WO2022036542A1

WO2022036542A1 - Slice-aware cell selection and reselection based on broadcast system information

Info

Publication number: WO2022036542A1
Application number: PCT/CN2020/109728
Authority: WO
Inventors: Peng Cheng
Original assignee: Qualcomm Incorporated
Priority date: 2020-08-18
Filing date: 2020-08-18
Publication date: 2022-02-24

Abstract

Aspects of the present disclosure provide apparatus, methods, processing systems, and computer readable mediums for slice aware network selection. An example method generally includes receiving a system information block (SIB) including network slice information indicating one or more slice identifiers supported by one or more cells of a network; identifying a frequency priority list based on the network slice information and a set of desired services; and performing cell selection or reselection based on the frequency priority list.

Description

SLICE-AWARE CELL SELECTION AND RESELECTION BASED ON BROADCAST SYSTEM INFORMATION

BACKGROUND

Field of the Disclosure

Aspects of the present disclosure relate to wireless communications, and more particularly, to techniques for selecting a network based, at least in part, on network slice information broadcast by a network.

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 improved network slice selection assistance information (NSSAI) signaling.

One innovative aspect of the subject matter described in this disclosure can be implemented in a method for wireless communication by a user equipment (UE) . The method generally includes receiving a system information block (SIB) including network slice information indicating one or more slice identifiers supported by one or more cells of a network; identifying a frequency priority list based on the network slice information and a set of desired services; and performing cell selection or reselection based on the frequency priority list.

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 determining slice information indicating one or more slice identifiers supported by one or more cells of a network; and sending a system information block (SIB) including the network slice information.

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 is a call flow illustrating example NSSAI signaling.

FIG. 8 illustrates example operations for slice-aware cell selection and/or reselection by a user equipment (UE) , in accordance with certain aspects of the present disclosure.

FIG. 9 illustrates example operations for supporting slice-aware cell selection and/or reselection by a network entity, in accordance with certain aspects of the present disclosure.

FIG. 10 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. 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 slice aware cell selection and/or reselection. As will be described in greater detail below, cell selection and/or reselection may be performed based, at least in part, on network slice information broadcast by a network entity in one or more system information blocks (SIBs) .

The following description provides examples 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, one or more UEs 120 may be configured to perform slice-aware cell selection and/or reselection (in accordance with operations 800 of FIG. 8) , and one or more base stations 110 may be configured to perform operations to support slice-aware cell selection and/or reselection (in accordance with operations 900 of FIG. 9) .

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 B Ss 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) 110a-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

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 user equipment (UEs) 120a-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., 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.

The wireless communication network 100 may be in communication with the CN 132, which includes one or more CN nodes 132a. 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 132a.

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. 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’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) 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 demodulators 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.

The controller/processor 280 and/or other processors and modules at the UE 120a may perform or direct the execution of processes for the techniques described herein. 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.

As mentioned above, aspects of the present disclosure relate to network slice selection assistance information (NSSAI) signaling. 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.

After initial registration, the UE 702 includes the Requested NSSAI IE in the REGISTRATION REQUEST message to the AMF 704, except when the procedure is triggered for a periodic update. Also, the Requested NSSAI IE is included in the NAS message during initial registration even if the UE already has a configured NSSAI or an allowed NSSAI from a previous registration. The Requested NSSAI IE (which can be up to 74 octets long) may be considered duplicated if the UE is operating in NSSAI inclusion mode A or B for which the same information is provided via the AS layer. FIG. 7 is a call flow 700 illustrating example NSSAI signaling. As shown in FIG. 7, NSSAI signaling overhead can be occurred during initial attachment (e.g., such as in registration request messages 710 and registration accept messages 708, 712) , during a configuration update (e.g., such as in configuration update commands 714) , and/or during PDU session establishment (e.g., such as in UL NAS transport messages 718 and PDU session accept messages 722) .

Thus, the NSSAI signaling may be large, involving high overhead. Further, lower layers may be configured to repeat a transmission many times, leading to further overhead, and an increase in UE power consumption. The large overhead, and increased power consumption, may be undesirable for Internet-of-Things (IoT) devices, and especially so for narrowband IoT (NB-IoT) devices.

Accordingly, what is needed are techniques and apparatuses for signaling NSSAI with reduced overhead for cell selection and/or reselection.

Example Slice-Aware Cell Selection and Cell Reselection Based on Broadcast System Information

Aspects of the present disclosure provide apparatus, methods, processing systems, and computer readable mediums for slice-aware cell selection and/or reselection. As will be described in greater detail below, slice-aware cell selection and/or reselection may be performed based on network slice information (e.g., S-NSSAI information) communicated to a UE via one or more system information blocks (SIBs) .

Generally, network slices may be negotiated during the non-access stratum (NAS) registration procedure. A set of allowed network slices (e.g., NSSAIs) negotiated during the NAS registration procedure may include a minimal common set of requested NSSAIs, default S-NSSAIs if no valid S-NSSAIs are requested, subscribed NSSAIs, and/or a current tracking area identity (TAI) supported NSSAI. In some aspects, an autonomous system (AS) -requested NSSAI included in a radio resource control (RRC) message sent to a network entity as part of a registration procedure may be used for access and mobility function (AMF) selection and may be a subset of a NAS requested NSSAI, as the RRC message sent to the network entity may not include security protection.

For cell reselection with network slicing, indirect UE dedicated priority may be supported via the RRC release message. A network entity may assign a dedicated priority list based on an allowed NSSAI, and UE cell selection based on the dedicated priority list may indirectly achieve slice-based cell reselection. However, a UE may attempt to access a slice that is not included in the allowed NSSAI, and cell selection and/or reselection methods may not be able to aid a UE in accessing an appropriate slice. Further, because the dedicated priority list for a UE may be conveyed to a UE via an RRC release message (i.e., a message received when a UE is in a connected mode to initiate the release of an RRC connection) , slice selection and prioritization may not be applied to UEs when these UEs attempt cell selection or reselection from an idle state. Still further, the dedicated frequency priority list included in an RRC release message may be released when a timer expires.

Many network slices may be supported in a cell. Because each UE may support up to eight slices, and multiple slices and many frequencies may be supported in a cell, there may be a large number of slices within any cell. Thus, it may not be practical to broadcast network slice information in existing system information blocks (SIBs) , as the information about the supported network slices in a network may be larger than a size of an existing SIB.

FIG. 8 illustrates example operations 800 that may be performed by a user equipment (UE) to perform cell selection and/or reselection based on network slice information included in one or more SIBs. Operations 800 may be performed, for example, by a UE 120 illustrated in FIG. 1.

As illustrated, operations 800 begin at block 802, where the UE receives a system information block (SIB) including network slice information indicating one or more slice identifiers supported by one or more cells of a network.

At block 804, the UE identifies a frequency priority list based on the network slice information and a set of desired services.

At block 806, the UE performs cell selection or reselection based on the frequency priority list.

FIG. 9 illustrates example operations 900 that may be performed by a network entity in a network to facilitate cell selection and/or reselection based on network slice information included in one or more SIBs. Operations 900 may be performed, for example, by a base station 110 illustrated in FIG. 1 or other infrastructure components in a wireless network.

As illustrated, operations 900 begin at block 902, where the network entity determines slice information indicating one or more slice identifiers supported by one or more cells of a network.

At block 904, the network entity sends a system information block (SIB) including the network slice information.

Generally, the network may broadcast supported S-NSSAIs in a new SIB, and the UE may perform cell selection and/or reselection based on the network slice information (e.g., the supported S-NSSAIs) in the SIB and non-access stratum (NAS) information. A UE may determine a frequency priority list including frequencies that support the requested S-NSSAI (s) from the SIB and NAS information. Based on this frequency priority list, the UE can perform cell selection and/or reselection and transmit, via a UE assistance information message, a slicing interest indication including network slice information (e.g., a list of frequencies and associated S-NSSAIs) to the network after entering an RRC connected state.

Network entities may broadcast intra-frequency and inter-frequency supported S-NSSAIs in the new SIB. As discussed in further detail below, the new SIB may be segmented and transmitted on demand to reduce overhead involved in performing cell selection and/or reselection based on network slice information included in SIBs. When the network entity receives the slicing interest indication (e.g., during cell selection and/or reselection) , the receiving network entity may forward the slicing interest indication to a target network entity (e.g., gNodeB) as part of access stratum (AS) context information exchanged during handover. By forwarding the slicing interest indication to the target network entity, the radio access network (RAN) may be aware of the full set of allowed NSSAIs, and the network may attempt to ensure service continuity during UE mobility.

As discussed, network entities in a network may broadcast supported S-NSSAIs in a new SIB. To reduce overhead, the new SIB may be segmented into a plurality of segments, and the new SIB may be broadcast on demand by the network. Network entities in the network may indicate whether the new SIB is broadcast on demand using an indication in a system information block broadcast by the serving cell. This indication may be, for example, a one-bit indication in SIB1 that UEs can use to determine whether to monitor for SIBs transmitted on demand (i.e., SIBs broadcast outside of typical locations at which an SIB would be transmitted) .

In some aspects, the new SIB may include information about supported S-NSSAIs in a frequency that is the same as a frequency of a cell serving the UE (i.e., may include only intra-frequency slicing information) . The NAS may provide mappings of network slices (e.g., S-NSSAIs) to frequencies in order of a slicing priority for the UE. In another example, the new SIB may include information for supported intra-frequency and inter-frequency network slices (e.g., S-NSSAIs) . For intra-frequency S-NSSAIs, the SIB may include a list of supported S-NSSAIs on the frequency of a primary cell (PCell) for the UE. For inter-frequency S-NSSAIs, the SIB may include a list associating each of a plurality of channels (e.g., identified by absolute radio frequency channel numbers (ARFCNs) ) with supported S-NSSAIs. In another example, for inter-frequency S-NSSAIs, the SIB may include a list of S-NSSAIs associated with at least a list of supported channels (e.g., ARFCNs) ) . Each of the supported channels for a specific S-NSSAI may also be associated with a frequency priority value.

The UE may determine its frequency priority in a variety of manners. In one example, the NAS may provide a mapping of S-NSSAIs to frequencies in order of a slicing priority of the UE. The UE may then examine information in an SSB broadcast by a new cell (e.g., a candidate cell with which the UE is to perform cell selection and/or reselection) to determine whether the new cell provides the correct S-NSSAI or other supported services. In another example, the NAS may provide each UE with dedicated slice priority information for the UE. The new SIB may, in some aspects, provide network slice information in a list in which each of a plurality of channels (e.g., ARFCNs) is associated with a list of S-NSSAIs. The new SIB may, in some aspects, provide network slice information in a list in which each of a plurality of network slices (e.g., S-NSSAIs) is associated with supported channels (e.g., ARFCNs) and, in some aspects, frequency priority information.

If a UE determines, during a cell selection and/or reselection procedure, that one frequency provides all services that a UE is interested in (e.g., one frequency supports all of the S-NSSAIs or other services requested by a UE) , the UE may prioritize the one frequency for cell selection and/or reselection. If more than one frequency provides all services that the UE is interested in, the frequencies that provide all services that the UE is interested in may be prioritized based on the priority of a frequency corresponding to a slice with a highest slice priority.

If, however, a UE determines that no frequency provides all services that the UE is interested in, the UE may prioritize the frequencies based on the number of available slices with the highest priorities. For example, assume that a UE has prioritized four network slices in order of slice 1, slice 2, slice 3, and slice 4. If Frequency 1 provides

slices

1, 3, and 4; Frequency 2 provides

slices

2, 3, and 4; and Frequency 3 provides

slices

1 and 4, the UE can prioritize cell selection and/or reselection to cells supporting Frequency 1, since Frequency 1 supports the slice with the highest priority (i.e., slice 1) and more slices with a lower priority than Frequency 3. In some aspects, frequencies may be prioritized based on a frequency priority corresponding to a slice with the highest priority.

After the UE enters an RRC connected state (e.g., after cell selection and/or reselection) , the UE can transmit slicing interest indication information to the network via a UE Assistance Information message. The slicing interest indication may include the interested frequency list for a UE and the associated S-NSSAIs for the interested frequency or frequencies. The slicing interest indication may be formatted as a list of channels (e.g., ARFCNs) mapped to a list of S-NSSAIs supported by each channel, and a list of slice priority information. When a UE moves, the RAN may not be aware of the full list of allowed S-NSSAIs for the UE. The list of allowed S-NSSAIs may be a capability coordination outcome with the UE’s requested S-NSSAIs and the network’s supported S-NSSAIs, and the list of allowed S-NSSAIs may change as the UE moves. A source cell may forward the slicing interest indication to a target network entity (e.g., gNodeB) during a handover procedure as part of access stratum (AS) context information exchanged between source and target network entities.

FIG. 10 illustrates a communications device 1000 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 1000 includes a processing system 1002 coupled to a transceiver 1008. The transceiver 1008 is configured to transmit and receive signals for the communications device 1000 via an antenna 1010, such as the various signals as described herein. The processing system 1002 may be configured to perform processing functions for the communications device 1000, including processing signals received and/or to be transmitted by the communications device 1000.

The processing system 1002 includes a processor 1004 coupled to a computer-readable medium/memory 1012 via a bus 1006. In certain aspects, the computer-readable medium/memory 1012 is configured to store instructions (e.g., computer-executable code) that when executed by the processor 1004, cause the processor 1004 to perform the operations illustrated in FIG. 8, or other operations for performing the various techniques discussed herein for performing slice-aware cell reselection based on broadcast system information. In certain aspects, computer-readable medium/memory 1012 stores code for receiving a system information block (SIB) including network slice information indicating one or more slice identifiers supported by one or more cells of a network, code for identifying a frequency priority list based on the network slice information and a set of desired services 1016, and code for performing cell selection or reselection based on the frequency priority list 1018. In certain aspects, the processor 1004 has circuitry configured to implement the code stored in the computer-readable medium/memory 1012. The processor 1004 includes circuitry for receiving a system information block (SIB) including network slice information indicating one or more slice identifiers supported by one or more cells of a network 1020, circuitry for identifying a frequency priority list based on the network slice information and a set of desired services 1022, and circuitry for performing cell reselection based on the frequency priority list 1024.

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. 9. The communications device 1100 includes a processing system 1102 coupled to a transceiver 1108. The transceiver 1108 is configured to transmit and receive signals for the communications device 1100 via an antenna 1110, 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. 9, or other operations for performing the various techniques discussed herein for supporting slice-aware cell reselection based on broadcast system information. In certain aspects, computer-readable medium/memory 1112 stores code for determining slice information indicating one or more slice identifiers supported by one or more cells of a network 1114, and code for sending a system information block (SIB) including the network slice information 1116. 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 for determining slice information indicating one or more slice identifiers supported by one or more cells of a network 1120, and circuitry for sending a system information block (SIB) including the network slice information 1122.

Example Embodiments

Embodiment 1: A method for wireless communications by a user equipment (UE) , comprising: receiving a system information block (SIB) including network slice information indicating one or more slice identifiers supported by one or more cells of a network, identifying a frequency priority list based on the network slice information and a set of desired services, and performing cell selection or reselection based on the frequency priority list.

Embodiment 2: The method of Embodiment 1, further comprising: sending UE assistance information indicating slicing interest of the UE to the network.

Embodiment 3: The method of Embodiment 2, wherein the indication comprises an indication of an interested frequency list and associated single network slice selection assistance informations (S-NSSAIs) .

Embodiment 4: The method of Embodiment 3, wherein the indication comprises an indication of slicing priority among the S-NSSAIs.

Embodiment 5: The method of any of Embodiments 1 to 4, wherein the SIB comprises a segmented SIB including a portion of the slice identifiers supported by one or more cells of the network.

Embodiment 6: The method of any of Embodiments 1 to 5, further comprising: transmitting, to a network entity in the network, a request for network slice information, wherein the SIB is received in response to the request for network slice information.

Embodiment 7: The method of Embodiment 6, wherein the request for network slice information is transmitted based on system information from the network entity indicating that the SIB is transmitted on demand.

Embodiment 8: The method of any of Embodiments 1 to 7, wherein the SIB comprises information about supported single network slice selection informations (S-NSSAIs) in a serving frequency.

Embodiment 9: The method of any of Embodiments 1 to 8, wherein the SIB comprises information about inter-frequency and intra-frequency single network slice selection informations (S-NSSAIs) supported in the network.

Embodiment 10: The method of Embodiment 9, wherein the information about intra-frequency S-NSSAIs slices comprises information identifying S-NSSAIs operating on a frequency on which the UE is communicating.

Embodiment 11: The method of Embodiments 9 or 10, wherein the information about inter-frequency S-NSSAIs comprises a list of supported S-NSSAIs for each of a plurality of radio frequency channels.

Embodiment 12: The method of any of Embodiments 9 to 11, wherein the information about inter-frequency S-NSSAIs comprises supported radio frequency channels for each S-NSSAI of the S-NSSAIs supported by a network entity.

Embodiment 13: The method of Embodiment 12, wherein the information further includes a frequency priority for each supported radio frequency channel.

Embodiment 14: The method of any of Embodiments 1 to 13, further comprising: determining the frequency priority based on a mapping between S-NSSAIs and frequencies ordered by slicing priority.

Embodiment 15: The method of any of Embodiments 1 to 14, further comprising: receiving, from a network entity in the network, information related to the frequency priority, wherein the information related to the frequency priority comprises a dedicated slicing priority for the UE.

Embodiment 16: The method of any of Embodiments 1 to 15, wherein performing cell selection or reselection comprises: identifying one or more frequencies that support a requested service; and selecting or reselecting to cells operating on one of the identified one or more frequencies.

Embodiment 17: The method of Embodiment 16, wherein selecting or reselecting to cells on one of the identified one or more frequencies comprises: determining that a plurality of frequencies support the requested service; and selecting one of the plurality of frequencies based on a frequency associated with an S-NSSAI having a highest priority of the requested S-NSSAIs.

Embodiment 18: The method of any of Embodiments 1 to 17, wherein performing cell selection or reselection comprises: prioritizing frequencies based on a number of slices with highest priorities that each frequency of a plurality of frequencies supports; and selecting a frequency of the plurality of frequencies having a highest priority.

Embodiment 19: A method for wireless communications by a network entity, comprising: determining slice information indicating one or more slice identifiers supported by one or more cells of a network; and sending a system information block (SIB) including the network slice information.

Embodiment 20: The method of Embodiment 19, further comprising: receiving, from a user equipment (UE) , UE assistance information indicating slicing interest of the UE.

Embodiment 21: The method of Embodiment 20, wherein the indication comprises an indication of an interested frequency list and associated single network slice selection assistance informations (S-NSSAIs) for the UE.

Embodiment 22: The method of Embodiment 21, wherein the indication comprises an indication of slicing priority among the S-NSSAIs for the UE.

Embodiment 23: The method of any of Embodiments 19 to 22, wherein the SIB comprises a segmented SIB including a portion of the slice identifiers supported by one or more cells of the network.

Embodiment 24: The method of any of Embodiments 19 to 23, further comprising: receiving, from a user equipment, a request for network slice information, wherein the SIB is sent in response to the request for network slice information.

Embodiment 25: The method of Embodiment 24, wherein the request for network slice information is received based on system information broadcast by the network entity indicating that the SIB is transmitted on demand.

Embodiment 26: The method of any of Embodiments 19 to 25, wherein the SIB comprises information about supported single network slice selection informations (S-NSSAIs) in a serving frequency.

Embodiment 27: The method of any of Embodiments 19 to 26, wherein the SIB comprises information about inter-frequency and intra-frequency single network slice selection informations (S-NSSAIs) supported in the network.

Embodiment 28: The method of Embodiment 27, wherein the information about intra-frequency S-NSSAIs slices comprises information identifying S-NSSAIs operating on a frequency on which the UE is communicating.

Embodiment 29: The method of Embodiments 27 or 28, wherein the information about inter-frequency S-NSSAIs comprises a list of supported S-NSSAIs for each of a plurality of radio frequency channels.

Embodiment 30: The method of any of Embodiments 27 to 29, wherein the information about inter-frequency S-NSSAIs comprises supported radio frequency channels for each S-NSSAI of the S-NSSAIs supported by the network entity.

Embodiment 31: The method of Embodiment 30, wherein the information further includes a frequency priority for each supported radio frequency channel.

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

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. 8 and/or FIG. 9.

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 communications by a user equipment (UE) , comprising:

receiving a system information block (SIB) including network slice information indicating one or more slice identifiers supported by one or more cells of a network;

identifying a frequency priority list based on the network slice information and a set of desired services; and

performing cell selection or reselection based on the frequency priority list.
The method of claim 1, further comprising:

sending UE assistance information indicating slicing interest of the UE to the network.
The method of claim 2, wherein the indication comprises an indication of an interested frequency list and associated single network slice selection assistance informations (S-NSSAIs) .
The method of claim 3, wherein the indication comprises an indication of slicing priority among the S-NSSAIs.
The method of claim 1, wherein the SIB comprises a segmented SIB including a portion of the slice identifiers supported by one or more cells of the network.
The method of claim 1, further comprising:

transmitting, to a network entity in the network, a request for network slice information, wherein the SIB is received in response to the request for network slice information.
The method of claim 6, wherein the request for network slice information is transmitted based on system information from the network entity indicating that the SIB is transmitted on demand.
The method of claim 1, wherein the SIB comprises information about supported single network slice selection informations (S-NSSAIs) in a serving frequency.
The method of claim 1, wherein the SIB comprises information about inter-frequency and intra-frequency single network slice selection informations (S-NSSAIs) supported in the network.
The method of claim 9, wherein the information about intra-frequency S-NSSAIs slices comprises information identifying S-NSSAIs operating on a frequency on which the UE is communicating.
The method of claim 9, wherein the information about inter-frequency S-NSSAIs comprises a list of supported S-NSSAIs for each of a plurality of radio frequency channels.
The method of claim 9, wherein the information about inter-frequency S-NSSAIs comprises supported radio frequency channels for each S-NSSAI of the S-NSSAIs supported by a network entity.
The method of claim 12, wherein the information further includes a frequency priority for each supported radio frequency channel.
The method of claim 1, further comprising:

determining the frequency priority based on a mapping between S-NSSAIs and frequencies ordered by slicing priority.
The method of claim 1, further comprising:

receiving, from a network entity in the network, information related to the frequency priority, wherein the information related to the frequency priority comprises a dedicated slicing priority for the UE.
The method of claim 1, wherein performing cell selection or reselection comprises:

identifying one or more frequencies that support a requested service; and

selecting or reselecting to cells operating on one of the identified one or more frequencies.
The method of claim 16, wherein selecting or reselecting to cells on one of the identified one or more frequencies comprises:

determining that a plurality of frequencies support the requested service; and

selecting one of the plurality of frequencies based on a frequency associated with an S-NSSAI having a highest priority of requested S-NSSAIs.
The method of claim 1, wherein performing cell selection or reselection comprises:

prioritizing frequencies based on a number of slices with highest priorities that each frequency of a plurality of frequencies supports; and

selecting a frequency of the plurality of frequencies having a highest priority.
A method for wireless communications by a network entity, comprising:

determining slice information indicating one or more slice identifiers supported by one or more cells of a network; and

sending a system information block (SIB) including the network slice information.
The method of claim 19, further comprising:

receiving, from a user equipment (UE) , UE assistance information indicating slicing interest of the UE.
The method of claim 20, wherein the indication comprises an indication of an interested frequency list and associated single network slice selection assistance informations (S-NSSAIs) for the UE.
The method of claim 21, wherein the indication comprises an indication of slicing priority among the S-NSSAIs for the UE.
The method of claim 19, wherein the SIB comprises a segmented SIB including a portion of the slice identifiers supported by one or more cells of the network.
The method of claim 19, further comprising:

receiving, from a user equipment, a request for network slice information, wherein the SIB is sent in response to the request for network slice information.
The method of claim 24, wherein the request for network slice information is received based on system information broadcast by the network entity indicating that the SIB is transmitted on demand.
The method of claim 19, wherein the SIB comprises information about supported single network slice selection informations (S-NSSAIs) in a serving frequency.
The method of claim 19, wherein the SIB comprises information about inter-frequency and intra-frequency single network slice selection informations (S-NSSAIs) supported in the network.
The method of claim 27, wherein the information about intra-frequency S-NSSAIs slices comprises information identifying S-NSSAIs operating on a frequency on which a UE is communicating.
The method of claim 27, wherein the information about inter-frequency S-NSSAIs comprises a list of supported S-NSSAIs for each of a plurality of radio frequency channels.
The method of claim 27, wherein the information about inter-frequency S-NSSAIs comprises supported radio frequency channels for each S-NSSAI of the S-NSSAIs supported by the network entity.
The method of claim 30, wherein the information further includes a frequency priority for each supported radio frequency channel.
An apparatus for wireless communications by a user equipment (UE) , comprising:

a processor configured to:

receive a system information block (SIB) including network slice information indicating one or more slice identifiers supported by one or more cells of a network;

identify a frequency priority list based on the network slice information and a set of desired services; and

perform cell selection or reselection based on the frequency priority list; and

a memory.
The apparatus of claim 32, wherein the processor is further configured to:

send UE assistance information indicating slicing interest of the UE to the network.
The apparatus of claim 33, wherein the indication comprises an indication of an interested frequency list and associated single network slice selection assistance informations (S-NSSAIs) .
The apparatus of claim 34, wherein the indication comprises an indication of slicing priority among the S-NSSAIs.
The apparatus of claim 32, wherein the SIB comprises a segmented SIB including a portion of the slice identifiers supported by one or more cells of the network.
The apparatus of claim 32, wherein the processor is further configured to:

transmit, to a network entity in the network, a request for network slice information, wherein the SIB is received in response to the request for network slice information.
The apparatus of claim 37, wherein the request for network slice information is transmitted based on system information from the network entity indicating that the SIB is transmitted on demand.
The apparatus of claim 32, wherein the SIB comprises information about supported single network slice selection informations (S-NSSAIs) in a serving frequency.
The apparatus of claim 32, wherein the SIB comprises information about inter-frequency and intra-frequency single network slice selection informations (S-NSSAIs) supported in the network.
The apparatus of claim 40, wherein the information about intra-frequency S-NSSAIs slices comprises information identifying S-NSSAIs operating on a frequency on which the UE is communicating.
The apparatus of claim 40, wherein the information about inter-frequency S-NSSAIs comprises a list of supported S-NSSAIs for each of a plurality of radio frequency channels.
The apparatus of claim 40, wherein the information about inter-frequency S-NSSAIs comprises supported radio frequency channels for each S-NSSAI of the S-NSSAIs supported by a network entity.
The apparatus of claim 43, wherein the information further includes a frequency priority for each supported radio frequency channel.
The apparatus of claim 32, wherein the processor is further configured to:

determine the frequency priority based on a mapping between S-NSSAIs and frequencies ordered by slicing priority.
The apparatus of claim 32, wherein the processor is further configured to:

receive, from a network entity in the network, information related to the frequency priority, wherein the information related to the frequency priority comprises a dedicated slicing priority for the UE.
The apparatus of claim 32, wherein the processor is configured to perform cell selection or reselection by:

identifying one or more frequencies that support a requested service; and

selecting or reselecting to cells operating on one of the identified one or more frequencies.
The apparatus of claim 47, wherein the selecting or reselecting to cells on one of the identified one or more frequencies comprises:

determining that a plurality of frequencies support the requested service; and

selecting one of the plurality of frequencies based on a frequency associated with an S-NSSAI having a highest priority of requested S-NSSAIs.
The apparatus of claim 32, wherein the processor is configured to perform cell selection or reselection by:

prioritizing frequencies based on a number of slices with highest priorities that each frequency of a plurality of frequencies supports; and

selecting a frequency of the plurality of frequencies having a highest priority.
An apparatus for wireless communications by a network entity, comprising:

a processor configured to:

determine slice information indicating one or more slice identifiers supported by one or more cells of a network; and

send a system information block (SIB) including the network slice information; and

a memory.
The apparatus of claim 50, wherein the processor is further configured to:

receive, from a user equipment (UE) , UE assistance information indicating slicing interest of the UE.
The apparatus of claim 51, wherein the indication comprises an indication of an interested frequency list and associated single network slice selection assistance informations (S-NSSAIs) for the UE.
The apparatus of claim 52, wherein the indication comprises an indication of slicing priority among the S-NSSAIs for the UE.
The apparatus of claim 50, wherein the SIB comprises a segmented SIB including a portion of the slice identifiers supported by one or more cells of the network.
The apparatus of claim 50, wherein the processor is further configured to:

receive, from a user equipment, a request for network slice information, wherein the SIB is sent in response to the request for network slice information.
The apparatus of claim 55, wherein the request for network slice information is received based on system information broadcast by the network entity indicating that the SIB is transmitted on demand.
The apparatus of claim 50, wherein the SIB comprises information about supported single network slice selection informations (S-NSSAIs) in a serving frequency.
The apparatus of claim 50, wherein the SIB comprises information about inter-frequency and intra-frequency single network slice selection informations (S-NSSAIs) supported in the network.
The apparatus of claim 58, wherein the information about intra-frequency S-NSSAIs slices comprises information identifying S-NSSAIs operating on a frequency on which a UE is communicating.
The apparatus of claim 58, wherein the information about inter-frequency S-NSSAIs comprises a list of supported S-NSSAIs for each of a plurality of radio frequency channels.
The apparatus of claim 58, wherein the information about inter-frequency S-NSSAIs comprises supported radio frequency channels for each S-NSSAI of the S-NSSAIs supported by the network entity.
The apparatus of claim 61, wherein the information further includes a frequency priority for each supported radio frequency channel.
An apparatus for wireless communications by a user equipment (UE) , comprising:

means for receiving a system information block (SIB) including network slice information indicating one or more slice identifiers supported by one or more cells of a network;

means for identifying a frequency priority list based on the network slice information and a set of desired services; and

means for performing cell selection or reselection based on the frequency priority list.
An apparatus for wireless communications by a network entity, comprising:

means for determining slice information indicating one or more slice identifiers supported by one or more cells of a network; and

means for sending a system information block (SIB) including the network slice information.