WO2022006840A1

WO2022006840A1 - Returning to a standalone network instead of a non-standalone network

Info

Publication number: WO2022006840A1
Application number: PCT/CN2020/101265
Authority: WO
Inventors: Shouqiao ZHU; Haojun WANG; Kaikai YANG; Zhenqing CUI
Original assignee: Qualcomm Inc
Current assignee: Qualcomm Inc
Priority date: 2020-07-10
Filing date: 2020-07-10
Publication date: 2022-01-13
Anticipated expiration: 2023-01-10

Abstract

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may transmit, to a first base station, a request for voice service based at least in part on receiving a fallback message from a second base station; receive, from the first base station and after receiving the voice service, a reconfiguration message that instructs the UE to connect to a non-standalone network including the second base station; and transmit, to the second base station and based at least in part on receiving the reconfiguration message, a request for data service that includes a request to camp to a standalone network associated with the second base station and that is based at least in part on determining that a network cell associated with the second base station is present on a list of approved network cells. Numerous other aspects are provided.

Description

RETURNING TO A STANDALONE NETWORK INSTEAD OF A NON-STANDALONE NETWORK

FIELD OF THE DISCLOSURE

Aspects of the present disclosure generally relate to wireless communication and to techniques and apparatuses for returning to a standalone (SA) network instead of a non-standalone (NSA) network.

BACKGROUND

Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, and/or the like) . Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency-division multiple access (FDMA) systems, orthogonal frequency-division multiple access (OFDMA) systems, single-carrier frequency-division multiple access (SC-FDMA) systems, time division synchronous code division multiple access (TD-SCDMA) systems, and Long Term Evolution (LTE) . LTE/LTE-Advanced is a set of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile standard promulgated by the Third Generation Partnership Project (3GPP) .

A wireless network may include a number of base stations (BSs) that can support communication for a number of user equipment (UEs) . A user equipment (UE) may communicate with a base station (BS) via the downlink and uplink. The downlink (or forward link) refers to the communication link from the BS to the UE, and the uplink (or reverse link) refers to the communication link from the UE to the BS. As will be described in more detail herein, a BS may be referred to as a Node B, a gNB, an access point (AP) , a radio head, a transmit receive point (TRP) , a New Radio (NR) BS, a 5G Node B, and/or the like.

The above multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different user equipment to communicate on a municipal, national, regional, and even global level. New Radio (NR) , which may also be referred to as 5G, is a set of enhancements to the LTE mobile standard promulgated by the Third Generation Partnership Project (3GPP) . NR is designed to better support mobile broadband Internet access by improving spectral efficiency, lowering costs, improving services, making use of new spectrum, and better integrating with other open standards using orthogonal frequency division multiplexing (OFDM) with a cyclic prefix (CP) (CP-OFDM) on the downlink (DL) , using CP-OFDM and/or SC-FDM (e.g., also known as discrete Fourier transform spread OFDM (DFT-s-OFDM) ) on the uplink (UL) , as well as supporting beamforming, multiple-input multiple-output (MIMO) antenna technology, and carrier aggregation. As the demand for mobile broadband access continues to increase, further improvements in LTE, NR, and other radio access technologies remain useful.

SUMMARY

In some aspects, a method of wireless communication performed by a user equipment (UE) includes: transmitting, to a first base station, a request for voice service based at least in part on receiving a fallback message from a second base station; receiving, from the first base station and after receiving the voice service, a reconfiguration message that instructs the UE to connect to a non-standalone (NSA) network including the second base station; and transmitting, to the second base station and based at least in part on receiving the reconfiguration message, a request for data service, wherein the request for data service includes a request to camp to a standalone (SA) network associated with the second base station and is based at least in part on determining that a network cell associated with the second base station is present on a list of approved network cells.

In some aspects, a method of wireless communication performed by a base station includes: transmitting, to a UE, a fallback message based at least in part on receiving a request for voice service from the UE; and receiving, from the UE and after transmitting the fallback message, a request for data service, wherein the request for data service includes a request to camp to an SA network including the base station and is based at least in part on a previous camping between the base station and the UE.

In some aspects, a method of wireless communication performed by a first base station includes: receiving, from a UE, a request for voice service; transmitting, to the UE and after providing the voice service, a reconfiguration message that instructs the UE to connect to an NSA network including a second base station; and receiving, from the UE and based at least in part on transmitting the reconfiguration message, an indication of a release of a connection between the first base station and the UE.

In some aspects, a UE for wireless communication includes: a memory; and one or more processors coupled with the memory, the memory and the one or more processors configured to: transmit, to a first base station, a request for voice service based at least in part on receiving a fallback message from a second base station; receive, from the first base station and after receiving the voice service, a reconfiguration message that instructs the UE to connect to an NSA network including the second base station; and transmit, to the second base station and based at least in part on receiving the reconfiguration message, a request for data service, wherein the request for data service includes a request to camp to an SA network associated with the second base station and is based at least in part on determining that a network cell associated with the second base station is present on a list of approved network cells.

In some aspects, a base station for wireless communication includes: a memory; and one or more processors coupled with the memory, the memory and the one or more processors configured to: transmit, to a UE, a fallback message based at least in part on receiving a request for voice service from the UE; and receive, from the UE and after transmitting the fallback message, a request for data service, wherein the request for data service includes a request to camp to an SA network including the base station and is based at least in part on a previous camping between the base station and the UE.

In some aspects, a first base station for wireless communication includes: a memory; and one or more processors coupled with the memory, the memory and the one or more processors configured to: receive, from a UE, a request for voice service; transmit, to the UE and after providing the voice service, a reconfiguration message that instructs the UE to connect to an NSA network including a second base station; and receive, from the UE and based at least in part on transmitting the reconfiguration message, an indication of a release of a connection between the first base station and the UE.

In some aspects, a non-transitory computer-readable medium storing a set of instructions for wireless communication includes: one or more instructions that, when executed by one or more processors of a UE, cause the UE to: transmit, to a first base station, a request for voice service based at least in part on receiving a fallback message from a second base station; receive, from the first base station and after receiving the voice service, a reconfiguration message that instructs the UE to connect to an NSA network including the second base station; and transmit, to the second base station and based at least in part on receiving the reconfiguration message, a request for data service, wherein the request for data service includes a request to camp to an SA network associated with the second base station and is based at least in part on determining that a network cell associated with the second base station is present on a list of approved network cells.

In some aspects, a non-transitory computer-readable medium storing a set of instructions for wireless communication includes: one or more instructions that, when executed by one or more processors of a base station, cause the base station to: transmit, to a UE, a fallback message based at least in part on receiving a request for voice service from the UE; and receive, from the UE and after transmitting the fallback message, a request for data service, wherein the request for data service includes a request to camp to an SA network including the base station and is based at least in part on a previous camping between the base station and the UE.

In some aspects, a non-transitory computer-readable medium storing a set of instructions for wireless communication includes: one or more instructions that, when executed by one or more processors of a first base station, cause the first base station to: receive, from a UE, a request for voice service; transmit, to the UE and after providing the voice service, a reconfiguration message that instructs the UE to connect to an NSA network including a second base station; and receive, from the UE and based at least in part on transmitting the reconfiguration message, an indication of a release of a connection between the first base station and the UE.

In some aspects, an apparatus for wireless communication includes: means for transmitting, to a first base station, a request for voice service based at least in part on receiving a fallback message from a second base station; means for receiving, from the first base station and after receiving the voice service, a reconfiguration message that instructs the apparatus to connect to an NSA network including the second base station; and means for transmitting, to the second base station and based at least in part on receiving the reconfiguration message, a request for data service, wherein the request for data service includes a request to camp to an SA network associated with the second base station and is based at least in part on determining that a network cell associated with the second base station is present on a list of approved network cells.

In some aspects, an apparatus for wireless communication includes: means for transmitting, to a UE, a fallback message based at least in part on receiving a request for voice service from the UE; and means for receiving, from the UE and after transmitting the fallback message, a request for data service, wherein the request for data service includes a request to camp to an SA network including the apparatus and is based at least in part on a previous camping between the apparatus and the UE.

In some aspects, an apparatus for wireless communication includes: means for receiving, from a UE, a request for voice service; means for transmitting, to the UE and after providing the voice service, a reconfiguration message that instructs the UE to connect to an NSA network including a base station; and means for receiving, from the UE and based at least in part on transmitting the reconfiguration message, an indication of a release of a connection between the apparatus and the UE.

Aspects generally include a method, apparatus, system, computer program product, non-transitory computer-readable medium, user equipment, base station, wireless communication device, and/or processing system as substantially described herein with reference to and as illustrated by the drawings and specification.

The foregoing has outlined rather broadly the features and technical advantages of examples according to the disclosure in order that the detailed description that follows may be better understood. Additional features and advantages will be described hereinafter. The conception and specific examples disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure. Such equivalent constructions do not depart from the scope of the appended claims. Characteristics of the concepts disclosed herein, both their organization and method of operation, together with associated advantages will be better understood from the following description when considered in connection with the accompanying figures. Each of the figures is provided for the purposes of illustration and description, and not as a definition of the limits of the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the above-recited features of the present disclosure can be understood in detail, a more particular description, briefly summarized above, may be had by reference to aspects, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only certain typical aspects of this disclosure and are therefore not to be considered limiting of its scope, for the description may admit to other equally effective aspects. The same reference numbers in different drawings may identify the same or similar elements.

Fig. 1 is a diagram illustrating an example of a wireless network, in accordance with various aspects of the present disclosure.

Fig. 2 is a diagram illustrating an example of a base station in communication with a UE in a wireless network, in accordance with various aspects of the present disclosure.

Fig. 3 is a diagram illustrating an example of connecting to an SA network, in accordance with various aspects of the present disclosure.

Fig. 4 is a diagram illustrating an example of performing evolved packet system (EPS) fallback, in accordance with various aspects of the present disclosure.

Fig. 5 is a diagram illustrating an example of returning to an SA network instead of an NSA network, in accordance with various aspects of the present disclosure.

Fig. 6 is a diagram illustrating an example process performed by a UE, in accordance with various aspects of the present disclosure.

Fig. 7 is a diagram illustrating an example process performed by a base station providing, for example, LTE service, in accordance with various aspects of the present disclosure.

Fig. 8 is a diagram illustrating an example process performed by a base station providing, for example, 5G service, in accordance with various aspects of the present disclosure.

DETAILED DESCRIPTION

Various aspects of the disclosure are described more fully hereinafter with reference to the accompanying drawings. This disclosure may, however, be embodied in many different forms and should not be construed as limited to any specific structure or function presented throughout this disclosure. Rather, these aspects are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. Based on the teachings herein, one skilled in the art should appreciate that the scope of the disclosure is intended to cover any aspect of the disclosure disclosed herein, whether implemented independently of or combined with any other aspect of the disclosure. For example, an apparatus may be implemented or a method may be practiced using any number of the aspects set forth herein. In addition, the scope of the disclosure is intended to cover such an apparatus or method which is practiced using other structure, functionality, or structure and functionality in addition to or other than the various aspects of the disclosure set forth herein. It should be understood that any aspect of the disclosure disclosed herein may be embodied by one or more elements of a claim.

Several aspects of telecommunication systems will now be presented with reference to various apparatuses and techniques. These apparatuses and techniques will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, modules, components, circuits, steps, processes, algorithms, and/or the like (collectively referred to as “elements” ) . These elements may be implemented using hardware, software, or combinations thereof. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system.

It should be noted that while aspects may be described herein using terminology commonly associated with a 5G or NR radio access technology (RAT) , aspects of the present disclosure can be applied to other RATs, such as a 3G RAT, a 4G RAT, and/or a RAT subsequent to 5G (e.g., 6G) .

Fig. 1 is a diagram illustrating an example of a wireless network 100, in accordance with various aspects of the present disclosure. The wireless network 100 may be or may include elements of a 5G (NR) network, an LTE network, and/or the like. The wireless network 100 may include a number of base stations 110 (shown as BS 110a, BS 110b, BS 110c, and BS 110d) and other network entities. A base station (BS) is an entity that communicates with user equipment (UEs) and may also be referred to as an NR BS, a Node B, a gNB, a 5G node B (NB) , an access point, a transmit receive point (TRP) , and/or the like. Each BS may provide communication coverage for a particular geographic area. In 3GPP, the term “cell” can refer to a coverage area of a BS and/or a BS subsystem serving this coverage area, depending on the context in which the term is used.

A BS may provide communication coverage for a macro cell, a pico cell, a femto cell, and/or another type of cell. A macro cell may cover a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs with service subscription. A pico cell may cover a relatively small geographic area and may allow unrestricted access by UEs with service subscription. A femto cell may cover a relatively small geographic area (e.g., a home) and may allow restricted access by UEs having association with the femto cell (e.g., UEs in a closed subscriber group (CSG) ) . A BS for a macro cell may be referred to as a macro BS. A BS for a pico cell may be referred to as a pico BS. A BS for a femto cell may be referred to as a femto BS or a home BS. In the example shown in Fig. 1, a BS 110a may be a macro BS for a macro cell 102a, a BS 110b may be a pico BS for a pico cell 102b, and a BS 110c may be a femto BS for a femto cell 102c. A BS may support one or multiple (e.g., three) cells. The terms “eNB” , “base station” , “NR BS” , “gNB” , “TRP” , “AP” , “node B” , “5G NB” , and “cell” may be used interchangeably herein.

In some aspects, a cell may not necessarily be stationary, and the geographic area of the cell may move according to the location of a mobile BS. In some aspects, the BSs may be interconnected to one another and/or to one or more other BSs or network nodes (not shown) in the wireless network 100 through various types of backhaul interfaces such as a direct physical connection, a virtual network, and/or the like using any suitable transport network.

Wireless network 100 may also include relay stations. A relay station is an entity that can receive a transmission of data from an upstream station (e.g., a BS or a UE) and send a transmission of the data to a downstream station (e.g., a UE or a BS) . A relay station may also be a UE that can relay transmissions for other UEs. In the example shown in Fig. 1, a relay station 110d may communicate with macro BS 110a and a UE 120d in order to facilitate communication between BS 110a and UE 120d. A relay BS may also be referred to as a relay station, a relay base station, a relay, and/or the like.

Wireless network 100 may be a heterogeneous network that includes BSs of different types, e.g., macro BSs, pico BSs, femto BSs, relay BSs, and/or the like. These different types of BSs may have different transmit power levels, different coverage areas, and different impacts on interference in wireless network 100. For example, macro BSs may have a high transmit power level (e.g., 5 to 40 watts) whereas pico BSs, femto BSs, and relay BSs may have lower transmit power levels (e.g., 0.1 to 2 watts) .

A network controller 130 may couple to a set of BSs and may provide coordination and control for these BSs. Network controller 130 may communicate with the BSs via a backhaul. The BSs may also communicate with one another, e.g., directly or indirectly via a wireless or wireline backhaul.

UEs 120 (e.g., 120a, 120b, 120c) may be dispersed throughout wireless network 100, and each UE may be stationary or mobile. A UE may also be referred to as an access terminal, a terminal, a mobile station, a subscriber unit, a station, and/or the like. A UE may be a cellular phone (e.g., a smart phone) , a personal digital assistant (PDA) , a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL) station, a tablet, a camera, a gaming device, a netbook, a smartbook, an ultrabook, a medical device or equipment, biometric sensors/devices, wearable devices (smart watches, smart clothing, smart glasses, smart wrist bands, smart jewelry (e.g., smart ring, smart bracelet) ) , an entertainment device (e.g., a music or video device, or a satellite radio) , a vehicular component or sensor, smart meters/sensors, industrial manufacturing equipment, a global positioning system device, or any other suitable device that is configured to communicate via a wireless or wired medium.

Some UEs may be considered machine-type communication (MTC) or evolved or enhanced machine-type communication (eMTC) UEs. MTC and eMTC UEs include, for example, robots, drones, remote devices, sensors, meters, monitors, location tags, and/or the like, that may communicate with a base station, another device (e.g., remote device) , or some other entity. A wireless node may provide, for example, connectivity for or to a network (e.g., a wide area network such as Internet or a cellular network) via a wired or wireless communication link. Some UEs may be considered Internet-of-Things (IoT) devices, and/or may be implemented as NB-IoT (narrowband internet of things) devices. Some UEs may be considered a Customer Premises Equipment (CPE) . UE 120 may be included inside a housing that houses components of UE 120, such as processor components, memory components, and/or the like. In some aspects, the processor components and the memory components may be coupled together. For example, the processor components (e.g., one or more processors) and the memory components (e.g., a memory) may be operatively coupled, communicatively coupled, electronically coupled, electrically coupled, and/or the like.

In general, any number of wireless networks may be deployed in a given geographic area. Each wireless network may support a particular RAT and may operate on one or more frequencies. A RAT may also be referred to as a radio technology, an air interface, and/or the like. A frequency may also be referred to as a carrier, a frequency channel, and/or the like. Each frequency may support a single RAT in a given geographic area in order to avoid interference between wireless networks of different RATs. In some cases, NR or 5G RAT networks may be deployed.

In some aspects, two or more UEs 120 (e.g., shown as UE 120a and UE 120e) may communicate directly using one or more sidelink channels (e.g., without using a base station 110 as an intermediary to communicate with one another) . For example, the UEs 120 may communicate using peer-to-peer (P2P) communications, device-to-device (D2D) communications, a vehicle-to-everything (V2X) protocol (e.g., which may include a vehicle-to-vehicle (V2V) protocol, a vehicle-to-infrastructure (V2I) protocol, and/or the like) , a mesh network, and/or the like. In this case, the UE 120 may perform scheduling operations, resource selection operations, and/or other operations described elsewhere herein as being performed by the base station 110.

Devices of wireless network 100 may communicate using the electromagnetic spectrum, which may be subdivided based on frequency or wavelength into various classes, bands, channels, and/or the like. For example, devices of wireless network 100 may communicate using an operating band having a first frequency range (FR1) , which may span from 410 MHz to 7.125 GHz, and/or may communicate using an operating band having a second frequency range (FR2) , which may span from 24.25 GHz to 52.6 GHz. The frequencies between FR1 and FR2 are sometimes referred to as mid-band frequencies. Although a portion of FR1 is greater than 6 GHz, FR1 is often referred to as a “sub-6 GHz” band. Similarly, FR2 is often referred to as a “millimeter wave” band despite being different from the extremely high frequency (EHF) band (30 GHz –300 GHz) which is identified by the International Telecommunications Union (ITU) as a “millimeter wave” band. Thus, unless specifically stated otherwise, it should be understood that the term “sub-6 GHz” or the like, if used herein, may broadly represent frequencies less than 6 GHz, frequencies within FR1, and/or mid-band frequencies (e.g., greater than 7.125 GHz) . Similarly, unless specifically stated otherwise, it should be understood that the term “millimeter wave” or the like, if used herein, may broadly represent frequencies within the EHF band, frequencies within FR2, and/or mid-band frequencies (e.g., less than 24.25 GHz) . It is contemplated that the frequencies included in FR1 and FR2 may be modified, and techniques described herein are applicable to those modified frequency ranges.

As indicated above, Fig. 1 is provided as an example. Other examples may differ from what is described with regard to Fig. 1.

Fig. 2 is a diagram illustrating an example 200 of a base station 110 in communication with a UE 120 in a wireless network 100, in accordance with various aspects of the present disclosure. Base station 110 may be equipped with T antennas 234a through 234t, and UE 120 may be equipped with R antennas 252a through 252r, where in general T ≥ 1 and R ≥ 1.

At base station 110, a transmit processor 220 may receive data from a data source 212 for one or more UEs, select one or more modulation and coding schemes (MCS) for each UE based at least in part on channel quality indicators (CQIs) received from the UE, process (e.g., encode and modulate) the data for each UE based at least in part on the MCS (s) selected for the UE, and provide data symbols for all UEs. Transmit processor 220 may also process system information (e.g., for semi-static resource partitioning information (SRPI) and/or the like) and control information (e.g., CQI requests, grants, upper layer signaling, and/or the like) and provide overhead symbols and control symbols. Transmit processor 220 may also generate reference symbols for reference signals (e.g., a cell-specific reference signal (CRS) , a demodulation reference signal (DMRS) , and/or the like) and synchronization signals (e.g., the primary synchronization signal (PSS) and secondary synchronization signal (SSS) ) . A transmit (TX) multiple-input multiple-output (MIMO) processor 230 may perform spatial processing (e.g., precoding) on the data symbols, the control symbols, the overhead symbols, and/or the reference symbols, if applicable, and may provide T output symbol streams to T modulators (MODs) 232a through 232t. Each modulator 232 may process a respective output symbol stream (e.g., for OFDM and/or the like) to obtain an output sample stream. Each modulator 232 may further process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal. T downlink signals from modulators 232a through 232t may be transmitted via T antennas 234a through 234t, respectively.

At UE 120, antennas 252a through 252r may receive the downlink signals from base station 110 and/or other base stations and may provide received signals to demodulators (DEMODs) 254a through 254r, respectively. Each demodulator 254 may condition (e.g., filter, amplify, downconvert, and digitize) a received signal to obtain input samples. Each demodulator 254 may further process the input samples (e.g., for OFDM and/or the like) to obtain received symbols. A MIMO detector 256 may obtain received symbols from all R demodulators 254a through 254r, perform MIMO detection on the received symbols if applicable, and provide detected symbols. A receive processor 258 may process (e.g., demodulate and decode) the detected symbols, provide decoded data for UE 120 to a data sink 260, and provide decoded control information and system information to a controller/processor 280. The term "controller/processor" may refer to one or more controllers, one or more processors, or a combination thereof. A channel processor may determine reference signal received power (RSRP) , received signal strength indicator (RSSI) , reference signal received quality (RSRQ) , channel quality indicator (CQI) , and/or the like. In some aspects, one or more components of UE 120 may be included in a housing 284.

Network controller 130 may include communication unit 294, controller/processor 290, and memory 292. Network controller 130 may include, for example, one or more devices in a core network. Network controller 130 may communicate with base station 110 via communication unit 294.

On the uplink, at UE 120, a transmit processor 264 may receive and process data from a data source 262 and control information (e.g., for reports that include RSRP, RSSI, RSRQ, CQI, and/or the like) from controller/processor 280. Transmit processor 264 may also generate reference symbols for one or more reference signals. The symbols from transmit processor 264 may be precoded by a TX MIMO processor 266 if applicable, further processed by modulators 254a through 254r (e.g., for DFT-s-OFDM, CP-OFDM, and/or the like) , and transmitted to base station 110. In some aspects, the UE 120 includes a transceiver. The transceiver may include any combination of antenna (s) 252, modulators and/or demodulators 254, MIMO detector 256, receive processor 258, transmit processor 264, and/or TX MIMO processor 266. The transceiver may be used by a processor (e.g., controller/processor 280) and memory 282 to perform aspects of any of the methods described herein, for example, as described with reference to Figs. 5-8.

At base station 110, the uplink signals from UE 120 and other UEs may be received by antennas 234, processed by demodulators 232, detected by a MIMO detector 236 if applicable, and further processed by a receive processor 238 to obtain decoded data and control information sent by UE 120. Receive processor 238 may provide the decoded data to a data sink 239 and the decoded control information to controller/processor 240. Base station 110 may include communication unit 244 and communicate to network controller 130 via communication unit 244. Base station 110 may include a scheduler 246 to schedule UEs 120 for downlink and/or uplink communications. In some aspects, the base station 110 includes a transceiver. The transceiver may include any combination of antenna (s) 234, modulators and/or demodulators 232, MIMO detector 236, receive processor 238, transmit processor 220, and/or TX MIMO processor 230. The transceiver may be used by a processor (e.g., controller/processor 240) and memory 242 to perform aspects of any of the methods described herein, for example, as described with reference to Figs. 5-8.

Controller/processor 240 of base station 110, controller/processor 280 of UE 120, and/or any other component (s) of Fig. 2 may perform one or more techniques associated with returning to an SA network instead of an NSA network, as described in more detail elsewhere herein. For example, controller/processor 240 of base station 110, controller/processor 280 of UE 120, and/or any other component (s) of Fig. 2 may perform or direct operations of, for example, process 600 of Fig. 6, process 700 of Fig. 7, process 800 of Fig. 8, and/or other processes as described herein.

Memories

242 and 282 may store data and program codes for base station 110 and UE 120, respectively. In some aspects, memory 242 and/or memory 282 may include a non-transitory computer-readable medium storing one or more instructions (e.g., code, program code, and/or the like) for wireless communication. For example, the one or more instructions, when executed (e.g., directly, or after compiling, converting, interpreting, and/or the like) by one or more processors of the base station 110 and/or the UE 120, may cause the one or more processors, the UE 120, and/or the base station 110 to perform or direct operations of, for example, process 600 of Fig. 6, process 700 of Fig. 7, process 800 of Fig. 8, and/or other processes as described herein. In some aspects, executing instructions may include running the instructions, converting the instructions, compiling the instructions, interpreting the instructions, and/or the like.

In some aspects, a UE (e.g., UE 120) may include means for transmitting, to a first base station, a request for voice service based at least in part on receiving a fallback message from a second base station; means for receiving, from the first base station and after receiving the voice service, a reconfiguration message that instructs the UE to connect to an NSA network including the second base station; means for transmitting, to the second base station and based at least in part on receiving the reconfiguration message, a request for data service, wherein the request for data service includes a request to camp to an SA network associated with the second base station and is based at least in part on determining that a network cell associated with the second base station is present on a list of approved network cells; and/or the like. In some aspects, such means may include one or more components of UE 120 described in connection with Fig. 2, such as controller/processor 280, transmit processor 264, TX MIMO processor 266, MOD 254, antenna 252, DEMOD 254, MIMO detector 256, receive processor 258, and/or the like.

In some aspects, a base station (e.g., base station 110) may include means for transmitting, to a UE, a fallback message based at least in part on receiving a request for voice service from the UE; means for receiving, from the UE and after transmitting the fallback message, a request for data service, wherein the request for data service includes a request to camp to an SA network including the base station and is based at least in part on a previous camping between the base station and the UE; and/or the like. In some aspects, such means may include one or more components of base station 110 described in connection with Fig. 2, such as antenna 234, DEMOD 232, MIMO detector 236, receive processor 238, controller/processor 240, transmit processor 220, TX MIMO processor 230, MOD 232, antenna 234, and/or the like.

In some aspects, a first base station (e.g., base station 110) may include means for receiving, from a UE, a request for voice service; means for transmitting, to the UE and after providing the voice service, a reconfiguration message that instructs the UE to connect to an NSA network including a second base station; means for receiving, from the UE and based at least in part on transmitting the reconfiguration message, an indication of a release of a connection between the first base station and the UE; and/or the like. In some aspects, such means may include one or more components of base station 110 described in connection with Fig. 2, such as antenna 234, DEMOD 232, MIMO detector 236, receive processor 238, controller/processor 240, transmit processor 220, TX MIMO processor 230, MOD 232, antenna 234, and/or the like.

While blocks in Fig. 2 are illustrated as distinct components, the functions described above with respect to the blocks may be implemented in a single hardware, software, or combination component or in various combinations of components. For example, the functions described with respect to the transmit processor 264, the receive processor 258, and/or the TX MIMO processor 266 may be performed by or under the control of controller/processor 280.

As indicated above, Fig. 2 is provided as an example. Other examples may differ from what is described with regard to Fig. 2.

Fig. 3 is a diagram illustrating an example 300 of connecting to an SA network, in accordance with various aspects of the present disclosure. As shown in Fig. 3, example 300 includes a UE 120 camping on a wireless cell including a base station 110a. The base station 110 and the UE 120 may be included in a wireless network, such as wireless network 100 illustrated and described above in connection with Fig. 1.

As shown in connection with reference number 305, the UE 120 may transmit, and the base station 110a may receive, a request for service. In some aspects, the request for service may include a radio resource control (RRC) message, such as an RRC Setup Req message (e.g., as defined in 3GPP specifications) and/or the like.

As shown in connection with reference number 310, the base station 110a may transmit, and the UE 120 may receive, a message to setup service to the UE 120, based at least in part on the request for service. In some aspects, the message to setup service may include an RRC message, such as an RRC Setup message (e.g., as defined in 3GPP specifications) and/or the like.

As shown in connection with reference number 315, the UE 120 may transmit, and the base station 110a may receive, a confirmation message, based at least in part on the message to setup service. In some aspects, the confirmation message may include an RRC message, such as an RRCSetup Complete message (e.g., as defined in 3GPP specifications) and/or the like.

In some aspects, the base station 110a may provide 5G data service to the UE 120 after performing the camping procedure described in connection with Fig. 3. For example, the UE 120 may transmit data to the base station 110a on an uplink (e.g., a physical uplink control channel (PUCCH) , a physical uplink shared channel (PUSCH) , a random access channel (RACH) , and/or the like) . Additionally, or alternatively, the base station 110a may transmit data to the UE 120 on a downlink (e.g., physical downlink control channel (PDCCH) , a physical downlink shared channel (PDSCH) , a RACH, and/or the like) .

As indicated above, Fig. 3 is provided as an example. Other examples may differ from what is described with respect to Fig. 3.

Fig. 4 is a diagram illustrating an example 400 of performing EPS fallback, in accordance with various aspects of the present disclosure. As shown in Fig. 4, example 400 includes a UE 120 camping on a wireless cell including a base station 110a. For example, the UE 120 may have camped on the cell using a procedure similar to that described above in connection with Fig. 3. In some aspects, the base station 110a may provide 5G data service to the UE 120.

As further shown in Fig. 4, another base station (e.g., base station 110b) may be included in another wireless cell. For example, the base station 110b may provide LTE data service and/or other legacy RATs. In some aspects, the base station 110b may be included in a wireless network, such as wireless network 100 illustrated and described above in connection with Fig. 1.

As shown in connection with reference number 405, the UE 120 and the base station 110a may conduct an Internet protocol (IP) multimedia services (IMS) registration procedure. For example, the base station 110a may transmit, and the UE 120 may receive, an invite message (e.g., an IMS session initiation protocol (SIP) INVITE message as defined in Internet Engineering Task Force (IETF) specifications and/or the like) . The UE 120 may transmit, and the base station 110a may receive, a response to the invite message (e.g., an IMS SIP TRYING response as defined in IETF specifications and/or the like) . In some aspects, additionally, or alternatively, the UE 120 may transmit, and the base station 110a may receive, a status message (e.g., an IMS SIP SESSION PROGRESS message as defined in IETF specifications and/or the like) . Accordingly, after completing the IMS registration procedure, the base station 110a may provide multimedia services, such as voice service, to the UE 120.

As shown in connection with reference number 410, the UE 120 and the base station 110a may perform an RRC reconfiguration. For example, the RRC reconfiguration may be at least a portion of an EPS fallback procedure. In some aspects, the UE 120 may transmit, and the base station 110a may receive, a request for voice service. If voice service is unavailable on the 5G network including the base station 110a (e.g., due to signal quality, mobility of the UE 120, and/or the like) , the base station 110a may trigger network reconfiguration.

In some aspects, as part of the RRC reconfiguration, the base station 110a may transmit, and the UE 120 may receive a fallback message, such as an RRCConnectionReconfiguration message (e.g., as defined in 3GPP specifications) and/or the like. Based at least in part on the RRC reconfiguration message, the UE 120 may perform measurements (e.g., RSRP measurements, CQI measurements, and/or the like) on nearby network cells providing LTE service and/or other legacy RATs, including a network cell associated with the base station 110b. Further, the UE 120 may transmit, and the base station 110b may receive, the measurements (e.g., included in a MeasurementReport (e.g., as defined in 3GPP specifications) and/or the like) . Additionally, or alternatively, the UE 120 may transmit, and the base station 110b may receive, confirmation of the RRC reconfiguration message, such as an RRCConfigurationComplete message (e.g., as defined in 3GPP specifications) and/or the like. Based at least in part on the measurements, the base station 110a may transmit, and the UE 120 may receive, a mobility command, such as a mobilityFromNRCommand (e.g., as defined in 3GPP specifications) and/or the like. In some aspects, the mobility command may complete the EPS fallback procedure.

Accordingly, after completing the EPS fallback procedure, and as shown in connection with reference number 415, the UE 120 and the base station 110b may perform an RRC reconfiguration. For example, the UE 120 may camp on the cell including the base station 110b as at least a portion of the RRC reconfiguration. In some aspects, the UE 120 and the base station 110b may perform a camping procedure similar to that described above in connection with Fig. 3. For example, the UE 120 may transmit, and the base station 110b may receive, a request for service. In some aspects, the request for service may include an RRC message, such as an RRCConnectionReconfiguration message (e.g., as defined in 3GPP specifications) and/or the like. Moreover, the base station 110b may transmit, and the UE 120 may receive, a message to setup service to the UE 120, based at least in part on the request for service. In some aspects, the message to setup service may include an RRC message, such as an RRCConnectionReconfiguration message (e.g., as defined in 3GPP specifications) and/or the like. Further, the UE 120 may transmit, and the base station 110b may receive, a confirmation message, based at least in part on the message to setup service. In some aspects, the confirmation message may include an RRC message, such as an RRCConnectionReconfigurationComplete message (e.g., as defined in 3GPP specifications) and/or the like.

As shown in connection with reference number 420, the UE 120 and the base station 110b may conduct an IMS registration procedure. For example, the base station 110b may transmit, and the UE 120 may receive, an invite message (e.g., an IMS SIP INVITE message as defined in IETF specifications and/or the like) and/or an update message (e.g., an IMS SIP UPDATE message as defined in IETF specifications and/or the like) . The UE 120 may transmit, and the base station 110b may receive, a response to the invite message (e.g., an IMS SIP ACK and/or an IMS SIP PRACK response as defined in IETF specifications and/or the like) . In some aspects, additionally, or alternatively, the UE 120 may transmit, and the base station 110b may receive, a status message (e.g., an IMS SIP SESSION PROGRESS message as defined in IETF specifications and/or the like) . Accordingly, after completing the IMS registration procedure, the base station 110b may provide multimedia services, such as voice service, to the UE 120.

As shown in connection with reference number 425, the UE 120 may transmit, and the base station 110b may receive, a request for voice service (e.g., a VoLTE session and/or the like) . Accordingly, the base station 110b may provide the requested voice service to the UE 120.

As shown in connection with reference number 430, the base station 110b and the UE 120 may terminate a voice session after the UE 120 is provided the voice service by the base station 110b. For example, the base station 110b may transmit, and the UE 120 may receive, a termination message (e.g., an IMS SIP BYE message as defined in IETF specifications and/or the like) . Additionally, or alternatively, the UE 120 may transmit, and the base station 110b may receive, the termination message.

As indicated above, Fig. 4 is provided as an example. Other examples may differ from what is described with respect to Fig. 4.

In some situations, after an LTE network and/or other legacy RAT provides voice service to a UE, the UE may reconnect to a 5G network and/or other NR network as an NSA network. As used herein, a network may be referred to as an NSA network when a control plane for the NSA network is provided by an anchor network and/or when the NSA network is supported by a core network of the anchor network rather than the NSA network’s own core network. However, the UE and the 5G network will experience slower communications when the UE connects to the 5G network as an NSA network rather than an SA network.

Techniques and apparatuses described herein allow a UE (e.g., UE 120) to maintain a list (e.g., a whitelist) of 5G networks and/or other NR networks and to reconnect to networks on the list as SA networks, rather than as NSA networks, after an LTE network and/or other legacy RATs provides voice service to the UE 120. Accordingly, the UE 120 and base stations on the 5G network (e.g., base station 110a) may improve communication speeds. Moreover, base stations on the LTE network (e.g., base station 110b) may incur less network overhead by not serving as an anchor for the 5G network.

Fig. 5 is a diagram illustrating an example 500 of returning to an SA network instead of an NSA network, in accordance with various aspects of the present disclosure. As shown in Fig. 5, example 500 includes a UE 120 camping on a wireless cell including a base station 110b. For example, the UE 120 may have camped on the cell after undergoing EPS fallback similar to that described above in connection with Fig. 4. In some aspects, the base station 110b may provide voice service (e.g., VoLTE service and/or the like) to the UE 120.

As further shown in Fig. 5, another base station (e.g., base station 110a) may be included in another wireless cell. In some aspects, the base station 110a may provide 5G data service and/or other NR data service.

In some aspects, the UE 120 may have previously received data service from the base station 110a. For example, the UE 120 and the base station 110a may have previously performed a camping procedure similar to that described above in connection with Fig. 3. In some aspects, the UE 120 may have added a network cell associated with the base station 110a to a list of approved network cells (e.g., a whitelist and/or the like) , based at least in part on performing the camping procedure.

In some aspects, the UE 120 may additionally begin a timer associated with the network cell when adding the network cell to the list. For example, the timer may be 5 minutes, 10 minutes, 20 minutes, and/or the like. Accordingly, when the network cell is already on the list of approved network cells, the UE 120 may reset the timer associated with network cell based at least in part on performing the camping procedure and based at least in part on determining that the network cell is present on the list. In some aspects, the UE 120 may remove network cells from the list when timers associated with the network cells expire.

Additionally, or alternatively, the UE 120 may remove network cells from the list when a maximum number of cells associated with the list is exceeded. For example, when adding a new network cell that would cause the maximum number of cells to be exceeded, the UE 120 may remove a network cell already on the list (e.g., based at least in part on a timer associated with the network cell having the shortest amount of time remaining before expiry) . The maximum number of cells and/or a length for each timer may be configured by the UE 120 and/or RRC configured by one or more base stations (e.g., base station 110a, base station 110b, and/or like) . In some aspects, the UE 120 may dynamically select the maximum number of cells and/or the length for each timer, or may be programmed or otherwise preconfigured according to one or more standards (e.g., standards in 3GPP specifications and/or the like) .

In some aspects, the base station 110a may further have transmitted, and the UE 120 may have received, a fallback message based at least in part on the UE 120 transmitting, and the base station 110a receiving, a request for voice service. Moreover, the UE 120 may have transmitted, and the base station 110b may have received, a request for voice service, based at least in part on the UE 120 receiving the fallback message from the base station 110a. For example, the UE 120 and the base station 110a may have performed an EPS fallback procedure, and the UE 120 and the base station 110b may have performed an IMS registration procedure, as described above in connection with Fig. 4.

As shown in connection with reference number 505, the base station 110b may transmit, and the UE 120 may receive, a reconfiguration message. In some aspects, the reconfiguration message may instruct the UE 120 to connect to an NSA network including the base station 110a. For example, the reconfiguration message may include an RRC message, such as an RRCConnectionReconfiguration message (e.g., as defined in 3GPP specifications) and/or the like. In some aspects, the base station 110b may transmit the reconfiguration message after the UE 120 receives the voice service from the base station 110b.

Additionally, or alternatively, the reconfiguration message may instruct the UE 120 to measure signals from one or more 5G networks. For example, the UE 120 may measure signals from the NSA network including the base station 110a. In some aspects, the UE 120 may perform RSRP measurements, CQI measurements, and/or the like on nearby network cells providing 5G data service and/or other NR data service, including the cell with the base station 110a.

As shown in connection with reference number 510, the UE 120 may transmit, and the base station 110b may receive, a confirmation message, based at least in part on the reconfiguration message. In some aspects, the confirmation message may include an RRC message, such as an RRCConnectionReconfigurationComplete message (e.g., as defined in 3GPP specifications) and/or the like.

Additionally, or alternatively, as shown in connection with reference number 515, the UE 120 may transmit, and the base station 110b may receive, a measurement report based at least in part on the NSA network including the base station 110a. For example, the UE 120 may transmit, and the base station 110b may receive, a MeasurementReport (e.g., as defined in 3GPP specifications) and/or the like.

As shown in connection with reference number 520, the base station 110b may transmit, and the UE 120 may receive, a reconfiguration message. In some aspects, the reconfiguration message may instruct the UE 120 to connect to an NSA network including the base station 110a. For example, the reconfiguration message may include an RRC message, such as an RRCConnectionReconfiguration message (e.g., as defined in 3GPP specifications) and/or the like. In some aspects, the base station 110b may transmit the reconfiguration message based at least in part on receiving the measurement report.

As shown in connection with reference number 525, the UE 120 may determine that a network cell associated with the base station 110a is present on the list of approved network cells. For example, the UE 120 may determine that a physical cell ID (PCI) and/or the like is on the list. In some aspects, the cell associated with the base station 110a may have been added to the list by the UE 120, as described above.

As further shown in connection with reference number 530a, the UE 120 may transmit, and the base station 110b may receive, an indication of a release of a connection between the base station 110b and the UE 120. In some aspects, the UE 120 may trigger the release based at least in part on receiving the reconfiguration message (e.g., as described above in connection with reference number 505 and/or as described above in connection with reference number 520) . Additionally, or alternatively, the UE 120 may trigger the release based at least in part on determining that the network cell associated with the base station 110a is present on the list of approved network cells, as described above in connection with reference number 525.

As further shown in connection with reference number 530a, the UE 120 may transmit, and the base station 110a may receive, a request to camp to an SA network associated with the base station 110a. In some aspects, the UE 120 may transmit, and the base station 110a may receive, a request for data service, based at least in part on receiving the reconfiguration message (e.g., as described above in connection with reference number 505 and/or as described above in connection with reference number 520) . For example, the UE 120 and the base station 110a may perform a camping procedure similar to that described above in connection with Fig. 3.

In some aspects, the UE 120 may transmit, and the base station 110a may receive, the request for data service, based at least in part on previous camping between the base station and the UE. For example, the UE 120 and the base station 110a may have previously performed a camping procedure similar to that described above in connection with Fig. 3. Additionally, or alternatively, the UE 120 may transmit, and the base station 110a may receive, the request for data service, based at least in part on determining that the network cell associated with the base station 110a is present on the list of approved network cells, as described above in connection with reference number 525.

In some aspects, the UE 120 may additionally, or alternatively, determine that a measurement associated with the network cell including the base station 110a is greater than another measurement associated with another network cell. For example, the UE 120 may determine that multiple network cells are present on the list of approved network cells and select the network cell associated with the base station 110a based at least in part on measurements taken by the UE 120. Accordingly, the UE 120 may transmit, and the base station 110a may receive, the request for data service, based at least in part on determining that the measurement associated with the network cell including the base station 110a is greater than another measurement associated with another network cell.

As shown in connection with reference number 530b, when the network cell associated with the base station 110a is not present on the list of approved network cells, the UE 120 may transmit, and the base station 110a may receive, a request to camp to an NSA network associated with the base station 110a, based at least in part on receiving the reconfiguration message (e.g., as described above in connection with reference number 505 and/or as described above in connection with reference number 520) . For example, the UE 120 may connect to the base station 110a as part of a secondary cell group such that the NSA network including the base station 110a is anchored by the network including the base station 110b.

By maintaining the list of approved network cells, as described above in connection with Fig. 5, the UE 120 may improve communication speed by connecting to the 5G network including the base station 110a as an SA network rather than an NSA network. Moreover, the base station 110a may also improve communication speed by functioning as an SA network rather than NSA network. The base station 110b may reduce network overhead by no longer serving as an anchor network for the 5G network.

As indicated above, Fig. 5 is provided as an example. Other examples may differ from what is described with respect to Fig. 5.

Fig. 6 is a diagram illustrating an example process 600 performed, for example, by a UE, in accordance with various aspects of the present disclosure. Example process 600 is an example where the UE (e.g., UE 120 and/or the like) performs operations associated with returning to an SA network instead of an NSA network.

As shown in Fig. 6, in some aspects, process 600 may include transmitting, to a first base station (e.g., base station 110b and/or the like) , a request for voice service based at least in part on receiving a fallback message from a second base station (e.g., base station 110a and/or the like) (block 610) . For example, the UE (e.g., using receive processor 258, transmit processor 264, controller/processor 280, memory 282, and/or the like) may transmit, to the first base station, the request for voice service based at least in part on receiving the fallback message from the second base station, as described above. In some aspects, the first base station may provide LTE service and/or other RATs, and the second base station may provide 5G service and/or other NR service.

As further shown in Fig. 6, in some aspects, process 600 may include receiving, from the first base station and after receiving the voice service, a reconfiguration message that instructs the UE to connect to an NSA network including the second base station (block 620) . For example, the UE (e.g., using receive processor 258, transmit processor 264, controller/processor 280, memory 282, and/or the like) may receive, from the first base station and after receiving the voice service, the reconfiguration message that instructs the UE to connect to the NSA network including the second base station, as described above.

As further shown in Fig. 6, in some aspects, process 600 may include transmitting, to the second base station and based at least in part on receiving the reconfiguration message, a request for data service (block 630) . For example, the UE (e.g., using receive processor 258, transmit processor 264, controller/processor 280, memory 282, and/or the like) may transmit, to the second base station and based at least in part on receiving the reconfiguration message, the request for data service, as described above. In some aspects, the request for data service includes a request to camp to an SA network associated with the second base station and is based at least in part on determining that a network cell associated with the second base station is present on a list of approved network cells.

Process 600 may include additional aspects, such as any single aspect or any combination of aspects described below and/or in connection with one or more other processes described elsewhere herein.

In a first aspect, process 600 includes transmitting, to the second base station and before transmitting the request for voice service, an RRC request.

In a second aspect, alone or in combination with the first aspect, process 600 further includes at least one of: adding, to the list of approved network cells, the network cell associated with the second base station based at least in part on the RRC request; or resetting a timer that is associated with the network cell associated with the second base station based at least in part on the RRC request and based at least in part on determining that the network cell including the second base station is present on the list of approved network cells.

In a third aspect, alone or in combination with one or more of the first and second aspects, process 600 further includes: adding the network cell associated with the second base station to the list of approved network cells based at least in part on the RRC request; and removing another network cell from the list of approved network cells based at least in part on a maximum number of cells associated with the list of approved network cells.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, process 600 further includes: adding the network cell associated with the second base station to the list of approved network cells based at least in part on the RRC request; and removing the network cell associated with the second base station from the list of approved network cells when a timer that is associated with the network cell associated with the second base station expires.

In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, process 600 further includes transmitting, to the first base station and after receiving the voice service, a measurement report based at least in part on the NSA network including the second base station, wherein the UE receives the reconfiguration message based at least in part on transmitting the measurement report.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, the UE transmits the request for data service based at least in part on determining that a measurement associated with the network cell including the second base station is greater than another measurement associated with another network cell.

In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, process 600 further includes transmitting, to the first base station and based at least in part on determining that the network cell including the second base station is present on the list of approved network cells, an indication of a release of a connection between the UE and the first base station.

In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, the UE receives LTE service from the first base station, and the UE receives 5G service from the second base station.

Although Fig. 6 shows example blocks of process 600, in some aspects, process 600 may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted in Fig. 6. Additionally, or alternatively, two or more of the blocks of process 600 may be performed in parallel.

Fig. 7 is a diagram illustrating an example process 700 performed, for example, by a base station, in accordance with various aspects of the present disclosure. Example process 700 is an example where the base station (e.g., base station 110a and/or the like) performs operations associated with returning to an SA network instead of an NSA network.

As shown in Fig. 7, in some aspects, process 700 may include transmitting, to a UE (e.g., UE 120 and/or the like) , a fallback message based at least in part on receiving a request for voice service from the UE (block 710) . For example, the base station (e.g., using transmit processor 220, receive processor 238, controller/processor 240, memory 242, and/or the like) may transmit, to the UE, the fallback message based at least in part on receiving the request for voice service from the UE, as described above. In some aspects, the base station may provide 5G service and/or other NR service to the UE.

As further shown in Fig. 7, in some aspects, process 700 may include receiving, from the UE and after transmitting the fallback message, a request for data service (block 720) . For example, the base station (e.g., using transmit processor 220, receive processor 238, controller/processor 240, memory 242, and/or the like) may receive, from the UE and after transmitting the fallback message, the request for data service, as described above. In some aspects, the request for data service includes a request to camp to a standalone network including the base station and is based at least in part on a previous camping between the base station and the UE.

Process 700 may include additional aspects, such as any single aspect or any combination of aspects described below and/or in connection with one or more other processes described elsewhere herein.

In a first aspect, the previous camping between the base station and the UE includes receiving, from the UE and before transmitting the fallback message, an RRC request.

In a second aspect, alone or in combination with the first aspect, the UE receives 5G service from the base station.

Although Fig. 7 shows example blocks of process 700, in some aspects, process 700 may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted in Fig. 7. Additionally, or alternatively, two or more of the blocks of process 700 may be performed in parallel.

Fig. 8 is a diagram illustrating an example process 800 performed, for example, by a first base station, in accordance with various aspects of the present disclosure. Example process 800 is an example where the first base station (e.g., base station 110b and/or the like) performs operations associated with returning to an SA network instead of an NSA network.

As shown in Fig. 8, in some aspects, process 800 may include receiving, from a UE (e.g., UE 120 and/or the like) , a request for voice service (block 810) . For example, the first base station (e.g., using transmit processor 220, receive processor 238, controller/processor 240, memory 242, and/or the like) may receive, from the UE, the request for voice service, as described above. In some aspects, the first base station may provide LTE service and/or other RATs to the UE.

As further shown in Fig. 8, in some aspects, process 800 may include transmitting, to the UE and after providing the voice service, a reconfiguration message that instructs the UE to connect to an NSA network including a second base station (block 820) . For example, the first base station (e.g., using transmit processor 220, receive processor 238, controller/processor 240, memory 242, and/or the like) may transmit, to the UE and after providing the voice service, the reconfiguration message that instructs the UE to connect to the NSA network including the second base station, as described above. In some aspects, the second base station may provide 5G service and/or other NR service to the UE.

As further shown in Fig. 8, in some aspects, process 800 may include receiving, from the UE and based at least in part on transmitting the reconfiguration message, an indication of a release of a connection between the first base station and the UE (block 830) . For example, the first base station (e.g., using transmit processor 220, receive processor 238, controller/processor 240, memory 242, and/or the like) may receive, from the UE and based at least in part on transmitting the reconfiguration message, the indication of the release of the connection between the first base station and the UE, as described above.

Process 800 may include additional aspects, such as any single aspect or any combination of aspects described below and/or in connection with one or more other processes described elsewhere herein.

In a first aspect, the first base station receives the request for voice service based at least in part on a fallback message from the second base station.

In a second aspect, alone or in combination with the first aspect, process 800 further includes receiving, from the UE and after providing the voice service, a measurement report based at least in part on the NSA network including the second base station, wherein the first base station transmits the reconfiguration message based at least in part on receiving the measurement report.

In a third aspect, alone or in combination with one or more of the first and second aspects, the first base station provides LTE service to the UE, and the second base station provides 5G service to the UE.

Although Fig. 8 shows example blocks of process 800, in some aspects, process 800 may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted in Fig. 8. Additionally, or alternatively, two or more of the blocks of process 800 may be performed in parallel.

The foregoing disclosure provides illustration and description, but is not intended to be exhaustive or to limit the aspects to the precise form disclosed. Modifications and variations may be made in light of the above disclosure or may be acquired from practice of the aspects.

As used herein, the term “component” is intended to be broadly construed as hardware, firmware, and/or a combination of hardware and software. As used herein, a processor is implemented in hardware, firmware, and/or a combination of hardware and software. It will be apparent that systems and/or methods described herein may be implemented in different forms of hardware, firmware, and/or a combination of hardware and software. The actual specialized control hardware or software code used to implement these systems and/or methods is not limiting of the aspects. Thus, the operation and behavior of the systems and/or methods were described herein without reference to specific software code-it being understood that software and hardware can be designed to implement the systems and/or methods based, at least in part, on the description herein.

As used herein, satisfying a threshold may, depending on the context, refer to a value being greater than the threshold, greater than or equal to the threshold, less than the threshold, less than or equal to the threshold, equal to the threshold, not equal to the threshold, and/or the like.

Even though particular combinations of features are recited in the claims and/or disclosed in the specification, these combinations are not intended to limit the disclosure of various aspects. In fact, many of these features may be combined in ways not specifically recited in the claims and/or disclosed in the specification. Although each dependent claim listed below may directly depend on only one claim, the disclosure of various aspects includes each dependent claim in combination with every other claim in the claim set. A phrase referring to “at least one of” a list of items refers to any combination of those items, including single members. As an example, “at least one of: a, b, or c” is intended to cover a, b, c, a-b, a-c, b-c, and a-b-c, as well as any combination with multiples of the same element (e.g., a-a, a-a-a, a-a-b, a-a-c, a-b-b, a-c-c, b-b, b-b-b, b-b-c, c-c, and c-c-c or any other ordering of a, b, and c) .

No element, act, or instruction used herein should be construed as critical or essential unless explicitly described as such. Also, as used herein, the articles “a” and “an” are intended to include one or more items and may be used interchangeably with “one or more. ” Further, as used herein, the article “the” is intended to include one or more items referenced in connection with the article “the” and may be used interchangeably with “the one or more. ” Furthermore, as used herein, the terms “set” and “group” are intended to include one or more items (e.g., related items, unrelated items, a combination of related and unrelated items, and/or the like) , and may be used interchangeably with “one or more. ” Where only one item is intended, the phrase “only one” or similar language is used. Also, as used herein, the terms “has, ” “have, ” “having, ” and/or the like are intended to be open-ended terms. Further, the phrase “based on” is intended to mean “based, at least in part, on” unless explicitly stated otherwise. Also, as used herein, the term “or” is intended to be inclusive when used in a series and may be used interchangeably with “and/or, ” unless explicitly stated otherwise (e.g., if used in combination with “either” or “only one of” ) .

Claims

A method of wireless communication performed by a user equipment (UE) , comprising:

transmitting, to a first base station, a request for voice service based at least in part on receiving a fallback message from a second base station;

receiving, from the first base station and after receiving the voice service, a reconfiguration message that instructs the UE to connect to a non-standalone network including the second base station; and

transmitting, to the second base station and based at least in part on receiving the reconfiguration message, a request for data service, wherein the request for data service includes a request to camp to a standalone network associated with the second base station and is based at least in part on determining that a network cell associated with the second base station is present on a list of approved network cells.
The method of claim 1, further comprising:

transmitting, to the second base station and before transmitting the request for voice service, a radio resource control request.
The method of claim 2, further comprising at least one of:

adding, to the list of approved network cells, the network cell associated with the second base station based at least in part on the radio resource control request; or

resetting a timer that is associated with the network cell associated with the second base station based at least in part on the radio resource control request and based at least in part on determining that the network cell including the second base station is present on the list of approved network cells.
The method of claim 2, further comprising:

adding the network cell associated with the second base station to the list of approved network cells based at least in part on the radio resource control request; and

removing another network cell from the list of approved network cells based at least in part on a maximum number of cells associated with the list of approved network cells.
The method of claim 2, further comprising:

adding the network cell associated with the second base station to the list of approved network cells based at least in part on the radio resource control request; and

removing the network cell associated with the second base station from the list of approved network cells when a timer that is associated with the network cell associated with the second base station expires.
The method of claim 1, further comprising:

transmitting, to the first base station and after receiving the voice service, a measurement report based at least in part on the non-standalone network including the second base station, wherein the UE receives the reconfiguration message based at least in part on transmitting the measurement report.
The method of claim 1, wherein the UE transmits the request for data service based at least in part on determining that a measurement associated with the network cell including the second base station is greater than another measurement associated with another network cell.
The method of claim 1, further comprising:

transmitting, to the first base station and based at least in part on determining that the network cell including the second base station is present on the list of approved network cells, an indication of a release of a connection between the UE and the first base station.
The method of claim 1, wherein the UE receives long term evolution service from the first base station, and the UE receives 5G service from the second base station.
A method of wireless communication performed by a base station, comprising:

transmitting, to a user equipment (UE) , a fallback message based at least in part on receiving a request for voice service from the UE; and

receiving, from the UE and after transmitting the fallback message, a request for data service, wherein the request for data service includes a request to camp to a standalone network including the base station and is based at least in part on a previous camping between the base station and the UE.
The method of claim 10, wherein the previous camping between the base station and the UE includes:

receiving, from the UE and before transmitting the fallback message, a radio resource control request.
The method of claim 10, the UE receives 5G service from the base station.
A method of wireless communication performed by a first base station, comprising:

receiving, from a user equipment (UE) , a request for voice service;

transmitting, to the UE and after providing the voice service, a reconfiguration message that instructs the UE to connect to a non-standalone network including a second base station; and

receiving, from the UE and based at least in part on transmitting the reconfiguration message, an indication of a release of a connection between the first base station and the UE.
The method of claim 13, wherein the first base station receives the request for voice service based at least in part on a fallback message from the second base station.
The method of claim 13, further comprising:

receiving, from the UE and after providing the voice service, a measurement report based at least in part on the non-standalone network including the second base station, wherein the first base station transmits the reconfiguration message based at least in part on receiving the measurement report.
The method of claim 13, wherein the first base station provides long term evolution service to the UE, and the second base station provides 5G service to the UE.
A user equipment (UE) for wireless communication, comprising:

a memory; and

one or more processors coupled with the memory, the memory and the one or more processors configured to:

transmit, to a first base station, a request for voice service based at least in part on receiving a fallback message from a second base station;

receive, from the first base station and after receiving the voice service, a reconfiguration message that instructs the UE to connect to a non-standalone network including the second base station; and

transmit, to the second base station and based at least in part on receiving the reconfiguration message, a request for data service, wherein the request for data service includes a request to camp to a standalone network associated with the second base station and is based at least in part on determining that a network cell associated with the second base station is present on a list of approved network cells.
A base station for wireless communication, comprising:

a memory; and

one or more processors coupled with the memory, the memory and the one or more processors configured to:

transmit, to a user equipment (UE) , a fallback message based at least in part on receiving a request for voice service from the UE; and

receive, from the UE and after transmitting the fallback message, a request for data service, wherein the request for data service includes a request to camp to a standalone network including the base station and is based at least in part on a previous camping between the base station and the UE.
A first base station for wireless communication, comprising:

a memory; and

one or more processors coupled with the memory, the memory and the one or more processors configured to:

receive, from a user equipment (UE) , a request for voice service;

transmit, to the UE and after providing the voice service, a reconfiguration message that instructs the UE to connect to a non-standalone network including a second base station; and

receive, from the UE and based at least in part on transmitting the reconfiguration message, an indication of a release of a connection between the first base station and the UE.
A non-transitory computer-readable medium storing a set of instructions for wireless communication, the set of instructions comprising:

one or more instructions that, when executed by one or more processors of a user equipment (UE) , cause the UE to:

transmit, to a first base station, a request for voice service based at least in part on receiving a fallback message from a second base station;

receive, from the first base station and after receiving the voice service, a reconfiguration message that instructs the UE to connect to a non-standalone network including the second base station; and

transmit, to the second base station and based at least in part on receiving the reconfiguration message, a request for data service, wherein the request for data service includes a request to camp to a standalone network associated with the second base station and is based at least in part on determining that a network cell associated with the second base station is present on a list of approved network cells.
A non-transitory computer-readable medium storing a set of instructions for wireless communication, the set of instructions comprising:

one or more instructions that, when executed by one or more processors of a base station, cause the base station to:

transmit, to a user equipment (UE) , a fallback message based at least in part on receiving a request for voice service from the UE; and

receive, from the UE and after transmitting the fallback message, a request for data service, wherein the request for data service includes a request to camp to a standalone network including the base station and is based at least in part on a previous camping between the base station and the UE.
A non-transitory computer-readable medium storing a set of instructions for wireless communication, the set of instructions comprising:

one or more instructions that, when executed by one or more processors of a first base station, cause the first base station to:

receive, from a user equipment (UE) , a request for voice service;

transmit, to the UE and after providing the voice service, a reconfiguration message that instructs the UE to connect to a non-standalone network including a second base station; and

receive, from the UE and based at least in part on transmitting the reconfiguration message, an indication of a release of a connection between the first base station and the UE.
An apparatus for wireless communication, comprising:

means for transmitting, to a first base station, a request for voice service based at least in part on receiving a fallback message from a second base station;

means for receiving, from the first base station and after receiving the voice service, a reconfiguration message that instructs the apparatus to connect to a non-standalone network including the second base station; and

means for transmitting, to the second base station and based at least in part on receiving the reconfiguration message, a request for data service, wherein the request for data service includes a request to camp to a standalone network associated with the second base station and is based at least in part on determining that a network cell associated with the second base station is present on a list of approved network cells.
An apparatus for wireless communication, comprising:

means for transmitting, to a user equipment (UE) , a fallback message based at least in part on receiving a request for voice service from the UE; and

means for receiving, from the UE and after transmitting the fallback message, a request for data service, wherein the request for data service includes a request to camp to a standalone network including the apparatus and is based at least in part on a previous camping between the apparatus and the UE.
An apparatus for wireless communication, comprising:

means for receiving, from a user equipment (UE) , a request for voice service;

means for transmitting, to the UE and after providing the voice service, a reconfiguration message that instructs the UE to connect to a non-standalone network including a base station; and

means for receiving, from the UE and based at least in part on transmitting the reconfiguration message, an indication of a release of a connection between the apparatus and the UE.