WO2022067623A1

WO2022067623A1 - Mapped single network slice selection assistance information (s-nssai) for equivalent public land mobile networks (eplmn)

Info

Publication number: WO2022067623A1
Application number: PCT/CN2020/119243
Authority: WO
Inventors: Hao Zhang; Jian Li; Meng Liu
Original assignee: Qualcomm Incorporated
Priority date: 2020-09-30
Filing date: 2020-09-30
Publication date: 2022-04-07

Abstract

Certain aspects of the present disclosure provide techniques for providing a S-NSSAI to a PLMN based on an S-NSSAI from an EPLMN. An example method that may be performed by a user equipment (UE) generally includes transmitting, to a first visiting public land mobile network (VPLMN), a registration request including a mapped S-NSSAI for a slice/service type (SST) and a slice differentiator (SD) of an equivalent EPLMN of the first VPLMN and receiving, from the first VPLMN, a registration accept message for the mapped S-NSSAI for the SST and the SD.

Description

MAPPED SINGLE NETWORK SLICE SELECTION ASSISTANCE INFORMATION (S-NSSAI) FOR EQUIVALENT PUBLIC LAND MOBILE NETWORKS (EPLMN)

BACKGROUND

Field of the Disclosure

Aspects of the present disclosure relate to wireless communications, and more particularly, to techniques for providing a mapped single network slice selection assistance information (S-NSSAI) to a public land mobile network (PLMN) based on an S-NSSAI from an equivalent PLMN.

Description of Related Art

Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, broadcasts, etc. These 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, etc. ) . Examples of such multiple-access systems include 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) systems, LTE Advanced (LTE-A) systems, 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, and time division synchronous code division multiple access (TD-SCDMA) systems, to name a few.

These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level. New radio (e.g., 5G NR) is an example of an emerging telecommunication standard. NR is a set of enhancements to the LTE mobile standard promulgated by 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 OFDMA with a cyclic prefix (CP) on the downlink (DL) and on the uplink (UL) . To these ends, NR supports beamforming, multiple-input multiple-output (MIMO) antenna technology, and carrier aggregation.

However, as the demand for mobile broadband access continues to increase, there exists a need for further improvements in NR and LTE technology. Preferably, these improvements should be applicable to other multi-access technologies and the telecommunication standards that employ these technologies.

SUMMARY

The systems, methods, and devices of the disclosure each have several aspects, no single one of which is solely responsible for its desirable attributes. Without limiting the scope of this disclosure as expressed by the claims which follow, some features will now be discussed briefly. After considering this discussion, and particularly after reading the section entitled “Detailed Description” one will understand how the features of this disclosure provide advantages that include providing a mapped single network slice selection assistance information (S-NSSAI) to a public land mobile network (PLMN) based on an S-NSSAI from an equivalent PLMN.

Aspects of the subject matter described in this disclosure can be implemented in a method for wireless communication by a UE. The method generally includes transmitting, to a first visiting PLMN (VPLMN) , a registration request including a mapped S-NSSAI for a slice/service type (SST) and a slice differentiator (SD) of an equivalent PLMN (EPLMN) of the first VPLMN. The method generally includes receiving, from the first VPLMN, a registration accept message for the mapped S-NSSAI for the SST and the SD.

Aspects of the present disclosure provide means for, apparatus, processors, and computer-readable mediums for performing the methods described herein.

To the accomplishment of the foregoing and related ends, the one or more aspects comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and the appended drawings set forth in detail certain illustrative features of the one or more aspects. These features are indicative, however, of but a few of the various ways in which the principles of various aspects may be employed.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which 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 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.

FIG. 1 is a block diagram conceptually illustrating an example telecommunications system, in accordance with certain aspects of the present disclosure.

FIG. 2 is a block diagram conceptually illustrating a design of an example a base station (BS) and user equipment (UE) , in accordance with certain aspects of the present disclosure.

FIG. 3 is a block diagram illustrating an example architecture of a core network (CN) and radio access network (RAN) , in accordance with certain aspects of the present disclosure.

FIG. 4 is an example frame format for new radio (NR) , in accordance with certain aspects of the present disclosure.

FIG. 5 illustrates example services capable of using resources provided by network slices, in accordance with certain aspects of the present disclosure.

FIG. 6 is an example format of a single network slice selection assistance information (S-NSSAI) information element (IE) , in accordance with certain aspects of the present disclosure.

FIG. 7 is a table showing information carried in the S-NSSAI IE, in accordance with certain aspects of the present disclosure.

FIG. 8 is a call flow diagram of example signaling for a UE transmitting a registration request to a first visiting public land mobile network (VPLMN) without a mapped S-NSSAI.

FIG. 9 is a call flow diagram of example signaling for a UE transmitting a registration request to a first visiting public land mobile network (VPLMN) with a mapped S-NSSAI, in accordance with certain aspects of the present disclosure.

FIG. 10 illustrates example operations that may be performed by a UE, in accordance with certain aspects of the present disclosure.

FIG. 11 illustrates a communications device that may include various components configured to perform operations for the techniques disclosed herein in accordance with aspects of the present disclosure.

To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements disclosed in one aspect may be beneficially utilized on other aspects without specific recitation.

DETAILED DESCRIPTION

Aspects of the present disclosure provide apparatus, methods, processing systems, and computer readable mediums for providing a mapped single network slice selection assistance information (S-NSSAI) to a public land mobile network (PLMN) based on an S-NSSAI from an equivalent PLMN (EPLMN) .

In 5G-NR, core and RAN functions are divided into multiple logical networks to allow network support for a broad variety of 5G services (e.g., enhanced mobile broadband (eMBB) , ultra-low latency communication (URLLC) , massive Internet of Things (MIoT) ) . These logical networks are network slices, comprising functions specific to individual 5G services. When connected to a wireless network (e.g., a PLMN) , a user equipment (UE) may access one or more network slices according to network slice selection assistance information (NSSAI) . The PLMN provides network slicing services based on one or more S-NSSAIs received from the UE. The S-NSSAIs may be based on the allowed NSSAI of the PLMN, or based on general NSSAI values.

According to certain aspects, when a UE sends a registration request to a PLMN, the request may contain a mapped S-NSSAI configuration that provides network slicing information of the PLMN. The PLMN may use the mapped S-NSSAI to provide network slicing services specific to the UE. When a UE is away from its home PLMN (HPLMN) , it may connect to a visiting PLMN (VPLMN) for wireless service. A problem arises when the UE may not have a mapped S-NSSAI to send in the registration request to a VPLMN. This causes the VPLMN to fail to provide network slicing services to the UE.

The following description provides examples of providing a mapped S-NSSAI to a VPLMN based on an S-NSSAI from an EPLMN, in accordance with certain aspects of the present disclosure, and is not limiting of the scope, applicability, or examples set forth in the claims. Changes may be made in the function and arrangement of elements discussed without departing from the scope of the disclosure. Various examples may omit, substitute, or add various procedures or components as appropriate. For instance, the methods described may be performed in an order different from that described, and various steps may be added, omitted, or combined. Also, features described with respect to some examples may be combined in some other examples. 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. The word “exemplary” is used herein to mean “serving as an example, instance, or illustration. ” Any aspect described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects.

In general, any number of wireless networks may be deployed in a given geographic area. Each wireless network may support a particular radio access technology (RAT) and may operate on one or more frequencies. A RAT may also be referred to as a radio technology, an air interface, etc. A frequency may also be referred to as a carrier, a subcarrier, a frequency channel, a tone, a subband, etc. Each frequency may support a single RAT in a given geographic area in order to avoid interference between wireless networks of different RATs.

The techniques described herein may be used for various wireless networks and radio technologies me. For clarity, while aspects may be described herein using terminology commonly associated with 3G, 4G, and/or new radio (e.g., 5G NR) wireless technologies, aspects of the present disclosure can be applied in other generation-based communication systems, including later technologies.

NR access may support various wireless communication services, such as enhanced mobile broadband (eMBB) targeting wide bandwidth, millimeter wave (mmW) targeting high carrier frequency, massive machine type communications MTC (mMTC) targeting non-backward compatible MTC techniques, and/or mission critical targeting ultra-reliable low-latency communications (URLLC) . These services may include latency and reliability requirements. These services may also have different transmission time intervals (TTI) to meet respective quality of service (QoS) requirements. In addition, these services may co-exist in the same subframe.

The electromagnetic spectrum is often subdivided, based on frequency/wavelength, into various classes, bands, channels, etc. In 5G NR two initial operating bands have been identified as frequency range designations FR1 (410 MHz –7.125 GHz) and FR2 (24.25 GHz –52.6 GHz) . The frequencies between FR1 and FR2 are often referred to as mid-band frequencies. Although a portion of FR1 is greater than 6 GHz, FR1 is often referred to (interchangeably) as a “Sub-6 GHz” band in various documents and articles. A similar nomenclature issue sometimes occurs with regard to FR2, which is often referred to (interchangeably) as a “millimeter wave” band in documents and articles, 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.

With the above aspects in mind, unless specifically stated otherwise, it should be understood that the term “sub-6 GHz” or the like if used herein may broadly represent frequencies that may be less than 6 GHz, may be within FR1, or may include mid-band frequencies. Further, unless specifically stated otherwise, it should be understood that the term “millimeter wave” or the like if used herein may broadly represent frequencies that may include mid-band frequencies, may be within FR2, or may be within the EHF band.

NR supports beamforming and beam direction may be dynamically configured. MIMO transmissions with precoding may also be supported. MIMO configurations in the DL may support up to 8 transmit antennas with multi-layer DL transmissions up to 8 streams and up to 2 streams per UE. Multi-layer transmissions with up to 2 streams per UE may be supported. Aggregation of multiple cells may be supported with up to 8 serving cells.

FIG. 1 illustrates an example wireless communication network 100 in which aspects of the present disclosure may be performed. For example, the wireless communication network 100 may be an NR system (e.g., a 5G NR network) . As shown in FIG. 1, the wireless communication network 100 may be in communication with a core network 132. As shown in FIG. 1, the wireless communication network 100 may be in communication with a core network 132. The core network 132 may in communication with one or more base station (BSs) 110110a-z (each also individually referred to herein as BS 110 or collectively as BSs 110) and/or user equipment (UE) 120a-y (each also individually referred to herein as UE 120 or collectively as UEs 120) in the wireless communication network 100 via one or more interfaces as discussed more detail below with respect to FIG. 3.

A BS 110 may provide communication coverage for a particular geographic area, sometimes referred to as a “cell” , which may be stationary or may move according to the location of a mobile BS 110. In some examples, the BSs 110 may be interconnected to one another and/or to one or more other BSs or network nodes (not shown) in wireless communication network 100 through various types of backhaul interfaces (e.g., a direct physical connection, a wireless connection, a virtual network, or the like) using any suitable transport network. In the example shown in FIG. 1, the

BSs

110a, 110b and 110c may be macro BSs for the

macro cells

102a, 102b and 102c, respectively. The BS 110x may be a pico BS for a pico cell 102x. The BSs 110y and 110z may be femto BSs for the

femto cells

102y and 102z, respectively. A BS may support one or multiple cells.

The BSs 110 communicate with UEs 120 in the wireless communication network 100. The UEs 120 (e.g., 120x, 120y, etc. ) may be dispersed throughout the wireless communication network 100, and each UE 120 may be stationary or mobile. Wireless communication network 100 may also include relay stations (e.g., relay station 110r) , also referred to as relays or the like, that receive a transmission of data and/or other information from an upstream station (e.g., a BS 110a or a UE 120r) and sends a transmission of the data and/or other information to a downstream station (e.g., a UE 120 or a BS 110) , or that relays transmissions between UEs 120, to facilitate communication between devices.

A network controller 130 may be in communication with a set of BSs 110 and provide coordination and control for these BSs 110 (e.g., via a backhaul) . In aspects, the network controller 130 may be in communication with a core network 132 (e.g., a 5G Core Network (5GC) ) , which provides various network functions such as Access and Mobility Management, Session Management, User Plane Function, Policy Control Function, Authentication Server Function, Unified Data Management, Application Function, Network Exposure Function, Network Repository Function, Network Slice Selection Function, etc.

According to certain aspects, the BSs 110 and UE 120a may be configured with a mapped S-NSSAI in wireless communication network 100. As shown in FIG. 1, the UE 120a includes a network slicing manager 122. The network slicing manager 122 may be configured with mapped S-NSSAI for EPLMN, in accordance with certain aspects of the present disclosure. As shown in FIG. 1, the BS 110a includes a network slicing manager 112. The S-network slicing manager 112 may be configured with mapped S-NSSAI for EPLMNs, in accordance with aspects of the present disclosure. One or more PLMNs (e.g., a VPLMN, HPLMN) may include the network slicing manager 112 of the BS 110a, in accordance with aspects of the present disclosure.

FIG. 2 illustrates example components of BS 110a and UE 120a (e.g., in the wireless communication network 100 of FIG. 1) , which may be used to implement aspects of the present disclosure.

At the BS 110a, a transmit processor 220 may receive data from a data source 212 and control information from a controller/processor 240. The control information may be for the physical broadcast channel (PBCH) , physical control format indicator channel (PCFICH) , physical hybrid ARQ indicator channel (PHICH) , physical downlink control channel (PDCCH) , group common PDCCH (GC PDCCH) , etc. The data may be for the physical downlink shared channel (PDSCH) , etc. A medium access control (MAC) -control element (MAC-CE) is a MAC layer communication structure that may be used for control command exchange between wireless nodes. The MAC-CE may be carried in a shared channel such as a physical downlink shared channel (PDSCH) , a physical uplink shared channel (PUSCH) , or a physical sidelink shared channel (PSSCH) .

The processor 220 may process (e.g., encode and symbol map) the data and control information to obtain data symbols and control symbols, respectively. The transmit processor 220 may also generate reference symbols, such as for the primary synchronization signal (PSS) , secondary synchronization signal (SSS) , PBCH demodulation reference signal (DMRS) , and channel state information reference signal (CSI-RS) . A transmit (TX) multiple-input multiple-output (MIMO) processor 230 may perform spatial processing (e.g., precoding) on the data symbols, the control symbols, and/or the reference symbols, if applicable, and may provide output symbol streams to the modulators (MODs) 232a-232t. Each modulator 232 may process a respective output symbol stream (e.g., for OFDM, etc. ) to obtain an output sample stream. Each modulator may further process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal. Downlink signals from modulators 232a-232t may be transmitted via the antennas 234a-234t, respectively.

At the UE 120a, the antennas 252a-252r may receive the downlink signals from the BS 110a and may provide received signals to the demodulators (DEMODs) in transceivers 254a-254r, respectively. Each demodulator 254 may condition (e.g., filter, amplify, downconvert, and digitize) a respective received signal to obtain input samples. Each demodulator may further process the input samples (e.g., for OFDM, etc. ) to obtain received symbols. A MIMO detector 256 may obtain received symbols from all the demodulators 254a-254r, perform MIMO detection on the received symbols if applicable, and provide detected symbols. A receive processor 258 may process (e.g., demodulate, deinterleave, and decode) the detected symbols, provide decoded data for the UE 120a to a data sink 260, and provide decoded control information to a controller/processor 280.

On the uplink, at UE 120a, a transmit processor 264 may receive and process data (e.g., for the physical uplink shared channel (PUSCH) ) from a data source 262 and control information (e.g., for the physical uplink control channel (PUCCH) from the controller/processor 280. The transmit processor 264 may also generate reference symbols for a reference signal (e.g., for the sounding reference signal (SRS) ) . The symbols from the transmit processor 264 may be precoded by a TX MIMO processor 266 if applicable, further processed by the modulators in transceivers 254a-254r (e.g., for SC-FDM, etc. ) , and transmitted to the BS 110a. At the BS 110a, the uplink signals from the UE 120a may be received by the antennas 234, processed by the modulators 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 the UE 120a. The receive processor 238 may provide the decoded data to a data sink 239 and the decoded control information to the controller/processor 240.

The

memories

242 and 282 may store data and program codes for BS 110a and UE 120a, respectively. A scheduler 244 may schedule UEs for data transmission on the downlink and/or uplink.

Antennas 252,

processors

266, 258, 264, and/or controller/processor 280 of the UE 120a and/or antennas 234,

processors

220, 230, 238, and/or controller/processor 240 of the BS 110a may be used to perform the various techniques and methods described herein. As shown in FIG. 2, the controller/processor 280 of the UE 120a has an S-NSSAI manager 281 that may store a mapped S-NSSAI. Although shown at the controller/processor, other components of the UE 120a and BS 110a may be used to perform the operations described herein.

FIG. 3 is a block diagram illustrating an example architecture of a core network (CN) 300 (e.g., such as the CN 132 in FIG. 1) in communication with a RAN 324, in accordance with certain aspects of the present disclosure. As shown in FIG. 3, the example architecture includes the CN 300, RAN 324, UE 322, and data network (DN) 328 (e.g. operator services, Internet access or third party services) .

The CN 300 may host core network functions. CN 300 may be centrally deployed. CN 300 functionality may be offloaded (e.g., to advanced wireless services (AWS) ) , in an effort to handle peak capacity. As shown in FIG. 3, the example CN 300 may be implemented by one or more network entities that perform network functions (NF) including Network Slice Selection Function (NSSF) 304, Network Exposure Function (NEF) 306, NF Repository Function (NRF) 308, Policy Control Function (PCF) 310, Unified Data Management (UDM) 312, Application Function (AF) 314, Authentication Server Function (AUSF) 316, Access and Mobility Management Function (AMF) 318, Session Management Function (SMF) 320; User Plane Function (UPF) 326, and various other functions (not shown) such as Unstructured Data Storage Function (UDSF) ; Unified Data Repository (UDR) ; 5G-Equipment Identity Register (5G-EIR) ; and/or Security Edge Protection Proxy (SEPP) .

The AMF 318 may include the following functionality (some or all of the AMF functionalities may be supported in one or more instances of an AMF) : termination of RAN control plane (CP) interface (N2) ; termination of non-access stratum (NAS) (e.g., N1) , NAS ciphering and integrity protection; registration management; connection management; reachability management; mobility management; lawful intercept (for AMF events and interface to L1 system) ; transport for session management (SM) messages between UE 322 and SMF 320; transparent proxy for routing SM messages; access authentication; access authorization; transport for short message service (SMS) messages between UE 322 and a SMS function (SMSF) ; Security Anchor Functionality (SEAF) ; Security Context Management (SCM) , which receives a key from the SEAF that it uses to derive access-network specific keys; Location Services management for regulatory services; transport for Location Services messages between UE 322 and a location management function (LMF) as well as between RAN 324 and LMF; evolved packet service (EPS) bearer ID allocation for interworking with EPS; and/or UE mobility event notification; and/or other functionality.

SMF 320 may support: session management (e.g., session establishment, modification, and release) , UE IP address allocation and management, dynamic host configuration protocol (DHCP) functions, termination of NAS signaling related to session management, downlink data notification, and traffic steering configuration for UPF for proper traffic routing. UPF 326 may support: packet routing and forwarding, packet inspection, quality-of-service (QoS) handling, external protocol data unit (PDU) session point of interconnect to DN 328, and anchor point for intra-RAT and inter-RAT mobility. PCF 310 may support: unified policy framework, providing policy rules to control protocol functions, and/or access subscription information for policy decisions in UDR. AUSF 316 may acts as an authentication server. UDM 312 may support: generation of Authentication and Key Agreement (AKA) credentials, user identification handling, access authorization, and subscription management. NRF 308 may support: service discovery function, and maintain NF profile and available NF instances. NSSF may support: selecting of the Network Slice instances to serve the UE 322, determining the allowed network slice selection assistance information (NSSAI) , and/or determining the AMF set to be used to serve the UE 322.

NEF 306 may support: exposure of capabilities and events, secure provision of information from external application to 3GPP network, translation of internal/external information. AF 314 may support: application influence on traffic routing, accessing NEF 306, and/or interaction with policy framework for policy control.

As shown in FIG. 3, the CN 300 may be in communication with the AS 302, UE 322, RAN 324, and DN 328. In some examples, the CN 300 communicates with the external AS 302 via the NEF 306 and/or AF 314. In some examples, the CN 300 communicates with the RAN 324 (e.g., such as the BS 110a in the wireless communication network 100 illustrated in FIG. 1) and/or the UE 322 (e.g., such as the UE 120a in the wireless communication network 100 illustrated in FIG. 1) via the AMF 318.

The NSSF 304 supports the following functionality: selecting of the network slice instances to serve the UE 322; determining the allowed network slice selection assistance information (NSSAI) ; and/or determining the AMF set to be used to serve the UE 322.

NR may utilize orthogonal frequency division multiplexing (OFDM) with a cyclic prefix (CP) on the uplink and downlink. NR may support half-duplex operation using time division duplexing (TDD) . OFDM and single-carrier frequency division multiplexing (SC-FDM) partition the system bandwidth into multiple orthogonal subcarriers, which are also commonly referred to as tones, bins, etc. Each subcarrier may be modulated with data. Modulation symbols may be sent in the frequency domain with OFDM and in the time domain with SC-FDM. The spacing between adjacent subcarriers may be fixed, and the total number of subcarriers may be dependent on the system bandwidth. The minimum resource allocation, called a resource block (RB) , may be 12 consecutive subcarriers. The system bandwidth may also be partitioned into subbands. For example, a subband may cover multiple RBs. NR may support a base subcarrier spacing (SCS) of 15 KHz and other SCS may be defined with respect to the base SCS (e.g., 30 kHz, 60 kHz, 120 kHz, 240 kHz, etc. ) .

FIG. 4 is a diagram showing an example of a frame format 400 for NR. The transmission timeline for each of the downlink and uplink may be partitioned into units of radio frames. Each radio frame may have a predetermined duration (e.g., 10 ms) and may be partitioned into 10 subframes, each of 1 ms, with indices of 0 through 9. Each subframe may include a variable number of slots (e.g., 1, 2, 4, 8, 16, …slots) depending on the SCS. Each slot may include a variable number of symbol periods (e.g., 7 or 14 symbols) depending on the SCS. The symbol periods in each slot may be assigned indices. A mini-slot, which may be referred to as a sub-slot structure, refers to a transmit time interval having a duration less than a slot (e.g., 2, 3, or 4 symbols) . Each symbol in a slot may indicate a link direction (e.g., DL, UL, or flexible) for data transmission and the link direction for each subframe may be dynamically switched. The link directions may be based on the slot format. Each slot may include DL/UL data as well as DL/UL control information.

Example Network Slicing

As mentioned above, network slicing provides for isolating resources for different scenarios. A network slice may be defined as a logical network that provides specific network capabilities and network characteristics. A network slice instance may be defined as a set of network function instances and the required resources (e.g., compute, storage, and networking resources) which form a deployed network slice. Network slices instances may be used for specific use cases. Each use case receives a unique set of resources and network topology that suit the needs of the service and any application using the services.

Network slices may be used for various services, such as for various 5G services including Internet of Things (IoT) , Enhanced Mobile Broadband (eMBB) , and Ultra Reliable Low Latency Communication (URLLC) . Different devices may subscribe to different network slicing instances and/or the same device may subscribe to different network slicing instances for different applications. FIG. 5 illustrates some examples services, use cases, and associated service requirements that may provided by network slices. As shown in FIG. 5, services may include IoT, smart phones, autonomous cars, and gaming and/or high definition videos. IoT service use cases may include such things as water and/or gas sensors, which require low bandwidth and have a high latency. Smart phones use cases may require high bandwidth and medium latency. Autonomous car uses cases may require low bandwidth and very low latency. And gaming and/or high definition video use cases may require high bandwidth and low latency.

A network slice is identified by single network slice selection assistance information (S-NSSAI) . NSSAI is a list of one or more S-NSSAIs. An S-NSSAI includes a slice/service type (SST) , which refers to the expected network slice behavior (e.g., features and services) , and a slice differentiator (SD) , which is optional information that complements the SST (s) to differentiate amongst multiple network slices of the same SST. An S-NSSAI can have standard values (e.g., including an SST with a standardized SST value and no SD) or non-standard values (e.g., including an SST and an SD or including an SST without a standardized SST value and no SD) . An S-NSSAI with a non-standard value identifies a single network slice within a public land mobile network (PLMN) with which it is associated. An S-NSSAI with a non-standard value may not be used by the UE in access stratum procedures in any PLMN other than the one to which the S-NSSAI is associated.

Network slices may differ with respect to supported features and network functions optimizations. For example, different S-NSSAIs may have different SSTs. An operator can deploy multiple network slice instances delivering the same features, but for different groups of UEs (e.g., dedicated to a customer different S-NSSAIs with the same SST but different SDs) . The network may serve a single UE with one or more network slice instances simultaneously (e.g., via the 5G-AN) . In some examples, a UE may be associated with up to eight different S-NSSAIs in total.

Access and Mobility Management Function (AMF) instances can be common to network slice instances serving a UE. Selection of the set of network slice instances for a UE is triggered by the first contacted AMF in a registration procedure normally by interacting with the NSSF. A protocol data unit (PDU) session may belong to one specific network slice instance per PLMN. Different network slice instances may not share a PDU session, though different slices may have slice-specific PDU sessions using the same data network name (DNN) . In order to enable PDU transmission in a network slice, the UE may request establishment of a PDU session in a network slice towards a DN associated with an S-NSSAI and a DNN if there is no established PDU session adequate for the PDU transmission. The S-NSSAI included is part of allowed NSSAI of the serving PLMN, which is an S-NSSAI value valid in the serving PLMN, and in roaming scenarios the mapped S-NSSAI is also included for the PDU session if available.

In certain systems, S-NSSAI values are provided in an NSSAI information element (IE) . The NSSAI IE identifies a collection of S-NSSAIs. The example NSSAI IE may have a length of 4-146 octets. The NSSAI IE may indicate up to eight S-NSSAI values for requested NSSAI (sent by a UE) or an allowed NSSAI (sent by the network) . The NSSAI IE may indicate up to sixteen S-NSSAI values in a configured NSSAI (sent by the UE and/or the network) .

An example format of the S-NSSAI IE is shown in FIG. 6. The S-NSSAI IE may have a length of 3-10 octets. The S-NSSAI value is coded as the length and value part of the example S-NSSAI IE starting with the second octet. The length of S-NSSAI field may indicate the length of the included S-NSSAI contents. The SST field may indicate SST value. The SD field may indicate the SD value. The mapped home public land mobile network (HPLMN) SST field may indicate the SST value of an S-NSSAI in the S-NSSAI (s) of the HPLMN to which the SST value is mapped. The mapped HPLMN SD field may indicate the SD value of an S-NSSAI in the S-NSSAI (s) of the HPLMN to which the SST value is mapped. Further information for each octet of the S-NSSAI IE is provided in FIG. 7 and may be described in 3GPP Technical Standards TS 24.501 for S-NSSAI.

Example Mapped S-NSSAI for EPLMN

When a user equipment (UE) is away from its registered home public land mobile network (HPLMN) (i.e., “roaming” ) , the UE may receive network slicing services from visiting PLMNs (VPLMNs) . During roaming procedures, the UE may send a registration request containing a mapped S-NSSAI with associated SST and SD values. Because the UE is roaming, the UE may not have the mapped S-NSSAI (s) of the serving VPLMN, but has the mapped S-NSSAI (s) of an EPLMN. According to aspects the UE may provide the mapped S-NSSAI (s) of the EPLMN for the requested NSSAI in the registration request to the serving VPLMN. The VPLMN may then evaluate the slicing services it may provide to the UE based on the mapped S-NSSAI and the VPLMN’s own service capabilities.

FIG. 8 is a call flow of example signaling for a UE. In aspects, the UE 802 is roaming. To request service, a UE 802 sends a registration request 808 to a VPLMN 806. In response, the UE receives mapped S-NSSAI values for the VPLMN 806 in an acceptance request message 810. Like a mapped HPLMN, a mapped VPLMN may indicate slice/service type (SST) and slice differentiator (SD) of the S-NSSAI.

As illustrated in FIG. 8, the UE 802 may reselect 812 to VPLMN 804 from VPLMN 806. The UE 802 may reselect when, for example, the UE 802 falls beyond the range of VPLMN 806. The UE 802 may not be previously registered with the VPLMN 804, so the UE 802 may not have mapped N-SSAI values 814 for VPLMN 804.

The UE reselecting to VPLMN 804 may not receive slicing services from VPLMN 804 because the UE does not have a mapped S-NSSAI for the VPLMN 804. Without mapped S-NSSAI for a VPLMN 804, a registration request will not include the slicing service needs of the UE.

After reselecting, the UE 802 may send a registration request 816 without a mapped S-NSSAI for SST and SD values. The VPLMN 804 may send a registration acceptance 818, but the network slicing service may not be compatible with the service needs of the UE. At 820, the VPLMN 804 may reject network slicing service for the UE 802 because the VPLMN 804 cannot identify network slices without mapped S-NSSAI values.

In accordance with certain aspects of the present disclosure, a UE may receive slicing services from a VPLMN (e.g., VPLMN 804) , even when the UE has no mapped S-NSSAI for the VPLMN. As described herein, the use transmits mapped S-NSSAI values for an EPLMN in a registration request to the VPLMN 804. EPLMNs may exist where one operator has an agreement with another operator to share resources, creating a list of shared EPLMNs that both operators may offer as a wireless resource. A serving PLMN may offer a UE the same services as an in-network PLMN, where the PLMNs are EPLMNs.

During roaming, VPLMNs may be EPLMNs equipped with similar network slicing functions. The mapped SST and SD values from one VPLMN may apply to another VPLMN, where the VPLMNs are equivalent. A UE may, after receiving a registration acceptance from a first VPLMN 806 containing a mapped S-NSSAI values, send those same mapped N-SSAI values in its registration request to an EPLMN in order to receive network slicing services from the VPLMN 804 that is equivalent to VPLM 806.

FIG. 9 illustrates example operations for providing a mapped S-NSSAI to a PLMN based on an S-NSSAI from an equivalent PLMN. VPLMN 804 and VPLMN 806 are EPLMNs 902. As in FIG. 8, the UE 802 may reselect 812 to VPLMN 804 from VPLMN 806 after receiving a mapped S-NSSAI from VPLMN 806. The UE 802 may not have mapped N-SSAI values 814 for VPLMN 804. After reselecting, the UE 802 may send a registration request 904 to VPLMN 804 containing mapped S-NSSAI for SST and SD values from VPLMN 806. Because VPLMN 804 and VPLMN 806 are equivalent, the VPLMN 804 may send a registration acceptance 818, which includes mapped S-NSSAI values. Using the mapped S-NSSAI values, the VPLMN 804 may evaluate the UE 802 network slicing request and administer network slicing service compatible with the service needs of the UE.

In some cases, the VPLMN 804 cannot guarantee network slicing because the VPLMN 804 may not have allowed NSSAI consistent with the S-NSSAI (s) of the UE 802; however, the VPLMN may use the information to determine availability of service.

FIG. 10 is a flow diagram illustrating example operations 1000 for wireless communication, in accordance with certain aspects of the present disclosure. The operations 1000 may be performed, for example, by a UE (e.g., the UE 120a in the wireless communication network 100) . The operations 1000 may be implemented as software components that are executed and run on one or more processors (e.g., controller/processor 280 of FIG. 2) . Further, the transmission and reception of signals by the UE in operations 1000 may be enabled, for example, by one or more antennas (e.g., antennas 252 of FIG. 2) . In certain aspects, the transmission and/or reception of signals by the UE may be implemented via a bus interface of one or more processors (e.g., controller/processor 280) obtaining and/or outputting signals.

As illustrated, operations 1000 may begin at block 1002, where the UE transmits, to a first VPLMN, a registration request including a mapped S-NSSAI for a SST and a SD of an EPLMN of the first VPLMN. In some cases, the EPLMN comprises a second VPLMN. In some cases, the UE may, prior to transmitting the registration request to the first VPLMN, receive, from the second VPLMN, the mapped S-NSSAI for the SST and the SD. In some cases, the UE may reselect from the second VPLMN to the first VPLMN, wherein the registration request is transmitted in response to the reselection. In some cases, the first VPLMN and the EPLMN are associated with different network operators. In some cases, the UE comprises a 5GNR modem.

At block 1204, the UE receives, from the first VPLMN, a registration accept message for the mapped S-NSSAI for the SST and the SD.

FIG. 11 illustrates a communications device 1100 that may include various components (e.g., corresponding to means-plus-function components) configured to perform operations for the techniques disclosed herein, such as the operations illustrated in FIG. 10. The communications device 1100 includes a processing system 1102 coupled to a transceiver 1108 (e.g., a transmitter and/or a receiver) . The transceiver 1108 is configured to transmit and receive signals for the communications device 1100 via an antenna 1310, such as the various signals as described herein. The processing system 1102 may be configured to perform processing functions for the communications device 1100, including processing signals received and/or to be transmitted by the communications device 1100.

The processing system 1102 includes a processor 1104 coupled to a computer-readable medium/memory 1112 via a bus 1106. In certain aspects, the computer-readable medium/memory 1112 is configured to store instructions (e.g., computer-executable code) that when executed by the processor 1104, cause the processor 1104 to perform the operations illustrated in FIG. 11, or other operations for providing a mapped S-NSSAI to a PLMN based on an S-NSSAI from an equivalent PLMN. In certain aspects, computer-readable medium/memory 1112 stores code 1114 for transmitting, to a first VPLMN, a registration request including a mapped S-NSSAI for a SST and a SD of an EPLMN of the first VPLMN; and code 1116 for receiving, from the first VPLMN, a registration request accept message for the mapped S-NSSAI for the SST and the SD, in accordance with certain aspects of the present disclosure.

In certain aspects, the processor 1104 has circuitry configured to implement the code stored in the computer-readable medium/memory 1112. The processor 1104 includes circuitry 1118 for transmitting, to a first VPLMN, a registration request including a mapped S-NSSAI for a SST and a SD of an EPLMN of the first VPLMN; and circuitry 1120 for receiving, from the first VPLMN, a registration request accept message for the mapped S-NSSAI for the SST and the SD, in accordance with aspects of the disclosure.

The techniques described herein may be used for various wireless communication technologies, such as NR (e.g., 5G NR) , 3GPP Long Term Evolution (LTE) , LTE-Advanced (LTE-A) , code division multiple access (CDMA) , time division multiple access (TDMA) , frequency division multiple access (FDMA) , orthogonal frequency division multiple access (OFDMA) , single-carrier frequency division multiple access (SC-FDMA) , time division synchronous code division multiple access (TD-SCDMA) , and other networks. The terms “network” and “system” are often used interchangeably. A CDMA network may implement a radio technology such as Universal Terrestrial Radio Access (UTRA) , cdma2000, etc. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. cdma2000 covers IS-2000, IS-95 and IS-856 standards. A TDMA network may implement a radio technology such as Global System for Mobile Communications (GSM) . An OFDMA network may implement a radio technology such as NR (e.g. 5G RA) , Evolved UTRA (E-UTRA) , Ultra Mobile Broadband (UMB) , IEEE 802.11 (Wi-Fi) , IEEE 802.16 (WiMAX) , IEEE 802.20, Flash-OFDMA, etc. UTRA and E-UTRA are part of Universal Mobile Telecommunication System (UMTS) . LTE and LTE-A are releases of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A and GSM are described in documents from an organization named “3rd Generation Partnership Project” (3GPP) . cdma2000 and UMB are described in documents from an organization named “3rd Generation Partnership Project 2” (3GPP2) . NR is an emerging wireless communications technology under development.

In 3GPP, the term “cell” can refer to a coverage area of a Node B (NB) and/or a NB subsystem serving this coverage area, depending on the context in which the term is used. In NR systems, the term “cell” and BS, next generation NodeB (gNB or gNodeB) , access point (AP) , distributed unit (DU) , carrier, or transmission reception point (TRP) may be used interchangeably. A BS may provide communication coverage for a macro cell, a pico cell, a femto cell, and/or other types of cells. 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 an association with the femto cell (e.g., UEs in a Closed Subscriber Group (CSG) , UEs for users in the home, etc. ) . 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.

A UE may also be referred to as a mobile station, a terminal, an access terminal, a subscriber unit, a station, a Customer Premises Equipment (CPE) , a cellular phone, 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 computer, a camera, a gaming device, a netbook, a smartbook, an ultrabook, an appliance, a medical device or medical equipment, a biometric sensor/device, a wearable device such as a smart watch, smart clothing, smart glasses, a smart wrist band, smart jewelry (e.g., a smart ring, a smart bracelet, etc. ) , an entertainment device (e.g., a music device, a video device, a satellite radio, etc. ) , a vehicular component or sensor, a smart meter/sensor, 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) devices or evolved MTC (eMTC) devices. MTC and eMTC UEs include, for example, robots, drones, remote devices, sensors, meters, monitors, location tags, etc., that may communicate with a BS, 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, which may be narrowband IoT (NB-IoT) devices.

In some examples, access to the air interface may be scheduled. A scheduling entity (e.g., a BS) allocates resources for communication among some or all devices and equipment within its service area or cell. The scheduling entity may be responsible for scheduling, assigning, reconfiguring, and releasing resources for one or more subordinate entities. That is, for scheduled communication, subordinate entities utilize resources allocated by the scheduling entity. Base stations are not the only entities that may function as a scheduling entity. In some examples, a UE may function as a scheduling entity and may schedule resources for one or more subordinate entities (e.g., one or more other UEs) , and the other UEs may utilize the resources scheduled by the UE for wireless communication. In some examples, a UE may function as a scheduling entity in a peer-to-peer (P2P) network, and/or in a mesh network. In a mesh network example, UEs may communicate directly with one another in addition to communicating with a scheduling entity.

In some examples, two or more subordinate entities (e.g., UEs) may communicate with each other using sidelink signals. Real-world applications of such sidelink communications may include public safety, proximity services, UE-to-network relaying, vehicle-to-vehicle (V2V) communications, Internet of Everything (IoE) communications, IoT communications, mission-critical mesh, and/or various other suitable applications. Generally, a sidelink signal may refer to a signal communicated from one subordinate entity (e.g., UE1) to another subordinate entity (e.g., UE2) without relaying that communication through the scheduling entity (e.g., UE or BS) , even though the scheduling entity may be utilized for scheduling and/or control purposes. In some examples, the sidelink signals may be communicated using a licensed spectrum (unlike wireless local area networks, which typically use an unlicensed spectrum) .

The methods disclosed herein comprise one or more steps or actions for achieving the methods. The method steps and/or actions may be interchanged with one another without departing from the scope of the claims. In other words, unless a specific order of steps or actions is specified, the order and/or use of specific steps and/or actions may be modified without departing from the scope of the claims.

As used herein, 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) .

As used herein, the term “determining” encompasses a wide variety of actions. For example, “determining” may include calculating, computing, processing, deriving, investigating, looking up (e.g., looking up in a table, a database or another data structure) , ascertaining and the like. Also, “determining” may include receiving (e.g., receiving information) , accessing (e.g., accessing data in a memory) and the like. Also, “determining” may include resolving, selecting, choosing, establishing and the like.

The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but is to be accorded the full scope consistent with the language of the claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more. ” Unless specifically stated otherwise, the term “some” refers to one or more. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed under the provisions of 35 U.S.C. §112 (f) unless the element is expressly recited using the phrase “means for” or, in the case of a method claim, the element is recited using the phrase “step for. ”

The various operations of methods described above may be performed by any suitable means capable of performing the corresponding functions. The means may include various hardware and/or software component (s) and/or module (s) , including, but not limited to a circuit, an application specific integrated circuit (ASIC) , or processor. Generally, where there are operations illustrated in figures, those operations may have corresponding counterpart means-plus-function components with similar numbering.

The various illustrative logical blocks, modules and circuits described in connection with the present disclosure may be implemented or performed with a general purpose processor, a digital signal processor (DSP) , an application specific integrated circuit (ASIC) , a field programmable gate array (FPGA) or other programmable logic device (PLD) , discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any commercially available processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

If implemented in hardware, an example hardware configuration may comprise a processing system in a wireless node. The processing system may be implemented with a bus architecture. The bus may include any number of interconnecting buses and bridges depending on the specific application of the processing system and the overall design constraints. The bus may link together various circuits including a processor, machine-readable media, and a bus interface. The bus interface may be used to connect a network adapter, among other things, to the processing system via the bus. The network adapter may be used to implement the signal processing functions of the PHY layer. In the case of a user terminal 120 (see FIG. 1) , a user interface (e.g., keypad, display, mouse, joystick, etc. ) may also be connected to the bus. The bus may also link various other circuits such as timing sources, peripherals, voltage regulators, power management circuits, and the like, which are well known in the art, and therefore, will not be described any further. The processor may be implemented with one or more general-purpose and/or special-purpose processors. Examples include microprocessors, microcontrollers, DSP processors, and other circuitry that can execute software. Those skilled in the art will recognize how best to implement the described functionality for the processing system depending on the particular application and the overall design constraints imposed on the overall system.

If implemented in software, the functions may be stored or transmitted over as one or more instructions or code on a computer readable medium. Software shall be construed broadly to mean instructions, data, or any combination thereof, whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. Computer-readable media include both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. The processor may be responsible for managing the bus and general processing, including the execution of software modules stored on the machine-readable storage media. A computer-readable storage medium may be coupled to a processor such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. By way of example, the machine-readable media may include a transmission line, a carrier wave modulated by data, and/or a computer readable storage medium with instructions stored thereon separate from the wireless node, all of which may be accessed by the processor through the bus interface. Alternatively, or in addition, the machine-readable media, or any portion thereof, may be integrated into the processor, such as the case may be with cache and/or general register files. Examples of machine-readable storage media may include, by way of example, RAM (Random Access Memory) , flash memory, ROM (Read Only Memory) , PROM (Programmable Read-Only Memory) , EPROM (Erasable Programmable Read-Only Memory) , EEPROM (Electrically Erasable Programmable Read-Only Memory) , registers, magnetic disks, optical disks, hard drives, or any other suitable storage medium, or any combination thereof. The machine-readable media may be embodied in a computer-program product.

A software module may comprise a single instruction, or many instructions, and may be distributed over several different code segments, among different programs, and across multiple storage media. The computer-readable media may comprise a number of software modules. The software modules include instructions that, when executed by an apparatus such as a processor, cause the processing system to perform various functions. The software modules may include a transmission module and a receiving module. Each software module may reside in a single storage device or be distributed across multiple storage devices. By way of example, a software module may be loaded into RAM from a hard drive when a triggering event occurs. During execution of the software module, the processor may load some of the instructions into cache to increase access speed. One or more cache lines may then be loaded into a general register file for execution by the processor. When referring to the functionality of a software module below, it will be understood that such functionality is implemented by the processor when executing instructions from that software module.

Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) , or wireless technologies such as infrared (IR) , radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, include compact disc (CD) , laser disc, optical disc, digital versatile disc (DVD) , floppy disk, and

disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Thus, in some aspects computer-readable media may comprise non-transitory computer-readable media (e.g., tangible media) . In addition, for other aspects computer-readable media may comprise transitory computer-readable media (e.g., a signal) . Combinations of the above should also be included within the scope of computer-readable media.

Thus, certain aspects may comprise a computer program product for performing the operations presented herein. For example, such a computer program product may comprise a computer-readable medium having instructions stored (and/or encoded) thereon, the instructions being executable by one or more processors to perform the operations described herein, for example, instructions for performing the operations described herein and illustrated in FIG. 10.

Further, it should be appreciated that modules and/or other appropriate means for performing the methods and techniques described herein can be downloaded and/or otherwise obtained by a user terminal and/or base station as applicable. For example, such a device can be coupled to a server to facilitate the transfer of means for performing the methods described herein. Alternatively, various methods described herein can be provided via storage means (e.g., RAM, ROM, a physical storage medium such as a compact disc (CD) or floppy disk, etc. ) , such that a user terminal and/or base station can obtain the various methods upon coupling or providing the storage means to the device. Moreover, any other suitable technique for providing the methods and techniques described herein to a device can be utilized.

It is to be understood that the claims are not limited to the precise configuration and components illustrated above. Various modifications, changes and variations may be made in the arrangement, operation and details of the methods and apparatus described above without departing from the scope of the claims.

Claims

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

transmitting, to a first visiting public land mobile network (VPLMN) , a registration request including a mapped single network slice selection assistance information (S-NSSAI) for a slice/service type (SST) and a slice differentiator (SD) of an equivalent PLMN (EPLMN) of the first VPLMN; and

receiving, from the first VPLMN, a registration accept message for the mapped S-NSSAI for the SST and the SD.
The method of claim 1, wherein the EPLMN comprises a second VPLMN.
The method of claim 2, further comprising:

prior to transmitting the registration request to the first VPLMN, receiving, from the second VPLMN, the mapped S-NSSAI for the SST and the SD.
The method of claim 3, further comprising:

reselecting from the second VPLMN to the first VPLMN,

wherein the registration request is transmitted in response to the reselection.
The method of claim 1, wherein the first VPLMN and the EPLMN are associated with different network operators.
The method of claim 1, wherein the UE comprises a 5GNR modem.
An apparatus for wireless communication, comprising:

a memory; and

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

transmit, to a first visiting public land mobile network (VPLMN) , a registration request including a mapped single network slice selection assistance information (S-NSSAI) for a slice/service type (SST) and a slice differentiator (SD) of an equivalent PLMN (EPLMN) of the first VPLMN; and

receive, from the first VPLMN, a registration accept message for the mapped S-NSSAI for the SST and the SD.
An apparatus for wireless communication, comprising:

means for transmitting, to a first visiting public land mobile network (VPLMN) , a registration request including a mapped single network slice selection assistance information (S-NSSAI) for a slice/service type (SST) and a slice differentiator (SD) of an equivalent PLMN (EPLMN) of the first VPLMN; and

means for receiving, from the first VPLMN, a registration accept message for the mapped S-NSSAI for the SST and the SD.
A computer readable medium having computer executable code stored thereon for wireless communication, comprising:

code for transmitting, to a first visiting public land mobile network (VPLMN) , a registration request including a mapped single network slice selection assistance information (S-NSSAI) for a slice/service type (SST) and a slice differentiator (SD) of an equivalent PLMN (EPLMN) of the first VPLMN; and

code for receiving, from the first VPLMN, a registration accept message for the mapped S-NSSAI for the SST and the SD.