WO2022036668A1

WO2022036668A1 - Network slicing mobility enhancement

Info

Publication number: WO2022036668A1
Application number: PCT/CN2020/110431
Authority: WO
Inventors: Nan Zhang
Original assignee: Qualcomm Incorporated
Priority date: 2020-08-21
Filing date: 2020-08-21
Publication date: 2022-02-24

Abstract

Aspects of the disclosure relate to a method for wireless communication at a user equipment (UE). In some aspects, the UE obtains a set of tracking area lists for a set of network slice instances. Each of the set of tracking area lists is associated with a respective network slice instance in the set of network slice instances. The UE determines that a current tracking area of the user equipment or a target tracking area of the user equipment is excluded from the set of tracking area lists. The UE obtains information indicating at least one allowed network slice instance for the current tracking area of the user equipment or the target tracking area of the user equipment in response to the determination. Other aspects, embodiments, and features are also claimed and described.

Description

NETWORK SLICING MOBILITY ENHANCEMENT

TECHNICAL FIELD

The technology discussed below relates generally to wireless communication systems, and more particularly, to network slicing mobility enhancements.

INTRODUCTION

Some network slice instances or network slice types may not be available over the entire network (e.g., a public land mobile network (PLMN) ) . For example, network slice instances with multi-access edge computing (MEC) functions (also referred to as mobile edge computing functions) may be available in limited areas of a PLMN. As another example, an individual network slice instance may be available only within some tracking areas or a single tracking area. Therefore, in some scenarios, if a user equipment (UE) in a network moves out of tracking areas with network slice instance availability, the network may notify the UE to start a new registration procedure so that the UE may obtain information (e.g., network slice selection assistance information (NSSAI) ) indicating new allowed network slice instances (e.g., new single-network slice selection assistance information (S-NSSAI) ) .

Upon obtaining the information indicating the new allowed network slice instances, the UE may attempt to establish new connections (e.g., new PDU sessions) to other network slice instances. However, as the UE attempts to establish new connections to other network slice instances, existing connections between the UE and any network slice instances may break. This may cause the UE to lose data service for a noticeable period of time (e.g., the period of time needed to perform a registration procedure, release a PDU session, and establish a new PDU session) , which may negatively impact the user experience.

BRIEF SUMMARY OF SOME EXAMPLES

The following presents a summary of one or more aspects of the present disclosure, in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated features of the disclosure, and is intended neither to identify key or critical elements of all aspects of the disclosure nor to delineate the scope of any or all aspects of the disclosure. Its sole purpose is to present some concepts of one or more aspects of the disclosure in a form as a prelude to the more detailed description that is presented later.

In one example, a method of wireless communication at a user equipment is disclosed. The method may include obtaining a set of tracking area lists for a set of network slice instances, wherein each of the set of tracking area lists is associated with a respective network slice instance in the set of network slice instances, determining that a current tracking area of the user equipment or a target tracking area of the user equipment is excluded from the set of tracking area lists, and obtaining information indicating at least one allowed network slice instance for the current tracking area of the user equipment or the target tracking area of the user equipment in response to the determination.

In another example, a user equipment in a wireless communication network is disclosed. The user equipment includes means for obtaining a set of tracking area lists for a set of network slice instances, wherein each of the set of tracking area lists is associated with a respective network slice instance in the set of network slice instances, means for determining that a current tracking area of the apparatus or a target tracking area of the apparatus is excluded from the set of tracking area lists, and means for obtaining information indicating at least one allowed network slice instance for the current tracking area of the apparatus or the target tracking area of the apparatus in response to the determination.

In another example, a user equipment in a wireless communication network is disclosed. The user equipment may include a wireless transceiver, a memory, and a processor communicatively coupled to the wireless transceiver and the memory. The processor and memory may be configured to obtain a set of tracking area lists for a set of network slice instances, wherein each of the set of tracking area lists is associated with a respective network slice instance in the set of network slice instances. The processor and memory may be configured to determine that a current tracking area of the user equipment or a target tracking area of the user equipment is excluded from the set of tracking area lists. The processor and memory may be configured to obtain information indicating at least one allowed network slice instance for the current tracking area of the user equipment or the target tracking area of the user equipment in response to the determination.

In another example, an article of manufacture for use by a user equipment in a wireless communication network is disclosed. The article of manufacture may include a computer-readable medium having stored therein instructions that are executable by one or more processors of the user equipment. The instructions may cause the one or more processors of the user equipment to obtain a set of tracking area lists for a set of network slice instances, wherein each of the set of tracking area lists is associated with a respective network slice instance in the set of network slice instances, determine that a current tracking area of the user equipment or a target tracking area of the user equipment is excluded from the set of tracking area lists, and obtain information indicating at least one allowed network slice instance for the current tracking area of the user equipment or the target tracking area of the user equipment in response to the determination.

These and other aspects of the invention will become more fully understood upon a review of the detailed description, which follows. Other aspects, features, and embodiments will become apparent to those of ordinary skill in the art, upon reviewing the following description of specific, exemplary embodiments in conjunction with the accompanying figures. While features may be discussed relative to certain embodiments and figures below, all embodiments can include one or more of the advantageous features discussed herein. In other words, while one or more embodiments may be discussed as having certain advantageous features, one or more of such features may also be used in accordance with the various embodiments discussed herein. In similar fashion, while exemplary embodiments may be discussed below as device, system, or method embodiments it should be understood that such exemplary embodiments can be implemented in various devices, systems, and methods.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of a wireless communication system according to some aspects.

FIG. 2 is a conceptual illustration of an example of a radio access network according to some aspects.

FIG. 3 is a block diagram illustrating an example of a 5G wireless communication system (5GS) .

FIGS. 4A and 4B illustrate a signal flow diagram in accordance with various aspects of the present disclosure.

FIGS. 5A and 5B illustrate a signal flow diagram in accordance with various aspects of the present disclosure.

FIG. 6 is a block diagram conceptually illustrating an example of a hardware implementation for a user equipment according to some aspects of the disclosure.

FIG. 7 is a flow chart of an exemplary method of wireless communication at a user equipment according to some aspects of the disclosure.

FIG. 8 is a flow chart of an exemplary method of wireless communication at a user equipment according to some aspects of the disclosure.

DETAILED DESCRIPTION

The detailed description set forth below in connection with the appended drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well known structures and components are shown in block diagram form in order to avoid obscuring such concepts.

While aspects and embodiments are described in this application by illustration to some examples, those skilled in the art will understand that additional implementations and use cases may come about in many different arrangements and scenarios. Innovations described herein may be implemented across many differing platform types, devices, systems, shapes, sizes, and packaging arrangements. For example, embodiments and/or uses may come about via integrated chip embodiments and other non-module-component based devices (e.g., end-user devices, vehicles, communication devices, computing devices, industrial equipment, retail/purchasing devices, medical devices, AI-enabled devices, etc. ) . While some examples may or may not be specifically directed to use cases or applications, a wide assortment of applicability of described innovations may occur. Implementations may range a spectrum from chip-level or modular components to non-modular, non-chip-level implementations and further to aggregate, distributed, or OEM devices or systems incorporating one or more aspects of the described innovations. In some practical settings, devices incorporating described aspects and features may also necessarily include additional components and features for implementation and practice of claimed and described embodiments. For example, transmission and reception of wireless signals necessarily includes a number of components for analog and digital purposes (e.g., hardware components including antenna, RF-chains, power amplifiers, modulators, buffer, processor (s) , interleaver, adders/summers, etc. ) . It is intended that innovations described herein may be practiced in a wide variety of devices, chip-level components, systems, distributed arrangements, end-user devices, etc. of varying sizes, shapes and constitution.

The various concepts presented throughout this disclosure may be implemented across a broad variety of telecommunication systems, network architectures, and communication standards. Referring now to FIG. 1, as an illustrative example without limitation, various aspects of the present disclosure are illustrated with reference to a wireless communication system 100. The wireless communication system 100 includes three interacting domains: a core network 102, a radio access network (RAN) 104, and a user equipment (UE) 106. By virtue of the wireless communication system 100, the UE 106 may be enabled to carry out data communication with an external data network 110, such as (but not limited to) the Internet.

The RAN 104 may implement any suitable wireless communication technology or technologies to provide radio access to the UE 106. As one example, the RAN 104 may operate according to 3 ^rd Generation Partnership Project (3GPP) New Radio (NR) specifications, often referred to as 5G. As another example, the RAN 104 may operate under a hybrid of 5G NR and Evolved Universal Terrestrial Radio Access Network (eUTRAN) standards, often referred to as LTE. The 3GPP refers to this hybrid RAN as a next-generation RAN, or NG-RAN. Of course, many other examples may be utilized within the scope of the present disclosure.

As illustrated, the RAN 104 includes a plurality of base stations 108. Broadly, a base station is a network element in a radio access network responsible for radio transmission and reception in one or more cells to or from a UE. In different technologies, standards, or contexts, a base station may variously be referred to by those skilled in the art as a base transceiver station (BTS) , a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS) , an extended service set (ESS) , an access point (AP) , a Node B (NB) , an eNode B (eNB) , a gNode B (gNB) , or some other suitable terminology.

The radio access network 104 is further illustrated supporting wireless communication for multiple mobile apparatuses. A mobile apparatus may be referred to as user equipment (UE) in 3GPP standards, but may also be referred to by those skilled in the art as a mobile station (MS) , a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal (AT) , a mobile terminal, a wireless terminal, a remote terminal, a handset, a terminal, a user agent, a mobile client, a client, or some other suitable terminology. A UE may be an apparatus (e.g., a mobile apparatus) that provides a user with access to network services.

Within the present document, a “mobile” apparatus need not necessarily have a capability to move, and may be stationary. The term mobile apparatus or mobile device broadly refers to a diverse array of devices and technologies. UEs may include a number of hardware structural components sized, shaped, and arranged to help in communication; such components can include antennas, antenna arrays, RF chains, amplifiers, one or more processors, etc. electrically coupled to each other. For example, some non-limiting examples of a mobile apparatus include a mobile, a cellular (cell) phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal computer (PC) , a notebook, a netbook, a smartbook, a tablet, a personal digital assistant (PDA) , and a broad array of embedded systems, e.g., corresponding to an “Internet of things” (IoT) . A mobile apparatus may additionally be an automotive or other transportation vehicle, a remote sensor or actuator, a robot or robotics device, a satellite radio, a global positioning system (GPS) device, an object tracking device, a drone, a multi-copter, a quad-copter, a remote control device, a consumer and/or wearable device, such as eyewear, a wearable camera, a virtual reality device, a smart watch, a health or fitness tracker, a digital audio player (e.g., MP3 player) , a camera, a game console, etc. A mobile apparatus may additionally be a digital home or smart home device such as a home audio, video, and/or multimedia device, an appliance, a vending machine, intelligent lighting, a home security system, a smart meter, etc. A mobile apparatus may additionally be a smart energy device, a security device, a solar panel or solar array, a municipal infrastructure device controlling electric power (e.g., a smart grid) , lighting, water, etc. ; an industrial automation and enterprise device; a logistics controller; agricultural equipment; military defense equipment, vehicles, aircraft, ships, and weaponry, etc. Still further, a mobile apparatus may provide for connected medicine or telemedicine support, e.g., health care at a distance. Telehealth devices may include telehealth monitoring devices and telehealth administration devices, whose communication may be given preferential treatment or prioritized access over other types of information, e.g., in terms of prioritized access for transport of critical service data, and/or relevant QoS for transport of critical service data.

Wireless communication between a RAN 104 and a UE 106 may be described as utilizing an air interface. Transmissions over the air interface from a base station (e.g., base station 108) to one or more UEs (e.g., UE 106) may be referred to as downlink (DL) transmission. In accordance with certain aspects of the present disclosure, the term downlink may refer to a point-to-multipoint transmission originating at a scheduling entity (described further below; e.g., base station 108) . Another way to describe this scheme may be to use the term broadcast channel multiplexing. Transmissions from a UE (e.g., UE 106) to a base station (e.g., base station 108) may be referred to as uplink (UL) transmissions. In accordance with further aspects of the present disclosure, the term uplink may refer to a point-to-point transmission originating at a scheduled entity (described further below; e.g., UE 106) .

In some examples, access to the air interface may be scheduled, wherein a scheduling entity (e.g., a base station 108) allocates resources for communication among some or all devices and equipment within its service area or cell. Within the present disclosure, as discussed further below, the scheduling entity may be responsible for scheduling, assigning, reconfiguring, and releasing resources for one or more scheduled entities. That is, for scheduled communication, UEs 106, which may be scheduled entities, may utilize resources allocated by the scheduling entity 108.

Base stations 108 are not the only entities that may function as scheduling entities. That is, in some examples, a UE may function as a scheduling entity, scheduling resources for one or more scheduled entities (e.g., one or more other UEs) .

As illustrated in FIG. 1, a scheduling entity 108 may broadcast downlink traffic 112 to one or more scheduled entities 106. Broadly, the scheduling entity 108 is a node or device responsible for scheduling traffic in a wireless communication network, including the downlink traffic 112 and, in some examples, uplink traffic 116 from one or more scheduled entities 106 to the scheduling entity 108. On the other hand, the scheduled entity 106 is a node or device that receives downlink control information 114, including but not limited to scheduling information (e.g., a grant) , synchronization or timing information, or other control information from another entity in the wireless communication network such as the scheduling entity 108.

In general, base stations 108 may include a backhaul interface for communication with a backhaul portion 120 of the wireless communication system. The backhaul 120 may provide a link between a base station 108 and the core network 102. Further, in some examples, a backhaul network may provide interconnection between the respective base stations 108. Various types of backhaul interfaces may be employed, such as a direct physical connection, a virtual network, or the like using any suitable transport network.

The core network 102 may be a part of the wireless communication system 100, and may be independent of the radio access technology used in the RAN 104. In some examples, the core network 102 may be configured according to 5G standards (e.g., 5GC) . In other examples, the core network 102 may be configured according to a 4G evolved packet core (EPC) , or any other suitable standard or configuration.

Referring now to FIG. 2, by way of example and without limitation, a block diagram illustrating an example of various components of a 5G wireless communication system (5GS) 200 is provided. In some examples, the 5GS 200 may be the same wireless communication system 100 described above and illustrated in FIG. 1. The 5GS 200 includes a user equipment (UE) 202, a NR-RAN 204, and a core network 206. By virtue of the wireless communication system 200, the UE 202 may be enabled to carry out data communication with an external data network 214, such as (but not limited to) the Internet or an Ethernet network.

The core network 206 may include, for example, an access and mobility management function (AMF) 208, a session management function (SMF) 210, and a user plane function (UPF) 212. The AMF 208 and SMF 210 employ control plane (e.g., Non Access Stratum (NAS) ) signaling to perform various functions related to mobility management and session management for the UE 202. For example, the AMF 208 provides connectivity, mobility management and authentication of the UE 202, while the SMF 210 provides session management of the UE 202 (e.g., processes signaling related to protocol data unit (PDU) sessions between the UE 202 and the external DN 214) . The UPF 212 provides user plane connectivity to route 5G (NR) packets to/from the UE 202 via the NR-RAN 204.

The core network 206 may further include other functions, such as a policy control function (PCF) 216, authentication server function (AUSF) 218, unified data management (UDM) 220, network slice selection function (NSSF) 222, and other functions (not illustrated, for simplicity) . The PCF 216 provides policy information (e.g., rules) for control plane functions, such as network slicing, roaming, and mobility management. In addition, the PCF 216 supports 5G quality of service (QoS) policies, network slice policies, and other types of policies. The AUSF 218 performs authentication of UEs 202. The UDM 220 facilitates generation of authentication and key agreement (AKA) credentials, performs user identification and manages subscription information and UE context. The NSSF 222 redirects traffic to a network slice. Network slices may be defined, for example, for different classes of subscribers or use cases, such as smart home, Internet of Things (IoT) , connected car, smart energy grid, etc. Each use case may receive a unique set of optimized resources and network topology (e.g., a network slice) to meet the connectivity, speed, power, and capacity requirements of the use case.

To establish a connection to the core network 206 (e.g., a 5G core network) via the NR-RAN 204, the UE 202 may transmit a registration request and PDU session establishment request to the core network 206 via the NR-RAN 204. The AMF 208 and SMF 210 may process the registration request and PDU session establishment request and establish a data network session (DNS) between the UE 202 and the external DN 214 via the UPF 212. A DNS may include one or more sessions (e.g., data sessions or data flows) and may be served by multiple UPFs 212 (only one of which is shown for convenience) . Examples of data flows include, but are not limited to, IP flows, Ethernet flows and unstructured data flows.

A network slice may be viewed as a logical network with specific functions/elements dedicated for a particular use case, service type, traffic type, or other business arrangements with agreed-upon Service-level Agreement (SLA) . Network slice types may include, but not limited to, enhanced Mobile Broadband (eMBB) , Ultra-Reliable Low Latency Communications (URLLC) , massive Machine Type Communications (mMTC) , and massive IoT (mIoT) . A network slice may include both access and core network parts. The 5GS 200 may handle traffic for different network slices by different PDU sessions. In some examples, a single UE (e.g., UE 202) can simultaneously be served by as much as eight network slices at any time. In some scenarios, the network slices for the UE 202 can be changed at any time while the UE 202 is registered with the core network 206, and may be initiated by the core network 206 or by the UE 202.

The 5GS 200 may allow for multiple instances of a network slice (also referred to as network slice instances) . For example, a network slice instance may include a set of network function instances and resources (e.g., compute, storage, and networking resources) which form a network slice. Each network slice instance may provide the network characteristics associated with a service supported by the 5GS 200.

In the 5GS 200, network slice selection assistance information (NSSAI) may refer to a collection of identifiers for network slices, where each identifier is referred to as single-network slice selection assistance information (S-NSSAI) . In some examples, an S-NSSAI identity may include a slice/service type (SST) and a slice differentiator (SD) . The SST may indicate the expected network slice behavior in terms of features and services, and the SD may be optionally used to differentiate among multiple network slices of the same SST.

An S-NSSAI signaled by the UE to the network may assist the network in selecting a particular network slice instance. An S-NSSAI may have standard values or non-standard values. For example, an S-NSSAI with a standard value may mean that the S-NSSAI includes an SST with a standardized SST value. In one example, an SST value 1 may be associated with an eMBB network slice type, which may be suitable for handling 5G enhanced mobile broadband. In another example, an SST value 2 may be associated with a URLLC network slice type, which may be suitable for handling ultra-reliable low latency communications. In yet another example, an SST value 3 may be associated with an MIoT network slice type, which may be suitable for handling of massive IoT.

The core network 206, based on local policies, subscription changes, UE mobility, and/or operational reasons (e.g. a Network Slice instance is no longer available or load level information for a network slice instance provided by the network data analytics function (NWDAF) ) , may change the set of network slice (s) to which the UE 202 is registered and provide the UE 202 with a new registration area and/or allowed NSSAI and the mapping of this allowed NSSAI to home public land mobile network (HPLMN) S-NSSAIs, for each access type over which the UE 202 is registered. In addition, the network may provide the configured NSSAI for the serving PLMN, the associated mapping information, and the rejected S-NSSAIs. The network may perform such a change over each access type during a registration procedure or trigger a notification towards the UE 202 of the change of the network slices using a UE configuration update procedure.

In some examples, a network slice instance may be available in one or more tracking areas of a public land mobile network (PLMN) . For example, the availability of a network slice instance for the UE 202 may refer to the support of an S-NSSAI in the network functions of the core network 206 and/or policies applied by the core network 206 that restrict usage of certain network slices in particular tracking areas (e.g., depending on the HPLMN of the UE 202) . The availability of a network slice in a tracking area may be established end-to-end using a combination of operations, administration, and maintenance (OAM) , and signaling among network functions. For example, the availability of a network slice in a tracking area may be derived by using the S-NSSAIs supported per tracking area in the access network (e.g., NR-RAN 204) , the S-NSSAIs supported in the AMF (e.g., AMF 208) , and operator policies per tracking area in the NSSF (e.g., NSSF 222) .

Referring now to FIG. 3, by way of example and without limitation, a schematic illustration of a RAN 300 is provided. In some examples, the RAN 300 may be the same as the RAN 104 described above and illustrated in FIG. 1. The geographic area covered by the RAN 300 may be divided into cellular regions (cells) that can be uniquely identified by a user equipment (UE) based on an identification broadcasted from one access point or base station. FIG. 3 illustrates

macrocells

302, 304, and 306, and a small cell 308, each of which may include one or more sectors (not shown) . A sector is a sub-area of a cell. All sectors within one cell are served by the same base station. A radio link within a sector can be identified by a single logical identification belonging to that sector. In a cell that is divided into sectors, the multiple sectors within a cell can be formed by groups of antennas with each antenna responsible for communication with UEs in a portion of the cell.

In FIG. 3, two base stations 310 and 312 are shown in

cells

302 and 304; and a third base station 314 is shown controlling a remote radio head (RRH) 316 in cell 306. That is, a base station can have an integrated antenna or can be connected to an antenna or RRH by feeder cables. In the illustrated example, the

cells

302, 304, and 126 may be referred to as macrocells, as the

base stations

310, 312, and 314 support cells having a large size. Further, a base station 318 is shown in the small cell 308 (e.g., a microcell, picocell, femtocell, home base station, home Node B, home eNode B, etc. ) which may overlap with one or more macrocells. In this example, the cell 308 may be referred to as a small cell, as the base station 318 supports a cell having a relatively small size. Cell sizing can be done according to system design as well as component constraints.

It is to be understood that the radio access network 300 may include any number of wireless base stations and cells. Further, a relay node may be deployed to extend the size or coverage area of a given cell. The

base stations

310, 312, 314, 318 provide wireless access points to a core network for any number of mobile apparatuses. In some examples, the

base stations

310, 312, 314, and/or 318 may be the same as the base station/scheduling entity 108 described above and illustrated in FIG. 1.

In some examples, an unmanned aerial vehicle (UAV) 320, which may be a drone or quadcopter, can be a mobile network node and may be configured to function as a UE. For example, the UAV 320 may operate within cell 302 by communicating with base station 310.

Within the RAN 300, the cells may include UEs that may be in communication with one or more sectors of each cell. Further, each

base station

310, 312, 314, and 318 may be configured to provide an access point to a core network (e.g., as illustrated in FIG. 1 and/or 2) for all the UEs in the respective cells. For example,

UEs

322 and 324 may be in communication with base station 310;

UEs

326 and 328 may be in communication with base station 312;

UEs

330 and 332 may be in communication with base station 314 by way of RRH 316; and UE 334 may be in communication with base station 318. In some examples, the

UEs

322, 324, 326, 328, 330, 332, 334, 338, 340, and/or 342 may be the same as the UE/scheduled entity 106 described above and illustrated in FIG. 1 and/or the UE 202 described above and illustrated in FIG. 2.

In a further aspect of the RAN 300, sidelink signals may be used between UEs without necessarily relying on scheduling or control information from a base station. For example, two or more UEs (e.g., UEs 326 and 328) may communicate with each other using peer to peer (P2P) or sidelink signals 327 without relaying that communication through a base station (e.g., base station 312) . In a further example, UE 338 is illustrated communicating with

UEs

340 and 342. Here, the UE 338 may function as a scheduling entity or a primary sidelink device, and

UEs

340 and 342 may function as a scheduled entity or a non-primary (e.g., secondary) sidelink device. In still another example, a UE may function as a scheduling entity in a device-to-device (D2D) , peer-to-peer (P2P) , or vehicle-to-vehicle (V2V) network, and/or in a mesh network. In a mesh network example,

UEs

340 and 342 may optionally communicate directly with one another in addition to communicating with the scheduling entity 338. Thus, in a wireless communication system with scheduled access to time-frequency resources and having a cellular configuration, a P2P configuration, or a mesh configuration, a scheduling entity and one or more scheduled entities may communicate utilizing the scheduled resources.

In the radio access network 300, the ability for a UE to communicate while moving, independent of its location, is referred to as mobility. The various physical channels between the UE and the radio access network are generally set up, maintained, and released under the control of an access and mobility management function (AMF, not illustrated, part of the core network 102 in FIG. 1) , which may include a security context management function (SCMF) that manages the security context for both the control plane and the user plane functionality, and a security anchor function (SEAF) that performs authentication.

In various aspects of the disclosure, a radio access network 300 may utilize DL-based mobility or UL-based mobility to enable mobility and handovers (i.e., the transfer of a UE’s connection from one radio channel to another) . In a network configured for DL-based mobility, during a call with a scheduling entity, or at any other time, a UE may monitor various parameters of the signal from its serving cell as well as various parameters of neighboring cells. Depending on the quality of these parameters, the UE may maintain communication with one or more of the neighboring cells. During this time, if the UE moves from one cell to another, or if signal quality from a neighboring cell exceeds that from the serving cell for a given amount of time, the UE may undertake a handoff or handover from the serving cell to the neighboring (target) cell. For example, UE 324 (illustrated as a vehicle, although any suitable form of UE may be used) may move from the geographic area corresponding to its serving cell 302 to the geographic area corresponding to a neighbor cell 306. When the signal strength or quality from the neighbor cell 306 exceeds that of its serving cell 302 for a given amount of time, the UE 324 may transmit a reporting message to its serving base station 310 indicating this condition. In response, the UE 324 may receive a handover command, and the UE may undergo a handover to the cell 306.

In a network configured for UL-based mobility, UL reference signals from each UE may be utilized by the network to select a serving cell for each UE. In some examples, the

base stations

310, 312, and 314/316 may broadcast unified synchronization signals (e.g., unified Primary Synchronization Signals (PSSs) , unified Secondary Synchronization Signals (SSSs) and unified Physical Broadcast Channels (PBCH) ) . The

UEs

322, 324, 326, 328, 330, and 332 may receive the unified synchronization signals, derive the carrier frequency and slot timing from the synchronization signals, and in response to deriving timing, transmit an uplink pilot or reference signal. The uplink pilot signal transmitted by a UE (e.g., UE 324) may be concurrently received by two or more cells (e.g., base stations 310 and 314/316) within the radio access network 300. Each of the cells may measure a strength of the pilot signal, and the radio access network (e.g., one or more of the base stations 310 and 314/316 and/or a central node within the core network) may determine a serving cell for the UE 324. As the UE 324 moves through the radio access network 300, the network may continue to monitor the uplink pilot signal transmitted by the UE 324. When the signal strength or quality of the pilot signal measured by a neighboring cell exceeds that of the signal strength or quality measured by the serving cell, the network 300 may handover the UE 324 from the serving cell to the neighboring cell, with or without informing the UE 324.

Although the synchronization signal transmitted by the

base stations

310, 312, and 314/316 may be unified, the synchronization signal may not identify a particular cell, but rather may identify a zone of multiple cells operating on the same frequency and/or with the same timing. The use of zones in 5G networks or other next generation communication networks enables the uplink-based mobility framework and improves the efficiency of both the UE and the network, since the number of mobility messages that need to be exchanged between the UE and the network may be reduced.

In various implementations, the air interface in the radio access network 300 may utilize licensed spectrum, unlicensed spectrum, or shared spectrum. Licensed spectrum provides for exclusive use of a portion of the spectrum, generally by virtue of a mobile network operator purchasing a license from a government regulatory body. Unlicensed spectrum provides for shared use of a portion of the spectrum without need for a government-granted license. While compliance with some technical rules is generally still required to access unlicensed spectrum, generally, any operator or device may gain access. Shared spectrum may fall between licensed and unlicensed spectrum, wherein technical rules or limitations may be required to access the spectrum, but the spectrum may still be shared by multiple operators and/or multiple RATs. For example, the holder of a license for a portion of licensed spectrum may provide licensed shared access (LSA) to share that spectrum with other parties, e.g., with suitable licensee-determined conditions to gain access.

The air interface in the radio access network 300 may utilize one or more duplexing algorithms. Duplex refers to a point-to-point communication link where both endpoints can communicate with one another in both directions. Full duplex means both endpoints can simultaneously communicate with one another. Half duplex means only one endpoint can send information to the other at a time. In a wireless link, a full duplex channel generally relies on physical isolation of a transmitter and receiver, and suitable interference cancellation technologies. Full duplex emulation is frequently implemented for wireless links by utilizing frequency division duplex (FDD) or time division duplex (TDD) . In FDD, transmissions in different directions operate at different carrier frequencies. In TDD, transmissions in different directions on a given channel are separated from one another using time division multiplexing. That is, at some times the channel is dedicated for transmissions in one direction, while at other times the channel is dedicated for transmissions in the other direction, where the direction may change very rapidly, e.g., several times per slot.

The air interface in the radio access network 300 may utilize one or more multiplexing and multiple access algorithms to enable simultaneous communication of the various devices. For example, 5G NR specifications provide multiple access for UL transmissions from

UEs

322 and 324 to base station 310, and for multiplexing for DL transmissions from base station 310 to one or

more UEs

322 and 324, utilizing orthogonal frequency division multiplexing (OFDM) with a cyclic prefix (CP) . In addition, for UL transmissions, 5G NR specifications provide support for discrete Fourier transform-spread-OFDM (DFT-s-OFDM) with a CP (also referred to as single-carrier FDMA (SC-FDMA) ) . However, within the scope of the present disclosure, multiplexing and multiple access are not limited to the above schemes, and may be provided utilizing time division multiple access (TDMA) , code division multiple access (CDMA) , frequency division multiple access (FDMA) , sparse code multiple access (SCMA) , resource spread multiple access (RSMA) , or other suitable multiple access schemes. Further, multiplexing DL transmissions from the base station 310 to UEs 322 and 324 may be provided utilizing time division multiplexing (TDM) , code division multiplexing (CDM) , frequency division multiplexing (FDM) , orthogonal frequency division multiplexing (OFDM) , sparse code multiplexing (SCM) , or other suitable multiplexing schemes.

FIGS. 4A and 4B illustrate a signal flow diagram in accordance with various aspects of the present disclosure. The UE 402 may correspond, for example, to any of the UEs shown in FIGs. 1-3. The first base station (BS-1) 404 and/or the second base station (BS-2) 406 may be any of the base stations shown in FIGS. 1 and 3. In the example shown in FIGS. 4A and 4B, the core network includes a first AMF (AMF-1) 408, a first UPF (UPF-1) 410, a first SMF (SMF-1) 412, a second AMF (AMF-2) 414, a second UPF (UPF-2) 416, and a second SMF (SMF-2) 418. Each of the

AMF

408, 414,

UPF

410, 416, and

SMF

412, 418 may correspond, for example, to the corresponding nodes illustrated in FIG. 2. In the example of FIGS. 4A and 4B, AMF-1 408, UPF-1 410, and SMF-1 412 are associated with a first network slice 420 (also referred to as a first network slice instance) , and AMF-2 414, UPF-2 416, and SMF-2 418 are associated with a second network slice 422 (also referred to as a second network slice instance) .

With reference to FIG. 4A, the UE 402 may be connected to the BS-1 404 and may perform a registration procedure 423 with the core network via the BS-1 404. At 424 and 426, during the registration procedure 423, the UE 402 obtains information (e.g., NSSAI) indicating a set of allowed network slice instances (e.g., one or more S-NSSAIs) from the AMF-1 408 via the BS-1 404. As shown in FIG. 4A, for example, the UE 402 may obtain allowed NSSAI, which may include one or more single-network slice selection assistance information (S-NSSAI) identities. In some examples, the UE 402 may obtain the information indicating the set of allowed network slice instances via NAS level signaling. At 428 and 430, the UE 402 further obtains a set of tracking area lists for the set of network slice instances from the AMF-1 408 via the BS-1 404. Each tracking area list in the set of tracking area lists may be specific to a network slice instance in the set of network slice instances. For example, each tracking area list may be an S-NSSAI specific tracking area list. Accordingly, in some examples, the UE 402 may maintain a different tracking area list for each S-NSSAI in the allowed NSSAI.

The UE 402 may connect to the first network slice 420 and may establish a first PDU session 432. In this example, the UE 402 may be located in a first tracking area of the network and the tracking area list specific to the first network slice 420 may include the first tracking area. The UE 402 may transmit user data to the core network and/or may receive user data from the core network via the first data path 434. For example, the UE 402 may receive user data from the UPF-1 410 via the BS-1 404. As another example, the UE 402 may transmit user data to the UPF-1 410 via the BS-1 404.

At 436, the UE 402 enters an idle mode (e.g., a radio resource control (RRC) idle mode) or an inactive mode. At 438, the UE 402 determines that the current tracking area of the UE 402 is not included in the set of tracking area lists for the set of network slice instances. In one example scenario, the UE 402 may have moved out of a first cell which includes the BS-1 404 and which has a first tracking area ID, and may have moved into a second cell which includes the BS-2 406 and which has a second tracking area ID. In this scenario, the UE 402 may be camping on the second cell in the idle mode and may obtain the second tracking area ID of the second cell. Therefore, the second cell may be referred to as the current cell of the UE 402 and the tracking area of the second cell may be referred to as the current tracking area of the UE 402.

The UE 402 may compare the tracking area ID of its current cell (e.g., the second tracking area ID of the second cell) to one or more tracking area IDs included in the set of tracking area lists for the set of network slice instances (e.g., the one or more tracking area IDs included in the S-NSSAI specific tracking area list (s) previously received from the AMF-1 408) . If the tracking area ID of the current cell of the UE 402 does not match any of the tracking area IDs in the set of tracking area lists, the UE 402 may determine that the tracking area ID of its current cell is not included in the set of tracking area lists for the set of network slice instances.

With reference to FIG. 4B, at 440, the UE initiates a network slice reselection operation when its current tracking area is not included in the set of tracking area lists (e.g., in the S-NSSAI specific tracking area list (s) ) . For example, the network slice reselection operation may include a registration procedure with the network. Therefore, the UE 402 may come out of the idle mode or inactive mode, and may connect to a base station in the current cell of the UE 402 (e.g., the BS-2 406) to perform a registration procedure 442 with the core network via the BS-2 406.

At 444 and 446, during the registration procedure 442, the UE 402 obtains information indicating a set of allowed network slice instances from the AMF-2 414 via the BS-2 406. In some examples, the UE 402 may obtain new allowed NSSAI including one or more new single-network slice selection assistance information (S-NSSAI) identities. For example, the set of allowed network slice instances from the AMF-2 414 may include the second network slice 422. The UE 402 may connect to the second network slice 422 and may establish a second PDU session 452. Therefore, in some examples, the UE 402 may establish a new PDU session (e.g., the second PDU session 452) before any applications running on the UE 402 begin to initiate the transmission and/or reception of user data. The UE 402 may transmit user data to the core network and/or may receive user data from the core network via the second data path 454. For example, the UE 402 may receive user data from the UPF-2 416 via the BS-2 406. As another example, the UE 402 may transmit user data to the UPF-2 416 via the BS-2 406.

At 456, the UE 402 may release the connection to the first network slice 420. In some examples, the connection to the first network slice 420 may include a first PDU session. In these examples, the UE 420 may release the first PDU session. At 458, the UE 402 may enter a connected mode (e.g., RRC connected mode) . At 460, the UE 402 in the connected mode may transmit user data to the UPF-2 416 via the BS-2 406. In other examples, at 460, the UE 402 in the connected mode may receive user data from the UPF-2 416 via the BS-2 406.

FIGS. 5A and 5B illustrate a signal flow diagram in accordance with various aspects of the present disclosure. The UE 502 may correspond, for example, to any of the UEs shown in FIGs. 1-3. The first base station (BS-1) 504 and/or the second base station (BS-2) 506 may be any of the base stations shown in FIGS. 1 and 3. In the example shown in FIGS. 5A and 5B, the core network includes a first AMF (AMF-1) 508, a first UPF (UPF-1) 510, a first SMF (SMF-1) 512, a second AMF (AMF-2) 514, a second UPF (UPF-2) 516, a second SMF (SMF-2) 518. Each of the

AMF

508, 514,

UPF

510, 516, and

SMF

512, 518 may correspond, for example, to the corresponding nodes illustrated in FIG. 2. In the example of FIGS. 5A and 5B, AMF-1 508, UPF-1 510, and SMF-1 512 are associated with a first network slice 520 (also referred to as a first network slice instance) , and AMF-2 514, UPF-2 516, and SMF-2 518 are associated with a second network slice 422 (also referred to as a second network slice instance) .

With reference to FIG. 5A, at 524, the UE 502 may establish a connection to the BS-1 404 and may enter a connected mode (e.g., a radio resource control (RRC) connected mode) . The UE 502 may perform a registration procedure 526 with the core network via the BS-1 504. At 528 and 530, during the registration procedure 526, the UE 502 obtains information indicating a set of allowed network slice instances from the AMF-1 508 via the BS-1 504. In some examples, the UE 502 may obtain the information indicating the set of allowed network slice instances via NAS level signaling. For example, the UE 502 may obtain allowed NSSAI including one or more single-network slice selection assistance information (S-NSSAI) identities. In the example of FIG. 5A, the allowed NSSAI may include the S-NSSAI identity of the first network slice 520. The network slice type of the first network slice 520 may be mMTC, for example.

At 532 and 534, the UE 502 further obtains a set of tracking area lists for the set of network slice instances from the AMF-1 508 via the BS-1 504. Each tracking area list in the set of tracking area lists may be specific to a network slice instance in the set of network slice instances. For example, each tracking area list may be an S-NSSAI specific tracking area list. Accordingly, in some examples, the UE 502 may maintain a different tracking area list for each S-NSSAI in the allowed NSSAI. In the example of FIG. 5A, the set of tracking area lists may include a tracking area list for the S-NSSAI identity of the first network slice 520, where the tracking area list includes one or more available tracking areas (e.g., one or more tracking area IDs) for the first network slice 520.

The UE 502 may connect to the first network slice 520 and may establish a first PDU session 536. In this example, the UE 502 may be located in a first tracking area of the network and the tracking area list specific to the first network slice 520 may include the first tracking area. The UE 502 may transmit user data to the core network and/or may receive user data from the core network via the first data path 538. For example, the UE 502 may receive user data from the UPF-1 510 via the BS-1 504. As another example, the UE 502 may transmit user data to the UPF-1 510 via the BS-1 504. In some examples, there may be a continuous DL/UL data flow (e.g., over a PDU session) between the UE 502 and the first network slice 520.

At 540, the UE 502 may be in motion and may receive a handover command from the BS-1 504. For example, the handover command may indicate a target cell that includes the BS-2 506. In some examples, the handover command may be an RRC reconfiguration message including the information needed to access the target cell, such as the target cell ID and other suitable information. At 542, the UE 502 determines that the target tracking area of the UE 502 (e.g., the tracking area of the target cell to which the BS-1 504 will hand over to) is not included in the set of tracking area lists for the set of network slice instances. In other words, the first network slice 520 may not be available in the target cell. For example, the UE 402 may compare the tracking area ID of the target cell to one or more tracking area IDs included in the set of tracking area lists for the set of network slice instances (e.g., the one or more tracking area IDs included in the S-NSSAI specific tracking area list (s) previously received from the AMF-2 508) . If the tracking area ID of the target cell of the UE 402 does not match any of the tracking area IDs in the set of tracking area lists, the UE 502 may determine that the tracking area ID of the target cell is not included in the set of tracking area lists for the set of network slice instances.

With reference to FIG. 5B, at 544, the UE 502 initiates a registration procedure 546 with the core network via the target cell when the tracking area of the target cell is not included in the set of tracking area lists (e.g., in the S-NSSAI specific tracking area list (s) ) . Therefore, the UE 502 may connect to a base station in the target cell of the UE 502 (e.g., the BS-2 406) to perform the registration procedure 546 with the core network.

At 548 and 550, during the registration procedure 546, the UE 502 obtains information indicating a set of allowed network slice instances from the AMF-2 514 via the BS-2 506. In some examples, the UE 502 may obtain new allowed NSSAI including one or more new single-network slice selection assistance information (S-NSSAI) identities. For example, the set of allowed network slice instances from the AMF-2 514 may include the second network slice 522. The available tracking area of the second network slice 522 may include the target cell. In some aspects of the disclosure, the UE 502 may update the set of tracking area lists to include the set of allowed network slice instances from the AMF-2 514 (e.g., the S-NSSAI identity of the second network slice 522) .

The UE 502 may connect to the second network slice 522 and may establish a second PDU session 552. The second PDU session 552 may be for a user application, for example, and may be based on a UE route selection policy (URSP) . The UE 502 may transmit user data to the core network and/or may receive user data from the core network via the second data path 554. For example, the UE 502 may receive user data from the UPF-2 516 via the BS-2 506. As another example, the UE 502 may transmit user data to the UPF-2 516 via the BS-2 506.

At 556, the UE 556 may perform and complete the handover operation with the BS-2 506. At 558, the UE 502 may release the connection to the first network slice 520. In some examples, the connection to the first network slice 520 may include a first PDU session. In these examples, the UE 520 may release the first PDU session. It should be noted that since the UE 502 may connect to the second network slice 522 and establish the second PDU session 552 prior to moving to the target cell (e.g., prior to completing the handover operation) , the UE 502 may achieve a seamless handover of a network slice instance (e.g., from the first network slice instance 520 to the second network slice instance 522) . This may preserve a continuous DL/UL data flow between the UE 502 and the core network, despite the need for a handover operation to a target cell that may not include an active network slice of the UE 502. At 560, the UE 502 may transmit user data to the UPF-2 516 via the BS-2 506. In other examples, at 560, the UE 502 may receive user data from the UPF-2 516 via the BS-2 506.

FIG. 6 is a block diagram illustrating an example of a hardware implementation for a user equipment (UE) 600 employing a processing system 614. For example, the UE 600 may correspond to any of the UEs shown and described above in reference to FIGs. 1-5.

The UE 600 may be implemented with a processing system 614 that includes one or more processors 604. Examples of processors 604 include microprocessors, microcontrollers, digital signal processors (DSPs) , field programmable gate arrays (FPGAs) , programmable logic devices (PLDs) , state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionality described throughout this disclosure. In various examples, the UE 600 may be configured to perform any one or more of the functions described herein. That is, the processor 604, as utilized in the UE 600, may be used to implement any one or more of the processes and procedures described below and illustrated in FIG. 7.

In this example, the processing system 614 may be implemented with a bus architecture, represented generally by the bus 602. The bus 602 may include any number of interconnecting buses and bridges depending on the specific application of the processing system 614 and the overall design constraints. The bus 602 links together various circuits including one or more processors (represented generally by the processor 604) , a memory 605, and computer-readable media (represented generally by the computer-readable medium 606) . The bus 602 may also link various other circuits such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art, and therefore, will not be described any further.

A bus interface 608 provides an interface between the bus 602 and a transceiver 610. The transceiver 610 provides a means for communicating with various other apparatus over a transmission medium (e.g., air interface) . Depending upon the nature of the apparatus, a user interface 612 (e.g., keypad, display, touch screen, speaker, microphone, control knobs, etc. ) may also be provided. Of course, such a user interface 612 is optional, and may be omitted in some examples.

The processor 604 is responsible for managing the bus 602 and general processing, including the execution of software stored on the computer-readable medium 606. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. The software, when executed by the processor 604, causes the processing system 614 to perform the various functions described below for any particular apparatus. The computer-readable medium 606 and the memory 605 may also be used for storing data that is manipulated by the processor 604 when executing software.

The computer-readable medium 606 may be a non-transitory computer-readable medium. A non-transitory computer-readable medium includes, by way of example, a magnetic storage device (e.g., hard disk, floppy disk, magnetic strip) , an optical disk (e.g., a compact disc (CD) or a digital versatile disc (DVD) ) , a smart card, a flash memory device (e.g., a card, a stick, or a key drive) , a random access memory (RAM) , a read only memory (ROM) , a programmable ROM (PROM) , an erasable PROM (EPROM) , an electrically erasable PROM (EEPROM) , a register, a removable disk, and any other suitable medium for storing software and/or instructions that may be accessed and read by a computer. The computer-readable medium 606 may reside in the processing system 614, external to the processing system 614, or distributed across multiple entities including the processing system 614. The computer-readable medium 606 may be embodied in a computer program product. By way of example, a computer program product may include a computer-readable medium in packaging materials. In some examples, the computer-readable medium 606 may be part of the memory 605. Those skilled in the art will recognize how best to implement the described functionality presented throughout this disclosure depending on the particular application and the overall design constraints imposed on the overall system.

In some aspects of the disclosure, the processor 604 may include circuitry configured for various functions. For example, the processor 604 may include tracking area list obtaining circuitry 640 configured to obtain a set of tracking area lists for a set of network slice instances. In some aspects, each of the set of tracking area lists is associated with a respective network slice instance in the set of network slice instances.

The processor 604 may further include tracking area determination circuitry 642 configured to determine that a current tracking area of the UE or a target tracking area of the UE is excluded from the set of tracking area lists. In some aspects of the disclosure, the tracking area determination circuitry 642 may be configured to determine a tracking area of a current cell of the UE or a target cell of the UE, and compare the tracking area of the current cell of the UE or the target cell of the UE to one or more allowed tracking areas in the set of tracking area lists. In some aspects, the tracking area determination circuitry 642 may determine that the current tracking area of the UE is excluded from the set of tracking area lists when the UE is in an idle mode or an inactive mode. In some aspects, the tracking area determination circuitry 642 may be configured to determine that the target tracking area of the UE is excluded from the set of tracking area lists in response to a handover command from a network.

The processor 604 may further include network slice information obtaining circuitry 644 configured to obtain information indicating at least one allowed network slice instance for the current tracking area of the UE or the target tracking area of the UE in response to a determination (e.g., a determination that a current tracking area of the UE or a target tracking area of the UE is excluded from the set of tracking area) . The network slice information obtaining circuitry 644 may be further configured to obtain information indicating the set of network slice instances.

The processor 604 may further include network slice connection establishment circuitry 646 configured to establish a first connection to at least one network slice instance in the set of network slice instances. The network slice connection establishment circuitry 646 may be further configured to establish a second connection to the at least one allowed network slice instance for the current tracking area of the UE or the target tracking area of the UE. In some examples, the first connection to the at least one network slice instance in the set of network slice instances includes a first protocol data unit (PDU) session, and the second connection to the at least one allowed network slice instance for the current tracking area of the UE or the target tracking area of the UE includes a second protocol data unit (PDU) session.

The processor 604 may further include network slice connection releasing circuitry 648 configured to release the first connection to the at least one network slice instance in the set of network slice instances after the second connection to the at least one allowed network slice instance for the current tracking area of the UE or the target tracking area of the UE is established.

In one or more examples, the computer-readable storage medium 606 may include tracking area list obtaining software 660 configured to obtain a set of tracking area lists for a set of network slice instances. In some aspects, each of the set of tracking area lists is associated with a respective network slice instance in the set of network slice instances. For example, the tracking area list obtaining software 660 may be configured to implement one or more of the functions described below in relation to FIG. 7, including, e.g., block 704.

In one or more examples, the computer-readable storage medium 606 may further include tracking area determination software 662 configured to determine that a current tracking area of the UE or a target tracking area of the UE is excluded from the set of tracking area lists. In some aspects of the disclosure, the tracking area determination software 662 may be configured to determine a tracking area of a current cell of the UE or a target cell of the UE, and compare the tracking area of the current cell of the UE or the target cell of the UE to one or more allowed tracking areas in the set of tracking area lists. In some aspects, the tracking area determination software 662 may determine that the current tracking area of the UE is excluded from the set of tracking area lists when the UE is in an idle mode or an inactive mode. In some aspects, the tracking area determination software 662 may be configured to determine that the target tracking area of the UE is excluded from the set of tracking area lists in response to a handover command from a network. For example, the tracking area determination software 662 may be configured to implement one or more of the functions described below in relation to FIG. 7, including, e.g., block 708.

In one or more examples, the computer-readable storage medium 606 may further include network slice information obtaining software 664 configured to obtain information indicating at least one allowed network slice instance for the current tracking area of the UE or the target tracking area of the UE in response to a determination (e.g., a determination that a current tracking area of the UE or a target tracking area of the UE is excluded from the set of tracking area) . The network slice information obtaining software 664 may be further configured to obtain information indicating the set of network slice instances. For example, the network slice information obtaining software 664 may be configured to implement one or more of the functions described below in relation to FIG. 7, including, e.g., blocks 702, 710.

In one or more examples, the computer-readable storage medium 606 may further include network slice connection establishment software 668 configured to establish a first connection to at least one network slice instance in the set of network slice instances. The network slice connection establishment software 668 may be further configured to establish a second connection to the at least one allowed network slice instance for the current tracking area of the UE or the target tracking area of the UE. In some examples, the first connection to the at least one network slice instance in the set of network slice instances includes a first protocol data unit (PDU) session, and the second connection to the at least one allowed network slice instance for the current tracking area of the UE or the target tracking area of the UE includes a second protocol data unit (PDU) session. For example, the network slice connection establishment software 668 may be configured to implement one or more of the functions described below in relation to FIG. 7, including, e.g., blocks 706, 712.

In one or more examples, the computer-readable storage medium 606 may further include network slice connection releasing software 670 configured to release the first connection to the at least one network slice instance in the set of network slice instances after the second connection to the at least one allowed network slice instance for the current tracking area of the UE or the target tracking area of the UE is established. For example, the network slice connection releasing software 670 may be configured to implement one or more of the functions described below in relation to FIG. 7, including, e.g., block 714.

FIG. 7 is a flow chart 700 of a method for wireless communication at a UE in accordance with some aspects of the present disclosure. As described below, some or all illustrated features may be omitted in a particular implementation within the scope of the present disclosure, and some illustrated features may not be required for implementation of all embodiments. In some examples, the process 700 may be carried out by the UE 600 illustrated in FIG. 6. In some examples, the process 700 may be carried out by any suitable apparatus or means for carrying out the functions or algorithm described below. In FIG. 7, optional operations are indicated with dashed blocks (e.g., blocks 702, 706, 712, 714) .

At block 702, the UE obtains information indicating a set of network slice instances. For example, with reference to FIG. 4A, at 424 and 426, the UE 402 obtains information indicating a set of allowed network slice instances from the AMF-1 408 via the BS-1 404. As another example, with reference to FIG. 5A, at 528 and 530, the UE 502 obtains information indicating a set of allowed network slice instances from the AMF-1 508 via the BS-1 504. For example, the network slice information obtaining circuitry 644, together with the transceiver 610, shown and described above in connection with FIG. 6 may obtain information indicating a set of network slice instances.

At block 704, the UE obtains a set of tracking area lists for the set of network slice instances, wherein each of the set of tracking area lists is associated with a respective network slice instance in the set of network slice instances. For example, with reference to FIG. 4A, at 428 and 430, the UE 402 obtains a set of tracking area lists for the set of network slice instances from the AMF-1 408 via the BS-1 404. As another example, with reference to FIG. 5A, at 532 and 534, the UE 502 obtains a set of tracking area lists for the set of network slice instances from the AMF-1 508 via the BS-1 504. For example, the tracking area list obtaining circuitry 640, together with the transceiver 610, shown and described above in connection with FIG. 6 may obtain a set of tracking area lists for the set of network slice instances.

At block 706, the UE establishes a first connection to at least one network slice instance in the set of network slice instances. For example, with reference to FIG. 4A, the UE 402 may connect to the first network slice 420 and may establish a first PDU session 432. For example, with reference to FIG. 5A, the UE 502 may connect to the first network slice 520 and may establish a first PDU session 536. For example, the network slice connection establishment circuitry 646, together with the transceiver 610, shown and described above in connection with FIG. 6 may establish a first connection to at least one network slice instance in the set of network slice instances.

At block 708, the UE determines that a current tracking area of the UE or a target tracking area of the UE is excluded from the set of tracking area lists. For example, with reference to FIG. 4A, at 438, the UE 402 determines that the current tracking area of the UE 402 is not included in the set of tracking area lists for the set of network slice instances. In some examples, the UE 402 may be in an idle mode or an inactive mode when determining that the current tracking area of the UE 402 is excluded from the set of tracking area lists. For example, with reference to FIG. 5A, at 542, the UE 502 determines that the target tracking area of the UE 502 (e.g., the tracking area of the cell to which the BS-1 504 will hand over to, such as the tracking area of the BS-2 504) is not included in the set of tracking area lists for the set of network slice instances. In some examples, the UE 502 determines that the target tracking area of the UE 502 is excluded from the set of tracking area lists in response to a handover command from a network. For example, the tracking area determination circuitry 642 shown and described above in connection with FIG. 6 may determine that a current tracking area of the UE or a target tracking area of the UE is excluded from the set of tracking area lists.

In some aspects, the UE determines that the current tracking area of the UE or the target tracking area of the UE is excluded from the set of tracking areas by determining a tracking area of a current cell of the UE or a target cell of the UE, and comparing the tracking area of the current cell of the UE or the target cell of the UE to one or more allowed tracking areas in the set of tracking area lists.

At block 710, the UE obtains information (e.g., the allowed NSSAI at 444, 446 in FIG. 4B, the allowed NSSAI at 548, 550 in FIG. 5B) indicating at least one allowed network slice instance for the current tracking area of the UE or the target tracking area of the UE in response to the determination. For example, the network slice information obtaining circuitry 644, together with the transceiver 610, shown and described above in connection with FIG. 6 may obtain information indicating at least one allowed network slice instance for the current tracking area of the UE or the target tracking area of the UE in response to the determination.

At block 712, the UE establishes a second connection to the at least one allowed network slice instance for the current tracking area of the UE or the target tracking area of the UE. For example, the UE 402 may connect to the second network slice 422 and may establish a second PDU session 452. As another example, the UE 502 may connect to the second network slice 522 and may establish a second PDU session 552. For example, the network slice connection establishment circuitry 646, together with the transceiver 610, shown and described above in connection with FIG. 6 may establish a second connection to the at least one allowed network slice instance for the current tracking area of the UE or the target tracking area of the UE.

At block 714, the UE releases the first connection to the at least one network slice instance in the set of network slice instances after the second connection to the at least one allowed network slice instance for the current tracking area of the UE or the target tracking area of the UE is established. This may ensure that the UE does not experience a loss of service (e.g., a break in a PDU session) as the UE moves into a tracking area with no network slice availability. For example, with reference to FIG. 4B, at 456, the UE 402 may release the connection to the first network slice 420. In some examples, the connection to the first network slice 420 may include a first PDU session. In these examples, the UE 420 may release the first PDU session. As another example, with reference to FIG. 5B, at 558, the UE 502 may release the connection to the first network slice 520. In some examples, the connection to the first network slice 520 may include a first PDU session. In these examples, the UE 520 may release the first PDU session. For example, the network slice connection releasing circuitry 648, together with the transceiver 610, shown and described above in connection with FIG. 6 may release the first connection to the at least one network slice instance in the set of network slice instances after the second connection to the at least one allowed network slice instance for the current tracking area of the UE or the target tracking area of the UE is established

FIG. 8 is a flow chart 800 of a method for wireless communication at a UE in accordance with some aspects of the present disclosure. As described below, some or all illustrated features may be omitted in a particular implementation within the scope of the present disclosure, and some illustrated features may not be required for implementation of all embodiments. In some examples, the process 800 may be carried out by the UE 600 illustrated in FIG. 6. In some examples, the process 800 may be carried out by any suitable apparatus or means for carrying out the functions or algorithm described below.

At block 802, the UE obtains a set of tracking area lists for a set of network slice instances, wherein each of the set of tracking area lists is associated with a respective network slice instance in the set of network slice instances. For example, with reference to FIG. 4A, at 428 and 430, the UE 402 obtains a set of tracking area lists for the set of network slice instances from the AMF-1 408 via the BS-1 404. As another example, with reference to FIG. 5A, at 532 and 534, the UE 502 obtains a set of tracking area lists for the set of network slice instances from the AMF-1 508 via the BS-1 504. For example, the tracking area list obtaining circuitry 640, together with the transceiver 610, shown and described above in connection with FIG. 6 may obtain a set of tracking area lists for the set of network slice instances.

At block 804, the UE determines that a current tracking area of the UE or a target tracking area of the UE is excluded from the set of tracking area lists. For example, with reference to FIG. 4A, at 438, the UE 402 determines that the current tracking area of the UE 402 is not included in the set of tracking area lists for the set of network slice instances. In some examples, the UE 402 may be in an idle mode or an inactive mode when determining that the current tracking area of the UE 402 is excluded from the set of tracking area lists. For example, with reference to FIG. 5A, at 542, the UE 502 determines that the target tracking area of the UE 502 (e.g., the tracking area of the cell to which the BS-1 504 will hand over to, such as the tracking area of the BS-2 504) is not included in the set of tracking area lists for the set of network slice instances. In some examples, the UE 502 determines that the target tracking area of the UE 502 is excluded from the set of tracking area lists in response to a handover command from a network. For example, the tracking area determination circuitry 642 shown and described above in connection with FIG. 6 may determine that a current tracking area of the UE or a target tracking area of the UE is excluded from the set of tracking area lists.

At block 806, the UE obtains information (e.g., the allowed NSSAI at 444, 446 in FIG. 4B, the allowed NSSAI at 548, 550 in FIG. 5B) indicating at least one allowed network slice instance for the current tracking area of the UE or the target tracking area of the UE in response to the determination. For example, the network slice information obtaining circuitry 644, together with the transceiver 610, shown and described above in connection with FIG. 6 may obtain information indicating at least one allowed network slice instance for the current tracking area of the UE or the target tracking area of the UE in response to the determination.

In one configuration, the apparatus 600 for wireless communication includes means for obtaining information indicating the set of network slice instances, means for obtaining a set of tracking area lists for a set of network slice instances, wherein each of the set of tracking area lists is associated with a respective network slice instance in the set of network slice instances, means for determining that a current tracking area of the apparatus or a target tracking area of the apparatus is excluded from the set of tracking area lists, means for obtaining information indicating at least one allowed network slice instance for the current tracking area of the apparatus or the target tracking area of the apparatus in response to the determination, means for establishing a first connection to at least one network slice instance in the set of network slice instances, means for establishing a second connection to the at least one allowed network slice instance for the current tracking area of the apparatus or the target tracking area of the apparatus, and means for releasing the first connection to the at least one network slice instance in the set of network slice instances after the second connection to the at least one allowed network slice instance for the current tracking area of the apparatus or the target tracking area of the apparatus is established.

In one aspect, the aforementioned means may be the processor 604 shown in FIG. 6 configured to perform the functions recited by the aforementioned means. In another aspect, the aforementioned means may be a circuit or any apparatus configured to perform the functions recited by the aforementioned means.

Of course, in the above examples, the circuitry included in the processor 604 is merely provided as an example, and other means for carrying out the described functions may be included within various aspects of the present disclosure, including but not limited to the instructions stored in the computer-readable storage medium 606, or any other suitable apparatus or means described in any one of the FIGs. 1, 2, 3, 4 (including FIGS. 4A, 4B) , and/or 5 (including FIGS. 5A, 5B) , and utilizing, for example, the processes and/or algorithms described herein in relation to FIG. 7.

Several aspects of a wireless communication network have been presented with reference to an exemplary implementation. As those skilled in the art will readily appreciate, various aspects described throughout this disclosure may be extended to other telecommunication systems, network architectures and communication standards.

By way of example, various aspects may be implemented within other systems defined by 3GPP, such as Long-Term Evolution (LTE) , the Evolved Packet System (EPS) , the Universal Mobile Telecommunication System (UMTS) , and/or the Global System for Mobile (GSM) . Various aspects may also be extended to systems defined by the 3rd Generation Partnership Project 2 (3GPP2) , such as CDMA2000 and/or Evolution-Data Optimized (EV-DO) . Other examples may be implemented within systems employing IEEE 802.11 (Wi-Fi) , IEEE 802.16 (WiMAX) , IEEE 802.20, Ultra-Wideband (UWB) , Bluetooth, and/or other suitable systems. The actual telecommunication standard, network architecture, and/or communication standard employed will depend on the specific application and the overall design constraints imposed on the system.

Within the present disclosure, the word “exemplary” is used to mean “serving as an example, instance, or illustration. ” Any implementation or aspect described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects of the disclosure. Likewise, the term “aspects” does not require that all aspects of the disclosure include the discussed feature, advantage or mode of operation. The term “coupled” is used herein to refer to the direct or indirect coupling between two objects. For example, if object A physically touches object B, and object B touches object C, then objects A and C may still be considered coupled to one another-even if they do not directly physically touch each other. For instance, a first object may be coupled to a second object even though the first object is never directly physically in contact with the second object. The terms “circuit” and “circuitry” are used broadly, and intended to include both hardware implementations of electrical devices and conductors that, when connected and configured, enable the performance of the functions described in the present disclosure, without limitation as to the type of electronic circuits, as well as software implementations of information and instructions that, when executed by a processor, enable the performance of the functions described in the present disclosure. As used herein, the term “obtaining” may include one or more actions including, but not limited to, receiving, generating, determining, or any combination thereof.

One or more of the components, steps, features and/or functions illustrated in FIGs. 1-7 may be rearranged and/or combined into a single component, step, feature or function or embodied in several components, steps, or functions. Additional elements, components, steps, and/or functions may also be added without departing from novel features disclosed herein. The apparatus, devices, and/or components illustrated in FIGs. 1-7 may be configured to perform one or more of the methods, features, or steps described herein. The novel algorithms described herein may also be efficiently implemented in software and/or embedded in hardware.

It is to be understood that the specific order or hierarchy of steps in the methods disclosed is an illustration of exemplary processes. Based upon design preferences, it is understood that the specific order or hierarchy of steps in the methods may be rearranged. The accompanying method claims present elements of the various steps in a sample order, and are not meant to be limited to the specific order or hierarchy presented unless specifically recited therein.

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 are 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. 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 and b; a and c; b and c; and a, b and c. 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.

Claims

A method for wireless communication at a user equipment, the method comprising:

obtaining a set of tracking area lists for a set of network slice instances, wherein each of the set of tracking area lists is associated with a respective network slice instance in the set of network slice instances;

determining that a current tracking area of the user equipment or a target tracking area of the user equipment is excluded from the set of tracking area lists; and

obtaining information indicating at least one allowed network slice instance for the current tracking area of the user equipment or the target tracking area of the user equipment in response to the determination.
The method of claim 1, further comprising:

obtaining information indicating the set of network slice instances.
The method of any of claim 1 or 2, further comprising:

establishing a first connection to at least one network slice instance in the set of network slice instances; and

establishing a second connection to the at least one allowed network slice instance for the current tracking area of the user equipment or the target tracking area of the user equipment.
The method of claim 3, further comprising:

releasing the first connection to the at least one network slice instance in the set of network slice instances after the second connection to the at least one allowed network slice instance for the current tracking area of the user equipment or the target tracking area of the user equipment is established.
The method of any of claim 1, 2 or 3, wherein the determining that the current tracking area of the user equipment or the target tracking area of the user equipment is excluded from the set of tracking area lists comprises:

determining a tracking area of a current cell of the user equipment or a target cell of the user equipment; and

comparing the tracking area of the current cell of the user equipment or the target cell of the user equipment to one or more allowed tracking areas in the set of tracking area lists.
The method of any of claim 1, 2, or 5, wherein the user equipment is in an idle mode or an inactive mode when determining that the current tracking area of the user equipment is excluded from the set of tracking area lists.
The method of any of claim 1, 2, 3, or 5 wherein the determining that the target tracking area of the user equipment is excluded from the set of tracking area lists is performed in response to a handover command from a network.
The method of claim 3, wherein the first connection to the at least one network slice instance in the set of network slice instances includes a first protocol data unit (PDU) session, and the second connection to the at least one allowed network slice instance for the current tracking area of the user equipment or the target tracking area of the user equipment includes a second protocol data unit (PDU) session.
An apparatus for wireless communication, comprising:

means for obtaining a set of tracking area lists for a set of network slice instances, wherein each of the set of tracking area lists is associated with a respective network slice instance in the set of network slice instances;

means for determining that a current tracking area of the apparatus or a target tracking area of the apparatus is excluded from the set of tracking area lists; and

means for obtaining information indicating at least one allowed network slice instance for the current tracking area of the apparatus or the target tracking area of the apparatus in response to the determination.
The apparatus of claim 9, further comprising:

means for obtaining information indicating the set of network slice instances.
The apparatus of any of claim 9 or 10, further comprising:

means for establishing a first connection to at least one network slice instance in the set of network slice instances; and

means for establishing a second connection to the at least one allowed network slice instance for the current tracking area of the apparatus or the target tracking area of the apparatus.
The apparatus of claim 11, further comprising:

means for releasing the first connection to the at least one network slice instance in the set of network slice instances after the second connection to the at least one allowed network slice instance for the current tracking area of the apparatus or the target tracking area of the apparatus is established.
The apparatus of any of claim 9, 10, or 11, wherein the means for determining that the current tracking area of the apparatus or the target tracking area of the apparatus is excluded from the set of tracking area lists is configured to:

determine a tracking area of a current cell of the apparatus or a target cell of the apparatus; and

compare the tracking area of the current cell of the apparatus or the target cell of the apparatus to one or more allowed tracking areas in the set of tracking area lists.
The apparatus of any of claim 9, 10, or 13, wherein the apparatus is in an idle mode or an inactive mode when determining that the current tracking area of the apparatus is excluded from the set of tracking area lists.
The apparatus of any of claim 9, 10, 11, or 13 wherein the means for determining that the target tracking area of the apparatus is excluded from the set of tracking area lists is configured to perform the determination in response to a handover command from a network.
The apparatus of claim 11, wherein the first connection to the at least one network slice instance in the set of network slice instances includes a first protocol data unit (PDU) session, and the second connection to the at least one allowed network slice instance for the current tracking area of the apparatus or the target tracking area of the apparatus includes a second protocol data unit (PDU) session.
A user equipment, comprising:

a transceiver;

a memory; and

a processor communicatively coupled to the transceiver and the memory, wherein the processor and the memory are configured to:

obtain a set of tracking area lists for a set of network slice instances, wherein each of the set of tracking area lists is associated with a respective network slice instance in the set of network slice instances;

determine that a current tracking area of the user equipment or a target tracking area of the user equipment is excluded from the set of tracking area lists; and

obtain information indicating at least one allowed network slice instance for the current tracking area of the user equipment or the target tracking area of the user equipment in response to the determination.
The user equipment of claim 17, wherein the processor and memory are further configured to:

obtain information indicating the set of network slice instances.
The user equipment of any of claim 17 or 18, wherein the processor and memory are further configured to:

establish a first connection to at least one network slice instance in the set of network slice instances; and

establish a second connection to the at least one allowed network slice instance for the current tracking area of the user equipment or the target tracking area of the user equipment.
The user equipment of claim 19, wherein the processor and memory are further configured to:

release the first connection to the at least one network slice instance in the set of network slice instances after the second connection to the at least one allowed network slice instance for the current tracking area of the user equipment or the target tracking area of the user equipment is established.
The user equipment of any of claim 17, 18 or 19, wherein the processor and memory configured to determine that the current tracking area of the user equipment or the target tracking area of the user equipment is excluded from the set of tracking area lists are further configured to:

determine a tracking area of a current cell of the user equipment or a target cell of the user equipment; and

compare the tracking area of the current cell of the user equipment or the target cell of the user equipment to one or more allowed tracking areas in the set of tracking area lists.
The user equipment of any of claim 17, 18, or 21, wherein the user equipment is in an idle mode or an inactive mode when the processor and memory determine that the current tracking area of the user equipment is excluded from the set of tracking area lists.
The user equipment of any of claim 17, 18, 19, or 21 wherein the processor and memory determine that the target tracking area of the user equipment is excluded from the set of tracking area lists in response to a handover command from a network.
The user equipment of claim 19, wherein the first connection to the at least one network slice instance in the set of network slice instances includes a first protocol data unit (PDU) session, and the second connection to the at least one allowed network slice instance for the current tracking area of the user equipment or the target tracking area of the user equipment includes a second protocol data unit (PDU) session.
An article of manufacture for use by a user equipment in a wireless communication network, the article comprising:

a computer-readable medium having stored therein instructions executable by one or more processors of the user equipment to:

obtain a set of tracking area lists for a set of network slice instances, wherein each of the set of tracking area lists is associated with a respective network slice instance in the set of network slice instances;

determine that a current tracking area of the user equipment or a target tracking area of the user equipment is excluded from the set of tracking area lists; and

obtain information indicating at least one allowed network slice instance for the current tracking area of the user equipment or the target tracking area of the user equipment in response to the determination.
The article of claim 25, wherein the instructions executable by the one or more processors of the user equipment are further configured to:

obtain information indicating the set of network slice instances.
The article of any of claim 25 or 26, wherein the instructions executable by the one or more processors of the user equipment are further configured to:

establish a first connection to at least one network slice instance in the set of network slice instances; and

establish a second connection to the at least one allowed network slice instance for the current tracking area of the user equipment or the target tracking area of the user equipment.
The article of claim 27, wherein the instructions executable by the one or more processors of the user equipment are further configured to:

release the first connection to the at least one network slice instance in the set of network slice instances after the second connection to the at least one allowed network slice instance for the current tracking area of the user equipment or the target tracking area of the user equipment is established.
The article of any of claim 25, 26, or 27, wherein the instructions executable by the one or more processors of the user equipment configured to determine that the current tracking area of the user equipment or the target tracking area of the user equipment is excluded from the set of tracking area lists are further configured to:

determine a tracking area of a current cell of the user equipment or a target cell of the user equipment; and

compare the tracking area of the current cell of the user equipment or the target cell of the user equipment to one or more allowed tracking areas in the set of tracking area lists.
The article of any of claim 25, 26, or 29, wherein the instructions configured to determine that the current tracking area of the user equipment is excluded from the set of tracking area lists are further configured to:

determine that the current tracking area of the user equipment is excluded from the set of tracking area lists when the user equipment is in an idle mode or an inactive mode.
The article of any of claim 25, 26, 27, or 29, wherein the instructions configured to determine that the target tracking area of the user equipment is excluded from the set of tracking area lists are further configured to:

determine that the target tracking area of the user equipment is excluded from the set of tracking area lists in response to a handover command from a network.
The article of claim 27, wherein the first connection to the at least one network slice instance in the set of network slice instances includes a first protocol data unit (PDU) session, and the second connection to the at least one allowed network slice instance for the current tracking area of the user equipment or the target tracking area of the user equipment includes a second protocol data unit (PDU) session.