request message.

The attach module 1245 may receive the second control message that is an attach request message associated with the first radio access technology based on the detach accept message. In some examples, the attach module 1245 may transmit an attach accept message associated with the first radio access technology based on the attach request message. In some examples, the attach module 1245 may transmit an attach accept message associated with the second radio access technology based on the attach request message.

FIG. 13 shows a diagram of a system 1300 including a device 1305 in accordance with aspects of the present disclosure. The device 1305 may be an example of or include the components of device 1005, device 1105, or a base station 105 as described herein. The device 1305 may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including a communications manager 1310, a network communications manager 1315, a transceiver 1320, an antenna 1325, memory 1330, a processor 1340, and an inter-station communications manager 1345. These components may be in electronic communication via one or more buses (e.g., bus 1350) .

The communications manager 1310 may receive, from a UE via a first radio access technology, a first control message indicating a capability to communicate data using a second radio access technology, transmit a configuration message based on the first control message, the configuration message indicating a network configuration associated with the second radio access technology, and receive a second control message indicating a capability to communicate data using the first radio access technology based on the network configuration associated with the second radio access technology being unsupported by the UE.

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

The transceiver 1320 may communicate bi-directionally, via one or more antennas, wired, or wireless links as described above. For example, the transceiver 1320 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 1320 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 1325. However, in some cases the device may have more than one antenna 1325, which may be capable of concurrently transmitting or receiving multiple wireless transmissions.

The memory 1330 may include RAM, ROM, or a combination thereof. The memory 1330 may store computer-readable code 1335 including instructions that, when executed by a processor (e.g., the processor 1340) cause the device to perform various functions described herein. In some cases, the memory 1330 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 1340 may include an intelligent hardware device, (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof) . In some cases, the processor 1340 may be configured to operate a memory array using a memory controller. In some cases, a memory controller may be integrated into processor 1340. The processor 1340 may be configured to execute computer-readable instructions stored in a memory (e.g., the memory 1330) to cause the device 1305 to perform various functions (e.g., functions or tasks supporting service recovery techniques for wireless communications systems) .

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

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

FIG. 14 shows a flowchart illustrating a method 1400 in accordance with aspects of the present disclosure. The operations of method 1400 may be implemented by a UE 115 or its components as described herein. For example, the operations of method 1400 may be performed by a communications manager as described with reference to FIGs. 6 through 9. 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 1405, the UE may transmit, to a base station via a first radio access technology, a first control message indicating a capability to communicate data using a second radio access technology. The operations of 1405 may be performed according to the methods described herein. In some examples, aspects of the operations of 1405 may be performed by a first message component as described with reference to FIGs. 6 through 9.

At 1410, the UE may receive a configuration message based on the first control message, the configuration message indicating a network configuration associated with the second radio access technology. The operations of 1410 may be performed according to the methods described herein. In some examples, aspects of the operations of 1410 may be performed by a configuration component as described with reference to FIGs. 6 through 9.

At 1415, the UE may transmit a second control message indicating a capability to communicate data using the first radio access technology based on the network configuration associated with the second radio access technology being unsupported by the UE. The operations of 1415 may be performed according to the methods described herein. In some examples, aspects of the operations of 1415 may be performed by a second message component as described with reference to FIGs. 6 through 9.

FIG. 15 shows a flowchart illustrating a method 1500 in accordance with aspects of the present disclosure. The operations of method 1500 may be implemented by a UE 115 or its components as described herein. For example, the operations of method 1500 may be performed by a communications manager as described with reference to FIGs. 6 through 9. 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 1505, the UE may transmit, to a base station via a first radio access technology, a first control message indicating a capability to communicate data using a second radio access technology. The operations of 1505 may be performed according to the methods described herein. In some examples, aspects of the operations of 1505 may be performed by a first message component as described with reference to FIGs. 6 through 9.

At 1510, the UE may receive a configuration message based on the first control message, the configuration message indicating a network configuration associated with the second radio access technology. The operations of 1510 may be performed according to the methods described herein. In some examples, aspects of the operations of 1510 may be performed by a configuration component as described with reference to FIGs. 6 through 9.

At 1515, the UE may transmit a second control message indicating a capability to communicate data using the first radio access technology based on the network configuration associated with the second radio access technology being unsupported by the UE. The operations of 1515 may be performed according to the methods described herein. In some examples, aspects of the operations of 1515 may be performed by a second message component as described with reference to FIGs. 6 through 9.

At 1520, the UE may receive a second configuration message configuring a data service path associated with the first radio access technology based on transmitting the second control message. The operations of 1520 may be performed according to the methods described herein. In some examples, aspects of the operations of 1520 may be performed by a configuration component as described with reference to FIGs. 6 through 9.

At 1525, the UE may communicate with the base station via the data service path. The operations of 1525 may be performed according to the methods described herein. In some examples, aspects of the operations of 1525 may be performed by a data component as described with reference to FIGs. 6 through 9.

FIG. 16 shows a flowchart illustrating a method 1600 in accordance with aspects of the present disclosure. The operations of method 1600 may be implemented by a base station 105 or its components as described herein. For example, the operations of method 1600 may be performed by a communications manager as described with reference to FIGs. 10 through 13. In some examples, a base station may execute a set of instructions to control the functional elements of the base station to perform the functions described below. Additionally or alternatively, a base station may perform aspects of the functions described below using special-purpose hardware.

At 1605, the base station may receive, from a UE via a first radio access technology, a first control message indicating a capability to communicate data using a second radio access technology. The operations of 1605 may be performed according to the methods described herein. In some examples, aspects of the operations of 1605 may be performed by a first message module as described with reference to FIGs. 10 through 13.

At 1610, the base station may transmit a configuration message based on the first control message, the configuration message indicating a network configuration associated with the second radio access technology. The operations of 1610 may be performed according to the methods described herein. In some examples, aspects of the operations of 1610 may be performed by a configuration module as described with reference to FIGs. 10 through 13.

At 1615, the base station may receive a second control message indicating a capability to communicate data using the first radio access technology based on the network configuration associated with the second radio access technology being unsupported by the UE. The operations of 1615 may be performed according to the methods described herein. In some examples, aspects of the operations of 1615 may be performed by a second message module as described with reference to FIGs. 10 through 13.

FIG. 17 shows a flowchart illustrating a method 1700 in accordance with aspects of the present disclosure. The operations of method 1700 may be implemented by a base station 105 or its components as described herein. For example, the operations of method 1700 may be performed by a communications manager as described with reference to FIGs. 10 through 13. In some examples, a base station may execute a set of instructions to control the functional elements of the base station to perform the functions described below. Additionally or alternatively, a base station may perform aspects of the functions described below using special-purpose hardware.

At 1705, the base station may receive, from a UE via a first radio access technology, a first control message indicating a capability to communicate data using a second radio access technology. The operations of 1705 may be performed according to the methods described herein. In some examples, aspects of the operations of 1705 may be performed by a first message module as described with reference to FIGs. 10 through 13.

At 1710, the base station may transmit a configuration message based on the first control message, the configuration message indicating a network configuration associated with the second radio access technology. The operations of 1710 may be performed according to the methods described herein. In some examples, aspects of the operations of 1710 may be performed by a configuration module as described with reference to FIGs. 10 through 13.

At 1715, the base station may receive a second control message indicating a capability to communicate data using the first radio access technology based on the network configuration associated with the second radio access technology being unsupported by the UE. The operations of 1715 may be performed according to the methods described herein. In some examples, aspects of the operations of 1715 may be performed by a second message module as described with reference to FIGs. 10 through 13.

At 1720, the base station may transmit a second configuration message configuring a data service path associated with the first radio access technology based on the second control message. The operations of 1720 may be performed according to the methods described herein. In some examples, aspects of the operations of 1720 may be performed by a configuration module as described with reference to FIGs. 10 through 13.

At 1725, the base station may communicate with the UE via the data service path. The operations of 1725 may be performed according to the methods described herein. In some examples, aspects of the operations of 1725 may be performed by a data module as described with reference to FIGs. 10 through 13.

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 RAM, ROM, electrically erasable programmable ROM (EEPROM) , flash memory, compact disk (CD) ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that may be used to carry or store desired program code means in the form of instructions or data structures and that may be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) , or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of computer-readable medium. Disk and disc, as used herein, include CD, laser disc, optical disc, digital versatile disc (DVD) , floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media.

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

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

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

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

Claims

A method for wireless communications at a user equipment (UE) , comprising:

transmitting, to a base station via a first radio access technology, a first control message indicating a capability to communicate data using a second radio access technology;

receiving a configuration message based at least in part on the first control message, the configuration message indicating a network configuration associated with the second radio access technology; and

transmitting a second control message indicating a capability to communicate data using the first radio access technology based at least in part on the network configuration associated with the second radio access technology being unsupported by the UE.
The method of claim 1, wherein transmitting the second control message comprises:

transmitting the second control message that is a tracking area update request message indicating the capability to communicate data using the first radio access technology.
The method of claim 2, wherein transmitting the tracking area update request message comprises:

transmitting the tracking area update request message based at least in part on a determination that the network configuration is unsupported.
The method of claim 2, further comprising:

receiving a tracking area update accept message based at least in part on the tracking area update request message;

transmitting a service request message associated with the first radio access technology based at least in part on the tracking area update accept message; and

communicating with the base station via a data service path associated with the first radio access technology established based at least in part on the service request message.
The method of claim 1, further comprising:

transmitting a detach request message to the base station based at least in part the network configuration associated with the second radio access technology being unsupported.
The method of claim 5, wherein transmitting the detach request message further comprises:

transmitting the detach request message to the base station based at least in part on a determination that the network configuration is unsupported.
The method of claim 5, further comprising:

receiving a detach accept message based at least in part on the detach request message.
The method of claim 7, wherein transmitting the second control message comprises:

transmitting the second control message that is an attach request message associated with the first radio access technology based at least in part on receiving the detach accept message.
The method of claim 8, further comprising:

receiving an attach accept message associated with the first radio access technology based at least in part on the attach request message; and

communicating with the base station via a data service path associated with the first radio access technology established based at least in part on the attach request message.
The method of claim 1, wherein the first control message indicates a first value for a dual connectivity new radio (DCNR) parameter and the second control message indicates a second value for the DCNR parameter that differs from the first value.
The method of claim 1, wherein receiving the configuration message comprises:

receiving the configuration message that indicates to add a secondary cell group for a data service path.
The method of claim 1, further comprising:

receiving a second configuration message configuring a data service path associated with the first radio access technology based at least in part on transmitting the second control message; and

communicating with the base station via the data service path.
The method of claim 1, wherein the second control message indicates the capability to communicate data using the first radio access technology instead of the second radio access technology.
The method of claim 1, wherein transmitting the first control message comprises:

transmitting the first control message that is an attach request message associated with the second radio access technology.
The method of claim 14, further comprising:

receiving an attach accept message associated with the second radio access technology based at least in part on the attach request message; and

transmitting a service request message associated with the second radio access technology based at least in part on receiving the attach accept message, wherein receiving the configuration message is based at least in part on transmitting the service request message.
The method of claim 1, wherein the first radio access technology is a Long Term Evolution (LTE) radio access technology and the second radio access technology is a New Radio (NR) radio access technology.
A method for wireless communications at a base station, comprising:

receiving, from a user equipment (UE) via a first radio access technology, a first control message indicating a capability to communicate data using a second radio access technology;

transmitting a configuration message based at least in part on the first control message, the configuration message indicating a network configuration associated with the second radio access technology; and

receiving a second control message indicating a capability to communicate data using the first radio access technology based at least in part on the network configuration associated with the second radio access technology being unsupported by the UE.
The method of claim 17, wherein receiving the second control message comprises:

receiving the second control message that is a tracking area update request message indicating the capability to communicate data using the first radio access technology.
The method of claim 18, wherein receiving the tracking area update request message comprises:

receiving the tracking area update request message based at least in part on a determination that the network configuration is unsupported.
The method of claim 18, further comprising:

transmitting a tracking area update accept message based at least in part on the tracking area update request message;

receiving a service request message associated with the first radio access technology based at least in part on the tracking area update accept message; and

communicating with the UE via a data service path associated with the first radio access technology established based at least in part on the service request message.
The method of claim 17, further comprising:

receiving a detach request message from the UE based at least in part on the network configuration associated with the second radio access technology being unsupported.
The method of claim 21, wherein receiving the detach request message further comprises:

receiving the detach request message to the base station based at least in part on a determination that the network configuration is unsupported.
The method of claim 22, further comprising:

transmitting a detach accept message based at least in part on the detach request message.
The method of claim 23, wherein receiving the second control message comprises:

receiving the second control message that is an attach request message associated with the first radio access technology based at least in part on the detach accept message.
The method of claim 24, further comprising:

transmitting an attach accept message associated with the first radio access technology based at least in part on the attach request message; and

communicating with the UE via a data service path associated with the first radio access technology established based at least in part on the attach request message.
The method of claim 17, wherein the first control message indicates a first value for a dual connectivity new radio (DCNR) parameter and the second control message indicates a second value for the DCNR parameter that differs from the first value.
The method of claim 17, wherein transmitting the configuration message comprises:

transmitting the configuration message that indicates to add a secondary cell group for a data service path.
The method of claim 17, further comprising:

transmitting a second configuration message configuring a data service path associated with the first radio access technology based at least in part on the second control message; and

communicating with the UE via the data service path.
The method of claim 17, wherein the second control message indicates the capability to communicate data using the first radio access technology instead of the second radio access technology.
The method of claim 17, wherein receiving the first control message comprises:

receiving the first control message that is an attach request message associated with the second radio access technology.
The method of claim 30, further comprising:

transmitting an attach accept message associated with the second radio access technology based at least in part on the attach request message; and

receiving a service request message associated with the second radio access technology based at least in part on the attach accept message, wherein transmitting the configuration message is based at least in part on receiving the service request message.
The method of claim 17, wherein the first radio access technology is a Long Term Evolution (LTE) radio access technology and the second radio access technology is a New Radio (NR) radio access technology.
An apparatus for wireless communications 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:

transmit, to a base station via a first radio access technology, a first control message indicating a capability to communicate data using a second radio access technology;

receive a configuration message based at least in part on the first control message, the configuration message indicating a network configuration associated with the second radio access technology; and

transmit a second control message indicating a capability to communicate data using the first radio access technology based at least in part on the network configuration associated with the second radio access technology being unsupported by the UE.
The apparatus of claim 33, wherein the instructions to transmit the second control message are executable by the processor to cause the apparatus to:

transmit the second control message that is a tracking area update request message indicating the capability to communicate data using the first radio access technology.
The apparatus of claim 34, wherein the instructions to transmit the tracking area update request message are executable by the processor to cause the apparatus to:

transmit the tracking area update request message based at least in part on a determination that the network configuration is unsupported.
The apparatus of claim 34, wherein the instructions are further executable by the processor to cause the apparatus to:

receive a tracking area update accept message based at least in part on the tracking area update request message;

transmit a service request message associated with the first radio access technology based at least in part on the tracking area update accept message; and

communicate with the base station via a data service path associated with the first radio access technology established based at least in part on the service request message.
The apparatus of claim 33, wherein the instructions are further executable by the processor to cause the apparatus to:

transmit a detach request message to the base station based at least in part the network configuration associated with the second radio access technology being unsupported.
The apparatus of claim 37, wherein the instructions to transmit the detach request message further are executable by the processor to cause the apparatus to:

transmit the detach request message to the base station based at least in part on a determination that the network configuration is unsupported.
The apparatus of claim 37, wherein the instructions are further executable by the processor to cause the apparatus to:

receive a detach accept message based at least in part on the detach request message.
The apparatus of claim 39, wherein the instructions to transmit the second control message are executable by the processor to cause the apparatus to:

transmit the second control message that is an attach request message associated with the first radio access technology based at least in part on receiving the detach accept message.
The apparatus of claim 40, wherein the instructions are further executable by the processor to cause the apparatus to:

receive an attach accept message associated with the first radio access technology based at least in part on the attach request message; and

communicate with the base station via a data service path associated with the first radio access technology established based at least in part on the attach request message.
The apparatus of claim 33, wherein the first control message indicates a first value for a dual connectivity new radio (DCNR) parameter and the second control message indicates a second value for the DCNR parameter that differs from the first value.
The apparatus of claim 33, further comprising a transceiver, wherein the instructions to receive the configuration message are executable by the processor to cause the apparatus to:

receive, via the transceiver, the configuration message that indicates to add a secondary cell group for a data service path.
The apparatus of claim 33, wherein the instructions are further executable by the processor to cause the apparatus to:

receive a second configuration message configuring a data service path associated with the first radio access technology based at least in part on transmitting the second control message; and

communicate with the base station via the data service path.
The apparatus of claim 33, wherein the second control message indicates the capability to communicate data using the first radio access technology instead of the second radio access technology.
The apparatus of claim 33, wherein the instructions to transmit the first control message are executable by the processor to cause the apparatus to:

transmit the first control message that is an attach request message associated with the second radio access technology.
The apparatus of claim 46, wherein the instructions are further executable by the processor to cause the apparatus to:

receive an attach accept message associated with the second radio access technology based at least in part on the attach request message; and

transmit a service request message associated with the second radio access technology based at least in part on receiving the attach accept message, wherein receiving the configuration message is based at least in part on transmitting the service request message.
The apparatus of claim 33, wherein the first radio access technology is a Long Term Evolution (LTE) radio access technology and the second radio access technology is a New Radio (NR) radio access technology.
An apparatus for wireless communications at a base station, comprising:

a processor,

memory coupled with the processor; and

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

receive, from a user equipment (UE) via a first radio access technology, a first control message indicating a capability to communicate data using a second radio access technology;

transmit a configuration message based at least in part on the first control message, the configuration message indicating a network configuration associated with the second radio access technology; and

receive a second control message indicating a capability to communicate data using the first radio access technology based at least in part on the network configuration associated with the second radio access technology being unsupported by the UE.
The apparatus of claim 49, wherein the instructions to receive the second control message are executable by the processor to cause the apparatus to:

receive the second control message that is a tracking area update request message indicating the capability to communicate data using the first radio access technology.
The apparatus of claim 50, wherein the instructions to receive the tracking area update request message are executable by the processor to cause the apparatus to:

receive the tracking area update request message based at least in part on a determination that the network configuration is unsupported.
The apparatus of claim 50, wherein the instructions are further executable by the processor to cause the apparatus to:

transmit a tracking area update accept message based at least in part on the tracking area update request message;

receive a service request message associated with the first radio access technology based at least in part on the tracking area update accept message; and

communicate with the UE via a data service path associated with the first radio access technology established based at least in part on the service request message.
The apparatus of claim 49, wherein the instructions are further executable by the processor to cause the apparatus to:

receive a detach request message from the UE based at least in part on the network configuration associated with the second radio access technology being unsupported.
The apparatus of claim 53, wherein the instructions to receive the detach request message further are executable by the processor to cause the apparatus to:

receive the detach request message to the base station based at least in part on a determination that the network configuration is unsupported.
The apparatus of claim 54, wherein the instructions are further executable by the processor to cause the apparatus to:

transmit a detach accept message based at least in part on the detach request message.
The apparatus of claim 55, wherein the instructions to receive the second control message are executable by the processor to cause the apparatus to:

receive the second control message that is an attach request message associated with the first radio access technology based at least in part on the detach accept message.
The apparatus of claim 56, wherein the instructions are further executable by the processor to cause the apparatus to:

transmit an attach accept message associated with the first radio access technology based at least in part on the attach request message; and

communicate with the UE via a data service path associated with the first radio access technology established based at least in part on the attach request message.
The apparatus of claim 49, wherein the first control message indicates a first value for a dual connectivity new radio (DCNR) parameter and the second control message indicates a second value for the DCNR parameter that differs from the first value.
The apparatus of claim 49, further comprising a transceiver, wherein the instructions to transmit the configuration message are executable by the processor to cause the apparatus to:

transmit, via the transceiver, the configuration message that indicates to add a secondary cell group for a data service path.
The apparatus of claim 49, wherein the instructions are further executable by the processor to cause the apparatus to:

transmit a second configuration message configuring a data service path associated with the first radio access technology based at least in part on the second control message; and

communicate with the UE via the data service path.
The apparatus of claim 49, wherein the second control message indicates the capability to communicate data using the first radio access technology instead of the second radio access technology.
The apparatus of claim 49, wherein the instructions to receive the first control message are executable by the processor to cause the apparatus to:

receive the first control message that is an attach request message associated with the second radio access technology.
The apparatus of claim 62, wherein the instructions are further executable by the processor to cause the apparatus to:

transmit an attach accept message associated with the second radio access technology based at least in part on the attach request message; and

receive a service request message associated with the second radio access technology based at least in part on the attach accept message, wherein transmitting the configuration message is based at least in part on receiving the service request message.
The apparatus of claim 49, wherein the first radio access technology is a Long Term Evolution (LTE) radio access technology and the second radio access technology is a New Radio (NR) radio access technology.
An apparatus for wireless communications at a user equipment (UE) , comprising:

means for transmitting, to a base station via a first radio access technology, a first control message indicating a capability to communicate data using a second radio access technology;

means for receiving a configuration message based at least in part on the first control message, the configuration message indicating a network configuration associated with the second radio access technology; and

means for transmitting a second control message indicating a capability to communicate data using the first radio access technology based at least in part on the network configuration associated with the second radio access technology being unsupported by the UE.
The apparatus of claim 65, wherein the means for transmitting the second control message comprises:

means for transmitting the second control message that is a tracking area update request message indicating the capability to communicate data using the first radio access technology.
The apparatus of claim 66, wherein the means for transmitting the tracking area update request message comprises:

means for transmitting the tracking area update request message based at least in part on a determination that the network configuration is unsupported.
The apparatus of claim 66, further comprising:

means for receiving a tracking area update accept message based at least in part on the tracking area update request message;

means for transmitting a service request message associated with the first radio access technology based at least in part on the tracking area update accept message; and

means for communicating with the base station via a data service path associated with the first radio access technology established based at least in part on the service request message.
The apparatus of claim 65, further comprising:

means for transmitting a detach request message to the base station based at least in part the network configuration associated with the second radio access technology being unsupported.
The apparatus of claim 69, wherein the means for transmitting the detach request message further comprises:

means for transmitting the detach request message to the base station based at least in part on a determination that the network configuration is unsupported.
The apparatus of claim 69, further comprising:

means for receiving a detach accept message based at least in part on the detach request message.
The apparatus of claim 71, wherein the means for transmitting the second control message comprises:

means for transmitting the second control message that is an attach request message associated with the first radio access technology based at least in part on receiving the detach accept message.
The apparatus of claim 72, further comprising:

means for receiving an attach accept message associated with the first radio access technology based at least in part on the attach request message; and

means for communicating with the base station via a data service path associated with the first radio access technology established based at least in part on the attach request message.
The apparatus of claim 65, wherein the first control message indicates a first value for a dual connectivity new radio (DCNR) parameter and the second control message indicates a second value for the DCNR parameter that differs from the first value.
The apparatus of claim 65, wherein the means for receiving the configuration message comprises:

means for receiving the configuration message that indicates to add a secondary cell group for a data service path.
The apparatus of claim 65, further comprising:

means for receiving a second configuration message configuring a data service path associated with the first radio access technology based at least in part on transmitting the second control message; and

means for communicating with the base station via the data service path.
The apparatus of claim 65, wherein the second control message indicates the capability to communicate data using the first radio access technology instead of the second radio access technology.
The apparatus of claim 65, wherein the means for transmitting the first control message comprises:

means for transmitting the first control message that is an attach request message associated with the second radio access technology.
The apparatus of claim 78, further comprising:

means for receiving an attach accept message associated with the second radio access technology based at least in part on the attach request message; and

means for transmitting a service request message associated with the second radio access technology based at least in part on receiving the attach accept message, wherein receiving the configuration message is based at least in part on transmitting the service request message.
The apparatus of claim 65, wherein the first radio access technology is a Long Term Evolution (LTE) radio access technology and the second radio access technology is a New Radio (NR) radio access technology.
An apparatus for wireless communications at a base station, comprising:

means for receiving, from a user equipment (UE) via a first radio access technology, a first control message indicating a capability to communicate data using a second radio access technology;

means for transmitting a configuration message based at least in part on the first control message, the configuration message indicating a network configuration associated with the second radio access technology; and

means for receiving a second control message indicating a capability to communicate data using the first radio access technology based at least in part on the network configuration associated with the second radio access technology being unsupported by the UE.
The apparatus of claim 81, wherein the means for receiving the second control message comprises:

means for receiving the second control message that is a tracking area update request message indicating the capability to communicate data using the first radio access technology.
The apparatus of claim 82, wherein the means for receiving the tracking area update request message comprises:

means for receiving the tracking area update request message based at least in part on a determination that the network configuration is unsupported.
The apparatus of claim 82, further comprising:

means for transmitting a tracking area update accept message based at least in part on the tracking area update request message;

means for receiving a service request message associated with the first radio access technology based at least in part on the tracking area update accept message; and

means for communicating with the UE via a data service path associated with the first radio access technology established based at least in part on the service request message.
The apparatus of claim 81, further comprising:

means for receiving a detach request message from the UE based at least in part on the network configuration associated with the second radio access technology being unsupported.
The apparatus of claim 85, wherein the means for receiving the detach request message further comprises:

means for receiving the detach request message to the base station based at least in part on a determination that the network configuration is unsupported.
The apparatus of claim 86, further comprising:

means for transmitting a detach accept message based at least in part on the detach request message.
The apparatus of claim 87, wherein the means for receiving the second control message comprises:

means for receiving the second control message that is an attach request message associated with the first radio access technology based at least in part on the detach accept message.
The apparatus of claim 88, further comprising:

means for transmitting an attach accept message associated with the first radio access technology based at least in part on the attach request message; and

means for communicating with the UE via a data service path associated with the first radio access technology established based at least in part on the attach request message.
The apparatus of claim 81, wherein the first control message indicates a first value for a dual connectivity new radio (DCNR) parameter and the second control message indicates a second value for the DCNR parameter that differs from the first value.
The apparatus of claim 81, wherein the means for transmitting the configuration message comprises:

means for transmitting the configuration message that indicates to add a secondary cell group for a data service path.
The apparatus of claim 81, further comprising:

means for transmitting a second configuration message configuring a data service path associated with the first radio access technology based at least in part on the second control message; and

means for communicating with the UE via the data service path.
The apparatus of claim 81, wherein the second control message indicates the capability to communicate data using the first radio access technology instead of the second radio access technology.
The apparatus of claim 81, wherein the means for receiving the first control message comprises:

means for receiving the first control message that is an attach request message associated with the second radio access technology.
The apparatus of claim 94, further comprising:

means for transmitting an attach accept message associated with the second radio access technology based at least in part on the attach request message; and

means for receiving a service request message associated with the second radio access technology based at least in part on the attach accept message, wherein transmitting the configuration message is based at least in part on receiving the service request message.
The apparatus of claim 81, wherein the first radio access technology is a Long Term Evolution (LTE) radio access technology and the second radio access technology is a New Radio (NR) radio access technology.
A non-transitory computer-readable medium storing code for wireless communications at a user equipment (UE) , the code comprising instructions executable by a processor to:

transmit, to a base station via a first radio access technology, a first control message indicating a capability to communicate data using a second radio access technology;

receive a configuration message based at least in part on the first control message, the configuration message indicating a network configuration associated with the second radio access technology; and

transmit a second control message indicating a capability to communicate data using the first radio access technology based at least in part on the network configuration associated with the second radio access technology being unsupported by the UE.
The non-transitory computer-readable medium of claim 97, wherein the instructions to transmit the second control message are executable to:

transmit the second control message that is a tracking area update request message indicating the capability to communicate data using the first radio access technology.
The non-transitory computer-readable medium of claim 98, wherein the instructions to transmit the tracking area update request message are executable to:

transmit the tracking area update request message based at least in part on a determination that the network configuration is unsupported.
The non-transitory computer-readable medium of claim 98, wherein the instructions are further executable to:

receive a tracking area update accept message based at least in part on the tracking area update request message;

transmit a service request message associated with the first radio access technology based at least in part on the tracking area update accept message; and

communicate with the base station via a data service path associated with the first radio access technology established based at least in part on the service request message.
The non-transitory computer-readable medium of claim 97, wherein the instructions are further executable to:

transmit a detach request message to the base station based at least in part the network configuration associated with the second radio access technology being unsupported.
The non-transitory computer-readable medium of claim 101, wherein the instructions to transmit the detach request message further are executable to:

transmit the detach request message to the base station based at least in part on a determination that the network configuration is unsupported.
The non-transitory computer-readable medium of claim 101, wherein the instructions are further executable to:

receive a detach accept message based at least in part on the detach request message.
The non-transitory computer-readable medium of claim 103, wherein the instructions to transmit the second control message are executable to:

transmit the second control message that is an attach request message associated with the first radio access technology based at least in part on receiving the detach accept message.
The non-transitory computer-readable medium of claim 104, wherein the instructions are further executable to:

receive an attach accept message associated with the first radio access technology based at least in part on the attach request message; and

communicate with the base station via a data service path associated with the first radio access technology established based at least in part on the attach request message.
The non-transitory computer-readable medium of claim 97, wherein the first control message indicates a first value for a dual connectivity new radio (DCNR) parameter and the second control message indicates a second value for the DCNR parameter that differs from the first value.
The non-transitory computer-readable medium of claim 97, wherein the instructions to receive the configuration message are executable to:

receive the configuration message that indicates to add a secondary cell group for a data service path.
The non-transitory computer-readable medium of claim 97, wherein the instructions are further executable to:

receive a second configuration message configuring a data service path associated with the first radio access technology based at least in part on transmitting the second control message; and

communicate with the base station via the data service path.
The non-transitory computer-readable medium of claim 97, wherein the second control message indicates the capability to communicate data using the first radio access technology instead of the second radio access technology.
The non-transitory computer-readable medium of claim 97, wherein the instructions to transmit the first control message are executable to:

transmit the first control message that is an attach request message associated with the second radio access technology.
The non-transitory computer-readable medium of claim 110, wherein the instructions are further executable to:

receive an attach accept message associated with the second radio access technology based at least in part on the attach request message; and

transmit a service request message associated with the second radio access technology based at least in part on receiving the attach accept message, wherein receiving the configuration message is based at least in part on transmitting the service request message.
The non-transitory computer-readable medium of claim 97, wherein the first radio access technology is a Long Term Evolution (LTE) radio access technology and the second radio access technology is a New Radio (NR) radio access technology.
A non-transitory computer-readable medium storing code for wireless communications at a base station, the code comprising instructions executable by a processor to:

receive, from a user equipment (UE) via a first radio access technology, a first control message indicating a capability to communicate data using a second radio access technology;

transmit a configuration message based at least in part on the first control message, the configuration message indicating a network configuration associated with the second radio access technology; and

receive a second control message indicating a capability to communicate data using the first radio access technology based at least in part on the network configuration associated with the second radio access technology being unsupported by the UE.
The non-transitory computer-readable medium of claim 113, wherein the instructions to receive the second control message are executable to:

receive the second control message that is a tracking area update request message indicating the capability to communicate data using the first radio access technology.
The non-transitory computer-readable medium of claim 114, wherein the instructions to receive the tracking area update request message are executable to:

receive the tracking area update request message based at least in part on a determination that the network configuration is unsupported.
The non-transitory computer-readable medium of claim 114, wherein the instructions are further executable to:

transmit a tracking area update accept message based at least in part on the tracking area update request message;

receive a service request message associated with the first radio access technology based at least in part on the tracking area update accept message; and

communicate with the UE via a data service path associated with the first radio access technology established based at least in part on the service request message.
The non-transitory computer-readable medium of claim 113, wherein the instructions are further executable to:

receive a detach request message from the UE based at least in part on the network configuration associated with the second radio access technology being unsupported.
The non-transitory computer-readable medium of claim 117, wherein the instructions to receive the detach request message further are executable to:

receive the detach request message to the base station based at least in part on a determination that the network configuration is unsupported.
The non-transitory computer-readable medium of claim 118, wherein the instructions are further executable to:

transmit a detach accept message based at least in part on the detach request message.
The non-transitory computer-readable medium of claim 119, wherein the instructions to receive the second control message are executable to:

receive the second control message that is an attach request message associated with the first radio access technology based at least in part on the detach accept message.
The non-transitory computer-readable medium of claim 120, wherein the instructions are further executable to:

transmit an attach accept message associated with the first radio access technology based at least in part on the attach request message; and

communicate with the UE via a data service path associated with the first radio access technology established based at least in part on the attach request message.
The non-transitory computer-readable medium of claim 113, wherein the first control message indicates a first value for a dual connectivity new radio (DCNR) parameter and the second control message indicates a second value for the DCNR parameter that differs from the first value.
The non-transitory computer-readable medium of claim 113, wherein the instructions to transmit the configuration message are executable to:

transmit the configuration message that indicates to add a secondary cell group for a data service path.
The non-transitory computer-readable medium of claim 113, wherein the instructions are further executable to:

transmit a second configuration message configuring a data service path associated with the first radio access technology based at least in part on the second control message; and

communicate with the UE via the data service path.
The non-transitory computer-readable medium of claim 113, wherein the second control message indicates the capability to communicate data using the first radio access technology instead of the second radio access technology.
The non-transitory computer-readable medium of claim 113, wherein the instructions to receive the first control message are executable to:

receive the first control message that is an attach request message associated with the second radio access technology.
The non-transitory computer-readable medium of claim 126, wherein the instructions are further executable to:

transmit an attach accept message associated with the second radio access technology based at least in part on the attach request message; and

receive a service request message associated with the second radio access technology based at least in part on the attach accept message, wherein transmitting the configuration message is based at least in part on receiving the service request message.
The non-transitory computer-readable medium of claim 113, wherein the first radio access technology is a Long Term Evolution (LTE) radio access technology and the second radio access technology is a New Radio (NR) radio access technology.