Patent Publication Number: US-2023141754-A1

Title: Ensuring compatibility between network slice operating frequencies and user equipment (ue) radio capabilities

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims benefit to Greek Provisional Patent Application Serial No. 20200100270, entitled “Ensuring Compatibility Between Network Slice Operating Frequencies and User Equipment (UE) Radio Capabilities,” filed May 22, 2020, and assigned to the assignee hereof, the contents of which are hereby incorporated by reference in its entirety. 
     BACKGROUND 
     Field of the Disclosure 
     Aspects of the present disclosure relate to wireless communications, and more particularly, to techniques for ensuring compatibility between network slice operating frequencies and user equipment (UE) radio capabilities. 
     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 compatibility between network slice operating frequencies and UE radio capabilities. 
     One innovative aspect of the subject matter described in this disclosure can be implemented in a method for wireless communication by a network entity. The method generally includes receiving, from a network core entity, a request for information about capabilities of a user equipment (UE) and information about a plurality of network slices in an allowed set of network slices for the UE; identifying, based on UE capability information, a subset of the allowed set of network slices that the UE can use for communications between the UE and the network entity; generating a response including at least the subset of the allowed set of network slices that the UE can use for communications between the UE and the network entity; and transmitting the response to the network core entity. 
     One innovative aspect of the subject matter described in this disclosure can be implemented in a method for wireless communication by a network core entity. The method generally includes transmitting, to a network entity, a request for information about capabilities of a user equipment (UE) and information about a plurality of network slices in an allowed set of network slices for the UE; receiving, from the network entity, a response including a subset of the allowed set of network slices that the UE can use for communications between the UE and the network entity; and modifying the allowed set of network slices for the UE based on the received response. 
     One innovative aspect of the subject matter described in this disclosure can be implemented in a method for wireless communication by a network entity. The method generally includes receiving, from a network core entity, a request for information about a plurality of network slices in an allowed set of network slices for a user equipment (UE) connected with the network entity; identifying, based on UE capability information for the UE, a subset of the allowed set of network slices that the UE can use for communications between the UE and the network entity; and communicating with the UE using the identified subset of the allowed set of network slices. 
     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 format of a network slice selection assistance information (NSSAI) information element (IE). 
         FIG.  5    is an example format of a single NSSAI (S-NSSAI) IE. 
         FIG.  6    is a table showing example NSSAI inclusion modes. 
         FIG.  7    illustrates example operations that may be performed by a network entity to ensure compatibility between network slice operating frequencies and user equipment (UE) radio capabilities, in accordance with certain aspects of the present disclosure. 
         FIG.  8    illustrates example operations that may be performed by a network core entity to ensure compatibility between network slice operating frequencies and user equipment (UE) radio capabilities, in accordance with certain aspects of the present disclosure. 
         FIG.  9    is a message flow diagram illustrating messages that may be exchanged between a user equipment (UE), network entity, and a network core entity to ensure compatibility between network slice operating frequencies and user equipment (UE) radio capabilities, in accordance with certain aspects of the present disclosure. 
         FIG.  10    is a message flow diagram illustrating messages that may be exchanged between a network entity and a network core entity to ensure network slice operating frequencies and user equipment (UE) radio capabilities, in accordance with certain aspects of the present disclosure. 
         FIG.  11    illustrates an example radio capability check request message used to request information about radio capabilities of a UE, in accordance with certain aspects of the present disclosure. 
         FIG.  12    illustrates an example radio capability check response message used to indicate whether a UE supports communications using a network slice, in accordance with certain aspects of the present disclosure. 
         FIG.  13    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. 
         FIG.  14    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 ensuring compatibility between network slice operating frequencies and user equipment (UE) radio capabilities, in accordance with certain aspects of the present disclosure. 
     The following description provides examples of ensuring compatibility between network slice operating frequencies and user equipment (UE) radio capabilities, 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 (e.g., 80 MHz or beyond), millimeter wave (mmW) targeting high carrier frequency (e.g., 25 GHz or beyond), 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. 
     Certain wireless networks utilize orthogonal frequency division multiplexing (OFDM) on the downlink and single-carrier frequency division multiplexing (SC-FDM) on the uplink. OFDM and SC-FDM partition the system bandwidth into multiple (K) orthogonal subcarriers, which are also commonly referred to as tones, bins, etc. Each subcarrier may be modulated with data. In general, modulation symbols are 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 (K) may be dependent on the system bandwidth. The system bandwidth may also be partitioned into subbands. 
     5G NR may utilize OFDM with a cyclic prefix (CP) on the uplink and downlink and include support for half-duplex operation using time division duplexing (TDD). A subframe can be 1 ms, but the basic transmission time interval (TTI) may be referred to as a slot. A subframe contains a variable number of slots (e.g., 1, 2, 4, 8, 16, . . . slots) depending on the subcarrier spacing (SCS). The NR resource block (RB) may be 12 consecutive frequency subcarriers. NR may support a base SCS of 15 KHz and other subcarrier spacing may be defined with respect to the base SCS, for example, 30 kHz, 60 kHz, 120 kHz, 240 kHz, etc. The symbol and slot lengths scale with the SCS. The CP length also depends on the SCS. 5G NR may also support beamforming and beam direction may be dynamically configured. Multiple-input multiple-output (MIMO) transmissions with precoding may also be supported. In some examples, 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. In some examples, 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 . The core network  132  may in communication with one or more BSs  110  and/or UEs  120  via one or more interfaces as discussed more detail below with respect to  FIG.  3   . 
     As illustrated in  FIG.  1   , the wireless communication network  100  may include a number of base stations (BSs)  110   a - z  (each also individually referred to herein as BS  110  or collectively as BSs  110 ) and other network entities. 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  110   a ,  110   b  and  110   c  may be macro BSs for the macro cells  102   a ,  102   b  and  102   c , respectively. The BS  110   x  may be a pico BS for a pico cell  102   x . The BSs  110   y  and  110   z  may be femto BSs for the femto cells  102   y  and  102   z , respectively. A BS may support one or multiple cells. The BSs  110  communicate with user equipment (UEs)  120   a - y  (each also individually referred to herein as UE  120  or collectively as UEs  120 ) in the wireless communication network  100 . The UEs  120  (e.g.,  120   x ,  120   y , 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  110   r ), 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  110   a  or a UE  120   r ) 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. 
     The wireless communication network  100  may be in communication with the CN  132 , which includes one or more CN nodes  132   a . A network controller  130  may couple to a set of BSs  110  and provide coordination and control for these BSs  110 . The network controller  130  may communicate with the BSs  110  via a backhaul. The network controller  130  may also couple to one or more of the CN nodes  132   a.    
     According to certain aspects, the BSs  110  and core network  132  may be configured to manage network slices assigned to a UE such that compatibility is ensured between network slice operating frequencies and the radio capabilities of the UEs  120  in wireless communication network  100 . As shown in  FIG.  1   , the BS  110   a  includes a network slice manager  112 . The network slice manager  112  may be configured to exchange information with a network core entity (e.g., a core network node  132 ) to ensure compatibility between network slice operating frequencies and the radio capabilities of a UE served by the BS  110   a , in accordance with aspects of the present disclosure. As shown in  FIG.  1   , the core network nodes  132   a  include a network slice manager  134 . The network slice manager  132  may be configured to exchange information with a network entity (e.g., a BS  110 ) to ensure compatibility between network slice operating frequencies and the radio capabilities of a UE served by the BS  110   a , in accordance with aspects of the present disclosure. 
       FIG.  2    illustrates example components of BS  110   a  and UE  120   a  (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  110   a , 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. For example, a base station may transmit a MAC CE to a UE to put the UE into a discontinuous reception (DRX) mode to reduce the UE&#39;s power consumption. 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. A MAC-CE may also be used to communicate information that facilitates communication, such as information regarding buffer status and available power headroom. 
     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), and cell-specific reference signal (CRS). 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)  232   a - 232   t . 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  232   a - 232   t  may be transmitted via the antennas  234   a - 234   t , respectively. 
     At the UE  120   a , the antennas  252   a - 252   r  may receive the downlink signals from the BS  110   a  and may provide received signals to the demodulators (DEMODs) in transceivers  254   a - 254   r , 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  254   a - 254   r , 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  120   a  to a data sink  260 , and provide decoded control information to a controller/processor  280 . 
     On the uplink, at UE  120   a , 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 demodulators in transceivers  254   a - 254   r  (e.g., for SC-FDM, etc.), and transmitted to the BS  110   a . At the BS  110   a , the uplink signals from the UE  120   a  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  120   a . 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  110   a  and UE  120   a , respectively. A scheduler  244  may schedule UEs for data transmission on the downlink and/or uplink. 
     The controller/processor  280  and/or other processors and modules at the UE  120   a  may perform or direct the execution of processes for the techniques described herein. For example, as shown in  FIG.  2   , the controller/processor  240  of the BS  110   a  has a network slice manager  241  that may be configured to ensure compatibility between network slice operating frequencies and UE radio capabilities, according to aspects described herein. Although shown at the controller/processor, other components of the UE  120   a  and BS  110   a  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 3 GPP 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  110   a  in the wireless communication network  100  illustrated in  FIG.  1   ) and/or the UE  322  (e.g., such as the UE  120   a  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 . 
     As mentioned above, aspects of the present disclosure relate to network slice selection assistance information (NSSAI) signalling. 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. 
     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 the 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 respects 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. 
     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 PDU session may belong to one specific network slice instance per PLMN. Different network slice instances may not share a protocol data unit (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 The NSSAI IE identifies a collection of S-NSSAIs.  FIG.  4    is an example format of the NSSAI IE. As shown in  FIG.  4   , 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). 
     The S-NSSAI identifies a network slice. An example format of the S-NSSAI IE is shown in  FIG.  5   . 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 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. 
     In certain systems, such as 5G NR, the NSSAI IE may be exchanged (e.g., between the UE and the network) as part of mobility management procedures. The NSSAI may be sent at both the non-access stratum (NAS) layer and the AS layer. 
     In some examples, the Requested NSSAI IE can be sent in a REGISTRATION REQUEST message, except when triggered by a periodic update. As mentioned above, the Requested NSSAI IE may include up to eight S-NSSAI entries, with a size of up to 74 octets. 
     In some examples, the Allowed NSSAI IE can be sent in a REGISTRATION ACCEPT message, which may be included if the procedure is triggered by a periodic update. As mentioned above, the Allowed NSSAI IE may include up to eighth S-NSSAI entries, with a size of up to 74 octets. 
     In some examples, the Configured NSSAI IE can be sent in a REGISTRATION ACCEPT message. As mentioned above, the Configured NSSAI IE may include up to sixteen S-NSSAI entries, with a size of up to 146 octets. 
     In some examples, the Allowed NSSAI IE and the Configured NSSAI IE can be sent in a CONFIGURATION UPDATE COMMAND message. 
     Thus, the UE NAS layer may provide the lower layers with an NSSAI (either requested NSSAI or allowed NSSAI) when the UE in idle mode sends an initial NAS message. 
     In addition to exchanging NSSAI information at the NAS layer, the UE can be configured to send NSSAI information in the AS layer based on the NSSAI inclusion mode in which it is operating.  FIG.  6    is a table showing example NSSAI inclusion modes, based on which different NSSAI information are provided for different NAS procedures. The network (e.g., via the AMF) may indicate which mode the UE operates in via a NSSAI inclusion mode IE that may be sent in the REGISTRATION ACCEPT message. 
     Example Ensuring Compatibility Between Network Slice Operating Frequencies and User Equipment (UE) Radio Capabilities 
     Aspects of the present disclosure provide techniques for ensuring compatibility between network slice operating frequencies and user equipment (UE) radio capabilities. 
     In some cases, UE radio capability information exchanged between a network entity and a network core entity may include information about networks, network frequencies, and other capabilities that the UE supports. For example this information may include information about a UE power class, frequency bands, and the like. The UE can provide this information to a network entity (e.g., a serving base station), and the network entity can provide this information to a network core entity (e.g., an AMF), and the network core entity can store the UE radio capability information. Generally, the UE may provide this radio capability information during the CMIDLE state for the UE and the RM-REGISTERED state for the UE, and the network core entity can delete this information when the UE radio management (RM) state in the network core entity transitions to RM-DEREGISTERED. 
     The UE may generally provide radio capability information to the network upon request by a network entity or if the radio capabilities changed while the UE was in an idle mode. During a registration request procedure, the UE may not provide the radio capability information if not otherwise solicited when establishing connectivity or sending a registration request message. During a registration process, the network core entity can receive radio capability information from a UE by sending a radio capability match request message to the network entity; however, the network core entity may send the radio capability match request message only in certain situations, such as when the network core entity is attempting to set the IP over Multimedia Subsystem (IMS) voice over packet switched session supported indication. 
     During registration, the network core entity may set the IMS voice over PS session supported indication. To set this indication, the UE may perform a UE capability match request procedure to check the compatibility of the UE and network entity radio capabilities related to IMS voice over PS. If the network core entity has not received the voice support match indicator from the network entity, the network core entity may set the IMS over PS session supported indication and update the indication at a later stage. 
     In both of these cases, the network core entity may only receive, from the network entity, a voice support match indicator indicating whether the UE supports voice over packet switched communications. However, the UE may only support some frequencies that the network can communicate on, but a flag indicating that the UE supports voice over packet switched communications may not indicate which frequencies that the UE can support communications on. Thus, the network core entity may also not be aware of the frequencies on which the UE supports communications and cannot determine whether the network slices selected by the network core entity for the allowed set of network slices matches the UE radio capabilities. Further, because the network core entity may not be able to determine whether the network slices selected by the network core entity for the allowed set of network slices, the network core entity may include network slices associated with incompatible frequencies to the allowed set of network slices. 
       FIG.  7    illustrates example operations  700  that may be performed by a network entity (e.g., a gNodeB, a transmit receive point, a base station, etc.) to ensure compatibility between network slice operating frequencies and user equipment (UE) radio capabilities, in accordance with certain aspects of the present disclosure. As illustrated, operations  700  may begin at block  702 , where the network entity receives, from a network core entity, a request for information about a plurality of network slices in an allowed set of network slices for the UE. The request may be received, for example, as an indication that the network core entity is requesting information about UE support for a particular feature or a request for information about UE support for a particular feature on slices in the allowed set of network slices for the UE. 
     In some aspects, the network entity may receive, from a network core entity, information about an allowed set of network slices for the UE. The information about the allowed set of network slices for the UE may be received in a standalone message from the network core entity or may be included in the request for information about the plurality of network slices received by the network entity at block  702 . As discussed, the information about the allowed set of network slices may include information about network slices on which the UE may communicate, some of which may be network slices that the UE can use for voice communications with the network entity. 
     At block  704 , the network entity identifies, based on UE capability information, a subset of the allowed set of network slices that the UE can use for communications between the UE and the network entity. As discussed in further detail below, the UE capability information may have been previously provided to the network entity upon request by the network entity. In some aspects, the UE capability information may have been previously provided to the network entity when the UE previously attached to the network entity, may be provided to the network entity during the UE attachment process, or the like. 
     In some aspects, the network entity can communicate with the UE based on the identified subset of the allowed set of network slices. For example, the UE may initiate a voice communications session with the network entity on the identified subset of the allowed set of network slices, where the identified subset of network slices in the allowed set of network slices correspond to network slices for which voice communications are supported. More generally, the network entity may communicate with the UE using features supported by the UE on the identified subset of the allowed set of network slices, but may not communicate with the UE using those features on network slices outside of the identified subset of the allowed set of network slices. 
     At block  706 , the network entity generates a response including at least the subset of the allowed set of network slices that the UE can use for communications between the UE and the network entity. 
     At block  708 , the network entity transmits the response to the network core entity. 
       FIG.  8    illustrates example operations  800  that may be performed by a network core entity (e.g., an AMF) to ensure compatibility between network slice operating frequencies and user equipment (UE) radio capabilities, in accordance with certain aspects of the present disclosure. As illustrated, operations  800  may begin at block  802 , where the network core entity transmits, to a network entity, a request for information about a plurality of network slices in an allowed set of network slices for the UE. 
     At block  804 , the network core entity receives, from the network entity, a response including subset of the allowed set of network slices that the UE can use for communications between the UE and the network entity. 
     At block  806 , the network core entity modifies the allowed set of network slices for the UE based on the received response. Generally, in modifying the allowed set of network slices for the UE, the network core entity can identify the subset of network slices that are not included in the received response (e.g., the subset of network slices that are the complement to the subset of the allowed set of network slices included in the received response) and remove this subset from the allowed set of network slices. 
     To ensure compatibility between network slice operating frequencies and UE radio capabilities, the network core entity may provide, to a network entity (e.g., a serving base station), a list of network slices included in the allowed set of network slices. The list of network slices may, for example, identify the frequency band associated with each network slice in the list of network slices, and the network entity can use this frequency band information to determine which network slices are associated with frequency bands that the UE supports and which network slices are associated with frequency bands other than those that the UE supports. As discussed, in response, the network core entity may receive, from the network entity, information identifying the network slices associated with frequency bands that are supported by the UE. Upon receiving this information, the network core entity may modify the allowed set of network slices to include the network slices associated with frequency bands that are supported by the UE and exclude network slices associated with frequency bands that are not supported by the UE from the allowed set of network slices. 
       FIG.  9    illustrates an example capability match request procedure  900  used to ensure compatibility between network slice operating frequencies and user equipment (UE) radio capabilities, in accordance with certain aspects of the present disclosure. Generally, the capability match request procedure  900  may be used to allow the network core entity to set the IMS voice over PS session supported indication and/or identifying matches between network slices in the allowed set of network slices and the network slices supported by the UE on one or more frequency bands. 
     As illustrated, the network core entity (e.g., AMF  906 ) can initiate the capability match request procedure  900  by transmitting, to the network entity (e.g., NG-RAN  904 ) a UE capability match request message  910 . The UE capability match request message  910  may indicate the information that the network core entity is requesting, such as whether the network core entity is requesting the voice support match indicator. The UE capability match request message  910  may also include the allowed set of network slices, which may include the UE NSSAI containing the S-NSSAIs in the allowed set of network slices determined during a UE registration procedure. In some embodiments, the UE capability match request message  910  may further include previously received UE radio capability information. 
     In response to receiving the UE capability match request message  910 , and if the network entity  904  has not already received the UE radio capabilities from the UE  902  or from the network core entity  906 , network entity  904  may transmit a UE capability enquiry message  912  to the UE  902  to request that the UE provide its radio capability information to network entity  904 . Responsive to receiving the UE capability enquire message  912  from network entity  904 , the UE  902  may provide its radio capability information in a UE capability information message  914  transmitted to network entity  904 . 
     After the network entity  904  receives the UE capability information message  914 , network entity  904  may determine whether the UE radio capabilities (e.g., reported by the UE in the UE capability information message) are compatible with the network configuration. For example, in a voice call scenario, if the network core entity  906  requests a voice support match indicator in the capability match request message, the network entity  904  can determine whether the UE radio capabilities are compatible with the network configuration for ensuring voice service continuity of voice calls using IMS PS. To determine the appropriate response to the UE capability match request message, the network entity may be configured to determine whether the UE supports specific capabilities needed for voice continuity of voice calls (e.g., on a per-PLMN basis). For example, the network entity  904  can check the UE capability information for an ability to support voice over packet switched communications (e.g., whether the UE supports one or both of E-UTRAN or NG-RAN voice over packet switched communications), radio capabilities for frequency domain duplexing and/or time domain duplexing, supported frequency bands (e.g., for one or both of an E-UTRAN network or an NG-RAN network), support for single radio voice call continuity (SRVCC) from a network supporting a first radio access technology to a network supporting a second radio access technology and support for frequency bands used by the network supporting the second radio access technology, and the like. 
     In some embodiments, the network core entity  906  may provide, to the network entity  904 , the allowed set of network slices for the UE in the UE capability match request message. If the allowed set of network slices for the UE (e.g., the Allowed NSSAI) is provided to the network entity  904 , the network entity  904  may determine whether frequencies supported for or otherwise associated with each network slice (e.g., each S-NSSAI) is compatible with the UE radio capabilities based on the UE capability information provided to the network entity  904 , discussed above. The network entity  904  may thus identify a subset of network slices in the allowed set of network slices for the UE that the UE is compatible with and report the identified subset of network slices to the network core entity  906  in the UE capability match response message  916  (e.g., in a Supported NSSAI information element in the UE capability match response message). 
     In some embodiments, if the network entity  904  has requested radio capability information from the UE (e.g., in a situation where the UE has not previously reported such information to the network entity or to the network core entity), the network entity  904  may send the UE radio capability information to the network core entity in UE radio capability information indication message  918 . The network core entity may store information about the UE radio capabilities for further provision to a network entity. 
       FIG.  10    is a call flow diagram illustrating a UE radio capability check procedure used by a network core entity to request that a network entity identifies and informs the network core entity whether the UE radio capabilities are compatible with a network configuration. 
     As illustrated, the network core entity  1004  may initiate the procedure by transmitting a UE radio capability check request message  1010  to the network entity  1002 . The UE radio capability may include one or both of an indication of whether the network core entity  1004  is requesting a voice support match indicator or UE NSSAI information (e.g., including information about the allowed set of network slices for the UE). If the UE radio capability check message includes an indication that the network entity is requesting a voice support match indicator, the network entity can determine whether the UE radio capabilities are compatible with the network configuration for IMS voice communications. The UE radio capability check response message  1012  transmitted in response to receiving the UE radio capability check request message  1010  may include the voice support match indicator, and the value of the voice support match indicator may correspond to a first value if the UE is compatible with the network configuration or a second value if the UE is not compatible with the network configuration. 
     If the UE radio capability check request message includes the UE NSSAI (e.g., information about the allowed set of network slices), the network entity  1002  can determine whether the UE radio capabilities are compatible with the frequencies supported for or otherwise associated with each network slice in the allowed set of network slices. The UE radio capability check response message transmitted in response to receiving the UE radio capability check request message may include information (e.g., in a Supported NSSAI information element) identifying the network slices that the UE is compatible with. For example, the information identifying these network slices may be transmitted as a bitmap, a list of compatible network slices, etc. 
       FIG.  11    illustrates an example UE radio capability check request message  1100 , in accordance with certain aspects of the present disclosure. As discussed above, the UE radio capability check request message  1100  may be transmitted by a network core entity (e.g., an AMF) to request that a network entity (e.g., a base station, gNodeB, transmit receive point (TRP), etc.) check compatibility between UE radio capabilities and a network configuration. As illustrated, a UE NSSAI information element, which may be an optional information element, may be included in the UE radio capability check quest. The UE NSSAI information element may include the allowed set of network slices that the network core entity has identified for the UE. Upon receipt of a UE radio capability check request message  1100  including the UE NSSAI information element, the network entity may proceed to determine whether radio capabilities of the UE for which the UE radio capability check request message  1100  is transmitted is compatible with the network configuration (e.g., operating frequencies of the network slices identified in the UE NSSAI information element. 
       FIG.  12    illustrates an example UE radio capability check response message  1200 , in accordance with certain aspects of the present disclosure. As discussed above, the UE radio capability check response message  1200  may be transmitted by a network entity in response to receiving a UE radio capability check request message  1100  illustrated in  FIG.  11    from the network core entity. As illustrated, the UE radio capability check response message  1200  includes a Supported NSSAI information element. The Supported NSSAI information element may be an optional information element that may be included in the UE radio capability check response message  1200  if the UE NSSAI information element is included in the corresponding UE radio capability check request message  1100  and may be excluded from the UE radio capability check response message  1200  otherwise. As discussed, the Supported NSSAI information element may carry information identifying the network slices with which the UE is compatible. A receiving network core entity may use the information carried in the Supported NSSAI information element to modify the allowed set of network slices for the UE (e.g., to remove network slices that are incompatible with the UE from the allowed set of network slices). 
       FIG.  13    illustrates a communications device  1300  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.  7   . The communications device  1300  includes a processing system  1302  coupled to a transceiver  1308  (e.g., a transmitter and/or a receiver). The transceiver  1308  is configured to transmit and receive signals for the communications device  1300  via an antenna  1310 , such as the various signals as described herein. The processing system  1302  may be configured to perform processing functions for the communications device  1300 , including processing signals received and/or to be transmitted by the communications device  1300 . 
     The processing system  1302  includes a processor  1304  coupled to a computer-readable medium/memory  1312  via a bus  1306 . In certain aspects, the computer-readable medium/memory  1312  is configured to store instructions (e.g., computer-executable code) that when executed by the processor  1304 , cause the processor  1304  to perform the operations illustrated in  FIG.  7   , or other operations for performing the various techniques discussed herein for ensuring compatibility between network slice operating frequencies and UE radio capabilities. In certain aspects, computer-readable medium/memory  1312  stores code  1314  for receiving, from a network core entity, a request for information about a plurality of network slices in an allowed set of network slices for the UE, code  1316  for identifying, based on UE capability information, a subset of the allowed set of network slices that the UE can use for communications between the UE and the network entity, code  1318  for generating a response including at least the subset of the allowed set of network slices, and code  1320  for transmitting the response, in accordance with aspects of the disclosure. In certain aspects, the processor  1304  has circuitry configured to implement the code stored in the computer-readable medium/memory  1312 . The processor  1304  includes circuitry  1322  for receiving, from a network core entity, a request for information about a plurality of network slices in an allowed set of network slices for the UE, circuitry  1324  for identifying, based on UE capability information, a subset of the allowed set of network slices that the UE can use for communications between the UE and the network entity, circuitry  1326  for generating a response including at least the subset of the allowed set of network slices, and circuitry  1328  for transmitting the response, in accordance with aspects of the disclosure. 
       FIG.  14    illustrates a communications device  1400  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.  8   . The communications device  1400  includes a processing system  1402  coupled to a transceiver  1408  (e.g., a transmitter and/or a receiver). The transceiver  1408  is configured to transmit and receive signals for the communications device  1400  via an antenna  1410 , such as the various signals as described herein. The processing system  1402  may be configured to perform processing functions for the communications device  1400 , including processing signals received and/or to be transmitted by the communications device  1400 . 
     The processing system  1402  includes a processor  1404  coupled to a computer-readable medium/memory  1412  via a bus  1406 . In certain aspects, the computer-readable medium/memory  1412  is configured to store instructions (e.g., computer-executable code) that when executed by the processor  1404 , cause the processor  1404  to perform the operations illustrated in  FIG.  8   , or other operations for performing the various techniques discussed herein for ensuring compatibility between network slice operating frequencies and UE radio capabilities. In certain aspects, computer-readable medium/memory  1412  stores code  1414  for transmitting, to a network entity, a request for information about a plurality of network slices in an allowed set of network slices for the UE, code  1416  for receiving, from the network entity, a response including a subset of the allowed set of network slices that the UE can use for communications between the UE and the network entity, and code  1418  for modifying the allowed set of network slices based on the received response, in accordance with aspects of the disclosure. In certain aspects, the processor  1404  has circuitry configured to implement the code stored in the computer-readable medium/memory  1412 . The processor  1404  includes circuitry  1420  for transmitting, to a network entity, a request for information about a plurality of network slices in an allowed set of network slices for the UE, circuitry  1422  for receiving, from the network entity, a response including a subset of the allowed set of network slices that the UE can use for communications between the UE and the network entity, and circuitry  1424  for modifying the allowed set of network slices based on the received response, in accordance with aspects of the disclosure. 
     Example Clauses 
     Clause 1: A method for wireless communications by a network entity, comprising: receiving, from a network core entity, a request for information about a plurality of network slices in an allowed set of network slices for a user equipment (UE) connected with the network entity; identifying, based on UE capability information for the UE, a subset of the allowed set of network slices that the UE can use for communications between the UE and the network entity; generating a response including at least the subset of the allowed set of network slices that the UE can use for communications between the UE and the network entity; and transmitting the response to the network core entity. 
     Clause 2: The method of Clause 1, further comprising: communicating with the UE using at least the subset of the allowed set of network slices. 
     Clause 3: The method of any one of Clauses 1 or 2, wherein the UE comprises a UE for which a registration process is currently being performed. 
     Clause 4: The method of any one of Clauses 1 through 3, wherein the request for information about capabilities of the UE comprises an indication that the network core entity is requesting information about UE support for a particular feature on slices in the allowed set of network slices for the UE. 
     Clause 5: The method of Clause 4, wherein the indication that the network core entity is requesting information about the allowed set of network slices for the UE comprises an indication that the network core entity is requesting a voice support match indicator. 
     Clause 6: The method of any one of Clauses 1 through 5, wherein the response comprises: a first message including an indication of whether the UE supports a particular feature, and a second message including the subset of the allowed set of network slices that the UE can use for communications between the UE and the network entity using the particular feature. 
     Clause 7: The method of any one of Clauses 1 through 6, further comprising: requesting, from the UE, the UE capability information; and receiving the UE capability information from the UE. 
     Clause 8: The method of Clause 7, wherein the UE capability information comprises one or more of: frequencies that the UE supports communications on for one or more radio access technologies (RATs); or radio capabilities for one or both of frequency division duplexing or time domain duplexing. 
     Clause 9: The method of any one of Clauses 1 through 8, wherein identifying the subset of the allowed set of network slices that the UE can use for communications between the UE and the network entity comprises identifying, from the plurality of network slices in the allowed set of network slices, network slices associated with frequencies supported by the UE. 
     Clause 10: A method for wireless communications by a network core entity, comprising: transmitting, to a network entity, a request for information about a plurality of network slices in an allowed set of network slices for a user equipment (UE); receiving, from the network entity, a response including a subset of the allowed set of network slices that the UE can use for communications between the UE and the network entity; and modifying the allowed set of network slices for the UE based on the received response. 
     Clause 11: The method of Clause 10, wherein the UE comprises a UE for which a registration process is currently being performed. 
     Clause 12: The method of any one of Clauses 10 or 11, wherein the request for information about capabilities of the UE includes a request for information about UE support for a particular feature on slices in the allowed set of network slices. 
     Clause 13: The method of Clause 12, wherein the request for information about the allowed set of network slices comprises a voice support match indicator. 
     Clause 14: The method of any one of Clauses 10 through 13, wherein the response comprises: a first message including an indication of whether the UE supports a particular feature, and a second message including the subset of the allowed set of network slices that the UE can use for communications between the UE and the network entity using the particular feature. 
     Clause 15: The method of any one of Clauses 10 through 14, wherein the subset of the allowed set of network slices that the UE can use for communications between the UE and the network entity comprises network slices associated with frequencies supported by the UE. 
     Clause 16: A method for wireless communications by a network entity, comprising: receiving, from a network core entity, information about a plurality of network slices in an allowed set of network slices for a user equipment (UE) connected with the network entity; identifying, based on UE capability information for the UE, a subset of the allowed set of network slices that the UE can use for communications between the UE and the network entity; and communicating with the UE using one or more slices in the identified subset of the allowed set of network slices. 
     Clause 17: The method of Clause 16, wherein the UE comprises a UE for which a registration process is currently being performed. 
     Clause 18: The method of any one of Clauses 16 or 17, further comprising: generating a response including at least the subset of the allowed set of network slices that the UE can use for communications between the UE and the network entity; and transmitting the response to the network core entity. 
     Clause 19: The method of Clause 18, wherein the response comprises: a first message including an indication of whether the UE supports a particular feature, and a second message including the subset of the allowed set of network slices that the UE can use for communications between the UE and the network entity using the particular feature. 
     Clause 20: The method of any one of Clauses 16 through 19, further comprising: requesting, from the UE, the UE capability information; and receiving the UE capability information from the UE. 
     Clause 21: The method of any one of Clauses 16 through 20, wherein identifying the subset of the allowed set of network slices that the UE can use for communications between the UE and the network entity comprises identifying, from the plurality of network slices in the allowed set of network slices, network slices associated with frequencies supported by the UE. 
     Clause 22: A system, comprising: a memory having executable instructions stored thereon; and a processor configured to execute the executable instructions to perform the operations of any one of Clauses 1 through 21. 
     Clause 23: A system, comprising: means for performing the operations of any one of Clauses 1 through 21. 
     Clause 24: A computer-readable medium having instructions stored thereon which, when executed by a processor, performs the operations of any one of Clauses 1 through 21. 
     Additional Considerations 
     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 Blu-ray® 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.  7    and/or  FIG.  8   . 
     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.