Methods, architectures, devices and systems for supporting network slice service areas

Abstract

Methods, architectures, devices, and systems are described for supporting network slice service areas. The WTRU includes a processor and a transceiver configured to transmit a first registration request message including an SSSA information support indication and a first requested NSSAI, where the first requested NSSAI includes a set of one or more S-NSSAIs; receiving, in response to the first registration request message, a first registration acceptance message including information indicating the first RA and SSSA information indicating that a first S-NSSAI included in the first requested NSSAI is rejected and indicating a set of TAs in the first RA that do not support the first S-NSSAI; transmitting a second registration request message including information indicating a second requested NSSAI based on the WTRU moving to a TA not included in the set of TAs in the first RA, wherein the second requested NSSAI includes at least the first S-NSSAI; and receiving, in response to the second registration request message, a second registration acceptance message including information indicating that at least the first S-NSSAI included in the second requested NSSAI is allowed.

Description

[0001] This application is a divisional application of a Chinese patent application with an application date of January 23, 2023, an application number of 202380023234.5 (international application number PCT / US2023 / 011308), and an invention title of "Methods, Architectures, Devices, and Systems for Supporting Network Slice Service Areas".

[0002] Cross - reference to related applications

[0003] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 303,574, filed on January 27, 2023, which is incorporated herein by reference. Technical field

[0004] The present disclosure generally relates to the fields of communications, software, and coding, including, for example, methods, architectures, devices, and systems related to network slicing and mobility management. Summary of the invention

[0005] In certain representative embodiments, a wireless transmit / receive unit (WTRU) is configured to perform (e.g., implement a method) actions that include sending (e.g., to a network entity) a first registration request message associated with a first tracking area (TA) of a registration area (RA). For example, the first registration request may include (1) information indicating a set of slices requested by the WTRU. The WTRU may receive (e.g., from the network entity) a first registration acceptance message that may include (1) information indicating that a first slice of the set of slices is rejected and (2) slice - specific service area (SSSA) information indicating at least one second TA of the RA in which the first slice is available. Under the condition (e.g., after) that the WTRU receives the SSSA and the WTRU has entered the at least one second TA, the WTRU may send (e.g., to the network entity) a second registration request message associated with the second TA of the RA. For example, the second registration request may include (1) information indicating at least the first slice of the set of slices requested by the WTRU. The WTRU may also receive (e.g., from the network entity) a second registration acceptance message that may include (1) information indicating that the WTRU is allowed to access the first slice of the set of slices in the second TA.

[0006] In certain representative embodiments, the information indicating the set of slices requested by the WTRU may be provided as network slice selection assistance information (NSSAI).

[0007] In certain representative embodiments, the RA includes at least the first TA and the second TA.

[0008] In certain representative embodiments, the information indicating that the first slice of the set of slices is rejected may be provided as a single NSSAI (S-NSSAI).

[0009] In certain representative embodiments, the SSSA information may indicate that the first slice is accessible in TAs in the RA other than the first TA.

[0010] In certain representative embodiments, the first registration acceptance message may include a slice rejection cause code that indicates that the first slice is rejected only for the current TA and not for the entire RA.

[0011] In certain representative embodiments, the first registration acceptance message may include a service area restricted NSSAI information element that indicates that one or more slices in the set of slices are accessible in less than all TAs in the RA.

[0012] In certain representative embodiments, the first registration request message may include information indicating that the WTRU understands or is capable of receiving SSSA information. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] A more detailed understanding can be obtained from the following detailed description, which is given by way of example in conjunction with its accompanying drawings. Like the detailed description, the figures in such drawings are examples. Accordingly, the drawings (FIGs.) and the detailed description should not be considered restrictive, and other equally valid examples are possible and contemplated. Additionally, like reference numerals (“ref.”) in the figures indicate like elements, and in which:

[0014] Figure 1A is a system diagram of an exemplary communication system;

[0015] Figure 1B is an example of Figure 1A a system diagram of an exemplary wireless transmit / receive unit (WTRU) that can be used within the communication system shown;

[0016] Figure 1C is an example of Figure 1A a system diagram of an exemplary radio access network (RAN) and an exemplary core network (CN) that can be used within the communication system shown;

[0017] Figure 1D is an example of Figure 1A a system diagram of another exemplary RAN and another exemplary CN that can be used within the communication system shown;

[0018] Figure 2is a flowchart illustrating an example scenario where a WTRU attempts to register with a slice that is not available in a tracking area; and

[0019] Figure 3 is a flowchart illustrating an example scenario where a WTRU can use messaging from the RAN to determine slice support;

[0020] Figure 4 is a program diagram illustrating an example program for slice registration;

[0021] Figure 5 is a program diagram illustrating another example program for slice registration;

[0022] Figure 6 is a program diagram illustrating an example program for slice deregistration;

[0023] Figure 7 is a program diagram illustrating another example program for slice deregistration;

[0024] Figure 8 is a program diagram illustrating an example program for slice registration;

[0025] Figure 9 is a program diagram illustrating another example program for slice registration;

[0026] Figure 10 is a program diagram illustrating an example program for slice deregistration;

[0027] Figure 11 is a program diagram illustrating another example program for slice deregistration;

[0028] Figure 12 is a program diagram illustrating another example program for slice registration; and

[0029] Figure 13 is a program diagram illustrating another example program for slice deregistration. Detailed Description

[0030] In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments and / or examples disclosed herein. However, it should be understood that such embodiments and examples may be practiced without some or all of the specific details set forth herein. In other instances, well-known methods, procedures, components, and circuits have not been described in detail so as not to obscure the following description. Further, embodiments and examples not specifically described herein may be practiced in lieu of, or in combination with, the embodiments and other examples explicitly, implicitly, and / or inherently described, disclosed, or otherwise provided (collectively referred to as "provided") herein. Although various embodiments are described and / or claimed herein in which devices, systems, apparatuses, etc. and / or any of their elements perform operations, processes, algorithms, functions, etc. and / or any part thereof, it should be understood that any embodiment described and / or claimed herein assumes that any device, system, apparatus, etc. and / or any of their elements is configured to perform any operation, process, algorithm, function, etc. and / or any part thereof.

[0031] Example Communication System

[0032] The methods, apparatuses, and systems provided herein are well-suited for communication involving both wired and wireless networks. With respect to Figures 1A to 1D An overview of various types of wireless devices and infrastructure is provided, where various elements of the network may utilize, execute, be arranged according to, and / or be adapted and / or configured for the methods, apparatuses, and systems provided herein.

[0033] Figure 1A FIG. is a system diagram of an exemplary communication system 100 in which one or more of the disclosed embodiments may be implemented. The communication system 100 may be a multi-access system that provides content such as voice, data, video, messaging, broadcasting, etc. to a plurality of wireless users. The communication system 100 may enable a plurality of wireless users to access such content through the sharing of system resources, including wireless bandwidth. For example, the communication system 100 may employ one or more channel access methods such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single carrier FDMA (SC-FDMA), zero tail (ZT) unique word (UW) discrete Fourier transform (DFT) spread OFDM (ZT UW DTS-sOFDM), unique word OFDM (UW-OFDM), resource block filtered OFDM, filter bank multicarrier (FBMC), etc.

[0034] As Figure 1AAs shown, the communication system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, a radio access network (RAN) 104 / 113, a core network (CN) 106 / 115, a public switched telephone network (PSTN) 108, the Internet 110, and other networks 112. However, it should be understood that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of the WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and / or communicate in a wireless environment. By way of example, the UEs 102a, 102b, 102c, 102d (where any one of the WTRUs may be referred to as a "station" and / or "STA") may be configured to transmit and / or receive wireless signals and may include (or may be) a user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a subscription-based unit, a pager, a cellular phone, a personal digital assistant (PDA), a smart phone, a laptop computer, a netbook, a personal computer, a wireless sensor, a hotspot or Mi-Fi device, an Internet of Things (IoT) device, a watch or other wearable device, a head-mounted display (HMD), a vehicle, a drone, a medical device and application (e.g., remote surgery), an industrial device and application (e.g., a robot and / or other wireless devices operating in an industrial and / or automation processing chain environment), a consumer electronic device, a device operating on a commercial and / or industrial wireless network, etc. Any one of the WTRUs 102a, 102b, 102c, and 102d may be interchangeably referred to as a UE.

[0035] The communication system 100 may further include base station 114a and / or base station 114b. Each of the base stations 114a, 114b may be any type of device configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, 102d to facilitate access to one or more communication networks such as the CN 106 / 115, the Internet 110, and / or the network 112. By way of example, the base stations 114a, 114b may be any one of a base transceiver station (BTS), a Node B (NB), an evolved Node B (eNB), a home Node B (HNB), a home evolved Node B (HeNB), a g Node B (gNB), an NR Node B (NR NB), a site controller, an access point (AP), a wireless router, etc. Although each of the base stations 114a, 114b is depicted as a single element, it should be understood that the base stations 114a, 114b may include any number of interconnected base stations and / or network elements.

[0036] Base station 114a may be part of RAN 104 / 113, which may also include other base stations and / or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), a relay node, etc. Base station 114a and / or base station 114b may be configured to transmit and / or receive wireless signals on one or more carrier frequencies, which may be referred to as a cell (not shown). These frequencies may be in licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. The cell may provide coverage of wireless services to a specific geographical area, which may be relatively fixed or may change over time. The cell may be further divided into cell sectors. For example, the cell associated with base station 114a may be divided into three sectors. Thus, in one embodiment, base station 114a may include three transceivers, i.e., one transceiver for each sector of the cell. In one embodiment, base station 114a may employ multiple-input multiple-output (MIMO) technology and may utilize multiple transceivers for each or any sector of the cell. For example, beamforming may be used to transmit and / or receive signals in a desired spatial direction.

[0037] Base stations 114a, 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d via air interface 116, which may be any suitable wireless communication link (e.g., radio frequency (RF), microwave, centimeter wave, millimeter wave, infrared (IR), ultraviolet (UV), visible light, etc.). Any suitable radio access technology (RAT) may be used to establish air interface 116.

[0038] More specifically, as noted above, communication system 100 may be a multi-access system and may employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, etc. For example, base station 114a in RAN 104 / 113 and WTRUs 102a, 102b, 102c may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may use Wideband CDMA (WCDMA) to establish air interface 116. WCDMA may include communication protocols such as High Speed Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA may include High Speed Downlink Packet Access (HSDPA) and / or High Speed Uplink Packet Access (HSUPA).

[0039] In an embodiment, base station 114a and WTRUs 102a, 102b, 102c may implement a radio technology such as evolved UMTS terrestrial radio access (E-UTRA), which may use Long Term Evolution (LTE) and / or Long Term Evolution-Advanced (LTE-A) and / or LTE-A Pro to establish an air interface 116.

[0040] In one embodiment, base station 114a and WTRUs 102a, 102b, 102c may implement a radio technology such as NR radio access, which may use New Radio (NR) to establish an air interface 116.

[0041] In an embodiment, base station 114a and WTRUs 102a, 102b, 102c may implement multiple radio access technologies. For example, base station 114a and WTRUs 102a, 102b, 102c may implement LTE radio access and NR radio access together using, for example, the dual connectivity (DC) principle. Thus, the air interface utilized by WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and / or transmissions sent to / from multiple types of base stations (e.g., eNBs and gNBs).

[0042] In one embodiment, base station 114a and WTRUs 102a, 102b, 102c may implement radio technologies such as IEEE 802.11 (i.e., Wi-Fi), IEEE 802.16 (i.e., WiMAX), CDMA2000, CDMA2000 1X, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile Communications (GSM), Enhanced Data Rate for GSM Evolution (EDGE), GSM EDGE (GERAN), etc.

[0043] Figure 1AThe base station 114b therein may be, for example, a wireless router, a home Node B, a home evolved Node B, or an access point, and may utilize any suitable RAT to facilitate wireless connectivity in a local area such as a business venue, a home, a vehicle, a campus, an industrial facility, an air corridor (e.g., for drones), a road, etc. In one embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.11 to establish a wireless local area network (WLAN). In an embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology (such as IEEE 802.15) to establish a wireless personal area network (WPAN). In one embodiment, the base station 114b and the WTRUs 102c, 102d may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.) to establish any one of a microcell, a picocell, or a femtocell. As Figure 1A shown, the base station 114b may have a direct connection to the Internet 110. Thus, the base station 114b may not need to access the Internet 110 via the CN 106 / 115.

[0044] The RAN 104 / 113 may communicate with the CN 106 / 115, which may be any type of network configured to provide voice, data, applications, and / or voice over Internet protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have different quality of service (QoS) requirements, such as different throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, etc. The CN 106 / 115 may provide call control, billing services, location-based services, prepaid calls, Internet connectivity, video distribution, etc., and / or perform advanced security functions such as user authentication. Although not shown in Figure 1A it, it should be understood that the RAN 104 / 113 and / or the CN 106 / 115 may communicate directly or indirectly with other RANs employing the same RAT or a different RAT as the RAN 104 / 113. For example, in addition to being connected to the RAN 104 / 113 that may utilize NR radio technology, the CN 106 / 115 may also communicate with another RAN (not shown) employing any one of GSM, UMTS, CDMA2000, WiMAX, E-UTRA, or Wi-Fi radio technology.

[0045] CN 106 / 115 can also act as a gateway for WTRU 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and / or other networks 112. The PSTN 108 may include a circuit-switched telephone network that provides plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices that use common communication protocols such as the Transmission Control Protocol (TCP), the User Datagram Protocol (UDP), and / or the Internet Protocol (IP) in the TCP / IP Internet protocol suite. The network 112 may include a wired communication network and / or a wireless communication network owned and / or operated by other service providers. For example, the network 112 may include another CN connected to one or more RANs, and the one or more RANs may employ the same RAT or a different RAT as the RAN 104 / 114.

[0046] Some or all of the WTRUs in the communication system 100, such as WTRU 102a, 102b, 102c, 102d, may include multimode capabilities (e.g., WTRU 102a, 102b, 102c, 102d may include multiple transceivers for communicating with different wireless networks over different wireless links). For example, Figure 1A the illustrated WTRU 102c may be configured to communicate with a base station 114a that may employ a cellular-based radio technology and with a base station 114b that may employ IEEE 802 radio technology.

[0047] Figure 1B is a system diagram of an exemplary WTRU 102. As Figure 1B shown, the WTRU 102 may include a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keypad 126, a display / touchpad 128, a non-removable memory 130, a removable memory 132, a power supply 134, a Global Positioning System (GPS) chipset 136, and / or other elements / peripherals 138, etc. It should be understood that the WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with the embodiments.

[0048] The processor 118 can be a general-purpose processor, a dedicated processor, a conventional processor, a digital signal processor (DSP), multiple microprocessors, one or more microprocessors associated with a DSP core, a controller, a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) circuit, any other type of integrated circuit (IC), a state machine, etc. The processor 118 can perform signal decoding, data processing, power control, input / output processing, and / or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 can be coupled to a transceiver 120, which can be coupled to a transmit / receive element 122. Although Figure 1B the processor 118 and the transceiver 120 are depicted as separate components, it should be understood that the processor 118 and the transceiver 120 can be integrated together, for example, in an electronic package or a chip.

[0049] The transmit / receive element 122 can be configured to transmit signals to or receive signals from a base station (e.g., base station 114a) via an air interface 116. For example, in one embodiment, the transmit / receive element 122 can be an antenna configured to transmit and / or receive RF signals. In an embodiment, the transmit / receive element 122 can be a transmitter / detector configured to transmit and / or receive, for example, IR, UV, or visible light signals. In one embodiment, the transmit / receive element 122 can be configured to transmit and / or receive both RF signals and optical signals. It should be understood that the transmit / receive element 122 can be configured to transmit and / or receive any combination of wireless signals.

[0050] Although the transmit / receive element 122 is depicted as a single element in Figure 1B the WTRU 102 can include any number of transmit / receive elements 122. For example, the WTRU 102 can employ MIMO technology. Thus, in one embodiment, the WTRU 102 can include two or more transmit / receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals via the air interface 116.

[0051] The transceiver 120 can be configured to modulate the signals to be transmitted by the transmit / receive element 122 and demodulate the signals received by the transmit / receive element 122. As noted above, the WTRU 102 can have multi-mode capabilities. For example, thus, the transceiver 120 can include multiple transceivers for enabling the WTRU 102 to communicate via multiple RATs (such as NR and IEEE 802.11).

[0052] The processor 118 of the WTRU 102 may be coupled to the speaker / microphone 124, keypad 126, and / or the display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or an organic light emitting diode (OLED) display unit) and may receive user input data therefrom. The processor 118 may also output user data to the speaker / microphone 124, keypad 126, and / or the display / touchpad 128. In addition, the processor 118 may access information from any type of suitable memory (such as non-removable memory 130 and / or removable memory 132) and store data in any type of suitable memory. The non-removable memory 130 may include random access memory (RAM), read-only memory (ROM), a hard disk, or any other type of memory storage device. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, etc. In other embodiments, the processor 118 may access information from a memory that is not physically located on the WTRU 102 (such as on a server or a home computer (not shown)) and store data in that memory.

[0053] The processor 118 may receive power from a power source 134 and may be configured to distribute and / or control power to other components in the WTRU 102. The power source 134 may be any suitable device for powering the WTRU 102. For example, the power source 134 may include one or more dry cell battery packs (e.g., nickel cadmium (NiCd), nickel zinc (NiZn), nickel metal hydride (NiMH), lithium ion (Li-ion), etc.), a solar cell, a fuel cell, etc.

[0054] The processor 118 may also be coupled to a GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to or instead of the information from the GPS chipset 136, the WTRU 102 may receive location information via an air interface 116 from a base station (e.g., base stations 114a, 114b) and / or determine its location based on the timing of signals received from two or more nearby base stations. It should be understood that the WTRU 102 may obtain location information by any suitable location determination method while remaining consistent with the embodiments.

[0055] The processor 118 may also be coupled to other elements / peripherals 138, which may include one or more software modules / units and / or hardware modules / units that provide additional features, functionality, and / or wired or wireless connectivity. For example, the element / peripheral 138 may include an accelerometer, an electronic compass, a satellite transceiver, a digital camera (e.g., for photos and / or videos), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands-free headset, a module, a frequency modulation (FM) radio unit, a digital music player, a media player, a video game player module, an Internet browser, a virtual reality and / or augmented reality (VR / AR) device, an activity tracker, etc. The element / peripheral 138 may include one or more sensors, which may be one or more of the following: a gyroscope, an accelerometer, a Hall effect sensor, a magnetometer, an orientation sensor, a proximity sensor, a temperature sensor, a time sensor; a geographical location sensor; an altimeter, a light sensor, a touch sensor, a magnetometer, a barometer, a gesture sensor, a biometric sensor, and / or a humidity sensor.

[0056] The WTRU 102 may include a full-duplex radio, for which the transmission and reception of some or all signals (e.g., associated with a particular subframe for both uplink (e.g., for transmission) and downlink (e.g., for reception)) may be concurrent and / or simultaneous. The full-duplex radio may include an interference management unit for reducing and / or substantially eliminating self-interference via signal processing performed by hardware (e.g., a choke) or via a processor (e.g., a separate processor (not shown) or via the processor 118). In one embodiment, the WTRU 102 may include a half-duplex radio, for which the transmission and reception of some or all signals (e.g., associated with a particular subframe for uplink (e.g., for transmission) or downlink (e.g., for reception)).

[0057] Figure 1C is a system diagram of the RAN 104 and the CN 106 according to an embodiment. As noted above, the RAN 104 may employ E-UTRA radio technology to communicate with the WTRU 102a, 102b, and 102c via the air interface 116. The RAN 104 may also communicate with the CN 106.

[0058] The RAN 104 may include evolved Node Bs 160a, 160b, 160c. However, it should be understood that the RAN 104 may include any number of evolved Node Bs while being consistent with the embodiments. Each of the evolved Node Bs 160a, 160b, 160c may include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c via the air interface 116. In one embodiment, the evolved Node Bs 160a, 160b, 160c may implement MIMO technology. Thus, the evolved Node B 160a, for example, may use multiple antennas to transmit wireless signals to the WTRU 102a and receive wireless signals from the WTRU.

[0059] Each of the evolved Node Bs 160a, 160b, and 160c may be associated with a particular cell (not shown) and may be configured to manage radio resource management decisions, handover decisions, user scheduling in the uplink (UL) and / or downlink (DL), etc. As Figure 1C shown, the evolved Node Bs 160a, 160b, 160c may communicate with each other via the X2 interface.

[0060] Figure 1C The illustrated CN 106 may include a Mobility Management Entity (MME) 162, a Serving Gateway (SGW) 164, and a Packet Data Network (PDN) Gateway (PGW) 166. Although each of the foregoing elements is depicted as part of the CN 106, it should be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0061] The MME 162 may be connected to each of the evolved Node Bs 160a, 160b, 160c in the RAN 104 via the S1 interface and may act as a control node. For example, the MME 162 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, bearer activation / deactivation, selecting a particular serving gateway during the initial attachment of the WTRUs 102a, 102b, 102c, etc. The MME 162 may provide control plane functions for interworking between the RAN 104 and other RANs (not shown) employing other radio technologies such as GSM and / or WCDMA.

[0062] The SGW 164 can be connected via the S1 interface to each of the evolved Node Bs 160a, 160b, 160c in the RAN 104. The SGW 164 can generally route and forward user data packets to / from the WTRUs 102a, 102b, 102c. The SGW 164 can perform other functions such as anchoring the user plane during handovers between evolved Node Bs, triggering paging when DL data is available for the WTRUs 102a, 102b, 102c, managing and storing the contexts of the WTRUs 102a, 102b, 102c, etc.

[0063] The SGW 164 can be connected to the PGW 166, which can provide the WTRUs 102a, 102b, 102c with access to a packet switched network (such as the Internet 110) to facilitate communication between the WTRUs 102a, 102b, 102c and IP-enabled devices.

[0064] The CN 106 can facilitate communication with other networks. For example, the CN 106 can provide the WTRUs 102a, 102b, 102c with access to a circuit switched network (such as the PSTN 108) to facilitate communication between the WTRUs 102a, 102b, 102c and traditional landline communication devices. For example, the CN 106 can include an IP gateway (such as an IP Multimedia Subsystem (IMS) server) that acts as an interface between the CN 106 and the PSTN 108 or can communicate with the IP gateway. In addition, the CN 106 can provide the WTRUs 102a, 102b, 102c with access to other networks 112, which can include other wired and / or wireless networks owned and / or operated by other service providers.

[0065] Although the WTRU is Figures 1A to 1D described as a wireless terminal, it is contemplated that in certain representative embodiments, such a terminal may (e.g., temporarily or permanently) use a wired communication interface with the communication network.

[0066] In a representative embodiment, the other network 112 can be a WLAN.

[0067] A WLAN in infrastructure basic service set (BSS) mode can have an access point (AP) for the BSS and one or more stations (STAs) associated with the AP. The AP can have access or an interface to a distribution system (DS) or another type of wired / wireless network that carries traffic to and / or from the BSS. Traffic originating from outside the BSS and destined for an STA can reach the STA through the AP and can be delivered to the STA. Traffic originating from an STA and destined for a destination outside the BSS can be sent to the AP to be delivered to the corresponding destination. Traffic between STAs within the BSS can be sent through the AP. For example, the source STA can send traffic to the AP, and the AP can deliver the traffic to the destination STA. Traffic between STAs within the BSS can be considered and / or referred to as peer-to-peer traffic. Peer-to-peer traffic can be sent between a source STA and a destination STA using direct link setup (DLS) (e.g., directly between them). In some representative embodiments, DLS can use 802.11e DLS or 802.11z tunnel DLS (TDLS). A WLAN using independent BSS (IBSS) mode may not have an AP, and STAs within the IBSS or using the IBSS (e.g., all STAs in the STA) can communicate directly with each other. The IBSS communication mode may sometimes be referred to as the "ad hoc" communication mode in this document.

[0068] When using 802.11ac infrastructure operation mode or a similar operation mode, the AP can transmit beacons on a fixed channel (such as the primary channel). The primary channel can be of a fixed width (e.g., 20 MHz bandwidth) or a width dynamically set via signaling. The primary channel can be the operating channel of the BSS and can be used by the STA to establish a connection with the AP. In some representative embodiments, for example, carrier sense multiple access / collision avoidance (CSMA / CA) can be implemented in an 802.11 system. For CSMA / CA, the STA (e.g., each STA) (including the AP) can sense the primary channel. If the primary channel is sensed / detected and / or determined to be busy by a particular STA, the particular STA can back off. One STA (e.g., only one station) can transmit at any given time in a given BSS.

[0069] High throughput (HT) STAs can communicate using 40 MHz wide channels, e.g., via a combination of the primary 20 MHz channel and an adjacent or non-adjacent 20 MHz channel to form a 40 MHz wide channel.

[0070] A very high throughput (VHT) STA can support channels that are 20 MHz, 40 MHz, 80 MHz, and / or 160 MHz wide. A 40 MHz channel and / or an 80 MHz channel can be formed by combining contiguous 20 MHz channels. A 160 MHz channel can be formed by combining eight contiguous 20 MHz channels or by combining two non - contiguous 80 MHz channels (which can be referred to as an 80+80 configuration). For the 80+80 configuration, after channel coding, the data can pass through a segment parser that can divide the data into two streams. The inverse fast Fourier transform (IFFT) processing and time - domain processing can be performed separately on each stream. These streams can be mapped to two 80 MHz channels, and the data can be transmitted by a transmitting STA. At the receiver of the receiving STA, the operations for the 80+80 configuration described above can be reversed, and the combined data can be delivered to the media access control (MAC) layer, entity, etc.

[0071] 802.11af and 802.11ah support operation modes below 1 GHz. Compared to those used in 802.11n and 802.11ac, the channel operation bandwidth and carriers are reduced in 802.11af and 802.11ah. 802.11af supports 5 MHz, 10 MHz, and 20 MHz bandwidths in the TV white space (TVWS) spectrum, and 802.11ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non - TVWS spectrum. According to a representative embodiment, 802.11ah can support meter - type control / machine - type communication (MTC), such as MTC devices in a macro - coverage area. MTC devices can have certain capabilities, for example, limited capabilities, including supporting (e.g., only supporting) certain bandwidths and / or limited bandwidths. MTC devices can include a battery with a battery life higher than a threshold (e.g., to maintain a very long battery life).

[0072] A WLAN system that can support multiple channels and channel bandwidths (such as 802.11n, 802.11ac, 802.11af, and 802.11ah) includes channels that can be designated as primary channels. The primary channel can have a bandwidth equal to the maximum common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel can be set and / or restricted by the STA (which supports the minimum bandwidth operation mode) from all STAs operating in the BSS. In the example of 802.11ah, for an STA that supports (e.g., only supports) the 1MHz mode (e.g., an MTC-type device), the primary channel can be 1MHz wide, even if the AP and other STAs in the BSS support 2MHz, 4MHz, 8MHz, 16MHz, and / or other channel bandwidth operation modes. Carrier sensing and / or network allocation vector (NAV) settings can depend on the state of the primary channel. If the primary channel is busy, for example, because an STA (only supporting the 1MHz operation mode) is sending to the AP, the entire available frequency band can be considered busy even if most of the frequency band remains idle and may be available.

[0073] In the United States, the available frequency band for 802.11ah is 902MHz to 928MHz. In Korea, the available frequency band is 917.5MHz to 923.5MHz. In Japan, the available frequency band is 916.5MHz to 927.5MHz. The total available bandwidth for 802.11ah is 6MHz to 26MHz, depending on the country code.

[0074] Figure 1D FIG. is a system diagram illustrating RAN 113 and CN 115 according to an embodiment. As noted above, RAN 113 can employ NR radio technology to communicate with WTRUs 102a, 102b, 102c via air interface 116. RAN 113 can also communicate with CN 115.

[0075] RAN 113 may include gNBs 180a, 180b, 180c, but it should be understood that RAN 113 may include any number of gNBs while remaining consistent with the embodiments. Each of gNBs 180a, 180b, 180c may include one or more transceivers for communicating with WTRUs 102a, 102b, 102c via air interface 116. In one embodiment, gNBs 180a, 180b, 180c may implement MIMO technology. For example, gNBs 180a, 180b may utilize beamforming to transmit signals to and / or receive signals from WTRUs 102a, 102b, 102c. Thus, gNB 180a, for example, may use multiple antennas to transmit wireless signals to WTRU 102a and / or receive wireless signals from this WTRU. In an embodiment, gNBs 180a, 180b, 180c may implement carrier aggregation technology. For example, gNB 180a may transmit multiple component carriers to WTRU 102a (not shown). A subset of these component carriers may be on unlicensed spectrum, while the remaining component carriers may be on licensed spectrum. In an embodiment, gNBs 180a, 180b, 180c may implement coordinated multi-point (CoMP) technology. For example, WTRU 102a may receive coordinated transmissions from gNB 180a and gNB 180b (and / or gNB 180c).

[0076] WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using transmissions associated with a parameter set that can be scaled. For example, the OFDM symbol interval and / or the OFDM subcarrier interval may vary for different transmissions, different cells, and / or different parts of the radio transmission spectrum. WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using various or scalable-length subframes or transmission time intervals (TTIs) (e.g., including different numbers of OFDM symbols and / or continuously varying absolute time lengths).

[0077] gNBs 180a, 180b, 180c can be configured to communicate with WTRUs 102a, 102b, 102c in a stand-alone configuration and / or a non-stand-alone configuration. In the stand-alone configuration, WTRUs 102a, 102b, 102c can communicate with gNBs 180a, 180b, 180c without accessing other RANs (e.g., such as evolved Node Bs 160a, 160b, 160c). In the stand-alone configuration, WTRUs 102a, 102b, 102c can use one or more of gNBs 180a, 180b, 180c as a mobility anchor point. In the stand-alone configuration, WTRUs 102a, 102b, 102c can communicate with gNBs 180a, 180b, 180c using signals in an unlicensed band. In the non-stand-alone configuration, WTRUs 102a, 102b, 102c can communicate / connect with gNBs 180a, 180b, 180c while also communicating / connecting with another RAN (such as evolved Node Bs 160a, 160b, 160c). For example, WTRUs 102a, 102b, 102c can implement the DC principle to communicate with one or more of gNBs 180a, 180b, 180c and one or more of evolved Node Bs 160a, 160b, 160c substantially simultaneously. In the non-stand-alone configuration, evolved Node Bs 160a, 160b, 160c can act as the mobility anchor for WTRUs 102a, 102b, 102c, and gNBs 180a, 180b, 180c can provide additional coverage and / or throughput for serving WTRUs 102a, 102b, 102c.

[0078] Each of gNBs 180a, 180b, 180c can be associated with a specific cell (not shown) and can be configured to manage radio resource management decisions, handover decisions, scheduling of users in UL and / or DL, support for network slicing, dual connectivity, interworking between NR and E-UTRA, routing of user plane data towards user plane functions (UPFs) 184a, 184b, routing of control plane information towards access and mobility management functions (AMFs) 182a, 182b, etc. As Figure 1D shown, gNBs 180a, 180b, 180c can communicate with each other via the Xn interface.

[0079] Figure 1DThe illustrated CN 115 may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one Session Management Function (SMF) 183a, 183b, and at least one Data Network (DN) 185a, 185b. Although each of the foregoing elements is depicted as part of CN 115, it should be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0080] AMF 182a, 182b may be connected to one or more of gNB 180a, 180b, 180c in RAN 113 via the N2 interface and may act as a control node. For example, AMF 182a, 182b may be responsible for authenticating users of WTRU 102a, 102b, 102c, support for network slicing (e.g., handling of different Protocol Data Unit (PDU) sessions with different requirements), selection of a particular SMF 183a, 183b, management of the registration area, termination of NAS signaling, mobility management, etc. AMF 182a, 182b may use network slicing to customize CN support for WTRU102a, 102b, 102c, for example, based on the type of service used by WTRU 102a, 102b, 102c. For example, different network slices may be established for different use cases (such as services that rely on Ultra-Reliable Low Latency (URLLC) access, services that rely on Enhanced Massive Mobile Broadband (eMBB) access, services for Machine-Type Communication (MTC) access, etc.). AMF 162 may provide control plane functions for handover between RAN 113 and other RANs (not shown) that employ other radio technologies (such as LTE, LTE-A, LTE-A Pro, and / or non-3GPP access technologies such as Wi-Fi).

[0081] SMF 183a, 183b may be connected to AMF 182a, 182b in CN 115 via the N11 interface. SMF 183a, 183b may also be connected to UPF 184a, 184b in CN 115 via the N4 interface. SMF 183a, 183b may select and control UPF184a, 184b and configure the traffic routing through UPF 184a, 184b. SMF 183a, 183b may perform other functions such as managing and allocating UE IP addresses, managing PDU sessions, controlling policy enforcement and QoS, providing downlink data notifications, etc. The PDU session type may be IP-based, non-IP-based, Ethernet-based, etc.

[0082] UPF 184a and 184b can be connected to one or more of gNBs 180a, 180b, and 180c in RAN 113 via the N3 interface. These gNBs can provide access to a packet-switched network (such as the Internet 110) to WTRU 102a, 102b, and 102c, for example, to facilitate communication between WTRU 102a, 102b, and 102c and IP-enabled devices. UPF 184a and 184b can perform other functions, such as routing and forwarding packets, implementing user plane policies, supporting multi-homed PDU sessions, handling user plane QoS, buffering downlink packets, providing mobility anchoring, etc.

[0083] CN 115 can facilitate communication with other networks. For example, CN 115 can include an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that serves as an interface between CN 115 and the PSTN 108 or can communicate with this IP gateway. In addition, CN 115 can provide access to other networks 112 to WTRU 102a, 102b, and 102c. These other networks can include other wired and / or wireless networks owned and / or operated by other service providers. In one embodiment, WTRU 102a, 102b, and 102c can be connected to DN 185a and 185b via UPF 184a and 184b through the N3 interface to UPF 184a and 184b and the N6 interface between UPF 184a, 184b and the local data network (DN) 185a, 185b.

[0084] In view of Figures 1A to 1D and Figures 1A to 1D In view of the corresponding descriptions, one or more or all of the functions described herein with reference to any of the following can be performed by one or more emulation elements / devices (not shown): WTRU 102a - 102d, base stations 114a - 114b, evolved Node Bs 160a - 160c, MME 162, SGW 164, PGW 166, gNBs 180a - 180c, AMF 182a - 182b, UPF 184a - 184b, SMF 183a - 183b, DN 185a - 185b, and / or any other element / device described herein. The emulation device can be one or more devices configured to mimic one or more or all of the functions described herein. For example, the emulation device can be used to test other devices and / or simulate network and / or WTRU functions.

[0085] The simulation device can be designed to implement one or more tests of other devices in a laboratory environment and / or in an operator network environment. For example, one or more simulation devices can perform one or more functions or all functions while being fully or partially implemented and / or deployed as part of a wired and / or wireless communication network to test other devices within the communication network. One or more simulation devices can perform one or more functions or all functions while being temporarily implemented / deployed as part of a wired and / or wireless communication network. The simulation device can be directly coupled to another device for testing purposes and / or can perform tests using over-the-air wireless communication.

[0086] One or more simulation devices can perform one or more (including all) functions without being implemented / deployed as part of a wired and / or wireless communication network. For example, the simulation device can be used in a test laboratory and / or in a test scenario in a non-deployed (e.g., test) wired and / or wireless communication network to implement tests of one or more components. One or more simulation devices can be test equipment. Direct RF coupling and / or wireless communication via an RF circuit system (e.g., which can include one or more antennas) can be used by the simulation device to transmit and / or receive data.

[0087] Introduction

[0088] For reference, the following abbreviations can be used throughout the disclosure:

[0089] AMF Access and Mobility Function

[0090] MM Mobility Management

[0091] NAS Non-Access Stratum

[0092] NSSAI Network Slice Selection Assistance Information

[0093] PDU Protocol Data Unit

[0094] PMF Performance Management Function

[0095] RA Registration Area

[0096] RAN Radio Access Network

[0097] RRC Radio Resource Control

[0098] SM Session Management

[0099] SMF Session Management Function

[0100] S-NSSAI Single NSSAI

[0101] SSSA Slice-Specific Service Area

[0102] TA Tracking Area

[0103] UDM Unified Data Management

[0104] UDR User Data Repository

[0105] UE User Equipment

[0106] UPF User Plane Function

[0107] In certain representative embodiments, a WTRU 102 may receive information from a network (such as network 104 / 113), and the WTRU 102 may use the information so received to perform procedures for determining slice availability in a TA. When the WTRU 102 registers with the network, the WTRU 102 may provide the network with an (explicit or implicit) indication that the WTRU 102 can understand slice-specific service area (SSSA) information (e.g., perform procedures using the SSSA information). The AMF 182 may use information from the WTRU 102 when determining how to construct an RA (such as whether to include a TA in the RA in which a rejected slice is available). The network may send information to the WTRU 102 such that it can be determined whether a slice is available in a TA. For example, the WTRU 102 may receive SSSA information from the network in a registration acceptance message. For example, the WTRU 102 may receive (e.g., also) receive slice group information that can be used to detect availability based on the broadcast information. By way of example, the network may send a service area-restricted NSSAI to the WTRU 102. The service area-restricted NSSAI may include, may be, and / or may indicate a list of slices that are available only in some (e.g., one or more) TAs of an RA. The service area-restricted NSSAI may be associated with the SSSA information.

[0108] In certain representative embodiments, a WTRU 102 and / or a network (such as network 104 / 113) may use slice availability information to detect a change in slice availability. For example, when there is a TA change, the WTRU 102 may use the SSSA information (e.g., received during registration) to check slice availability. The WTRU 102 may use slice group information to detect availability based on the broadcast information. For example, the AMF 182 may use a location report from the RAN (e.g., gNB) to detect that the slice availability of the WTRU 102 has changed, and the AMF may notify the WTRU 102 of the situation.

[0109] In certain representative embodiments, a change in slice availability may trigger the WTRU 102 and / or the network (such as network 104 / 113) to take action. For example, the WTRU 102 may send a (e.g., new) registration request to the network and add a rejected S-NSSAI to the requested NSSAI (e.g., because the associated slice is now available). For example, the WTRU 102 may send a (e.g., new) registration request to the network and may remove an S-NSSAI from its requested NSSAI (i.e., because the associated slice is now unavailable). For example, the WTRU 102 may receive a NAS message from the AMF 182. The NAS message may be, for example, a UE configuration update command that includes information indicating that a rejected S-NSSAI is to be added to the allowed NSSAI (e.g., because it is now available). As another example, the NAS message may be a NAS notification that includes information indicating that a previously rejected S-NSSAI is now accessible. As another example, the NAS message may be a UE configuration update command that removes an S-NSSAI from its allowed NSSAI (e.g., because it is now unavailable).

[0110] Overview

[0111] Slices, Tracking Areas, and Registration Areas

[0112] In certain representative embodiments, a registration area (RA) may refer to a set of tracking areas (TAs). The RA may be defined by a list of tracking area identifiers (TAIs) (e.g., a list of TAs). When the WTRU 102 registers with the network (e.g., sends a registration request to the AMF 182), the AMF 182 may allocate a registration area (e.g., a set of tracking areas in the TAI list) to the WTRU 102. For example, when allocating the TAI list, the AMF 182 may consider information such as the expected mobility pattern of the WTRU.

[0113] In certain representative embodiments, the configured NSSAI may be or may include information indicating a list or set of slices to which the WTRU 102 may have access. Any WTRU 102 may receive the configured NSSAI in a message such as a registration acceptance message and / or a WTRU configuration update message.

[0114] In certain representative embodiments, the requested NSSAI may be or may include information indicating a list or set of slices that the WTRU 102 sends to the network to request registration to the slices in the list. The WTRU 102 may send the requested NSSAI to the network in a registration request message.

[0115] In some representative embodiments, the allowed NSSAI may be or may include information indicating a list or set of slices to which the WTRU 102 may have access in the RA of the WTRU. For example, the list of slices includes the slices that the WTRU 102 may use in the RA of the WTRU.

[0116] In some representative embodiments, the rejected S-NSSAI may be an information element that the network may send to the WTRU 102 in a registration acceptance message and / or a WTRU configuration update message.

[0117] In some representative embodiments, the rejected S-NSSAI may be a slice that the WTRU 102 includes and / or indicates in the requested NSSAI and that the network determines the WTRU 102 may not have access to.

[0118] In some representative embodiments, as described herein, the phrases "attempt to register with a slice" and "include a slice in the requested NSSAI" may be interchangeable.

[0119] In some representative embodiments, the terms "slice" and "S-NSSAI" may be used interchangeably.

[0120] As will be understood by those skilled in the art, 3GPP TS23.501 describes S-NSSAIs provided by the WTRU 102 in the requested NSSAI that, when the NSSAI is not in the allowed NSSAI and is not provided as a rejected S-NSSAI, should not be considered rejected by the WTRU 102. For example, the WTRU 102 may request to register these S-NSSAIs again the next time the WTRU 102 sends the requested NSSAI to the network.

[0121] NG-RAN Location Reporting

[0122] As will be understood by those skilled in the art, 3GPP TS23.50 describes that the AMF 182 may request the RAN node to send a location report about the WTRU 102 to the AMF 182. If the AMF 182 requests WTRU location information, the RAN node may report the current location of the WTRU 102 based on the requested reporting parameters (e.g., one-time reporting or continuous reporting).

[0123] If the AMF 182 requests a report on the presence of the WTRU in the area of interest, the RAN node may report the WTRU location and / or an indication (e.g., inside, outside, or unknown) when the RAN node determines a change in the presence of the WTRU102 in the area of interest.

[0124] Slice Groups

[0125] As will be understood by those skilled in the art, 3GPP RP-2108928 describes that a slice group can consist of one or more slices, and each slice group can be uniquely identified by a slice group identifier.

[0126] In some representative embodiments, the NG-RAN cell can broadcast slice group information indicating what slices the cell supports. For example, the slice group identifier can indicate what slices the cell supports. For example, as a way to indicate what slices the cell supports, the NG-RAN cell can use RRC messaging to provide the slice group information to the WTRU 102. As another example, the network can use NAS signaling to provide information to the WTRU 102 such that the WTRU 102 can determine what slices (e.g., slices of the S-NSSAI) are associated with the slice group identifier.

[0127] PMF Protocol

[0128] In some representative embodiments, the PMF protocol can be used by the WTRU 102 and the PMF to exchange messages related to round-trip time (RTT) measurement results, packet loss rate (PLR) measurement results, access availability / unavailability information, and / or WTRU assistance data. The access availability / unavailability information can refer to a report sent from the WTRU 102 to the PMF to indicate whether cellular and / or non-3GPP access is available for the WTRU 102.

[0129] As described in 3GPP TS23.501 version 17.3.0, the availability of network slices is configured in the network according to the TA. Network functions such as the AMF 182 are configured to know on a per-TA basis whether a slice (e.g., S-NSSAI) is accessible. When the 5G-AN node establishes or updates the N2 connection with the AMF 182, the 5G-AN node notifies the AMF 182 of the S-NSSAIs supported by each TA.

[0130] Release 17.3.0 of 3GPP TS23.501 also describes that the WTRU 102 shall not include in the requested NSSAI any S-NSSAI that is currently rejected by the network (e.g., rejected in the current registration area or in the PLMN). If the WTRU 102 attempts to register to a slice while in a TA where the slice is not supported, the network shall indicate to the WTRU 102 that the S-NSSAI is rejected. This indication may be sent in the rejected S-NSSAI information element and delivered in the registration acceptance message. The rejected S-NSSAI information element includes a cause indication for indicating to the WTRU 102 why the S-NSSAI is rejected. The rejected S-NSSAI information element is specified in Release 17.5.0 of 3GPP TS24.501 and allows the network to indicate to the WTRU 102 one of three rejection causes. The first rejection cause indicates that the S-NSSAI is not available in the current PLMN or SNPN. The second rejection cause indicates that the S-NSSAI is not available in the current registration area. The third rejection cause indicates that the S-NSSAI is not available due to network slice specific authentication and authorization failure or revocation.

[0131] One problem with this approach is that the network can reject an S-NSSAI with RA granularity but not with TA granularity. Thus, when the WTRU 102 requests an S-NSSAI that is not accessible in a TA, the current 5G system only provides two options on how to handle the situation.

[0132] The first option is that the AMF 182 can provide the WTRU 102 with an RA that only includes the TAs in which the rejected S-NSSAI is not accessible. From the WTRU's perspective, this solution would not pose a problem. However, this approach may not be desirable for network operators. For example, this option may not be desirable for network operators because it forces the AMF to configure the registration area based on slice availability and / or complicates the formation of the registration area. Specifically, it is not desirable to force the AMF 182 to reduce the size of the RA (e.g., form a reduced set of TAs in the TAI list) because it may result in signaling overhead due to the allowed non-optimal RA of the S-NSSAI. If multiple slices are rejected in the WTRU's current TA but also have some non-overlapping availability, the formation of the RA may be even more complicated.

[0133] A second option is for the AMF to provide the WTRU 102 with a RA that includes one or more TAs in which the rejected S-NSSAI is accessible. From the perspective of the WTRU, there may be problems with this solution. For example, the problem with this approach is that the WTRU 102 will only be informed that the S-NSSAI is rejected in the registration area, and the current 5G system design stipulates that the WTRU 102 may not attempt to register with the slice anywhere in the RA, even if the slice is accessible in some other TAs of the RA. With this option, the WTRU 102 will be prevented from registering with the slice in some TAs where it should be accessible.

[0134] Accordingly, the above situation makes the network operator choose between informing the WTRU 102 that the slice is not accessible in some TAs where it should be accessible or forming a complex RA.

[0135] In certain representative embodiments described herein, a wireless system such as a 5G system can be enhanced such that the WTRU 102 can request an S-NSSAI that is rejected in a first TA of the RA but available in another TA of the RA. In certain representative embodiments, backward compatibility with existing systems will be considered.

[0136] In certain representative embodiments described herein, the WTRU 102 can receive from the network information that will be used by the WTRU 102 to determine slice availability in a TA. For example, this information can be used to detect changes in slice availability and / or trigger an action when the WTRU 102 detects a change in slice availability.

[0137] Receiving Information on Slice Availability

[0138] In certain representative embodiments, the WTRU 102 can send a registration request to the AMF 182. For example, the WTRU 102 can include a slice-specific service area (SSSA) information support indication in the registration request. The SSSA information support indication can indicate to the network that the WTRU 102 is capable of receiving and understanding the content of information elements containing SSSA information. For example, the SSSA information support indication can be sent in the NAS-MM part of the registration request. By way of example, the SSSA information support indication can be encoded in an information element such as the UE 5GMM core network capability information element.

[0139] In some representative embodiments, the WTRU 102 may receive SSSA information in a registration acceptance message. For example, the SSSA information may be stored in a NAS-MM information element and encoded such that it includes one or more slice identifiers (e.g., S-NSSAI) and a set of TAs belonging to the RA. The set of TAs may be the TAs in the registration area where the slice (e.g., S-NSSAI) is available to the WTRU 102. For example, under the condition that the WTRU 102 does not receive SSSA information for the slices in the configured NSSAI of the WTRU, the WTRU 102 may interpret the missing SSSA information as an indication that the slice is available to the WTRU 102 in all tracking areas of the RA. As another example, the set of TAs may be the tracking areas in the RA where the slice (e.g., S-NSSAI) is not available to the WTRU 102 (e.g., the slice is available in all other tracking areas of the registration area).

[0140] In some representative embodiments, the network (e.g., the AMF 182) may also send new and / or updated SSSA information to the WTRU 102 in a message such as a configuration update command message. For example, when receiving updated slice configuration information (such as from an OAM system), and / or when receiving updated WTRU 102 subscription information (such as from the UDM and / or UDR), the AMF 182 may be triggered to send a message.

[0141] In some representative embodiments, the SSSA information may include information that the WTRU 102 can use to obtain connectivity with the network (such as via a non-3GPP connection to a 5G system). For example, the SSSA information may include evolved packet data gateway (ePDG) identifier configuration, non-3GPP interworking function (N3IWF) identifier configuration, and / or non-3GPP access node selection information. The identified N3IWF or PDG may be used to obtain connectivity with a network slice. Including information that can be used to obtain non-3GPP connectivity with a network slice may assist the WTRU 102, such as when the WTRU 102 determines that it is in a TA where the desired network slice is not available. For example, when the WTRU 102 detects that a network slice is not available in a TA, it may use the information from the SSSA information to obtain non-3GPP connectivity with the 5G system and register with the network slice.

[0142] Detecting Slice Availability - Example 1

[0143] In some representative embodiments, the WTRU 102 may be configured with a configured NSSAI. The configured NSSAI may include a set or list of slices (e.g., S-NSSAI) to which the WTRU 102 may attempt to register. When the WTRU 102 sends a registration request to the AMF, the WTRU 102 may provide a requested NSSAI information element listing the slices (e.g., S-NSSAI) to which the WTRU 102 wishes to register. One or more of the slices (e.g., S-NSSAI) in the requested NSSAI may not be available to the WTRU 102 in the WTRU's current TA.

[0144] The registration area may be a set of tracking areas. The AMF 182 may determine that it is valid to define an RA for the WTRU 102 that includes some TAs in which slices of the WTRU's configured NSSAI are not available and other TAs in which the same slices of the WTRU's configured NSSAI are available. For example, slice X may be in the WTRU's configured NSSAI, and the WTRU's RA may include some TAs in which slice X is available and some TAs in which slice X is not available.

[0145] The WTRU 102 may send a registration request to the AMF 182. The registration request may include the requested NSSAI, and one or more of the slices in the requested NSSAI are not available in the WTRU's current TA. The AMF 182 may respond to the registration request by sending a registration acceptance message. The registration acceptance message may indicate to the WTRU 102 that registration for one or more slices that are not available in the WTRU's current TA has not been accepted. As described in 3GPP TS24.501 version 17.5.0, the rejection reason indication for each rejected slice in the rejected slices may indicate that the S-NSSAI is not available in the current RA. As described herein, the registration acceptance message may also include SSSA information.

[0146] When the WTRU 102 moves to a second TA in the RA, the WTRU 102 may use the SSSA information to determine that one or more of the rejected slices are available in the second TA. For example, the SSSA information may indicate that a slice is available in the second TA. Based on the determination that one or more of the rejected slices are available in the second TA, the WTRU 102 may register for one or more of the rejected slices by sending a registration request to the network and including one or more of the rejected slices in the requested NSSAI of the registration request.

[0147] For example, the WTRU 102 may be provided with a timer (e.g., a time period or interval) associated with the SSSA in registration acceptance. When the WTRU 102 moves to a second TA where the slice is available in the RA, the WTRU 102 may delay the request for the slice (e.g., until after the time period or interval has elapsed) based on the timer while in the second TA.

[0148] Detecting Slice Availability - Example 2

[0149] In some representative embodiments, the WTRU 102 may move to a second TA in the registration area. The WTRU 102 may receive network slice group information in broadcast message or RRC message transmission and use the network slice group information to determine that one or more of the rejected slices are available in the second TA. For example, the WTRU 102 may detect that one or more of the rejected slices are available in the current TA by detecting a network slice group identifier associated with one or more of the rejected slices in a message such as an RRC message or a broadcast message.

[0150] Detecting that one or more of the rejected slices are available in the second TA may trigger the WTRU 102 to attempt (e.g., again) to register to one or more of the rejected slices by sending a registration request to the network and including one or more of the rejected slices in the requested NSSAI of the registration request.

[0151] For example, in the case where the WTRU 102 uses network slice group information to determine whether a slice is accessible from a TA, the WTRU 102 receives network slice group information such that the WTRU 102 knows which slices (e.g., S-NSSAI) are associated with each network slice group. The WTRU 102 may (e.g., still) indicate to the network in the registration request that the WTRU 102 supports SSSA. The reason for including the support indication is that the support indication will make the AMF 182 aware that although the AMF 182 rejects the WTRU's attempt to register to a slice in one TA in the RA, the WTRU 102 is able to determine when a re-registration attempt can be made in that RA. On the other hand, if the WTRU 102 does not indicate to the AMF 182 that the WTRU 102 supports the feature, the AMF 182 will know that it may not reject slices that are available in other TAs in the RA because the WTRU 102 may not be able to detect when a slice becomes available.

[0152] Detecting Slice Availability - Example 3

[0153] In some representative embodiments, the AMF 182 may receive a WTRU location report from a RAN node (e.g., gNB 180). The WTRU location report may indicate that the WTRU 102 is in a second cell and / or a second TA. Based on the WTRU location report, the AMF 182 may determine that one or more slices previously sent to the WTRU 102 as a rejected S-NSSAI are available in the WTRU's current TA. The AMF 182 may determine to send to the WTRU 102 information (e.g., a notification) indicating that the previously rejected slices are now available.

[0154] For example, the notification from the AMF 182 to the WTRU 102 may be a DL NAS transport message indicating that the previously rejected slices are available in the TA. When the WTRU 102 receives this notification, the WTRU 102 may be triggered to send a new registration request to the network, the new registration request including the previously rejected S-NSSAI in the requested NSSAI. As another example, the notification from the AMF 182 to the WTRU 102 may be a UE configuration update (UCU) command message for the WTRU 102 and permitted NSSAI information including the previously rejected S-NSSAI.

[0155] Detecting Slice Unavailability - Example 1

[0156] In some representative embodiments, the WTRU 102 may move to a second TA of the RA. The WTRU 102 may use SSSA information to determine that one or more slices in the permitted NSSAI in the registration acceptance message are not available in the second TA. For example, the SSSA information may indicate that the slices are not available in the second TA. Detecting that one or more of the previously permitted slices are not available in the second TA may trigger the WTRU 102 to attempt to deregister from one or more of the previously permitted slices by sending a registration request to the network without including one or more of the previously permitted slices in the requested NSSAI of the registration request. For example, the WTRU 102 may also send a PDU session release message to the network for each PDU session, the PDU session release message being associated with the slice(s) from which it is deregistering.

[0157] Detecting Slice Unavailability - Example 2

[0158] In certain representative embodiments, the AMF 182 may receive a WTRU location report from a RAN node. The WTRU 102 location report may indicate that the WTRU 102 is in a second cell and / or a second TA. Based on the WTRU 102 location report, the AMF 182 may determine that one or more slices to which the WTRU 102 is currently registered should not be accessible to the WTRU 102 in the WTRU's current TA. Accordingly, the AMF 182 may determine that the WTRU 102 should no longer be registered to one or more slices. For example, this determination may trigger the AMF 182 to send an update message, such as a UE Configuration Update (UCU) command message, for the WTRU 102 with a permitted NSSAI information element that does not include information indicating one or more slices. The update message (e.g., UE Configuration Update command) may also indicate to the WTRU 102 that slices removed from the permitted NSSAI are not accessible in the WTRU's current TA.

[0159] As another example, the AMF 182 may send (e.g., still) the permitted NSSAI that includes slices not available in the WTRU's current TA to the WTRU 102, and may also send an additional (e.g., new) information element to the WTRU 102. The information element may be referred to as an accessible NSSAI. The accessible NSSAI information element may include and / or may be a set of slices that are accessible to the WTRU 102 at the WTRU's current location (e.g., TA). In some embodiments, the accessible NSSAI may include only slices from the permitted NSSAI that are accessible to the WTRU 102 in the WTRU's current TA. When the WTRU 102 detects that a slice has become accessible to the WTRU 102 due to a change in the WTRU's location, the AMF 182 may send (e.g., new) accessible NSSAI to the WTRU 102, and the accessible NSSAI may include information indicating the slice(s) that have become available. Detecting that a slice is not available for the WTRU 102 may (e.g., also) trigger the AMF 182 to notify any SMF 183 serving a PDU session associated with a network slice from which the WTRU 102 is to be deregistered. The notification may (e.g., will) indicate to the corresponding SMF 183 that the WTRU 102 is deregistering from the slice, thereby triggering the release of the associated PDU session.

[0160] In some representative embodiments, slices subject to SSSA restrictions (e.g., S-NSSAI) may be subject to network slice specific authentication and authorization (NSSAA). When the WTRU 102 transitions outside of the SSSA, the WTRU 102 may participate in an ongoing NSSAA procedure (e.g., the S-NSSAI is part of the pending NSSAI in the WTRU 102 and / or the AMF 182). When the AMF 182 determines that the WTRU 102 has moved outside of the SSSA for the S-NSSAI (e.g., based on a WTRU location report from the RAN), the AMF 182 may abort the NSSAA procedure. For example, the AMF 182 may send a UCU command as described above and include the S-NSSAI as part of the rejected S-NSSAI.

[0161] Detecting Slice Unavailability - Example 3

[0162] In some representative embodiments, when the WTRU 102 moves to a second TA of the RA, the WTRU 102 may receive network slice group information (such as in a broadcast message and / or RRC message transfer), and may use the network slice group information to determine that one or more slices in the permitted NSSAI of the WTRU are not available in the second TA. For example, the WTRU 102 may detect that one or more permitted slices in the permitted slices are not available in the current TA by detecting a network slice group identifier associated with the fact that one or more of the rejected slices in the rejected slices are not included in the message (e.g., an RRC message and / or a broadcast message).

[0163] Slice Unavailability Triggers Deregistration

[0164] In some representative embodiments, detecting that one or more permitted slices in the permitted slices are not available in the second TA may trigger the WTRU 102 to deregister from one or more of the permitted slices. For example, the WTRU 102 may deregister by sending a registration request to the network that does not include one or more of the previously permitted slices in the requested NSSAI of the registration request.

[0165] In some representative embodiments, slice availability may cause a change in how one or more PDU sessions are handled (e.g., by the WTRU 102 and / or the network).

[0166] As described herein, when the WTRU 102 registers to a slice and the WTRU 102 moves to a TA in the RA of the WTRU where the slice is not available, the WTRU 102 may deregister from the slice. Multiple examples of WTRU 102 and network (e.g., AMF) slice deregistration have been described above.

[0167] In some representative embodiments, the WTRU 102 may not be triggered to deregister from a slice (e.g., based on slice unavailability). For example, the WTRU 102 may remain registered to the slice, but the WTRU 102 may be blocked and / or prohibited from accessing any services of the slice when the WTRU 102 is in a TA where the slice is not accessible.

[0168] In some representative embodiments, the WTRU 102 may detect that the WTRU 102 is in a TA where a slice within the WTRU's permitted NSSAI is unavailable, such as but not limited to using the techniques described herein. The WTRU 102 may detect that it is in a TA where a slice within the WTRU's permitted NSSAI is unavailable, and the WTRU 102 may take steps to prevent the WTRU 102 or any WTRU-hosted application from accessing the services of the slice (e.g., placing communications on "hold" for that slice). The WTRU 102 may check whether the S-NSSAI for a PDU session is restricted by an SSSA and / or the availability of the S-NSSAI in the current TA before deciding to transmit SM signaling, messaging, or data for a PDU session. For example, the WTRU 102 may inhibit the activation (e.g., request activation) of the UP connection for a PDU session of a slice. For example, the WTRU 102 may inhibit the establishment and / or modification of a PDU session for a slice. For example, the WTRU 102 may inhibit the release of any PDU sessions of a slice. For example, the WTRU 102 may inhibit the generation of any NAS-SM signaling and / or mobile-originated (MO) data associated with a slice (e.g., inhibit sending any NAS-SM messages to the SMF for a slice).

[0169] In some representative embodiments, the WTRU 102 establishes a PDU session with a slice. When the WTRU 102 enters a TA where the slice is not accessible, the SMF 183 may subscribe to the AMF 182 to receive notifications. For example, when the SMF 183 receives a notification that the WTRU 102 is located in a position where the slice is not accessible (e.g., outside the SSSA), if the SMF is not notified that the WTRU 102 has moved back to a TA where the WTRU 102 can obtain service after a certain period of time, the SMF 183 may deactivate the UP connection for the PDU session while maintaining the PDU session, disable data notifications, and / or release the PDU session. As another example, when the WTRU 102 detects that it has entered a TA where the slice is not accessible, the WTRU 102 may send a NAS-SM message notifying the SMF 183 (e.g., that the PDU session activity should be suspended). After sending the notification to the SMF 183, the WTRU 102 may not send any additional NAS-SM signaling and / or MO data for the PDU session, such as until the WTRU 102 moves to a location where the slice is available.

[0170] In some representative embodiments, when the SMF 183 receives a notification that the WTRU 102 has returned to a position where the slice is accessible (e.g., within the SSSA), the SMF 183 may re-enable data notifications and / or trigger a network-triggered service request procedure for the PDU session to activate the UP connection when the SMF 183 receives downlink data or a data notification from the UPF 184. Based on the reactivation of the UP connection, the WTRU 102 may re-enable communication that was suspended for the slice based on the detected availability restricted by the SSSA. As another example, when the WTRU 102 detects that it has entered a TA where the slice has become accessible, the WTRU 102 may send a NAS-SM message notifying the SMF 183 that the PDU session activity should be resumed. After sending the notification to the SMF 183, the WTRU 102 may be allowed to send any NAS-SM signaling or MO data for the PDU session.

[0171] Slice Availability Report

[0172] In certain representative embodiments, the PMF protocol may be enhanced such that the WTRU 102 may send slice availability and / or unavailability reports to the network. A slice availability (or unavailability) report may be a message sent by the WTRU 102 to indicate to a function in the network that a slice (e.g., an S-NSSAI) is available (or unavailable) to the WTRU 102. For example, when the WTRU 102 detects that the WTRU 102 has moved to a TA where a network slice has become available (or unavailable), the WTRU 102 may be triggered to send an availability (or unavailability) report. The report may indicate to the network which slices have become available and / or unavailable.

[0173] For example, when the network receives a notification that a slice is unavailable to the WTRU 102 at the current location of the WTRU, the network may refrain from sending any mobile-terminated (MT) data or MT signaling for the slice to the WTRU 102. For example, when the network receives a notification that a slice is available to the WTRU 102 at the current location of the WTRU, the network may resume sending any MT data or MT signaling for the slice to the WTRU 102.

[0174] Cell Reselection Considerations

[0175] As described herein, the WTRU 102 may receive information (e.g., SSSA information) that the WTRU 102 may use to determine the availability of network slices in a TA. In certain representative embodiments, information regarding slice availability and / or desired network slices (e.g., slices that the WTRU 102 desires to be included in the requested NSSAI) in a TA may be provided to the access stratum by the non-access stratum. Information regarding slice availability and / or desired network slices in a TA may be used by the access stratum for cell reselection. For example, the WTRU 102 may provide the allowed NSSAI and a list of slices (e.g., S-NSSAIs) that the WTRU 102 recently attempted to register for but was rejected (e.g., a rejected S-NSSAI) to the access stratum. The access stratum may infer that the list of the allowed NSSAI and the recently rejected S-NSSAIs is the set of slices that the WTRU 102 wants to register to. When the access stratum performs cell reselection, the AS may consider the set of slices that the WTRU 102 wants to register to and how many slices from that set are available in the cell. The access stratum may use the slice availability information provided by the NAS to determine the slice availability in the cell.

[0176] For example, when the NAS provides the set of slices to which the WTRU 102 wants to register, the NAS can also provide priority information to the AS, which indicates which slices are the most important for the WTRU 102 to access (e.g., at the current time). This information can also be used by the access stratum during cell reselection. For example, if there are no cells available for accessing the entire set of desired slices, the access stratum can select a cell in which the highest-priority slice is available.

[0177] Detecting Slice Unavailability and Slice Availability - Example Program 1

[0178] Figure 2 is a flowchart illustrating an example scenario in which a WTRU attempts to register to a slice that is not available in the tracking area. As Figure 2 shown, the WTRU 102 can move into (e.g., a new) TA of an RA (e.g., the first), and attempt to register to a slice that is not available in that TA. In this example, the slice name is slice X. In this example, the AMF can (e.g., initially) not allow the WTRU 102 to register to slice X. Later in this example, the WTRU 102 moves to another (e.g., second) TA in the RA, and slice X is allowed in this TA. In this example, the WTRU 102 can (e.g., detect) that it is now in a TA in which slice X is allowed, and attempt to register to slice X again. The AMF can (e.g., respond) to this second attempt by allowing the WTRU to register to slice X.

[0179] At Figure 2 202 in, the WTRU 102 can enter a TA that is not part of the WTRU's current RA. For example, the WTRU 102 can have multiple slices in its allowed NSSAI, and one of those slices can be slice X. For purposes of explanation, assume there are 5 slices in the allowed NSSAI, and slice X is not accessible in the TA.

[0180] At Figure 2 204 in, the WTRU 102 can be triggered (e.g., due to leaving the previous RA and / or entering the current RA) to send a registration request. The WTRU 102 can provide the requested NSSAI, which includes the 5 slices that are currently in the WTRU's allowed NSSAI. Thus, the requested NSSAI includes slice X. As described herein, the registration request can include an SSSA information support indication. For example, the WTRU 102 can send an SSSA information support indication in an earlier registration request, in which case the AMF 182 can store the WTRU's SSSA information support indication in the WTRU's context.

[0181] At Figure 2 206, the network may send a registration acceptance message to the WTRU 102. For example, the allowed NSSAI in the registration acceptance message may include only 4 slices. The 4 slices may be the 5 slices requested by the WTRU 102 in the previous step minus slice X. Slice X is excluded from the allowed NSSAI because it is not accessible in the TA. As described above, since the AMF 182 receives the SSSA information support indication from the WTRU 102, the AMF will indicate that slice X is the rejected S-NSSAI and send the SSSA information to the WTRU 102. For example, the AMF 182 may indicate to the WTRU 102 that slice X is available in the RA but is rejected only in the TA. If the AMF 182 does not receive the SSSA information support indication from the WTRU 102, the AMF 182 may determine not to indicate that slice X is the rejected S-NSSAI, not to indicate to the WTRU 102 that the slice is rejected only in the TA, and may exclude slice X from the allowed NSSAI. By not indicating whether slice X is allowed or rejected, the WTRU 102 will not be blocked from attempting to register with slice X again in the RA. Thus, the SSSA information support indication can be used to indicate to the network that the WTRU 102 understands the rejection reason code that indicates that the slice is available in the RA but is rejected only in the TA.

[0182] In some representative embodiments, in the case where the WTRU 102 provides the SSSA information support indication at 204, the AMF 182 may determine that the WTRU 102 can understand (e.g., a new) slice rejection reason code that indicates to the WTRU 102 that the slice is rejected only for the current TA and not for the entire RA. Thus, when the AMF 182 rejects a slice, it may provide this slice rejection reason code to the WTRU 102.

[0183] For example, the SSSA information sent by the AMF to the WTRU 102 may include service area information for the slices of the configured NSSAI for the WTRU. As another example, the SSSA information may include service area information for the slices of the allowed NSSAI, the rejected S-NSSAI, and / or the pending S-NSSAI for the WTRU.

[0184] In some representative embodiments, when the AMF 182 determines that the WTRU 102 can only access a subset of the TAs in the RA for a slice, the AMF can determine not to include that slice in the allowed NSSAI of the WTRU. Instead, the AMF can send (e.g., new) information elements to the WTRU 102. This information element can be referred to as a service area restricted NSSAI. The service area restricted NSSAI information element can include or can be a list of slices (e.g., slices of the S-NSSAI) that the WTRU 102 can access in the RA rather than all TAs of the RA. The service area restricted NSSAI can be associated with the SSSA information or can be part of the SSSA information that indicates to the WTRU 102 where the slices of the service area restricted NSSAI are available in the RA. An advantage of this method can be that a WTRU 102 that does not support the service area restricted NSSAI information element will ignore the new IE. Since the slices in the service area restricted NSSAI will not be rejected or allowed, this non-supporting WTRU 102 will be able to attempt to register again in the RA. A WTRU 102 that does support the service area restricted NSSAI information element will be able to understand that there is a list of slices with restricted availability and understand the restrictions listed in the SSSA information element.

[0185] For example, a network slice (S-NSSAI) can be included in both the allowed NSSAI and the service area restricted NSSAI. For example, if the WTRU 102 registers in a TA where slice X is available, slice X can be included in the allowed NSSAI and / or the service area restricted NSSAI. When the WTRU 102 moves to another TA where slice X is not available, the network can detect that the WTRU 102 is now in a location where slice x is not available and can send a UE configuration update command to the WTRU 102 and provide a new allowed NSSAI that does not include slice X, or the WTRU 102 can send a new registration request. The new registration request can exclude slice X from the requested NSSAI, and the network can exclude slice X from the allowed NSSAI.

[0186] In one example, if the WTRU 102 registers in a TA where slice X is not available, slice X can be included in the service area restricted NSSAI but not in the allowed NSSAI, and slice X will not be rejected. The WTRU 102 can use the SSSA information associated with the service area restricted NSSAI to detect when slice X becomes available so that the WTRU 102 can attempt to register to slice X again.

[0187] In certain representative embodiments, in the case where the AMF 182 sends a registration rejection message to the WTRU 102, the registration rejection message may include SSSA information for the rejected S-NSSAI. The registration rejection message may cause the WTRU 102 to move to the RM deregistration state and store the SSSA information. Then, the SSSA information may be used by the WTRU 102 to determine to attempt a new registration request, such as when the WTRU 102 moves to a TA where one or more of the rejected slices in the rejected slice are available.

[0188] At Figure 2 208 in, the WTRU 102 moves to a second (e.g., new) TA (e.g., within the RA of the WTRU). The previously received SSSA information indicates that slice X is available in the second TA. The WTRU 102 uses the SSSA information to determine that slice X is available.

[0189] At Figure 2 210 in, the availability of slice X may trigger the WTRU 102 to send a registration request to the network in which it requests registration of slice X. The requested NSSAI of the registration request may include 4 slices from the allowed NSSAI and slice X.

[0190] At Figure 2 212 in, the AMF 182 may send a registration acceptance message to the WTRU 102, the registration acceptance message including information indicating 5 slices from the requested NSSAI previously provided at 210. Thus, the WTRU 102 is now registered to slice x.

[0191] Detecting Slice Unavailability and Slice Availability - Example Program 2

[0192] Figure 3 is a flowchart illustrating an example scenario in which a WTRU may use messaging from the RAN to determine slice support. At Figure 3 in, the WTRU 102 may use messaging from the RAN (e.g., a base station) (e.g., broadcast and / or RRC messaging) to determine whether a slice is supported in a TA. In this example, the WTRU 102 may detect whether the slice is supported before attempting to register. As in Figure 2 in, the registration target slice is named slice X.

[0193] For example, there may be a precondition that the WTRU 102 has 5 slices in its allowed NSSAI and one of the slices in the allowed NSSAI is slice X.

[0194] At Figure 3At 202, the WTRU 102 may receive information (e.g., from the AMF 182) indicating which slices (e.g., S-NSSAI) are associated with each slice group identifier. For example, this information may be received in a NAS-MM message such as a registration acceptance or a WTRU configuration update command.

[0195] At Figure 3 At 204, the WTRU 102 may enter a TA that is not part of the WTRU's current RA. For example, the WTRU 102 may have 5 slices in its permitted NSSAI, and one of these slices may be slice X.

[0196] At Figure 3 At 206, the WTRU 102 may receive broadcast and / or RRC messages from a base station (e.g., gNB 180a associated with TA1). The broadcast and / or RRC messages may include a slice group identifier. The WTRU 102 may use the slice group identifier and the slice group information from 202 to determine that slice X is not supported in the TA (e.g., TA1).

[0197] At Figure 3 At 208, the WTRU 102 may be triggered to send a registration request. Since slice X is not supported in the TA, the requested NSSAI may include 4 slices that are currently in the WTRU's permitted NSSAI minus slice X. That is, the requested NSSAI does not include slice X. As described herein, the registration request may include an SSSA information support indication.

[0198] At Figure 3 At 210, the network sends a registration acceptance message to the WTRU 102. By way of example, the permitted NSSAI in the registration acceptance message may include only 4 slices. The 4 slices may be 4 slices from the requested NSSAI.

[0199] At Figure 3 At 212, the WTRU 102 may move to a second (e.g., new) TA (e.g., TA2). The second TA may be in the WTRU's RA. Slice X is available in the second TA.

[0200] At Figure 3 At 214, the WTRU 102 may receive broadcast and / or RRC messages from a base station (e.g., gNB 180b associated with TA2). The broadcast or RRC message may include information indicating a slice group identifier. The WTRU 102 may use the slice group identifier and the slice group information from 202 to determine that slice X is supported in the TA. At 214, the broadcast and / or RRC message may include a slice group identifier associated with slice X.

[0201] At Figure 3 216 in, the availability of slice X (e.g., in the second TA) can trigger the WTRU 102 to send a registration request to the network. The requested NSSAI of the registration request may include information indicating 4 slices from the allowed NSSAI (e.g., at 210) and slice X.

[0202] At Figure 3 218 in, the AMF 182 sends a registration acceptance message to the WTRU 102, and the registration acceptance message may include all 5 slices from the requested NSSAI previously provided at 210. Thus, the WTRU 102 is now registered to slice X.

[0203] Figure 4 is a program diagram illustrating an example procedure for slice registration. In some representative embodiments, Figure 4 the procedure in can generally be implemented by the WTRU 102 (e.g., as a method). In Figure 4 , at 402, the WTRU 102 may send a first registration request that includes information indicating SSSA support and a first requested network slice selection assistance information NSSAI. At 404, the WTRU 102 may receive a first registration acceptance that includes information indicating that one or more S-NSSAIs of the first requested NSSAI are rejected and information indicating one or more first tracking areas TAs that support one or more of the rejected S-NSSAIs. For example, the first registration request may be sent to a network entity such as the AMF 182 described herein, and the first registration acceptance may be received from the network entity (e.g., as part of a registration procedure). At 406, under the condition that the WTRU 102 has entered a TA of at least one of the S-NSSAIs with rejected support among one or more first TAs, the WTRU 102 may send a second registration request that includes information indicating a second requested NSSAI. For example, the second requested NSSAI may be associated with at least one of the rejected S-NSSAIs.

[0204] In some representative embodiments, the WTRU 102 may receive a second registration acceptance (e.g., associated with the second registration request) that includes information indicating that at least one of the rejected S-NSSAIs associated with the second requested NSSAI is allowed. For example, the second registration request may be sent to a network entity such as the AMF 182 described herein, and the second registration acceptance may be received from the network entity (e.g., as part of a registration procedure).

[0205] In some representative embodiments, the WTRU 102 may receive a second registration acceptance (e.g., associated with a second registration request) that includes information indicating that at least one of the rejected S-NSSAIs is allowed.

[0206] In some representative embodiments, the WTRU 102 may receive information indicating a registration area that includes a plurality of TAs. For example, the plurality of TAs may include one or more first TAs. For example, the registration area may be provided to the WTRU 102 in a registration acceptance, such as at 404.

[0207] In some representative embodiments, a first registration request may be sent to a base station (e.g., gNB 180) that is associated with a second TA other than the one or more first TAs among the plurality of TAs. For example, the first registration request may be sent by the WTRU 102 in a TA that supports certain slices, and the second registration request may be sent by the WTRU 102 in another TA that supports certain other slices, as described herein.

[0208] In some representative embodiments, a second registration request may be sent to a base station (e.g., gNB 180) that is associated with the TA (e.g., the TA at 406) among the one or more first TAs.

[0209] In some representative embodiments, a first registration acceptance may be received from a base station (e.g., gNB 180) that is associated with a second TA other than the one or more first TAs among the plurality of TAs.

[0210] In some representative embodiments, a second registration acceptance may be received from a base station (e.g., gNB 180) that is associated with the TA (e.g., the TA at 406) among the one or more first TAs.

[0211] In some representative embodiments, the WTRU 102 may determine that the WTRU 102 has entered the TA (e.g., the TA at 406) among the one or more first TAs before sending the second registration request.

[0212] In some representative embodiments, the WTRU 102 may determine that the WTRU 102 is communicating with a base station (e.g., gNB 180) that is not part of the TA that received the first registration acceptance (e.g., at 406).

[0213] In some representative embodiments, information indicating one or more first TAs supporting one or more rejected S-NSSAIs may include an association between the one or more first TAs and the supported rejected S-NSSAIs among the rejected S-NSSAIs. For example, each first TA may be associated with at least one rejected S-NSSAI (e.g., support the at least one rejected S-NSSAI).

[0214] Figure 5 is a program diagram illustrating an example procedure for slice registration. In some representative embodiments, Figure 5 the procedure in may generally be implemented by the WTRU 102 (e.g., as a method). In Figure 5 , at 502, the WTRU 102 may send a first registration request that includes information indicating SSSA support and a first requested network slice selection assistance information NSSAI. At 504, the WTRU 102 may receive a first registration acceptance that includes information indicating one or more service area restricted S-NSSAIs of the first requested NSSAI and information indicating one or more first TAs supporting the one or more service area restricted S-NSSAIs. For example, the first registration request may be sent to a network entity such as the AMF 182 described herein, and the first registration acceptance may be received from the network entity (e.g., as part of a registration procedure). At 506, conditional on the WTRU 102 having entered a TA of the one or more first TAs that supports at least one service area restricted S-NSSAI among the one or more service area restricted S-NSSAIs, the WTRU 102 may send a second registration request that includes information indicating a second requested NSSAI. For example, the second requested NSSAI may be associated with at least one service area restricted S-NSSAI among the one or more service area restricted S-NSSAIs.

[0215] In some representative embodiments, the WTRU 102 may receive a second registration acceptance that includes information indicating that at least one service area restricted S-NSSAI associated with the second requested NSSAI among the service area restricted S-NSSAIs is allowed. For example, the second registration request may be sent to a network entity such as the AMF 182 described herein, and the second registration acceptance may be received from the network entity (e.g., as part of a registration procedure).

[0216] In some representative embodiments, the WTRU 102 may receive a second registration acceptance that includes information indicating that at least one service area restricted S-NSSAI among one or more service area restricted S-NSSAIs is allowed.

[0217] In some representative embodiments, the WTRU 102 may receive information indicating a registration area that includes a plurality of TAs. For example, the plurality of TAs may include one or more first TAs.

[0218] In some representative embodiments, a first registration request may be sent to a base station (e.g., gNB 180) that is associated with a second TA (e.g., which does not support one or more service area restricted S-NSSAIs) among the plurality of TAs other than the one or more first TAs.

[0219] In some representative embodiments, a second registration request may be sent to a base station (e.g., gNB 180) that is associated with the TA among the one or more first TAs.

[0220] In some representative embodiments, a first registration acceptance may be received from a base station (e.g., gNB 180) that is associated with a second TA (e.g., which does not support one or more service area restricted S-NSSAIs) among the plurality of TAs other than the one or more TAs.

[0221] In some representative embodiments, a second registration request may be sent to a base station (e.g., gNB 180) that is associated with the TA among the one or more first TAs.

[0222] In some representative embodiments, a first registration acceptance may be received from a base station (e.g., gNB 180) that is associated with a second TA (e.g., which does not support one or more service area restricted S-NSSAIs) among the plurality of TAs other than the one or more TAs.

[0223] In some representative embodiments, a second registration acceptance may be received from a base station (e.g., gNB 180) that is associated with the TA among the one or more TAs.

[0224] In some representative embodiments, the WTRU 102 may determine that the WTRU 102 has entered the TA among the one or more first TAs (e.g., at 506) before sending the second registration request.

[0225] In certain representative embodiments, the WTRU 102 may determine that the WTRU 102 is communicating with a base station (e.g., gNB 180) that is not part of the TA that received the first registration acceptance (e.g., at 504).

[0226] In certain representative embodiments, information for a single NSSAI indicating that one or more service areas of the first requested NSSAI are restricted may be included in a service area restricted information element (e.g., service area restricted of the first registration acceptance).

[0227] In certain representative embodiments, the first registration acceptance may include information indicating one allowed NSSAI or at least one allowed S-NSSAI.

[0228] In certain representative embodiments, the first registration acceptance may include information indicating one rejected NSSAI or at least one rejected S-NSSAI.

[0229] Figure 6 is a program diagram illustrating an example procedure for slice de-registration. In certain representative embodiments, Figure 6 the procedure in may generally be implemented by the WTRU 102 (e.g., as a method). In Figure 6 at 602, the WTRU 102 may send a first registration request that includes information indicating SSSA support and the first requested NSSAI. At 604, the WTRU 102 may receive a first registration acceptance that includes information indicating that one or more S-NSSAIs of the first requested NSSAI are allowed and information indicating one or more first TAs that do not support one or more of the allowed S-NSSAIs. For example, the first registration request may be sent to a network entity such as the AMF 182 described herein, and the first registration acceptance may be received from the network entity (e.g., as part of a registration procedure). At 606, under the condition that the WTRU 102 has entered a TA in one or more of the first TAs that does not support at least one of the allowed S-NSSAIs of the allowed S-NSSAIs, the WTRU 102 may de-register from at least one of the allowed S-NSSAIs of the allowed S-NSSAIs.

[0230] In certain representative embodiments, deregistration may include the WTRU 102 sending a second registration request that includes information indicating the second requested NSSAI. For example, the second registration request may include information indicating SSSA support. For example, the second registration request may include the second requested NSSAI associated with one or more S-NSSAIs supported in the first TA. For example, the second registration request may be sent to a network entity such as the AMF 182 described herein, and a second registration acceptance may be received from the network entity (e.g., as part of the registration procedure).

[0231] In certain representative embodiments, deregistration may include the WTRU 102 receiving a second registration acceptance that includes information indicating that one or more S-NSSAIs of the second requested NSSAI are permitted.

[0232] In certain representative embodiments, the WTRU 102 may receive information indicating a registration area that includes a plurality of TAs. For example, the plurality of TAs may include one or more first TAs.

[0233] In certain representative embodiments, a first registration request may be sent to a base station (e.g., gNB 180) that is associated with a second TA other than the one or more first TAs of the plurality of TAs.

[0234] In certain representative embodiments, a second registration request may be sent to a base station (e.g., gNB 180) that is associated with the TA of the one or more first TAs.

[0235] In certain representative embodiments, a first registration acceptance may be received from a base station (e.g., gNB 180) that is associated with a second TA other than the one or more first TAs of the plurality of TAs.

[0236] In certain representative embodiments, the WTRU 102 may determine that the WTRU 102 has entered the TA of the one or more first TAs (e.g., at 606) before deregistering from at least one permitted S-NSSAI of the permitted S-NSSAIs.

[0237] In certain representative embodiments, the WTRU 102 may determine that the WTRU 102 is communicating with a base station (e.g., gNB 180) that is not part of the TA that received the first registration acceptance (e.g., at 604) before deregistering from at least one permitted S-NSSAI of the permitted S-NSSAIs.

[0238] In certain representative embodiments, the information indicating one or more TAs that do not support one or more permitted S-NSSAIs includes the association between one or more TAs and one S-NSSAI among the S-NSSAIs of the first requested NSSAI. For example, each first TA may be associated with (e.g., not support) at least one permitted S-NSSAI.

[0239] Figure 7 is a flowchart illustrating an example procedure for slice deregistration. In certain representative embodiments, Figure 7 the procedure in may generally be implemented by the WTRU 102 (e.g., as a method). In Figure 7 at 702, the WTRU 102 may send a first registration request that includes information indicating SSSA support and the first requested NSSAI. At 704, the WTRU 102 may receive a first registration acceptance that includes information indicating that one or more S-NSSAIs of the first requested NSSAI are permitted. For example, the first registration request may be sent to a network entity such as the AMF 182 described herein, and the first registration acceptance may be received from the network entity (e.g., as part of a registration procedure). At 706, the WTRU 102 may receive network slice set information indicating one or more first TAs that do not support one or more permitted S-NSSAIs. At 708, under the condition that the WTRU 102 has entered a TA in one or more TAs that does not support at least one permitted S-NSSAI among one or more permitted S-NSSAIs, the WTRU 102 may deregister from at least one permitted S-NSSAI among the permitted S-NSSAIs.

[0240] In certain representative embodiments, deregistration may include the WTRU 102 sending a second registration request that includes information indicating a second requested NSSAI. For example, the second registration request may include information indicating SSSA support. For example, the second registration request may include the second requested NSSAI associated with one or more S-NSSAIs supported in the TA. For example, the second registration request may be sent to a network entity such as the AMF 182 described herein, and the second registration acceptance may be received from the network entity (e.g., as part of a registration procedure).

[0241] In certain representative embodiments, deregistration may include the WTRU 102 receiving a second registration acceptance that includes information indicating that one or more S-NSSAIs of the second requested NSSAI are permitted.

[0242] In some representative embodiments, the WTRU 102 may receive information indicating a registration area including multiple TAs. For example, the multiple TAs may include one or more first TAs.

[0243] In some representative embodiments, a first registration request may be sent to a base station (e.g., gNB 180) associated with a second TA (e.g., which supports a permitted S-NSSAI) other than the one or more first TAs among the multiple TAs.

[0244] In some representative embodiments, a second registration request may be sent to a base station (e.g., gNB 180) associated with the TA among the one or more first TAs.

[0245] In some representative embodiments, a first registration acceptance may be received from a base station (e.g., gNB 180) associated with a second TA (e.g., which supports a permitted S-NSSAI) other than the one or more first TAs among the multiple TAs.

[0246] In some representative embodiments, the WTRU 102 may determine that the WTRU 102 has entered the TA among the one or more first TAs (e.g., at 606) before deregistering from at least one permitted S-NSSAI among the permitted S-NSSAIs.

[0247] In some representative embodiments, the WTRU 102 may determine that the WTRU 102 is communicating with a base station (e.g., gNB 180) that is not part of the TA that received the first registration acceptance (e.g., at 604) before deregistering from at least one permitted S-NSSAI among the permitted S-NSSAIs.

[0248] In some representative embodiments, the information indicating one or more TAs that do not support one or more permitted S-NSSAIs includes the association between the one or more TAs and one S-NSSAI among the S-NSSAIs of the first requested NSSAI. For example, each first TA may be associated with at least one permitted S-NSSAI (e.g., without providing support for it).

[0249] Figure 8 is a program diagram illustrating an example procedure for slice registration. In some representative embodiments, Figure 8 the procedure in may generally be implemented (e.g., as a method) by a network entity such as the AMF 182. In Figure 8In [the figure], at 802, the AMF 182 may receive a first registration request (e.g., from the WTRU 102), the first registration request including information indicating SSSA support and a first requested network slice selection assistance information NSSAI. At 804, the AMF 182 may send a first registration acceptance (e.g., via the base station), the first registration acceptance including information indicating that one or more S-NSSAIs of the first requested NSSAI are rejected and information indicating one or more first tracking areas TAs supporting one or more of the rejected S-NSSAIs. At 806, after the WTRU 102 has entered a TA of one or more of the first TAs supporting at least one of the rejected S-NSSAIs of the rejected S-NSSAIs, the AMF 182 may receive (e.g., from the WTRU 102) a second registration request, the second registration request including information indicating a second requested NSSAI. For example, the second requested NSSAI may be associated with at least one of the rejected S-NSSAIs of the rejected S-NSSAIs.

[0250] In certain representative embodiments, the AMF 182 may send a second registration acceptance (e.g., associated with the second registration request), the second registration acceptance including information indicating that at least one of the rejected S-NSSAIs associated with the second requested NSSAI of the rejected S-NSSAIs is allowed.

[0251] In certain representative embodiments, the AMF 182 may send a second registration acceptance (e.g., associated with the second registration request), the second registration acceptance including information indicating that at least one of the rejected S-NSSAIs of the rejected S-NSSAIs is allowed.

[0252] In certain representative embodiments, the AMF 182 may send information indicating a registration area including a plurality of TAs. For example, the plurality of TAs may include one or more first TAs.

[0253] In certain representative embodiments, the first registration request may be sent by the WTRU 102 to a base station (e.g., gNB 180), the base station being associated with a second TA other than the one or more first TAs of the plurality of TAs.

[0254] In certain representative embodiments, the second registration request may be sent by the WTRU 102 to a base station (e.g., gNB 180), the base station being associated with the TA (e.g., the TA at 406) of the one or more first TAs.

[0255] In certain representative embodiments, the first registration acceptance may be sent using (e.g., via) a base station (e.g., gNB 180) associated with a second TA among a plurality of TAs other than one or more first TAs.

[0256] In certain representative embodiments, the second registration acceptance may be sent using (e.g., via) a base station (e.g., gNB 180) associated with the TA (e.g., the TA at 406) among the one or more first TAs.

[0257] In certain representative embodiments, the WTRU 102 may determine that the WTRU 102 has entered the TA (e.g., the TA at 406) among the one or more first TAs before sending a second registration request to the AMF 182.

[0258] In certain representative embodiments, the WTRU 102 may determine that the WTRU 102 is communicating with a base station (e.g., gNB 180) that is not part of the TA that received the first registration acceptance (e.g., at 406) before sending a second registration request to the AMF 182.

[0259] In certain representative embodiments, the information indicating one or more first TAs supporting one or more rejected S-NSSAIs may include the association between the one or more first TAs and the supported rejected S-NSSAIs among the rejected S-NSSAIs. For example, each first TA may be associated with at least one rejected S-NSSAI (e.g., support the at least one rejected S-NSSAI).

[0260] Figure 9 is a program diagram illustrating an example procedure for slice registration. In certain representative embodiments, Figure 9 the procedure in may generally be implemented (e.g., as a method) by a network entity such as the AMF 182. In Figure 9In [the figure], at 902, the AMF 182 may receive (e.g., from the WTRU 102) a first registration request that includes information indicating SSSA support and a first requested network slice selection assistance information NSSAI. At 904, the AMF 182 may send (e.g., to the WTRU 102) a first registration acceptance that includes information indicating one or more service area restricted S-NSSAIs of the first requested NSSAI and information indicating one or more first TAs that support one or more service area restricted S-NSSAIs. At 906, after the WTRU 102 has entered a TA of one or more first TAs that supports at least one service area restricted S-NSSAI among one or more service area restricted S-NSSAIs, the AMF 182 may receive (e.g., from the WTRU 102) a second registration request that includes information indicating a second requested NSSAI. For example, the second requested NSSAI may be associated with at least one service area restricted S-NSSAI among one or more service area restricted S-NSSAIs.

[0261] In some representative embodiments, the AMF 182 may send (e.g., to the WTRU 102) a second registration acceptance that includes information indicating that at least one service area restricted S-NSSAI associated with the second requested NSSAI among the service area restricted S-NSSAIs is allowed.

[0262] In some representative embodiments, the AMF 182 may send a second registration acceptance that includes information indicating that at least one service area restricted S-NSSAI among one or more service area restricted S-NSSAIs is allowed.

[0263] In some representative embodiments, the AMF 182 may send (e.g., in the registration acceptance) information indicating a registration area that includes multiple TAs. For example, the multiple TAs may include one or more first TAs.

[0264] In some representative embodiments, the first registration request may be sent to a base station (e.g., gNB 180) that is associated with a second TA (e.g., which does not support one or more service area restricted S-NSSAIs) among the multiple TAs other than one or more first TAs.

[0265] In some representative embodiments, the second registration request may be sent to a base station (e.g., gNB 180) that is associated with the TA among the one or more first TAs.

[0266] In some representative embodiments, a first registration acceptance may be received from a base station (e.g., gNB 180) associated with a second TA out of a plurality of TAs other than one or more TAs (e.g., which does not support one or more service area restricted S-NSSAIs).

[0267] In some representative embodiments, a second registration request may be sent by the WTRU 102 to a base station (e.g., gNB 180) associated with the TA out of the one or more first TAs.

[0268] In some representative embodiments, a first registration acceptance may be sent using (e.g., via) a base station (e.g., gNB 180) associated with a second TA out of a plurality of TAs other than one or more TAs (e.g., which does not support one or more service area restricted S-NSSAIs).

[0269] In some representative embodiments, a second registration acceptance may be sent (e.g., via) using a base station (e.g., gNB 180) associated with the TA out of the one or more TAs.

[0270] In some representative embodiments, the WTRU 102 may determine that the WTRU 102 has entered the TA out of the one or more first TAs (e.g., at 506) before sending the second registration request to the AMF 182.

[0271] In some representative embodiments, the WTRU 102 may determine that the WTRU 102 is communicating with a base station (e.g., gNB 180) that is not part of the TA that received the first registration acceptance (e.g., at 504).

[0272] In some representative embodiments, information of one or more service area restricted single NSSAIs indicating a first requested NSSAI may be included in a service area restricted information element (e.g., the service area restricted of the first registration acceptance).

[0273] In some representative embodiments, a first registration acceptance may include information indicating an allowed NSSAI or at least one allowed S-NSSAI.

[0274] In some representative embodiments, a first registration acceptance may include information indicating a rejected NSSAI or at least one rejected S-NSSAI.

[0275] Figure 10 is a program diagram illustrating an example procedure for slice de-registration. In some representative embodiments, Figure 10The procedures therein can generally be implemented (e.g., as a method) by a network entity such as the AMF 182. In Figure 10 In Figure 10 , at 1002, the WTRU 102 may send a first registration request received by the AMF 182, the first registration request including information indicating SSSA support and a first requested NSSAI. At 1004, the AMF 182 may send a first registration acceptance (e.g., to the WTRU 102), the first registration acceptance including information indicating that one or more S-NSSAIs of the first requested NSSAI are allowed and information indicating one or more first TAs that do not support one or more of the allowed S-NSSAIs. At 1006, after the WTRU 102 has entered a TA that does not support at least one of the allowed S-NSSAIs among the one or more first TAs, the AMF 182 may deregister from at least one of the allowed S-NSSAIs.

[0276] In certain representative embodiments, deregistration may include the AMF 182 receiving (e.g., from the WTRU 102) a second registration request, the second registration request including information indicating a second requested NSSAI. For example, the second registration request may include information indicating SSSA support. For example, the second registration request may include the second requested NSSAI associated with one or more S-NSSAIs supported in the first TA.

[0277] In certain representative embodiments, deregistration may include the AMF 182 sending (e.g., to the WTRU 102) a second registration acceptance, the second registration acceptance including information indicating that one or more S-NSSAIs of the second requested NSSAI are allowed.

[0278] In certain representative embodiments, the AMF 182 may send (e.g., in a registration acceptance) information indicating a registration area including a plurality of TAs. For example, the plurality of TAs may include one or more first TAs.

[0279] In certain representative embodiments, the first registration request may be sent by the WTRU 102 to a base station (e.g., gNB 180) associated with a second TA other than the one or more first TAs among the plurality of TAs.

[0280] In certain representative embodiments, the second registration request may be sent by the WTRU 102 to a base station (e.g., gNB 180) associated with the TA among the one or more first TAs.

[0281] In certain representative embodiments, the first registration acceptance can be sent by the AMF 182 (e.g., via) a base station (e.g., gNB 180) associated with a second TA among a plurality of TAs other than one or more first TAs.

[0282] In certain representative embodiments, the WTRU 102 can determine that the WTRU 102 has entered the TA (e.g., at 606) among the one or more first TAs before the AMF 182 deregisters the WTRU 102 from at least one permitted S-NSSAI among the permitted S-NSSAIs.

[0283] In certain representative embodiments, the WTRU 102 can determine that the WTRU 102 is communicating with a base station (e.g., gNB 180) that is not part of the TA that received the first registration acceptance (e.g., at 604) before the AMF 182 deregisters the WTRU 102 from at least one permitted S-NSSAI among the permitted S-NSSAIs.

[0284] In certain representative embodiments, the information indicating one or more TAs that do not support one or more permitted S-NSSAIs includes the association between the one or more TAs and one S-NSSAI among the S-NSSAIs of the first requested NSSAI. For example, each first TA can be associated with at least one permitted S-NSSAI (e.g., without providing support for it).

[0285] Figure 11 is a program diagram illustrating an example procedure for slice deregistration. In certain representative embodiments, Figure 11 the procedures in can generally be implemented (e.g., as a method) by a network entity such as the AMF 182. In Figure 11 at 1102, the AMF 182 can receive a first registration request from the WTRU 102, the first registration request including information indicating SSSA support and a first requested NSSAI. At 1104, the AMF 182 can send (e.g., to the WTRU 102) a first registration acceptance, the first registration acceptance including information indicating that one or more S-NSSAIs of the first requested NSSAI are permitted. For example, the WTRU 102 can receive network slice group information indicating one or more first TAs that do not support one or more permitted S-NSSAIs. At 1108, after the WTRU 102 has entered a TA among the one or more TAs that does not support at least one permitted S-NSSAI among the one or more permitted S-NSSAIs, the AMF 182 can deregister the WTRU 102 from at least one permitted S-NSSAI among the permitted S-NSSAIs.

[0286] In some representative embodiments, deregistration may include the AMF 182 receiving a second registration request from the WTRU 102, the second registration request including information indicating the second requested NSSAI. For example, the second registration request may include information indicating SSSA support. For example, the second registration request may include the second requested NSSAI associated with one or more S-NSSAIs supported in the TA.

[0287] In some representative embodiments, deregistration may include the AMF 182 sending a second registration acceptance to the WTRU 102, the second registration acceptance including information indicating that one or more S-NSSAIs indicating the second requested NSSAI are allowed.

[0288] In some representative embodiments, the AMF 182 may send (e.g., in a registration acceptance) information indicating a registration area including a plurality of TAs. For example, the plurality of TAs may include one or more first TAs.

[0289] In some representative embodiments, the first registration request may be sent by the WTRU 102 to a base station (e.g., gNB 180) associated with a second TA (e.g., which supports an allowed S-NSSAI) other than the one or more first TAs among the plurality of TAs.

[0290] In some representative embodiments, the second registration request may be sent by the WTRU 102 to a base station (e.g., gNB 180) associated with the TA among the one or more first TAs.

[0291] In some representative embodiments, the first registration acceptance may be sent by the AMF 182 using (e.g., via) a base station (e.g., gNB 180) associated with a second TA (e.g., which supports the allowed S-NSSAI) other than the one or more first TAs among the plurality of TAs.

[0292] In some representative embodiments, the WTRU 102 may determine that the WTRU 102 has entered the TA among the one or more first TAs (e.g., at 606) before the AMF 182 deregisters the WTRU 102 from at least one of the allowed S-NSSAIs in the allowed S-NSSAI.

[0293] In certain representative embodiments, the WTRU 102 may determine that the WTRU 102 is communicating with a base station (e.g., gNB 180) that is not part of the TA that received the first registration acceptance (e.g., at 604) before the WTRU 102 is deregistered from at least one of the allowed S-NSSAIs in the allowed S-NSSAI by the AMF 182.

[0294] In certain representative embodiments, the information indicating one or more TAs that do not support one or more allowed S-NSSAIs includes the association between the one or more TAs and an S-NSSAI among the S-NSSAIs of the first requested NSSAI. For example, each first TA may be associated with (e.g., not provide support for) at least one allowed S-NSSAI.

[0295] Figure 12 is a flowchart illustrating an example procedure for slice registration. In certain representative embodiments, Figure 12 the procedure in may generally be implemented by the WTRU 102 (e.g., as a method). In Figure 12 , at 1202, the WTRU 102 may send information indicating the first requested NSSAI (e.g., to a network entity) in a first TA (e.g., which does not support the set of slices available in the network). At 1204, the WTRU 102 may receive (e.g., from a network entity) information indicating that one or more S-NSSAIs of the first requested NSSAI are rejected and information indicating one or more second TAs that support one or more of the rejected S-NSSAIs. In some examples, the WTRU 102 may receive the information at 1204 as part of the registration procedure at 1202, such as in a registration acceptance message from a network entity (e.g., AMF 182). At 1206, after the WTRU 102 has entered a TA that supports at least one of the rejected S-NSSAIs of the one or more second TAs that support the rejected S-NSSAIs, the WTRU 102 may send information indicating a second requested NSSAI (e.g., to a network entity) in that TA (e.g., which does support the rejected slice). The second requested NSSAI may be associated with at least one of the rejected S-NSSAIs of the rejected S-NSSAIs.

[0296] Figure 13 is a flowchart illustrating an example procedure for slice registration. In certain representative embodiments, Figure 13 the procedure in may generally be implemented by the WTRU 102 (e.g., as a method). In Figure 13In [the figure], at 1302, the WTRU 102 may send information indicating a first requested NSSAI (e.g., to a network entity) in a first TA (e.g., which does not support a set of slices available in the network). At 1304, the WTRU 102 may receive (e.g., from a network entity) information indicating that one or more S-NSSAIs of the first requested NSSAI are allowed and information indicating one or more second TAs that do not support one or more of the allowed S-NSSAIs. In some examples, the WTRU 102 may receive, at 1304, information as part of the registration procedure at 1302, such as in a registration acceptance message from a network entity (e.g., the AMF 182). At 1306, after the WTRU 102 has entered a TA in one or more second TAs that does not support at least one of the allowed S-NSSAIs of the allowed S-NSSAIs, the WTRU 102 may deregister (e.g., from a network entity) from at least one of the allowed S-NSSAIs in the TA. For example, the WTRU 102 may send information indicating a second requested NSSAI at 1306. The second requested NSSAI may be associated with S-NSSAIs other than the allowed S-NSSAIs not supported by the TA.

[0297] In certain representative embodiments, a wireless transmit / receive unit (WTRU) may be configured to perform (e.g., implement a method) actions that include sending (e.g., to a network entity) a first registration request message associated with a first tracking area (TA) of a registration area (RA). For example, the first registration request may include (1) information indicating a set of slices requested by the WTRU. The WTRU may receive (e.g., from the network entity) a first registration acceptance message that may include (1) information indicating that a first slice of the set of slices is rejected and (2) slice-specific service area (SSSA) information indicating at least one second TA in the RA where the first slice is available. Under the condition that (e.g., after) the WTRU receives the SSSA and the WTRU has entered the at least one second TA, the WTRU may send (e.g., to a network entity) a second registration request message associated with the second TA of the RA. For example, the second registration request may include (1) information indicating at least the first slice of the set of slices requested by the WTRU. The WTRU may also receive (e.g., from the network entity) a second registration acceptance message that may include (1) information indicating that the WTRU is allowed to access the first slice of the set of slices in the second TA.

[0298] In some representative embodiments, information on the set of slices requested by the WTRU may be provided as network slice selection assistance information (NSSAI).

[0299] In some representative embodiments, the RA includes at least the first TA and the second TA.

[0300] In some representative embodiments, information indicating that the first slice of the set of slices is rejected may be provided as a single NSSAI (S-NSSAI).

[0301] In some representative embodiments, the SSSA information may indicate that the first slice is accessible in TAs of the RA other than the first TA.

[0302] In some representative embodiments, the first registration acceptance message may include a slice rejection reason code that indicates that the first slice is rejected only for the current TA and not for the entire RA.

[0303] In some representative embodiments, the first registration acceptance message may include a service area restricted NSSAI information element that indicates that one or more slices of the set of slices are accessible in less than all TAs of the RA.

[0304] In some representative embodiments, the first registration request message may include information indicating that the WTRU understands or is capable of receiving SSSA information.

[0305] In some embodiments, the various procedures and examples provided above may be combined and / or modified to incorporate one or more additional features as described herein.

[0306] Conclusion

[0307] Although the features and elements are provided above in a particular combination, one of ordinary skill in the art will appreciate that each feature or element can be used separately or in any combination with other features and elements. The present disclosure is not limited to the specific embodiments described in this patent application, which are intended to be illustrative of various aspects. Many modifications and variations can be made without departing from the spirit and scope of the invention, as will be apparent to those skilled in the art. Any element, act, or instruction used in the specification of this application should not be construed as critical or essential to the invention unless expressly so provided. Based on the foregoing description, methods and devices that are functionally equivalent within the scope of the present disclosure, other than those enumerated herein, will be apparent to those skilled in the art. Such modifications and variations are intended to fall within the scope of the appended claims. The present disclosure is limited only by the terms of the appended claims and the full scope of equivalents of such claims that are entitled to the rights. It should be understood that the present disclosure is not limited to a particular method or system.

[0308] For simplicity, the foregoing embodiments have been discussed in terms of terminology and structures for devices having wireless communication capabilities (e.g., radio wave transmitters and receivers). However, the embodiments discussed are not limited to these systems, but can be applied to other systems that use other forms of electromagnetic waves or non-electromagnetic waves (such as sound waves).

[0309] It should also be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, the term "video" or the term "image" can mean any of a snapshot, a single image, and / or multiple images displayed on a time basis. As another example, when referred to herein, the term "user equipment" and its abbreviation "UE", the term "remote", and / or the term "head-mounted display" or its abbreviation "HMD" can mean or include (i) a wireless transmit and / or receive unit (WTRU); (ii) any one of a plurality of embodiments of a WTRU; (iii) a device having wireless capabilities and / or having wired capabilities (e.g., tetherable) configured with some or all of the structures and functions of a WTRU, in particular; (iii) a device having wireless capabilities and / or having wired capabilities configured with less than all of the structures and functions of a WTRU; or (iv) etc. This article is relative to Figures 1A to 1DDetails of an example WTRU that can represent any WTRU described herein are provided. As another example, the various disclosed embodiments herein are described above and below as utilizing a head-mounted display. Those skilled in the art will recognize that devices other than a head-mounted display can be utilized and that some or all of the present disclosure and the various disclosed embodiments can be modified accordingly without undue experimentation. Examples of such other devices can include drones or other devices configured to stream information to provide an augmented reality experience.

[0310] Additionally, the methods provided herein can be implemented in a computer program, software, or firmware incorporated in a computer-readable medium for execution by a computer or processor. Examples of computer-readable media include electronic signals (transmitted via a wired or wireless connection) and computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, read-only memory (ROM), random access memory (RAM), registers, cache memory, semiconductor memory devices, magnetic media (such as internal hard disks and removable disks), magneto-optical media, and optical media (such as CD-ROM disks and digital versatile disks (DVDs)). A processor associated with the software can be used to implement a radio frequency transceiver for a WTRU, UE, terminal, base station, RNC, or any host computer.

[0311] Variations of the methods, devices, and systems provided above are possible without departing from the scope of the present invention. Given the various embodiments that are applicable, it should be understood that the illustrated embodiments are merely examples and should not be considered as limiting the scope of the following claims. For example, the embodiments provided herein include a handheld device that can include any suitable voltage source (such as a battery, etc.) that provides any suitable voltage or that is used in conjunction with such a voltage source.

[0312] Furthermore, in the embodiments provided above, processing platforms, computing systems, controllers, and other devices including a processor are indicated. These devices can include at least one central processing unit (“CPU”) and memory. In accordance with the practice of those skilled in the art of computer programming, references to symbolic representations of actions and operations or instructions can be performed by various CPUs and memories. Such actions and operations or instructions can be referred to as being “executed,” “computer-executed,” or “CPU-executed.”

[0313] Those of ordinary skill in the art will appreciate that the operations or instructions represented by the actions and symbols include the manipulation of electrical signals by a CPU. The electrical system represents data bits, which may result in the ultimate transformation or reduction of electrical signals and the retention of data bits at memory locations in a memory system, thereby reconfiguring or otherwise altering the operation of the CPU and performing other processing of the signals. The memory locations that retain the data bits are physical locations having specific electrical, magnetic, optical, or organic properties corresponding to or representing the data bits. It should be understood that the embodiments are not limited to the above platforms or CPUs, and other platforms and CPUs may also support the provided methods.

[0314] The data bits may also be retained on a computer-readable medium, which includes magnetic disks, optical disks, and any other volatile (e.g., random access memory (“RAM”)) or non-volatile (e.g., read-only memory (“ROM”)) mass storage systems readable by a CPU. The computer-readable medium may include cooperative or interconnected computer-readable media that exist uniquely on a processing system or are distributed among multiple interconnected processing systems, which may be local or remote to the processing system. It should be understood that the embodiments are not limited to the above memories, and other platforms and memories may also support the provided methods.

[0315] In an illustrative embodiment, any of the operations, processes, etc. described herein may be implemented as computer-readable instructions stored on a computer-readable medium. The computer-readable instructions may be executed by a processor of a mobile unit, a network element, and / or any other computing device.

[0316] There is little difference between the hardware implementation and the software implementation in various aspects of the system. The use of hardware or software is generally (but not always, as the choice between hardware and software may become important in certain contexts) a design choice representing a trade-off between cost and efficiency. There may be various media (e.g., hardware, software, and / or firmware) that can implement the processes and / or systems and / or other technologies described herein, and the preferred medium may vary with the context of the deployment of the process and / or system and / or other technology. For example, if the implementer determines that speed and accuracy are most important, the implementer may choose a medium that is primarily hardware and / or firmware. If flexibility is most important, the implementer may choose a software implementation. Alternatively, the implementer may choose some combination of hardware, software, and / or firmware.

[0317] The foregoing detailed description has set forth various embodiments of apparatuses and / or processes using block diagrams, flowcharts, and / or examples. In instances in which such block diagrams, flowcharts, and / or examples include one or more functions and / or operations, those skilled in the art will understand that each function and / or operation within such block diagrams, flowcharts, or examples can be implemented, individually and / or collectively, by a wide range of hardware, software, firmware, or virtually any combination thereof. In one embodiment, several parts of the subject matter described herein may be implemented via application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), digital signal processors (DSPs), and / or other integrated formats. However, those skilled in the art will recognize that some aspects of the embodiments disclosed herein may be equivalently implemented, wholly or in part, in integrated circuits as one or more computer programs running on one or more computers (e.g., one or more programs running on one or more computer systems), one or more programs running on one or more processors (e.g., one or more programs running on one or more microprocessors), firmware, or virtually any combination thereof, and that designing the circuitry and / or writing the code for the software and / or firmware would be well within the skill of one of ordinary skill in the art in light of this disclosure. Additionally, those skilled in the art will appreciate that the mechanisms of the subject matter described herein can be distributed in a variety of forms as a program product, and that illustrative embodiments of the subject matter described herein apply regardless of the particular type of signal bearing medium used to actually effect such distribution. Examples of signal bearing media include, but are not limited to, the following: recordable type media such as floppy disks, hard disk drives, CDs, DVDs, digital tape, computer memory, etc.; and transmission type media such as digital and / or analog communication media (e.g., fiber optic cables, waveguides, wired communication links, wireless communication links, etc.).

[0318] Those skilled in the art will recognize that it is common in the art to describe devices and / or processes in the manner set forth herein and then use engineering practice to integrate such described devices and / or processes into a data processing system. That is, at least a portion of the devices and / or processes described herein can be integrated into a data processing system via a reasonable amount of experimentation. Those skilled in the art will recognize that a typical data processing system generally may include one or more of the following: a system unit housing; a video display device; memory, such as volatile memory and non-volatile memory; processors, such as microprocessors and digital signal processors; computing entities, such as operating systems, drivers, graphical user interfaces, and application programs; one or more interaction devices, such as touchpads or screens; and / or control systems, including feedback loops and control motors (e.g., for feedback sensing position and / or speed, control motors for moving and / or adjusting components and / or quantities). A typical data processing system can be implemented using any suitable commercially available components, such as those commonly found in data computing / communication and / or network computing / communication systems.

[0319] The subject matter described herein sometimes illustrates different components included within or connected to different other components. It should be understood that such depicted architectures are merely examples and that in fact many other architectures can be implemented to achieve the same functionality. In a conceptual sense, any arrangement of components that achieves the same functionality is effectively "associated" such that the desired functionality can be achieved. Thus, any two components that are combined herein to achieve a particular function can be considered to be "associated" with each other such that the required function is achieved, regardless of the architecture or intermediate components. Similarly, any two components so associated can also be considered to be "operably connected" or "operably coupled" to each other to achieve the desired function, and any two components that can be so associated can also be considered to be "operably coupleable" to each other to achieve the desired function. Specific examples of operably coupleable include, but are not limited to, components that can physically mate and / or physically interact and / or components that can wirelessly interact and / or wirelessly interact and / or components that can logically interact and / or can logically interact.

[0320] Regarding substantially any plural and / or singular terms used herein, those skilled in the art can appropriately convert from plural to singular and / or from singular to plural depending on the context and / or application. For clarity, various singular / plural permutations may be explicitly set forth herein.

[0321] Those skilled in the art should understand that, generally speaking, the terms used in this text, especially in the appended claims (e.g., the subject matter of the appended claims), are usually intended to be "open-ended" terms (e.g., the term "comprising" should be interpreted as "comprising but not limited to", the term "having" should be interpreted as "having at least", the term "containing" should be interpreted as "containing but not limited to", etc.). Those skilled in the art should also understand that if the intention is to specify a particular number of introduced claim recitation objects, such intention will be explicitly recited in the claim, and in the absence of such recitation, there is no such intention. For example, in cases where only one item is expected, terms such as "single" or similar language may be used. To assist understanding, the following appended claims and / or the description herein may include the use of introductory phrases "at least one" and "one or more" to introduce claim recitation objects. However, the use of such phrases should not be construed as implying that any particular claim including such introduced claim recitation objects is limited to an embodiment including only one such recitation object by the indefinite article "a" or "an" introducing the claim recitation object. This is the case even when the same claim includes an introductory phrase "one or more" or "at least one" and an indefinite article such as "a" or "an" (e.g., "a" and / or "an" should be interpreted to mean "at least one" or "one or more"). This also applies to the use of the definite article for introducing claim recitation objects. In addition, even when a particular number of introduced claim recitation objects is explicitly recited, those skilled in the art will recognize that such recitation should be interpreted to mean at least the stated number (e.g., in the absence of other modifiers, the bare recitation of "two recitation objects" means at least two recitation objects or two or more recitation objects). Additionally, in those instances where a convention similar to "at least one of A, B, and C, etc." is used, generally speaking, the meaning of such construction is that those skilled in the art will understand the convention (e.g., "a system having at least one of A, B, and C" will include but not be limited to a system having A alone, having B alone, having C alone, having A and B simultaneously, having A and C simultaneously, having B and C simultaneously, and / or having A, B, and C simultaneously, etc.). In those instances where a convention similar to "at least one of A, B, or C, etc." is used, generally speaking, the meaning of such construction is that those skilled in the art will understand the convention (e.g., "a system having at least one of A, B, or C" will include but not be limited to a system having A alone, having B alone, having C alone, having A and B simultaneously, having A and C simultaneously, having B and C simultaneously, and / or having A, B, and C simultaneously, etc.). Those skilled in the art should also understand that, in fact, regardless of whether in the specification, claims, or drawings, any separate words and / or phrases presenting two or more alternative terms should be understood to contemplate the possibility of including one of the terms, any one of the terms, or both of the terms.For example, the phrase "A or B" will be understood to include the possibilities of "A" or "B" or "A and B". Additionally, as used herein, the term "any one of" followed by a listing of multiple items and / or multiple item categories is intended to include the item and / or item category "any one of", "any combination of", "any multiple of", and / or "any combination of multiples of" individually or in combination with other items and / or other item categories. Further, as used herein, the term "set" is intended to include any number of items, including zero. Additionally, as used herein, the term "quantity" is intended to include any quantity, including zero. And, as used herein, the term "plurality" is intended to be synonymous with "a plurality of".

[0322] Moreover, in cases where the features or aspects of the present disclosure are described in terms of a Markush group, those skilled in the art will recognize that the present disclosure is also described in terms of any individual member of the Markush group or a subgroup of the members.

[0323] As will be understood by those skilled in the art, for any and all purposes (such as for providing a written description), all ranges disclosed herein also cover any and all possible sub-ranges and combinations of their sub-ranges. Any listed range can be readily recognized as fully describing and enabling the same range to be divided into at least equal halves, thirds, quarters, fifths, tenths, etc. As a non-limiting example, each range discussed herein can be readily divided into a lower third, a middle third, and an upper third, etc. As will also be understood by those skilled in the art, all language such as "up to", "at least", "greater than", "less than", etc. includes the recited number and refers to a range that can subsequently be divided into sub-ranges as described above. Finally, as will be understood by those skilled in the art, a range includes each individual number. Thus, for example, a group having 1 to 3 cells refers to a group having 1, 2, or 3 cells. Similarly, a group having 1 to 5 cells refers to a group having 1, 2, 3, 4, or 5 cells, etc.

[0324] Furthermore, unless otherwise stated, the claims should not be construed as limited to the provided order or elements. Additionally, the use of the term "means for" in any claim is intended to invoke 35 U.S.C.§112, or the means-plus-function claim format, and any claim without the term "means for" is not intended to be so.

Claims

1. A wireless transmit / receive unit (WTRU), the wireless transmit / receive unit (WTRU) comprising: a processor and a transceiver, the processor and the transceiver being configured to: transmit a first registration request message, the first registration request message including a slice-specific service area (SSSA) information support indication and a first requested network slice selection assistance information (NSSAI), wherein the first requested NSSAI includes a set of one or more single NSSAIs (S-NSSAIs); in response to the first registration request message, receive a first registration acceptance message, the first registration acceptance message including information indicating: (i) a first registration area (RA) and (ii) SSSA information, the SSSA information indicating that a first S-NSSAI included in the first requested NSSAI is rejected and indicating a set of tracking areas (TAs) in the first RA that do not support the first S-NSSAI; based on the WTRU moving to a TA in the first RA that is not included in the set of TAs, transmit a second registration request message, the second registration request message including information indicating a second requested NSSAI, wherein the second requested NSSAI includes at least the first S-NSSAI; and in response to the second registration request message, receive a second registration acceptance message, the second registration acceptance message including information indicating that at least the first S-NSSAI included in the second requested NSSAI is allowed.

2. The WTRU according to claim 1, wherein the first registration acceptance message includes information indicating that a second S-NSSAI included in the first requested NSSAI is allowed in the first RA.

3. The WTRU according to claim 1, wherein the second registration acceptance message includes information indicating a second RA.

4. The WTRU according to claim 1, wherein the first RA includes a plurality of TAs, and the plurality of TAs includes the set of TAs that do not support the first S-NSSAI.

5. The WTRU according to claim 1, wherein the SSSA information support indication indicates that the WTRU is capable of receiving SSSA information, and the SSSA information support indication is included in a 5G mobility management (5GMM) core network capability information element of the first registration request message.

6. The WTRU according to claim 1, wherein the SSSA information is included in a non-access stratum mobility management (NAS-MM) information element of the first registration acceptance message.

7. The WTRU according to claim 1, wherein the second registration acceptance message is received by the WTRU in the TA in the first RA that is not included in the set of TAs.

8. The WTRU according to claim 1, wherein the second registration acceptance message is received from a base station associated with the TA in the first RA that is not included in the set of TAs.

9. The WTRU according to claim 1, wherein the processor and the transceiver are configured to: determine that the WTRU has entered a TA in the first RA that is not included in the set of TAs of the TA.

10. The WTRU according to claim 1, wherein the SSSA information further indicates a third S-NSSAI included in the first requested NSSAI and a set of TAs in the RA that do not support the third S-NSSAI.

11. A method implemented by a wireless transmit / receive unit (WTRU), the method comprising: sending a first registration request message, the first registration request message including a slice-specific service area (SSSA) information support indication and a first requested network slice selection assistance information (NSSAI), wherein the first requested NSSAI includes a set of one or more single NSSAIs (S-NSSAIs); in response to the first registration request message, receiving a first registration acceptance message, the first registration acceptance message including information indicating: (i) a first registration area (RA) and (ii) SSSA information, the SSSA information indicating that a first S-NSSAI included in the first requested NSSAI is rejected and indicating a set of first tracking areas (TAs) in the first RA that do not support the first S-NSSAI; sending a second registration request message based on the WTRU moving to a TA in the first RA that is not included in the set of TAs, the second registration request message including information indicating a second requested NSSAI, wherein the second requested NSSAI includes at least the first S-NSSAI; and in response to the second registration request message, receiving a second registration acceptance message, the second registration acceptance message including information indicating that at least the first S-NSSAI included in the second requested NSSAI is allowed.

12. The method according to claim 11, wherein the first registration acceptance message includes information indicating that a second S-NSSAI included in the first requested NSSAI is allowed in the first RA.

13. The method according to claim 11, wherein the second registration acceptance message includes information indicating a second RA.

14. The method according to claim 11, wherein the first RA includes a plurality of TAs, and the plurality of TAs includes the set of TAs that do not support the first S-NSSAI.

15. The method according to claim 11, wherein the SSSA information support indication indicates that the WTRU is capable of receiving SSSA information, and the SSSA information support indication is included in a 5G mobility management (5GMM) core network capability information element of the first registration request message.

16. The method according to claim 11, wherein the SSSA information is included in a non-access stratum mobility management (NAS-MM) information element of the first registration acceptance message.

17. The method according to claim 11, wherein the second registration acceptance message is received by the WTRU in a tracking area (TA) within the first registration area (RA) that is not included in the set of TAs.

18. The method according to claim 11, wherein the second registration acceptance message is received from a base station associated with a TA within the first RA that is not included in the set of TAs.

19. The method according to claim 11, the method further comprises: determining that the WTRU has entered a TA within the first RA that is not included in the set of TAs before transmitting the second registration request message.

20. The method according to claim 11, wherein the SSSA information further indicates a third single network slice selection assistance information (S-NSSAI) included in the first requested network slice selection assistance information (NSSAI) and a set of TAs within the first RA that do not support the third S-NSSAI.

21. A wireless transmit / receive unit (WTRU), the wireless transmit / receive unit (WTRU) comprises: a processor and a transceiver, the processor and the transceiver being configured to: transmit a first registration request message comprising a slice specific service area (SSSA) information support indication and a first requested network slice selection assistance information (NSSAI), wherein the first requested NSSAI comprises a set of single NSSAIs (S-NSSAIs); in response to the first registration request message, receive a first registration acceptance message comprising information indicating: (i) a first registration area (RA) comprising a plurality of tracking areas (TAs); (ii) SSSA information indicating that a first S-NSSAI included in the first requested NSSAI is rejected and indicating a subset of first TAs within the first RA that do not support the first S-NSSAI, and a second S-NSSAI included in the first requested NSSAI, and a subset of second TAs within the first RA that do not support the second S-NSSAI; determining that the WTRU has moved to a TA within the first RA that is not included in the set of TAs; based on the WTRU moving to the TA within the first RA that is not included in the set of TAs, transmit a second registration request message comprising information indicating a second requested NSSAI, wherein the second requested NSSAI comprises at least the first S-NSSAI; and in response to the second registration request message, receive a second registration acceptance message comprising information indicating that at least the first S-NSSAI included in the second requested NSSAI is allowed. wherein the SSSA information support indication is included in the 5G mobility management (5GMM) core network capability information element of the first registration request message; and wherein the SSSA information is included in the non-access stratum mobility management (NAS-MM) information element of the first registration acceptance message.

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