WO2022041239A1

WO2022041239A1 - Techniques for selecting cells using network slice selection assistance information

Info

Publication number: WO2022041239A1
Application number: PCT/CN2020/112669
Authority: WO
Inventors: Chaofeng HUI; Fojian ZHANG; Dongsheng Wang; Yuankun ZHU; Hao Zhang; Li Tan; Quanling ZHANG; Guojing LIU; Bo Yu
Original assignee: Qualcomm Incorporated
Priority date: 2020-08-31
Filing date: 2020-08-31
Publication date: 2022-03-03

Abstract

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive registration information from a first cell associated with a first registration area, wherein the registration information indicates a network slice selection assistance information (NSSAI) value that is rejected by the first cell. The UE may transmit a registration request to a second cell associated with a second registration area based at least in part on the NSSAI value and based at least in part on receiving the registration information indicating the NSSAI value that is rejected by the first cell. Numerous other aspects are provided.

Description

TECHNIQUES FOR SELECTING CELLS USING NETWORK SLICE SELECTION ASSISTANCE INFORMATION

FIELD OF THE DISCLOSURE

Aspects of the present disclosure generally relate to wireless communication and to techniques and apparatuses for cell selection using network slice selection assistance information (NSSAI) .

DESCRIPTION OF RELATED ART

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 receiving registration information from a first cell associated with a first registration area, wherein the registration information indicates a network slice selection assistance information (NSSAI) value that is rejected by the first cell; and transmitting a registration request to a second cell associated with a second registration area based at least in part on the NSSAI value and based at least in part on receiving the registration information indicating the NSSAI value that is rejected by the first cell.

In some aspects, the registration information comprises a registration accept message.

In some aspects, the method includes barring the first registration area from registration for a length of time based at least in part on the registration information indicating the NSSAI value that is rejected by the first cell.

In some aspects, the method includes transmitting another registration request indicating the NSSAI value to the first cell prior to transmitting the registration request to the second cell, wherein the registration information is based at least in part on the other registration request.

In some aspects, the NSSAI value is included in a set of rejected NSSAI values identified by the registration information.

In some aspects, the method includes receiving, from the second cell, other registration information indicating that the NSSAI value is accepted by the second cell; and establishing a session with the second cell based at least in part on the other registration information indicating that the NSSAI value is accepted by the second cell.

In some aspects, the method includes receiving, from the second cell, other registration information indicating that the NSSAI value is rejected by the second cell; and transmitting another registration request to a third cell associated with a third registration area based at least in part on the NSSAI value and based at least in part on receiving the other registration information indicating that the NSSAI value is rejected by the second cell.

In some aspects, the NSSAI value is a single NSSAI (S-NSSAI) value.

In some aspects, the NSSAI value corresponds to a URLLC service.

In some aspects, a UE for wireless communication includes a memory and one or more processors operatively coupled to the memory, the memory and the one or more processors configured to: receive registration information from a first cell associated with a first registration area, wherein the registration information indicates an NSSAI value that is rejected by the first cell; and transmit a registration request to a second cell associated with a second registration area based at least in part on the NSSAI value and based at least in part on receiving the registration information indicating the NSSAI value that is rejected by the first cell.

In some aspects, the one or more processors are further configured to bar the first registration area from registration for a length of time based at least in part on the registration information indicating the NSSAI value that is rejected by the first cell.

In some aspects, the one or more processors are further configured to transmit another registration request indicating the NSSAI value to the first cell prior to transmitting the registration request to the second cell, wherein the registration information is based at least in part on the other registration request.

In some aspects, the one or more processors are further configured to: receive, from the second cell, other registration information indicating that the NSSAI value is accepted by the second cell; and establish a session with the second cell based at least in part on the other registration information indicating that the NSSAI value is accepted by the second cell.

In some aspects, the one or more processors are further configured to: receive, from the second cell, other registration information indicating that the NSSAI value is rejected by the second cell; and transmit another registration request to a third cell associated with a third registration area based at least in part on the NSSAI value and based at least in part on receiving the other registration information indicating that the NSSAI value is rejected by the second cell.

In some aspects, the NSSAI value is a single NSSAI value.

In some aspects, the NSSAI value corresponds to a URLLC service.

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: receive registration information from a first cell associated with a first registration area, wherein the registration information indicates an NSSAI value that is rejected by the first cell; and transmit a registration request to a second cell associated with a second registration area based at least in part on the NSSAI value and based at least in part on receiving the registration information indicating the NSSAI value that is rejected by the first cell.

In some aspects, the one or more instructions further cause the UE to bar the first registration area from registration for a length of time based at least in part on the registration information indicating the NSSAI value that is rejected by the first cell.

In some aspects, the one or more instructions further cause the UE to transmit another registration request indicating the NSSAI value to the first cell prior to transmitting the registration request to the second cell, wherein the registration information is based at least in part on the other registration request.

In some aspects, the one or more instructions further cause the UE to: receive, from the second cell, other registration information indicating that the NSSAI value is accepted by the second cell; and establish a session with the second cell based at least in part on the other registration information indicating that the NSSAI value is accepted by the second cell.

In some aspects, the one or more instructions further cause the UE to: receive, from the second cell, other registration information indicating that the NSSAI value is rejected by the second cell; and transmit another registration request to a third cell associated with a third registration area based at least in part on the NSSAI value and based at least in part on receiving the other registration information indicating that the NSSAI value is rejected by the second cell.

In some aspects, the NSSAI value is a single NSSAI value.

In some aspects, the NSSAI value corresponds to a URLLC service.

In some aspects, an apparatus for wireless communication includes means for receiving registration information from a first cell associated with a first registration area, wherein the registration information indicates an NSSAI value that is rejected by the first cell; and means for transmitting a registration request to a second cell associated with a second registration area based at least in part on the NSSAI value and based at least in part on receiving the registration information indicating the NSSAI value that is rejected by the first cell.

In some aspects, the apparatus includes means for barring the first registration area from registration for a length of time based at least in part on the registration information indicating the NSSAI value that is rejected by the first cell.

In some aspects, the apparatus includes means for transmitting another registration request indicating the NSSAI value to the first cell prior to transmitting the registration request to the second cell, wherein the registration information is based at least in part on the other registration request.

In some aspects, the apparatus includes means for receiving, from the second cell, other registration information indicating that the NSSAI value is accepted by the second cell; and means for establishing a session with the second cell based at least in part on the other registration information indicating that the NSSAI value is accepted by the second cell.

In some aspects, the apparatus includes means for receiving, from the second cell, other registration information indicating that the NSSAI value is rejected by the second cell; and means for transmitting another registration request to a third cell associated with a third registration area based at least in part on the NSSAI value and based at least in part on receiving the other registration information indicating that the NSSAI value is rejected by the second cell.

In some aspects, the NSSAI value is a single NSSAI value.

In some aspects, the NSSAI value corresponds to a URLLC service.

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 signaling associated with selecting cells using network slide selection assistance information (NSSAI) , in accordance with various aspects of the present disclosure.

Fig. 4 is a diagram illustrating an example process associated with selecting cells using NSSAI, in accordance with various aspects of the present disclosure.

Figs. 5-6 are block diagrams of example apparatuses for wireless communication, 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 BS 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., the 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.

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.

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 selecting cells using network slide selection assistance information (NSSAI) , 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 400 of Fig. 4 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 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 400 of Fig. 4 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, the UE includes means for receiving registration information from a first cell associated with a first registration area, wherein the registration information indicates an NSSAI value that is rejected by the first cell; and/or means for transmitting a registration request to a second cell associated with a second registration area, based at least in part on the NSSAI value and based at least in part on receiving the registration information indicating the NSSAI value that is rejected by the first cell. The means for the UE to perform operations described herein may include, for example, antenna 252, demodulator 254, MIMO detector 256, receive processor 258, transmit processor 264, TX MIMO processor 266, modulator 254, controller/processor 280, and/or memory 282.

In some aspects, the UE includes means for barring the first registration area from registration for a length of time based at least in part on the registration information indicating the NSSAI value that is rejected by the first cell.

In some aspects, the UE includes means for transmitting another registration request indicating the NSSAI value to the first cell prior to transmitting the registration request to the second cell, wherein the registration information is based at least in part on the other registration request.

In some aspects, the UE includes means for receiving, from the second cell, other registration information indicating that the NSSAI value is accepted by the second cell; and/or means for establishing a session with the second cell based at least in part on the other registration information indicating that the NSSAI value is accepted by the second cell.

In some aspects, the UE includes means for receiving, from the second cell, other registration information indicating that the NSSAI value is rejected by the second cell; and/or means for transmitting another registration request to a third cell associated with a third registration area based at least in part on the NSSAI value and based at least in part on receiving the other registration information indicating that the NSSAI value is rejected by the second cell.

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

In a wireless communication system, such as a deployment using a 5G/NR radio access technology, network slicing allows for multiple virtual networks to run on a single physical network. Network slicing enables a physical network to support multiple services, applications, and/or entities. In some instances, when a UE requests a session (e.g., establishment of a protocol data unit (PDU) session) to the network for an application and/or service, the UE provides the network with information associated with the UE, the application, and/or the service. Such information can include network slice selection assistance information (NSSAI) , which can include one or more individual, single-network slice selection assistance information (S-NSSAI) (which can be referred to herein individually as an “S-NSSAI value” or “NSSAI value” or collectively as “S-NSSAI values” or “NSSAI values” ) that identify respective network slices associated with the UE, the application, and/or the service.

In some circumstances, a network may reject an NSSAI value. For example, the network may reject the NSSAI value because of a capability of the network, a traffic condition of the network, a configuration of the network, and/or the like. Rejection of an NSSAI value can occur for one or more particular registration areas, or across an entire public land mobile network (PLMN) . A registration area is a set of tracking areas that are grouped for a UE, and may define a paging area for the UE. For example, a registration area may take into account a mobility pattern of the UE. The network may indicate that the NSSAI value is rejected in a registration accept message. For example, the registration accept message may indicate one or more accepted NSSAI values and/or one or more rejected NSSAI values. However, some NSSAI values may be associated with stringent quality of service (QoS) requirements, such as ultra-reliable low latency communication (URLLC) requirements. If an NSSAI value is rejected for a registration area associated with a cell with which the UE attempts to establish a session, then an application associated with the NSSAI value may be downgraded to a lower-stringency NSSAI value, such as an NSSAI value associated with an enhanced mobile broadband service (eMBB service) . Thus, the QoS requirements of such an application may be violated, leading to diminished throughput and degraded performance.

Some techniques and apparatuses described herein enable a UE to determine that session establishment for a first registration area has failed based at least in part on registration information indicating a rejected NSSAI value, and establish a session in a second registration area based at least in part on the NSSAI value. By establishing the session in the second registration area, the UE is more likely to identify a registration area that accepts the NSSAI value, thus improving the likelihood that QoS requirements of applications or services of the UE are satisfied. In this way, throughput is increased and performance is improved.

Fig. 3 is a diagram illustrating an example 300 of signaling associated with selecting cells using NSSAI, in accordance with various aspects of the present disclosure. As shown, example 300 includes a UE (e.g., UE 120) , a first cell, and a second cell. “Cell” may refer to a BS (e.g., BS 110) or to a logical communication entity used for communication with a BS (e.g., via a carrier) . As further shown, the first cell is associated with a first registration area (RA1) and the second cell is associated with a second registration area (RA2) .

As shown by reference number 305, the UE may transmit a registration request to the first cell. As further shown, the registration request may indicate a requested NSSAI value (e.g., a requested S-NSSAI value) . For example, the registration request may indicate one or more requested NSSAI values. In some aspects, the one or more requested NSSAI values may be based at least in part on one or more applications associated with the UE. For example, an application may be associated with a QoS requirement and/or the like, and may indicate an NSSAI value associated with the QoS requirement and/or the like to the UE. The UE may request the NSSAI value indicated by the application. In example 300, the NSSAI value is a URLLC1 value, which may correspond to a URLLC QoS requirement. However, the techniques and apparatuses described with regard to example 300 can be applied for any NSSAI value.

As shown by reference number 310, the first cell may transmit a registration accept message to the UE. The registration accept message may be referred to herein as registration information. As further shown, the registration accept message may indicate one or more rejected NSSAI values. For example, the one or more rejected NSSAI values may be associated with the first registration area. In some aspects, the registration accept message may indicate one or more accepted NSSAI values, as described in more detail in connection with reference number 335. In example 300, the requested NSSAI value of URLLC1 is rejected for the first registration area. Therefore, if an application or service of the UE associated with the NSSAI value of URLLC1 attempts to establish a connection associated with a URLLC QoS requirement, the URLLC QoS requirement may be violated and/or the app may have to use a less stringent QoS requirement that is supported by the first registration area.

As shown by reference number 315, the UE may start an application (app) . For example, the application may be associated with a QoS requirement associated with the URLLC1 NSSAI value. Therefore, the application may bind to the URLLC1 NSSAI value. However, the URLLC1 NSSAI value is not supported by the first registration area. Therefore, as shown by reference number 320, the UE may bar the first registration area for a length of time. For example, the UE may bar the first registration area based at least in part on receiving the registration information indicating the NSSAI value that is rejected by the first cell. As another example, the UE may bar the first registration area based at least in part on the application binding to the NSSAI value that is rejected with regard to the first registration area. In some aspects, the length of time may be referred to as t_back_ra. In some aspects, the length of time may be configured, for example, via radio resource control (RRC) signaling. In some aspects, the length of time may be preconfigured for the UE (e.g., associated with a default setting, specified by a wireless communication standard, and/or the like) . In some aspects, the length of time may be determined by the UE.

In some aspects, the UE may determine whether to bar the first registration area. For example, the UE may determine whether to bar the first registration area based at least in part on whether the NSSAI value associated with the application (e.g., URLLC1, in example 300) is rejected by the first registration area. If the NSSAI value associated with the application is rejected by the first registration area, then the UE may bar the first registration area for the length of time. If the NSSAI value is accepted by the first registration area (which is not illustrated in example 300) , then the UE may not bar the first registration area, and may perform the steps indicated by

reference numbers

340, 345, and 350 with regard to the first cell and the first registration. In some aspects, the UE may determine whether to bar the first registration area based at least in part on the registration accept message (e.g., independent of the application binding to the NSSAI value) . For example, the UE may determine to bar the first registration area if the requested NSSAI value is rejected with regard to the first registration area, and may determine not to bar the first registration area if the requested NSSAI value is accepted with regard to the first registration area.

As shown by reference number 325, the UE may attempt to acquire service on the second cell. For example, the UE may attempt to acquire service on the second cell based at least in part on the NSSAI value being rejected by the first cell and/or based at least in part on the second cell being associated with a different registration area than the first cell. As shown by reference number 330, the UE may transmit a registration request to the second cell. As further shown, the registration request may indicate the NSSAI value.

As shown by reference number 335, the second cell may transmit a registration accept message to the UE. As further shown, the registration accept message may indicate that the NSSAI value is accepted. As shown by reference number 340, the UE may request to establish a session (e.g., a PDU session) with the second cell. For example, the UE may transmit a PDU session establishment request based at least in part on the registration accept message from the second cell indicating that the NSSAI value is accepted. As shown by reference number 345, the second cell may transmit a message indicating that the session is accepted. As shown by reference number 350, the UE may establish a data connection between the application and a server associated with the application. In this way, the UE identifies and connects to a cell that accepts an NSSAI value after identifying a cell that rejects the NSSAI value, which improves the likelihood that a QoS requirement associated with the NSSAI value is satisfied, thereby improving throughput and reliability of communications via the second cell.

In some aspects, the second cell may also reject the NSSAI value. For example, the second cell may transmit a registration accept message indicating that the NSSAI value is rejected. If the second cell rejects the NSSAI value, then the UE may perform the operations described with regard to

reference numbers

315 and 320 for the second cell, and may perform the operations described with regard to

reference numbers

325, 330, 335, 340, and 345 with regard to a third cell associated with a third registration area. Thus, the UE may attempt to establish connections on cells associated with respective registration areas until the UE identifies a registration area that accepts the NSSAI value or all registration areas are exhausted.

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

Fig. 4 is a diagram illustrating an example process 400 performed, for example, by a UE, in accordance with various aspects of the present disclosure. Example process 400 is an example where the UE (e.g., UE 120) performs operations associated with selecting cells using network slice selection assistance information.

As shown in Fig. 4, in some aspects, process 400 may include receiving registration information from a first cell associated with a first registration area, wherein the registration information indicates an NSSAI value that is rejected by the first cell (block 410) . For example, the UE (e.g., using reception component 502, depicted in Fig. 5) may receive registration information from a first cell associated with a first registration area, wherein the registration information indicates an NSSAI value that is rejected by the first cell, as described above.

As further shown in Fig. 4, in some aspects, process 400 may include transmitting a registration request to a second cell associated with a second registration area based at least in part on the NSSAI value and based at least in part on receiving the registration information indicating the NSSAI value that is rejected by the first cell (block 420) . For example, the UE (e.g., using transmission component 504, depicted in Fig. 5) may transmit a registration request to a second cell associated with a second registration area based at least in part on the NSSAI value and based at least in part on receiving the registration information indicating the NSSAI value that is rejected by the first cell, as described above.

Process 400 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 registration information comprises a registration accept message.

In a second aspect, alone or in combination with the first aspect, process 400 includes barring the first registration area from registration for a length of time based at least in part on the registration information indicating the NSSAI value that is rejected by the first cell.

In a third aspect, alone or in combination with one or more of the first and second aspects, process 400 includes transmitting another registration request indicating the NSSAI value to the first cell prior to transmitting the registration request to the second cell, wherein the registration information is based at least in part on the other registration request.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, the NSSAI value is included in a set of rejected NSSAI values identified by the registration information.

In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, process 400 includes receiving, from the second cell, other registration information indicating that the NSSAI value is accepted by the second cell, and establishing a session with the second cell based at least in part on the other registration information indicating that the NSSAI value is accepted by the second cell.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, process 400 includes receiving, from the second cell, other registration information indicating that the NSSAI value is rejected by the second cell, and transmitting another registration request to a third cell associated with a third registration area based at least in part on the NSSAI value and based at least in part on receiving the other registration information indicating that the NSSAI value is rejected by the second cell.

In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, the NSSAI value is a single NSSAI value.

In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, the NSSAI value corresponds to an ultra-reliable low latency communication service.

Although Fig. 4 shows example blocks of process 400, in some aspects, process 400 may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted in Fig. 4. Additionally, or alternatively, two or more of the blocks of process 400 may be performed in parallel.

Fig. 5 is a block diagram of an example apparatus 500 for wireless communication. The apparatus 500 may be a UE, or a UE may include the apparatus 500. In some aspects, the apparatus 500 includes a reception component 502 and a transmission component 504, which may be in communication with one another (for example, via one or more buses and/or one or more other components) . As shown, the apparatus 500 may communicate with another apparatus 506 (such as a UE, a base station, or another wireless communication device) using the reception component 502 and the transmission component 504. As further shown, the apparatus 500 may include one or more of a barring component 508 or an establishment component 510, among other examples.

In some aspects, the apparatus 500 may be configured to perform one or more operations described herein in connection with Fig. 3. Additionally or alternatively, the apparatus 500 may be configured to perform one or more processes described herein, such as process 400 of Fig. 4. In some aspects, the apparatus 500 and/or one or more components shown in Fig. 5 may include one or more components of the UE described above in connection with Fig. 2. Additionally, or alternatively, one or more components shown in Fig. 5 may be implemented within one or more components described above in connection with Fig. 2. Additionally or alternatively, one or more components of the set of components may be implemented at least in part as software stored in a memory. For example, a component (or a portion of a component) may be implemented as instructions or code stored in a non-transitory computer-readable medium and executable by a controller or a processor to perform the functions or operations of the component.

The reception component 502 may receive communications, such as reference signals, control information, data communications, or a combination thereof, from the apparatus 506. The reception component 502 may provide received communications to one or more other components of the apparatus 500. In some aspects, the reception component 502 may perform signal processing on the received communications (such as filtering, amplification, demodulation, analog-to-digital conversion, demultiplexing, deinterleaving, de-mapping, equalization, interference cancellation, or decoding, among other examples) , and may provide the processed signals to the one or more other components of the apparatus 506. In some aspects, the reception component 502 may include one or more antennas, a demodulator, a MIMO detector, a receive processor, a controller/processor, a memory, or a combination thereof, of the UE described above in connection with Fig. 2.

The transmission component 504 may transmit communications, such as reference signals, control information, data communications, or a combination thereof, to the apparatus 506. In some aspects, one or more other components of the apparatus 506 may generate communications and may provide the generated communications to the transmission component 504 for transmission to the apparatus 506. In some aspects, the transmission component 504 may perform signal processing on the generated communications (such as filtering, amplification, modulation, digital-to-analog conversion, multiplexing, interleaving, mapping, or encoding, among other examples) , and may transmit the processed signals to the apparatus 506. In some aspects, the transmission component 504 may include one or more antennas, a modulator, a transmit MIMO processor, a transmit processor, a controller/processor, a memory, or a combination thereof, of the UE described above in connection with Fig. 2. In some aspects, the transmission component 504 may be collocated with the reception component 502 in a transceiver.

The reception component 502 may receive registration information from a first cell associated with a first registration area, wherein the registration information indicates an NSSAI value that is rejected by the first cell. The transmission component 504 may transmit a registration request to a second cell associated with a second registration area based at least in part on the NSSAI value and based at least in part on receiving the registration information indicating the NSSAI value that is rejected by the first cell.

The barring component 508 may bar the first registration area from registration for a length of time based at least in part on the registration information indicating the NSSAI value that is rejected by the first cell. In some aspects, the barring component 508 may include one or more antennas, a demodulator, a MIMO detector, a receive processor, a modulator, a transmit MIMO processor, a transmit processor, a controller/processor, a memory, or a combination thereof, of the UE described above in connection with Fig. 2.

The transmission component 504 may transmit another registration request indicating the NSSAI value to the first cell prior to transmitting the registration request to the second cell, wherein the registration information is based at least in part on the other registration request.

The reception component 502 may receive, from the second cell, other registration information indicating that the NSSAI value is accepted by the second cell.

The establishment component 510 may establish a session with the second cell based at least in part on the other registration information indicating that the NSSAI value is accepted by the second cell. In some aspects, the establishment component 510 may include one or more antennas, a demodulator, a MIMO detector, a receive processor, a modulator, a transmit MIMO processor, a transmit processor, a controller/processor, a memory, or a combination thereof, of the UE described above in connection with Fig. 2.

The reception component 502 may receive, from the second cell, other registration information indicating that the NSSAI value is rejected by the second cell.

The transmission component 504 may transmit another registration request to a third cell associated with a third registration area based at least in part on the NSSAI value and based at least in part on receiving the other registration information indicating that the NSSAI value is rejected by the second cell.

The number and arrangement of components shown in Fig. 5 are provided as an example. In practice, there may be additional components, fewer components, different components, or differently arranged components than those shown in Fig. 5. Furthermore, two or more components shown in Fig. 5 may be implemented within a single component, or a single component shown in Fig. 5 may be implemented as multiple, distributed components. Additionally or alternatively, a set of (one or more) components shown in Fig. 5 may perform one or more functions described as being performed by another set of components shown in Fig. 5.

Fig. 6 is a block diagram of an example apparatus 600 for wireless communication. The apparatus 600 may be a base station, or a base station may include the apparatus 600. In some aspects, the apparatus 600 includes a reception component 602 and a transmission component 604, which may be in communication with one another (for example, via one or more buses and/or one or more other components) . As shown, the apparatus 600 may communicate with another apparatus 606 (such as a UE, a base station, or another wireless communication device) using the reception component 602 and the transmission component 604. As further shown, the apparatus 600 may include a determination component 608.

In some aspects, the apparatus 600 may be configured to perform one or more operations described herein in connection with Fig. 3. Additionally or alternatively, the apparatus 600 may be configured to perform one or more processes described herein, such as process 400 of Fig. 4. In some aspects, the apparatus 600 and/or one or more components shown in Fig. 6 may include one or more components of the base station described above in connection with Fig. 2. Additionally, or alternatively, one or more components shown in Fig. 6 may be implemented within one or more components described above in connection with Fig. 2. Additionally or alternatively, one or more components of the set of components may be implemented at least in part as software stored in a memory. For example, a component (or a portion of a component) may be implemented as instructions or code stored in a non-transitory computer-readable medium and executable by a controller or a processor to perform the functions or operations of the component.

The reception component 602 may receive communications, such as reference signals, control information, data communications, or a combination thereof, from the apparatus 606. The reception component 602 may provide received communications to one or more other components of the apparatus 600. In some aspects, the reception component 602 may perform signal processing on the received communications (such as filtering, amplification, demodulation, analog-to-digital conversion, demultiplexing, deinterleaving, de-mapping, equalization, interference cancellation, or decoding, among other examples) , and may provide the processed signals to the one or more other components of the apparatus 606. In some aspects, the reception component 602 may include one or more antennas, a demodulator, a MIMO detector, a receive processor, a controller/processor, a memory, or a combination thereof, of the base station described above in connection with Fig. 2.

The transmission component 604 may transmit communications, such as reference signals, control information, data communications, or a combination thereof, to the apparatus 606. In some aspects, one or more other components of the apparatus 606 may generate communications and may provide the generated communications to the transmission component 604 for transmission to the apparatus 606. In some aspects, the transmission component 604 may perform signal processing on the generated communications (such as filtering, amplification, modulation, digital-to-analog conversion, multiplexing, interleaving, mapping, or encoding, among other examples) , and may transmit the processed signals to the apparatus 606. In some aspects, the transmission component 604 may include one or more antennas, a modulator, a transmit MIMO processor, a transmit processor, a controller/processor, a memory, or a combination thereof, of the base station described above in connection with Fig. 2. In some aspects, the transmission component 604 may be collocated with the reception component 602 in a transceiver.

The reception component 602 may receive registration information for a cell associated with a registration area, wherein the registration information indicates an NSSAI value that is accepted or rejected by the first cell. The transmission component 604 may transmit a registration request associated with a cell associated with a registration area based at least in part on an NSSAI value. The determination component 608 may determine whether the NSSAI value is to be rejected or accepted for a cell associated with the apparatus 600.

The number and arrangement of components shown in Fig. 6 are provided as an example. In practice, there may be additional components, fewer components, different components, or differently arranged components than those shown in Fig. 6. Furthermore, two or more components shown in Fig. 6 may be implemented within a single component, or a single component shown in Fig. 6 may be implemented as multiple, distributed components. Additionally or alternatively, a set of (one or more) components shown in Fig. 6 may perform one or more functions described as being performed by another set of components shown in Fig. 6.

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:

receiving registration information from a first cell associated with a first registration area, wherein the registration information indicates a network slice selection assistance information (NSSAI) value that is rejected by the first cell; and

transmitting a registration request to a second cell associated with a second registration area based at least in part on the NSSAI value and based at least in part on receiving the registration information indicating the NSSAI value that is rejected by the first cell.
The method of claim 1, wherein the registration information comprises a registration accept message.
The method of claim 1, further comprising:

barring the first registration area from registration for a length of time based at least in part on the registration information indicating the NSSAI value that is rejected by the first cell.
The method of claim 1, further comprising:

transmitting another registration request indicating the NSSAI value to the first cell prior to transmitting the registration request to the second cell, wherein the registration information is based at least in part on the other registration request.
The method of claim 1, wherein the NSSAI value is included in a set of rejected NSSAI values identified by the registration information.
The method of claim 1, further comprising:

receiving, from the second cell, other registration information indicating that the NSSAI value is accepted by the second cell; and

establishing a session with the second cell based at least in part on the other registration information indicating that the NSSAI value is accepted by the second cell.
The method of claim 1, further comprising:

receiving, from the second cell, other registration information indicating that the NSSAI value is rejected by the second cell; and

transmitting another registration request to a third cell associated with a third registration area based at least in part on the NSSAI value and based at least in part on receiving the other registration information indicating that the NSSAI value is rejected by the second cell.
The method of claim 1, wherein the NSSAI value is a single NSSAI (S-NSSAI) value.
The method of claim 1, wherein the NSSAI value corresponds to an ultra-reliable low latency communication (URLLC) service.
A user equipment (UE) for wireless communication, comprising:

a memory; and

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

receive registration information from a first cell associated with a first registration area, wherein the registration information indicates a network slice selection assistance information (NSSAI) value that is rejected by the first cell; and

transmit a registration request to a second cell associated with a second registration area based at least in part on the NSSAI value and based at least in part on receiving the registration information indicating the NSSAI value that is rejected by the first cell.
The UE of claim 10, wherein the registration information comprises a registration accept message.
The UE of claim 10, wherein the one or more processors are further configured to:

bar the first registration area from registration for a length of time based at least in part on the registration information indicating the NSSAI value that is rejected by the first cell.
The UE of claim 10, wherein the one or more processors are further configured to:

transmit another registration request indicating the NSSAI value to the first cell prior to transmitting the registration request to the second cell, wherein the registration information is based at least in part on the other registration request.
The UE of claim 10, wherein the NSSAI value is included in a set of rejected NSSAI values identified by the registration information.
The UE of claim 10, wherein the one or more processors are further configured to:

receive, from the second cell, other registration information indicating that the NSSAI value is accepted by the second cell; and

establish a session with the second cell based at least in part on the other registration information indicating that the NSSAI value is accepted by the second cell.
The UE of claim 10, wherein the one or more processors are further configured to:

receive, from the second cell, other registration information indicating that the NSSAI value is rejected by the second cell; and

transmit another registration request to a third cell associated with a third registration area based at least in part on the NSSAI value and based at least in part on receiving the other registration information indicating that the NSSAI value is rejected by the second cell.
The UE of claim 10, wherein the NSSAI value is a single NSSAI (S-NSSAI) value.
The UE of claim 10, wherein the NSSAI value corresponds to an ultra-reliable low latency communication (URLLC) service.
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:

receive registration information from a first cell associated with a first registration area, wherein the registration information indicates a network slice selection assistance information (NSSAI) value that is rejected by the first cell; and

transmit a registration request to a second cell associated with a second registration area based at least in part on the NSSAI value and based at least in part on receiving the registration information indicating the NSSAI value that is rejected by the first cell.
The non-transitory computer-readable medium of claim 19, wherein the registration information comprises a registration accept message.
The non-transitory computer-readable medium of claim 19, wherein the one or more instructions further cause the UE to:

bar the first registration area from registration for a length of time based at least in part on the registration information indicating the NSSAI value that is rejected by the first cell.
The non-transitory computer-readable medium of claim 19, wherein the one or more instructions further cause the UE to:

transmit another registration request indicating the NSSAI value to the first cell prior to transmitting the registration request to the second cell, wherein the registration information is based at least in part on the other registration request.
The non-transitory computer-readable medium of claim 19, wherein the NSSAI value is included in a set of rejected NSSAI values identified by the registration information.
The non-transitory computer-readable medium of claim 19, wherein the one or more instructions further cause the UE to:

receive, from the second cell, other registration information indicating that the NSSAI value is accepted by the second cell; and

establish a session with the second cell based at least in part on the other registration information indicating that the NSSAI value is accepted by the second cell.
The non-transitory computer-readable medium of claim 19, wherein the one or more instructions further cause the UE to:

receive, from the second cell, other registration information indicating that the NSSAI value is rejected by the second cell; and

transmit another registration request to a third cell associated with a third registration area based at least in part on the NSSAI value and based at least in part on receiving the other registration information indicating that the NSSAI value is rejected by the second cell.
The non-transitory computer-readable medium of claim 19, wherein the NSSAI value is a single NSSAI (S-NSSAI) value.
The non-transitory computer-readable medium of claim 19, wherein the NSSAI value corresponds to an ultra-reliable low latency communication (URLLC) service.
An apparatus for wireless communication, comprising:

means for receiving registration information from a first cell associated with a first registration area, wherein the registration information indicates a network slice selection assistance information (NSSAI) value that is rejected by the first cell; and

means for transmitting a registration request to a second cell associated with a second registration area based at least in part on the NSSAI value and based at least in part on receiving the registration information indicating the NSSAI value that is rejected by the first cell.
The apparatus of claim 28, wherein the registration information comprises a registration accept message.
The apparatus of claim 28, further comprising:

means for barring the first registration area from registration for a length of time based at least in part on the registration information indicating the NSSAI value that is rejected by the first cell.
The apparatus of claim 28, further comprising:

means for transmitting another registration request indicating the NSSAI value to the first cell prior to transmitting the registration request to the second cell, wherein the registration information is based at least in part on the other registration request.
The apparatus of claim 28, wherein the NSSAI value is included in a set of rejected NSSAI values identified by the registration information.
The apparatus of claim 28, further comprising:

means for receiving, from the second cell, other registration information indicating that the NSSAI value is accepted by the second cell; and

means for establishing a session with the second cell based at least in part on the other registration information indicating that the NSSAI value is accepted by the second cell.
The apparatus of claim 28, further comprising:

means for receiving, from the second cell, other registration information indicating that the NSSAI value is rejected by the second cell; and

means for transmitting another registration request to a third cell associated with a third registration area based at least in part on the NSSAI value and based at least in part on receiving the other registration information indicating that the NSSAI value is rejected by the second cell.
The apparatus of claim 28, wherein the NSSAI value is a single NSSAI (S-NSSAI) value.
The apparatus of claim 28, wherein the NSSAI value corresponds to an ultra-reliable low latency communication (URLLC) service.