Communication based on network slice

Abstract

The present disclosure provides a method. The method may include: receiving a request message including requested NSSAI from a UE; determining a timer value for a bakckoff timer, based on a remaining time of the certain period; and transmitting a response message includes the timer value for the bakckoff timer to the UE.

Description

COMMUNICATION BASED ON NETWORK SLICE

[0001] The present specification relates to a radio communication.

[0002] 3rd Generation Partnership Project (3GPP) Long-Term Evolution (LTE) is a technology for enabling high-speed packet communications. Many schemes have been proposed for the LTE objective including those that aim to reduce user and provider costs, improve service quality, and expand and improve coverage and system capacity. The 3GPP LTE requires reduced cost per bit, increased service availability, flexible use of a frequency band, a simple structure, an open interface, and adequate power consumption of a terminal as an upper-level requirement.

[0003] Work has started in International Telecommunication Union (ITU) and 3GPP to develop requirements and specifications for New Radio (NR) systems. 3GPP has to identify and develop the technology components needed for successfully standardizing the new RAT timely satisfying both the urgent market needs, and the more long-term requirements set forth by the ITU Radio communication sector (ITU-R) International Mobile Telecommunications (IMT)-2020 process. Further, the NR should be able to use any spectrum band ranging at least up to 100 GHz that may be made available for wireless communications even in a more distant future.

[0004] The NR targets a single technical framework addressing all usage scenarios, requirements and deployment scenarios including enhanced Mobile BroadBand (eMBB), massive Machine Type Communications (mMTC), Ultra-Reliable and Low Latency Communications (URLLC), etc. The NR shall be inherently forward compatible.

[0005] Communication based on a network slice is intorduced. However, there are problems that communication based on a time validity criteria of a network slice cannot be performed efficiently and / or precisely, according to the prior arts.

[0006] In one aspect, a method is provided. The method may comprise: receiving a request message including requested NSSAI from a UE; determining a timer value for a bakckoff timer, based on a remaining time of the certain period; and transmitting a response message includes the timer value for the bakckoff timer to the UE.

[0007] In another aspect, an appartus performing the above method is provided.

[0008] In one aspect, a method performed by an AMF is provided. The method may comprise: transmitting a request message including requested NSSAI to a network entity; receiving a response message includes a timer value for a bakckoff timer from the network entity.

[0009] FIG. 1 shows an example of a communication system to which implementations of the present disclosure is applied.

[0010] FIG. 2 shows an example of wireless devices to which implementations of the present disclosure is applied.

[0011] FIG. 3 shows an example of UE to which implementations of the present disclosure is applied.

[0012] FIG. 4 shows an example of 5G system architecture to which implementations of the present disclosure is applied.

[0013] FIGS. 5 and 6 show an example of a registration procedure to which implementations of the present disclosure is applied.

[0014] FIG. 7 illustrates an example of a method according to an embodiment of the present disclosure.

[0015] FIG. 8 illustrates an example of a situation related to an embodiment of the present disclosure.

[0016] FIG. 9 illustrates an example of operations according to an embodiment of the present disclosure.

[0017] The following techniques, apparatuses, and systems may be applied to a variety of wireless multiple access systems. Examples of the multiple access systems include a Code Division Multiple Access (CDMA) system, a Frequency Division Multiple Access (FDMA) system, a Time Division Multiple Access (TDMA) system, an Orthogonal Frequency Division Multiple Access (OFDMA) system, a Single Carrier Frequency Division Multiple Access (SC-FDMA) system, and a Multi Carrier Frequency Division Multiple Access (MC-FDMA) system. CDMA may be embodied through radio technology such as Universal Terrestrial Radio Access (UTRA) or CDMA2000. TDMA may be embodied through radio technology such as Global System for Mobile communications (GSM), General Packet Radio Service (GPRS), or Enhanced Data rates for GSM Evolution (EDGE). OFDMA may be embodied through radio technology such as Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, or Evolved UTRA (E-UTRA). UTRA is a part of a Universal Mobile Telecommunications System (UMTS). 3rd Generation Partnership Project (3GPP) Long-Term Evolution (LTE) is a part of Evolved UMTS (E-UMTS) using E-UTRA. 3GPP LTE employs OFDMA in downlink (DL) and SC-FDMA in uplink (UL). Evolution of 3GPP LTE includes LTE-Advanced (LTE-A), LTE-A Pro, and / or 5G New Radio (NR).

[0018] For convenience of description, implementations of the present disclosure are mainly described in regards to a 3GPP based wireless communication system. However, the technical features of the present disclosure are not limited thereto. For example, although the following detailed description is given based on a mobile communication system corresponding to a 3GPP based wireless communication system, aspects of the present disclosure that are not limited to 3GPP based wireless communication system are applicable to other mobile communication systems.

[0019] For terms and technologies which are not specifically described among the terms of and technologies employed in the present disclosure, the wireless communication standard documents published before the present disclosure may be referenced.

[0020] In the present disclosure, "A or B" may mean "only A", "only B", or "both A and B". In other words, "A or B" in the present disclosure may be interpreted as "A and / or B". For example, "A, B or C" in the present disclosure may mean "only A", "only B", "only C", or "any combination of A, B and C".

[0021] In the present disclosure, slash ( / ) or comma (,) may mean "and / or". For example, "A / B" may mean "A and / or B". Accordingly, "A / B" may mean "only A", "only B", or "both A and B". For example, "A, B, C" may mean "A, B or C".

[0022] In the present disclosure, "at least one of A and B" may mean "only A", "only B" or "both A and B". In addition, the expression "at least one of A or B" or "at least one of A and / or B" in the present disclosure may be interpreted as same as "at least one of A and B".

[0023] In addition, in the present disclosure, "at least one of A, B and C" may mean "only A", "only B", "only C", or "any combination of A, B and C". In addition, "at least one of A, B or C" or "at least one of A, B and / or C" may mean "at least one of A, B and C".

[0024] Also, parentheses used in the present disclosure may mean "for example". In detail, when it is shown as "control information (PDCCH)", "PDCCH" may be proposed as an example of "control information". In other words, "control information" in the present disclosure is not limited to "PDCCH", and "PDCCH" may be proposed as an example of "control information". In addition, even when shown as "control information (i.e., PDCCH)", "PDCCH" may be proposed as an example of "control information".

[0025] Technical features that are separately described in one drawing in the present disclosure may be implemented separately or simultaneously.

[0026] Although not limited thereto, various descriptions, functions, procedures, suggestions, methods and / or operational flowcharts of the present disclosure disclosed herein can be applied to various fields requiring wireless communication and / or connection (e.g., 5G) between devices.

[0027] Hereinafter, the present disclosure will be described in more detail with reference to drawings. The same reference numerals in the following drawings and / or descriptions may refer to the same and / or corresponding hardware blocks, software blocks, and / or functional blocks unless otherwise indicated.

[0028] FIG. 1 shows an example of a communication system to which implementations of the present disclosure is applied.

[0029] The 5G usage scenarios shown in FIG. 1 are only exemplary, and the technical features of the present disclosure can be applied to other 5G usage scenarios which are not shown in FIG. 1.

[0030] Three main requirement categories for 5G include (1) a category of enhanced Mobile BroadBand (eMBB), (2) a category of massive Machine Type Communication (mMTC), and (3) a category of Ultra-Reliable and Low Latency Communications (URLLC).

[0031] Referring to FIG. 1, the communication system 1 includes wireless devices 100a to 100f, Base Stations (BSs) 200, and a network 300. Although FIG. 1 illustrates a 5G network as an example of the network of the communication system 1, the implementations of the present disclosure are not limited to the 5G system, and can be applied to the future communication system beyond the 5G system.

[0032] The BSs 200 and the network 300 may be implemented as wireless devices and a specific wireless device may operate as a BS / network node with respect to other wireless devices.

[0033] The wireless devices 100a to 100f represent devices performing communication using Radio Access Technology (RAT) (e.g., 5G NR or LTE) and may be referred to as communication / radio / 5G devices. The wireless devices 100a to 100f may include, without being limited to, a robot 100a, vehicles 100b-1 and 100b-2, an eXtended Reality (XR) device 100c, a hand-held device 100d, a home appliance 100e, an Internet-of-Things (IoT) device 100f, and an Artificial Intelligence (AI) device / server 400. For example, the vehicles may include a vehicle having a wireless communication function, an autonomous driving vehicle, and a vehicle capable of performing communication between vehicles. The vehicles may include an Unmanned Aerial Vehicle (UAV) (e.g., a drone). The XR device may include an Augmented Reality (AR) / Virtual Reality (VR) / Mixed Reality (MR) device and may be implemented in the form of a Head-Mounted Device (HMD), a Head-Up Display (HUD) mounted in a vehicle, a television, a smartphone, a computer, a wearable device, a home appliance device, a digital signage, a vehicle, a robot, etc. The hand-held device may include a smartphone, a smartpad, a wearable device (e.g., a smartwatch or a smartglasses), and a computer (e.g., a notebook). The home appliance may include a TV, a refrigerator, and a washing machine. The IoT device may include a sensor and a smartmeter.

[0034] In the present disclosure, the wireless devices 100a to 100f may be called User Equipments (UEs). A UE may include, for example, a cellular phone, a smartphone, a laptop computer, a digital broadcast terminal, a Personal Digital Assistant (PDA), a Portable Multimedia Player (PMP), a navigation system, a slate Personal Computer (PC), a tablet PC, an ultrabook, a vehicle, a vehicle having an autonomous traveling function, a connected car, an UAV, an AI module, a robot, an AR device, a VR device, an MR device, a hologram device, a public safety device, an MTC device, an IoT device, a medical device, a FinTech device (or a financial device), a security device, a weather / environment device, a device related to a 5G service, or a device related to a fourth industrial revolution field.

[0035] The wireless devices 100a to 100f may be connected to the network 300 via the BSs 200. An AI technology may be applied to the wireless devices 100a to 100f and the wireless devices 100a to 100f may be connected to the AI server 400 via the network 300. The network 300 may be configured using a 3G network, a 4G (e.g., LTE) network, a 5G (e.g., NR) network, and a beyond-5G network. Although the wireless devices 100a to 100f may communicate with each other through the BSs 200 / network 300, the wireless devices 100a to 100f may perform direct communication (e.g., sidelink communication) with each other without passing through the BSs 200 / network 300. For example, the vehicles 100b-1 and 100b-2 may perform direct communication (e.g., Vehicle-to-Vehicle (V2V) / Vehicle-to-everything (V2X) communication). The IoT device (e.g., a sensor) may perform direct communication with other IoT devices (e.g., sensors) or other wireless devices 100a to 100f.

[0036] Wireless communication / connections 150a, 150b and 150c may be established between the wireless devices 100a to 100f and / or between wireless device 100a to 100f and BS 200 and / or between BSs 200. Herein, the wireless communication / connections may be established through various RATs (e.g., 5G NR) such as uplink / downlink communication 150a, sidelink communication (or Device-to-Device (D2D) communication) 150b, inter-base station communication 150c (e.g., relay, Integrated Access and Backhaul (IAB)), etc. The wireless devices 100a to 100f and the BSs 200 / the wireless devices 100a to 100f may transmit / receive radio signals to / from each other through the wireless communication / connections 150a, 150b and 150c. For example, the wireless communication / connections 150a, 150b and 150c may transmit / receive signals through various physical channels. To this end, at least a part of various configuration information configuring processes, various signal processing processes (e.g., channel encoding / decoding, modulation / demodulation, and resource mapping / de-mapping), and resource allocating processes, for transmitting / receiving radio signals, may be performed based on the various proposals of the present disclosure.

[0037] NR supports multiples numerologies (and / or multiple Sub-Carrier Spacings (SCS)) to support various 5G services. For example, if SCS is 15 kHz, wide area can be supported in traditional cellular bands, and if SCS is 30 kHz / 60 kHz, dense-urban, lower latency, and wider carrier bandwidth can be supported. If SCS is 60 kHz or higher, bandwidths greater than 24.25 GHz can be supported to overcome phase noise.

[0038] The NR frequency band may be defined as two types of frequency range, i.e., Frequency Range 1 (FR1) and Frequency Range 2 (FR2). The numerical value of the frequency range may be changed. For example, the frequency ranges of the two types (FR1 and FR2) may be as shown in Table 1 below. For ease of explanation, in the frequency ranges used in the NR system, FR1 may mean "sub 6 GHz range", FR2 may mean "above 6 GHz range," and may be referred to as millimeter Wave (mmW).

[0039] Frequency Range designationCorresponding frequency rangeSubcarrier SpacingFR1450MHz - 6000MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0040] As mentioned above, the numerical value of the frequency range of the NR system may be changed. For example, FR1 may include a frequency band of 410MHz to 7125MHz as shown in Table 2 below. That is, FR1 may include a frequency band of 6GHz (or 5850, 5900, 5925 MHz, etc.) or more. For example, a frequency band of 6 GHz (or 5850, 5900, 5925 MHz, etc.) or more included in FR1 may include an unlicensed band. Unlicensed bands may be used for a variety of purposes, for example for communication for vehicles (e.g., autonomous driving).

[0041] Frequency Range designationCorresponding frequency rangeSubcarrier SpacingFR1410MHz - 7125MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0042] Here, the radio communication technologies implemented in the wireless devices in the present disclosure may include NarrowBand IoT (NB-IoT) technology for low-power communication as well as LTE, NR and 6G. For example, NB-IoT technology may be an example of Low Power Wide Area Network (LPWAN) technology, may be implemented in specifications such as LTE Cat NB1 and / or LTE Cat NB2, and may not be limited to the above-mentioned names. Additionally and / or alternatively, the radio communication technologies implemented in the wireless devices in the present disclosure may communicate based on LTE-M technology. For example, LTE-M technology may be an example of LPWAN technology and be called by various names such as enhanced MTC (eMTC). For example, LTE-M technology may be implemented in at least one of the various specifications, such as 1) LTE Cat 0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTE non-bandwidth limited (non-BL), 5) LTE-MTC, 6) LTE Machine Type Communication, and / or 7) LTE M, and may not be limited to the above-mentioned names. Additionally and / or alternatively, the radio communication technologies implemented in the wireless devices in the present disclosure may include at least one of ZigBee, Bluetooth, and / or LPWAN which take into account low-power communication, and may not be limited to the above-mentioned names. For example, ZigBee technology may generate Personal Area Networks (PANs) associated with small / low-power digital communication based on various specifications such as IEEE 802.15.4 and may be called various names.

[0043] FIG. 2 shows an example of wireless devices to which implementations of the present disclosure is applied.

[0044] In FIG. 2, The first wireless device 100 and / or the second wireless device 200 may be implemented in various forms according to use cases / services. For example, {the first wireless device 100 and the second wireless device 200} may correspond to at least one of {the wireless device 100a to 100f and the BS 200}, {the wireless device 100a to 100f and the wireless device 100a to 100f} and / or {the BS 200 and the BS 200} of FIG. 1. The first wireless device 100 and / or the second wireless device 200 may be configured by various elements, devices / parts, and / or modules.

[0045] The first wireless device 100 may include at least one transceiver, such as a transceiver 106, at least one processing chip, such as a processing chip 101, and / or one or more antennas 108.

[0046] The processing chip 101 may include at least one processor, such a processor 102, and at least one memory, such as a memory 104. Additional and / or alternatively, the memory 104 may be placed outside of the processing chip 101.

[0047] The processor 102 may control the memory 104 and / or the transceiver 106 and may be adapted to implement the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts described in the present disclosure. For example, the processor 102 may process information within the memory 104 to generate first information / signals and then transmit radio signals including the first information / signals through the transceiver 106. The processor 102 may receive radio signals including second information / signals through the transceiver 106 and then store information obtained by processing the second information / signals in the memory 104.

[0048] The memory 104 may be operably connectable to the processor 102. The memory 104 may store various types of information and / or instructions. The memory 104 may store a firmware and / or a software code 105 which implements codes, commands, and / or a set of commands that, when executed by the processor 102, perform the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed in the present disclosure. For example, the firmware and / or the software code 105 may implement instructions that, when executed by the processor 102, perform the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed in the present disclosure. For example, the firmware and / or the software code 105 may control the processor 102 to perform one or more protocols. For example, the firmware and / or the software code 105 may control the processor 102 to perform one or more layers of the radio interface protocol.

[0049] Herein, the processor 102 and the memory 104 may be a part of a communication modem / circuit / chip designed to implement RAT (e.g., LTE or NR). The transceiver 106 may be connected to the processor 102 and transmit and / or receive radio signals through one or more antennas 108. Each of the transceiver 106 may include a transmitter and / or a receiver. The transceiver 106 may be interchangeably used with Radio Frequency (RF) unit(s). In the present disclosure, the first wireless device 100 may represent a communication modem / circuit / chip.

[0050] The second wireless device 200 may include at least one transceiver, such as a transceiver 206, at least one processing chip, such as a processing chip 201, and / or one or more antennas 208.

[0051] The processing chip 201 may include at least one processor, such a processor 202, and at least one memory, such as a memory 204. Additional and / or alternatively, the memory 204 may be placed outside of the processing chip 201.

[0052] The processor 202 may control the memory 204 and / or the transceiver 206 and may be adapted to implement the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts described in the present disclosure. For example, the processor 202 may process information within the memory 204 to generate third information / signals and then transmit radio signals including the third information / signals through the transceiver 206. The processor 202 may receive radio signals including fourth information / signals through the transceiver 106 and then store information obtained by processing the fourth information / signals in the memory 204.

[0053] The memory 204 may be operably connectable to the processor 202. The memory 204 may store various types of information and / or instructions. The memory 204 may store a firmware and / or a software code 205 which implements codes, commands, and / or a set of commands that, when executed by the processor 202, perform the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed in the present disclosure. For example, the firmware and / or the software code 205 may implement instructions that, when executed by the processor 202, perform the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed in the present disclosure. For example, the firmware and / or the software code 205 may control the processor 202 to perform one or more protocols. For example, the firmware and / or the software code 205 may control the processor 202 to perform one or more layers of the radio interface protocol.

[0054] Herein, the processor 202 and the memory 204 may be a part of a communication modem / circuit / chip designed to implement RAT (e.g., LTE or NR). The transceiver 206 may be connected to the processor 202 and transmit and / or receive radio signals through one or more antennas 208. Each of the transceiver 206 may include a transmitter and / or a receiver. The transceiver 206 may be interchangeably used with RF unit. In the present disclosure, the second wireless device 200 may represent a communication modem / circuit / chip.

[0055] Hereinafter, hardware elements of the wireless devices 100 and 200 will be described more specifically. One or more protocol layers may be implemented by, without being limited to, one or more processors 102 and 202. For example, the one or more processors 102 and 202 may implement one or more layers (e.g., functional layers such as Physical (PHY) layer, Media Access Control (MAC) layer, Radio Link Control (RLC) layer, Packet Data Convergence Protocol (PDCP) layer, Radio Resource Control (RRC) layer, and Service Data Adaptation Protocol (SDAP) layer). The one or more processors 102 and 202 may generate one or more Protocol Data Units (PDUs), one or more Service Data Unit (SDUs), messages, control information, data, or information according to the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed in the present disclosure. The one or more processors 102 and 202 may generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data, or information according to the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed in the present disclosure and provide the generated signals to the one or more transceivers 106 and 206. The one or more processors 102 and 202 may receive the signals (e.g., baseband signals) from the one or more transceivers 106 and 206 and acquire the PDUs, SDUs, messages, control information, data, or information according to the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed in the present disclosure.

[0056] The one or more processors 102 and 202 may be referred to as controllers, microcontrollers, microprocessors, or microcomputers. The one or more processors 102 and 202 may be implemented by hardware, firmware, software, or a combination thereof. As an example, one or more Application Specific Integrated Circuits (ASICs), one or more Digital Signal Processors (DSPs), one or more Digital Signal Processing Devices (DSPDs), one or more Programmable Logic Devices (PLDs), or one or more Field Programmable Gate Arrays (FPGAs) may be included in the one or more processors 102 and 202. For example, the one or more processors 102 and 202 may be configured by a set of a communication control processor, an Application Processor (AP), an Electronic Control Unit (ECU), a Central Processing Unit (CPU), a Graphic Processing Unit (GPU), and a memory control processor.

[0057] The one or more memories 104 and 204 may be connected to the one or more processors 102 and 202 and store various types of data, signals, messages, information, programs, code, instructions, and / or commands. The one or more memories 104 and 204 may be configured by Random Access Memory (RAM), Dynamic RAM (DRAM), Read-Only Memory (ROM), electrically Erasable Programmable Read-Only Memory (EPROM), flash memory, volatile memory, non-volatile memory, hard drive, register, cash memory, computer-readable storage medium, and / or combinations thereof. The one or more memories 104 and 204 may be located at the interior and / or exterior of the one or more processors 102 and 202. The one or more memories 104 and 204 may be connected to the one or more processors 102 and 202 through various technologies such as wired or wireless connection.

[0058] The one or more transceivers 106 and 206 may transmit user data, control information, and / or radio signals / channels, mentioned in the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed in the present disclosure, to one or more other devices. The one or more transceivers 106 and 206 may receive user data, control information, and / or radio signals / channels, mentioned in the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed in the present disclosure, from one or more other devices. For example, the one or more transceivers 106 and 206 may be connected to the one or more processors 102 and 202 and transmit and receive radio signals. For example, the one or more processors 102 and 202 may perform control so that the one or more transceivers 106 and 206 may transmit user data, control information, or radio signals to one or more other devices. The one or more processors 102 and 202 may perform control so that the one or more transceivers 106 and 206 may receive user data, control information, or radio signals from one or more other devices.

[0059] The one or more transceivers 106 and 206 may be connected to the one or more antennas 108 and 208. Additionally and / or alternatively, the one or more transceivers 106 and 206 may include one or more antennas 108 and 208. The one or more transceivers 106 and 206 may be adapted to transmit and receive user data, control information, and / or radio signals / channels, mentioned in the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed in the present disclosure, through the one or more antennas 108 and 208. In the present disclosure, the one or more antennas 108 and 208 may be a plurality of physical antennas or a plurality of logical antennas (e.g., antenna ports).

[0060] The one or more transceivers 106 and 206 may convert received user data, control information, radio signals / channels, etc., from RF band signals into baseband signals in order to process received user data, control information, radio signals / channels, etc., using the one or more processors 102 and 202. The one or more transceivers 106 and 206 may convert the user data, control information, radio signals / channels, etc., processed using the one or more processors 102 and 202 from the base band signals into the RF band signals. To this end, the one or more transceivers 106 and 206 may include (analog) oscillators and / or filters. For example, the one or more transceivers 106 and 206 can up-convert OFDM baseband signals to OFDM signals by their (analog) oscillators and / or filters under the control of the one or more processors 102 and 202 and transmit the up-converted OFDM signals at the carrier frequency. The one or more transceivers 106 and 206 may receive OFDM signals at a carrier frequency and down-convert the OFDM signals into OFDM baseband signals by their (analog) oscillators and / or filters under the control of the one or more processors 102 and 202.

[0061] Although not shown in FIG. 2, the wireless devices 100 and 200 may further include additional components. The additional components 140 may be variously configured according to types of the wireless devices 100 and 200. For example, the additional components 140 may include at least one of a power unit / battery, an Input / Output (I / O) device (e.g., audio I / O port, video I / O port), a driving device, and a computing device. The additional components 140 may be coupled to the one or more processors 102 and 202 via various technologies, such as a wired or wireless connection.

[0062] In the implementations of the present disclosure, a UE may operate as a transmitting device in Uplink (UL) and as a receiving device in Downlink (DL). In the implementations of the present disclosure, a BS may operate as a receiving device in UL and as a transmitting device in DL. Hereinafter, for convenience of description, it is mainly assumed that the first wireless device 100 acts as the UE, and the second wireless device 200 acts as the BS. For example, the processor(s) 102 connected to, mounted on or launched in the first wireless device 100 may be adapted to perform the UE behavior according to an implementation of the present disclosure or control the transceiver(s) 106 to perform the UE behavior according to an implementation of the present disclosure. The processor(s) 202 connected to, mounted on or launched in the second wireless device 200 may be adapted to perform the BS behavior according to an implementation of the present disclosure or control the transceiver(s) 206 to perform the BS behavior according to an implementation of the present disclosure.

[0063] In the present disclosure, a BS is also referred to as a node B (NB), an eNode B (eNB), or a gNB.

[0064] FIG. 3 shows an example of UE to which implementations of the present disclosure is applied.

[0065] Referring to FIG. 3, a UE 100 may correspond to the first wireless device 100 of FIG. 2.

[0066] A UE 100 includes a processor 102, a memory 104, a transceiver 106, one or more antennas 108, a power management module 141, a battery 142, a display 143, a keypad 144, a Subscriber Identification Module (SIM) card 145, a speaker 146, and a microphone 147.

[0067] The processor 102 may be adapted to implement the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed in the present disclosure. The processor 102 may be adapted to control one or more other components of the UE 100 to implement the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed in the present disclosure. Layers of the radio interface protocol may be implemented in the processor 102. The processor 102 may include ASIC, other chipset, logic circuit and / or data processing device. The processor 102 may be an application processor. The processor 102 may include at least one of DSP, CPU, GPU, a modem (modulator and demodulator). An example of the processor 102 may be found in SNAPDRAGONTMseries of processors made by Qualcomm®, EXYNOSTMseries of processors made by Samsung®, A series of processors made by Apple®, HELIOTMseries of processors made by MediaTek®, ATOMTMseries of processors made by Intel®or a corresponding next generation processor.

[0068] The memory 104 is operatively coupled with the processor 102 and stores a variety of information to operate the processor 102. The memory 104 may include ROM, RAM, flash memory, memory card, storage medium and / or other storage device. When the embodiments are implemented in software, the techniques described herein can be implemented with modules (e.g., procedures, functions, etc.) that perform the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed in the present disclosure. The modules can be stored in the memory 104 and executed by the processor 102. The memory 104 can be implemented within the processor 102 or external to the processor 102 in which case those can be communicatively coupled to the processor 102 via various means as is known in the art.

[0069] The transceiver 106 is operatively coupled with the processor 102, and transmits and / or receives a radio signal. The transceiver 106 includes a transmitter and a receiver. The transceiver 106 may include baseband circuitry to process radio frequency signals. The transceiver 106 controls the one or more antennas 108 to transmit and / or receive a radio signal.

[0070] The power management module 141 manages power for the processor 102 and / or the transceiver 106. The battery 142 supplies power to the power management module 141.

[0071] The display 143 outputs results processed by the processor 102. The keypad 144 receives inputs to be used by the processor 102. The keypad 144 may be shown on the display 143.

[0072] The SIM card 145 is an　integrated circuit　that is intended to　securely store the　International Mobile Subscriber Identity　(IMSI) number and its related　key, which are used to identify and authenticate subscribers on　mobile telephony　devices (such as　mobile phones　and　computers). It is also possible to store contact information on many SIM cards.

[0073] The speaker 146 outputs sound-related results processed by the processor 102. The microphone 147 receives sound-related inputs to be used by the processor 102.

[0074] FIG. 4 shows an example of 5G system architecture to which implementations of the present disclosure is applied.

[0075] The 5G system (5GS) architecture consists of the following network functions (NF).

[0076] - Authentication Server Function (AUSF)

[0077] - Access and Mobility Management Function (AMF)

[0078] - Data Network (DN), e.g., operator services, Internet access or 3rd party services

[0079] - Unstructured Data Storage Function (UDSF)

[0080] - Network Exposure Function (NEF)

[0081] - Intermediate NEF (I-NEF)

[0082] - Network Repository Function (NRF)

[0083] - Network Slice Selection Function (NSSF)

[0084] - Policy Control Function (PCF)

[0085] - Session Management Function (SMF)

[0086] - Unified Data Management (UDM)

[0087] - Unified Data Repository (UDR)

[0088] - User Plane Function (UPF)

[0089] - UE radio Capability Management Function (UCMF)

[0090] - Application Function (AF)

[0091] - User Equipment (UE)

[0092] - (Radio) Access Network ((R)AN)

[0093] - 5G-Equipment Identity Register (5G-EIR)

[0094] - Network Data Analytics Function (NWDAF)

[0095] - CHarging Function (CHF)

[0096] Furthermore, the following network functions may be considered.

[0097] - Non-3GPP InterWorking Function (N3IWF)

[0098] - Trusted Non-3GPP Gateway Function (TNGF)

[0099] - Wireline Access Gateway Function (W-AGF)

[0100] FIG. 4 depicts the 5G system architecture in the non-roaming case, using the reference point representation showing how various network functions interact with each other.

[0101] In FIG. 4, for the sake of clarity of the point-to-point diagrams, the UDSF, NEF and NRF have not been depicted. However, all depicted Network Functions can interact with the UDSF, UDR, NEF and NRF as necessary.

[0102] For clarity, the UDR and its connections with other NFs, e.g., PCF, are not depicted in FIG. 4. For clarity, the NWDAF and its connections with other NFs, e.g., PCF, are not depicted in FIG. 4.

[0103] The 5G system architecture contains the following reference points:

[0104] - N1: Reference point between the UE and the AMF.

[0105] - N2: Reference point between the (R)AN and the AMF.

[0106] - N3: Reference point between the (R)AN and the UPF.

[0107] - N4: Reference point between the SMF and the UPF.

[0108] - N6: Reference point between the UPF and a Data Network.

[0109] - N9: Reference point between two UPFs.

[0110] The following reference points show the interactions that exist between the NF services in the NFs.

[0111] - N5: Reference point between the PCF and an AF.

[0112] - N7: Reference point between the SMF and the PCF.

[0113] - N8: Reference point between the UDM and the AMF.

[0114] - N10: Reference point between the UDM and the SMF.

[0115] - N11: Reference point between the AMF and the SMF.

[0116] - N12: Reference point between the AMF and the AUSF.

[0117] - N13: Reference point between the UDM and the AUSF.

[0118] - N14: Reference point between two AMFs.

[0119] - N15: Reference point between the PCF and the AMF in the case of non-roaming scenario, PCF in the visited network and AMF in the case of roaming scenario.

[0120] - N16: Reference point between two SMFs, (in roaming case between SMF in the visited network and the SMF in the home network).

[0121] - N22: Reference point between the AMF and the NSSF.

[0122] In some cases, a couple of NFs may need to be associated with each other to serve a UE.

[0123] A registration procedure is described. Section 4.2.2.2 of 3GPP TS 23.502 V16.3.0 (2019-12) can be referred.

[0124] FIGS. 5 and 6 show an example of a registration procedure to which implementations of the present disclosure is applied.

[0125] A UE needs to register with the network to get authorized to receive services, to enable mobility tracking and to enable reachability. The UE initiates the registration procedure using one of the following registration types:

[0126] - Initial registration to the 5GS; or

[0127] - Mobility registration update; or

[0128] - Periodic registration update; or

[0129] - Emergency registration.

[0130] The general registration procedure in FIGS. 5 and 6 applies on all these registration procedures, but the periodic registration update need not include all parameters that are used in other registration cases.

[0131] The general registration procedure in FIGS. 5 and 6 is also used for the case of registration in 3GPP access when the UE is already registered in a non-3GPP access, and vice versa. Registration in 3GPP access when the UE is already registered in a non-3GPP access scenario may require an AMF change.

[0132] First, procedures of FIG. 6 are described.

[0133] (1) Step 1: The UE transmits a Registration Request message to the (R)AN. The Registration Request message corresponds to AN message.

[0134] The Registration Request message may include AN parameters. In the case of NG-RAN, the AN parameters include, e.g., 5G SAE temporary mobile subscriber identity (5G-S-TMSI) or globally unique AMF ID (GUAMI), the selected public land mobile network (PLMN) ID (or PLMN ID and network identifier (NID)) and Requested network slice selection assistance information (NSSAI). The AN parameters also include establishment cause. The establishment cause provides the reason for requesting the establishment of an RRC connection. Whether and how the UE includes the Requested NSSAI as part of the AN parameters is dependent on the value of the access stratum connection establishment NSSAI inclusion mode parameter.

[0135] The Registration Request message may include a registration type. The registration type indicates if the UE wants to perform an initial registration (i.e., the UE is in RM-DEREGISTERED state), a mobility registration update (i.e., the UE is in RM-REGISTERED state and initiates a registration procedure due to mobility or due to the UE needs to update its capabilities or protocol parameters, or to request a change of the set of network slices it is allowed to use), a periodic registration update (i.e., the UE is in RM-REGISTERED state and initiates a registration procedure due to the periodic registration update timer expiry) or an emergency registration (i.e., the UE is in limited service state).

[0136] When the UE is performing an initial registration, the UE shall indicate its UE identity in the Registration Request message as follows, listed in decreasing order of preference:

[0137] i) a 5G globally unique temporary identifier (5G-GUTI) mapped from an evolved packet system (EPS) GUTI, if the UE has a valid EPS GUTI.

[0138] ii) a native 5G-GUTI assigned by the PLMN to which the UE is attempting to register, if available;

[0139] iii) a native 5G-GUTI assigned by an equivalent PLMN to the PLMN to which the UE is attempting to register, if available;

[0140] iv) a native 5G-GUTI assigned by any other PLMN, if available.

[0141] v) Otherwise, the UE shall include its subscriber concealed identifier (SUCI) in the Registration Request message.

[0142] When the UE performing an initial registration has both a valid EPS GUTI and a native 5G-GUTI, the UE shall also indicate the native 5G-GUTI as additional GUTI. If more than one native 5G-GUTIs are available, the UE shall select the 5G-GUTI in decreasing order of preference among items (ii)-(iv) in the list above.

[0143] When the UE is performing an initial registration with a native 5G-GUTI, then the UE shall indicate the related GUAMI information in the AN parameters. When the UE is performing an initial registration with its SUCI, the UE shall not indicate any GUAMI information in the AN parameters.

[0144] For an emergency registration, the SUCI shall be included if the UE does not have a valid 5G-GUTI available; the permanent equipment identifier (PEI) shall be included when the UE has no subscriber permanent identifier (SUPI) and no valid 5G-GUTI. In other cases, the 5G-GUTI is included and it indicates the last serving AMF.

[0145] The Registration Request message may also include security parameters, PDU Session Status, etc. The security parameters are used for authentication and integrity protection. The PDU Session Status indicates the previously established PDU sessions in the UE. When the UE is connected to the two AMFs belonging to different PLMN via 3GPP access and non-3GPP access then the PDU Session status indicates the established PDU Session of the current PLMN in the UE.

[0146] (2) Step 2: The (R)AN selects an AMF.

[0147] If a 5G-S-TMSI or GUAMI is not included or the 5G-S-TMSI or GUAMI does not indicate a valid AMF, the (R)AN, based on (R)AT and requested NSSAI, if available, selects an AMF.

[0148] If UE is in CM-CONNECTED state, the (R)AN can forward the Registration Request message to the AMF based on the N2 connection of the UE.

[0149] If the (R)AN cannot select an appropriate AMF, it forwards the Registration Request message to an AMF which has been configured, in the (R)AN, to perform AMF selection.

[0150] (3) Step 3: The (R)AN transmits a Registration Request message to the new AMF. The Registration Request message corresponds to N2 message.

[0151] The Registration Request message may include whole information and / or a part of information included in the Registration Request message received from the UE which is described in step 1.

[0152] The Registration Request message may include N2 parameters. When NG-RAN is used, the N2 parameters include the selected PLMN ID (or PLMN ID and NID), location information and cell identity related to the cell in which the UE is camping, UE context request which indicates that a UE context including security information needs to be setup at the NG-RAN. When NG-RAN is used, the N2 parameters shall also include the establishment cause.

[0153] If the Registration type indicated by the UE is Periodic Registration Update, then steps 4 to 19 may be omitted.

[0154] (4) Step 4: If the UE's 5G-GUTI was included in the Registration Request message and the serving AMF has changed since last registration procedure, the new AMF may invoke the Namf_Communication_UEContextTransfer service operation on the old AMF including the complete registration request non-access stratum (NAS) message to request the UE's SUPI and UE context.

[0155] (5) Step 5: The Old AMF may respond to the new AMF for the Namf_Communication_UEContextTransfer invocation by including the UE's SUPI and UE context.

[0156] (6) Step 6: If the SUCI is not provided by the UE nor retrieved from the old AMF, the identity request procedure may be initiated by the new AMF sending the Identity Request message to the UE requesting the SUCI.

[0157] (7) Step 7: The UE may respond with an Identity Response message including the SUCI. The UE derives the SUCI by using the provisioned public key of the home PLMN (HPLMN).

[0158] (8) Step 8: The new AMF may decide to initiate UE authentication by invoking an AUSF. In that case, the new AMF selects an AUSF based on SUPI or SUCI.

[0159] (9) Step 9: Authentication / security may be established by the UE, new AMF, AUSF and / or UDM.

[0160] (10) Step 10: If the AMF has changed, the new AMF may notify the old AMF that the registration of the UE in the new AMF is completed by invoking the Namf_Communication_RegistrationCompleteNotify service operation. If the authentication / security procedure fails, then the registration shall be rejected, and the new AMF may invoke the Namf_Communication_RegistrationCompleteNotify service operation with a reject indication reason code towards the old AMF. The old AMF may continue as if the UE context transfer service operation was never received.

[0161] (11) Step 11: If the PEI was not provided by the UE nor retrieved from the old AMF, the Identity Request procedure may be initiated by the new AMF sending an Identity Request message to the UE to retrieve the PEI. The PEI shall be transferred encrypted unless the UE performs emergency registration and cannot be authenticated.

[0162] (12) Step 12: Optionally, the new AMF may initiate ME identity check by invoking the N5g-eir_EquipmentIdentityCheck_Get service operation.

[0163] Now, procedures of FIG. 6, which follow the procedures of FIG. 5, are described.

[0164] (13) Step 13: If step 14 below is to be performed, the new AMF, based on the SUPI, may select a UDM, then UDM may select a UDR instance.

[0165] (14) Step 14: The new AMF may register with the UDM.

[0166] (15) Step 15: The new AMF may select a PCF.

[0167] (16) Step 16: The new AMF may optionally perform an AM Policy Association Establishment / Modification.

[0168] (17) Step 17: The new AMF may transmit Update / Release SM Context message (e.g., Nsmf_PDUSession_UpdateSMContext and / or Nsmf_PDUSession_ReleaseSMContext) to the SMF.

[0169] (18) Step 18: If the new AMF and the old AMF are in the same PLMN, the new AMF may send a UE Context Modification Request to the N3IWF / TNGF / W-AGF.

[0170] (19) Step 19: The N3IWF / TNGF / W-AGF may send a UE Context Modification Response to the new AMF.

[0171] (20) Step 20: After the new AMF receives the response message from the N3IWF / TNGF / W-AGF in step 19, the new AMF may register with the UDM.

[0172] (21) Step 21: The new AMF transmits a Registration Accept message to the UE.

[0173] The new AMF sends a Registration Accept message to the UE indicating that the Registration Request has been accepted. 5G-GUTI is included if the new AMF allocates a new 5G-GUTI. If the UE is already in RM-REGISTERED state via another access in the same PLMN, the UE shall use the 5G-GUTI received in the Registration Accept message for both registrations. If no 5G-GUTI is included in the Registration Accept message, then the UE uses the 5G-GUTI assigned for the existing registration also for the new registration. If the new AMF allocates a new registration area, it shall send the registration area to the UE via Registration Accept message. If there is no registration area included in the Registration Accept message, the UE shall consider the old registration area as valid. Mobility Restrictions is included in case mobility restrictions applies for the UE and registration type is not emergency registration. The new AMF indicates the established PDU sessions to the UE in the PDU Session status. The UE removes locally any internal resources related to PDU sessions that are not marked as established in the received PDU Session status. When the UE is connected to the two AMFs belonging to different PLMN via 3GPP access and non-3GPP access then the UE removes locally any internal resources related to the PDU session of the current PLMN that are not marked as established in received PDU Session status. If the PDU Session status information was in the Registration Request message, the new AMF shall indicate the PDU Session status to the UE.

[0174] The Allowed NSSAI provided in the Registration Accept message is valid in the registration area and it applies for all the PLMNs which have their tracking areas included in the registration area. The Mapping Of Allowed NSSAI is the mapping of each Single Network Slice Selection Assistance Information (S-NSSAI) of the Allowed NSSAI to the HPLMN S-NSSAIs. The Mapping Of Configured NSSAI is the mapping of each S-NSSAI of the Configured NSSAI for the serving PLMN to the HPLMN S-NSSAIs.

[0175] Furthermore, optionally the new AMF performs a UE Policy Association Establishment.

[0176] (22) Step 22: The UE may send a Registration Complete message to the new AMF when it has successfully updated itself.

[0177] The UE may send a Registration Complete message to the new AMF to acknowledge if a new 5G-GUTI was assigned.

[0178] (23) Step 23: For registration over 3GPP Access, if the new AMF does not release the signaling connection, the new AMF may send the RRC Inactive Assistance Information to the NG-RAN. For registration over non-3GPP Access, if the UE is also in CM-CONNECTED state on 3GPP access, the new AMF may send the RRC Inactive Assistance Information to the NG-RAN.

[0179] (24) Step 24: The new AMF may perform information update towards the UDM.

[0180] (25) Step 25: The UE may execute Network Slice-Specific Authentication and Authorization procedure.

[0181] Temporarily available network slices (TS 24.501 V18.1.0 S4.6.2.8), which allow time validity criteria to be set per network slice, were discussed. Standard behaviours for this were defined.

[0182] To support temporarily available network slices, the following behaviours may be performed. For example, the terminal may transmit a message to the network indicating that the terminal supports S-NSSAI time validity information. The network may transmit time validity information to the terminal for the S-NSSAI included in the configured NSSAI inlcuded in the message.

[0183] However, it is possible that the terminal does not support this feature (i.e., time validity criteria) and only the network supports time validity criteria.

[0184] In such cases, even if the network configures temporarily available network slices, the terminal does not know (or not understand) any information related to the configuration. As a result, even if a network slice is not available, the terminal may still transmit a request to the network to use that network slice. In this case, the network rejects the device request. Furthermore, a terminal that receives a reject does not know if or when it can request the network slice again.

[0185] In detail, in prior arts, the enhanced network slice validity policy has been discussed as the following:

[0186] - the enhanced network slice validity policy has been discussed to support network slices which have Area of Service that is not matching existing TAs. It provides network slice validity policy to the supporting UE which includes location information, via Registration Procedure or UE Configuration Update Procedure.

[0187] - the enhanced network slice validity policy has been discussed to support temporary network slices. It provides network slice validity policy to the supporting UE which includes timing information, via Registration Procedure or UE Configuration Update Procedure.

[0188] This enhanced network slice validity policy feature is not implemented previously deployed networks or pre-released UEs (e.g., UEs based on Release 17). The enhanced network slice validity policy feature may mean a feature for supporting time validity criteria and / or temporarilty available network slices.

[0189] There may be cases in which a network supports this feature(e.g., a feature related to temporarilty available network slices) and a UE does not support this feature. In this case, the UE may request a slice that is invalid at a certain point of time because the UE does not know the time validity criteria of the slice.

[0190] In this case, the network can reject the UE request to use the slice. When the network reject the UE request, more efficient handling is needed to clarify the UE behaviour. For example, when the network rejects the UE request, the network should not simply reject it, but should perform a method to make the network and the UE efficient in its handling.

[0191] According to the present disclosure, the mechanism for handling the UE not supporting the slice time validity criteria feature(e.g., a feature related to temporarilty available network slices) is supported.

[0192] For example, according to the present disclosure, a terminal that does not support time validity information may request to use a temporarily unavailable network slice. In this case, the network may calculate a backoff timer value based on the time validity criteria of the network slice. The network may include the backoff timer value in the response message to the terminal request. The network may send a response message to the terminal that includes the backoff timer value. Based on this, the network may indicate to the terminal at what point the terminal may request the network slice again.

[0193] For refernce, non-supporting UE and UE not supporting the slice time validity criteria feature(e.g., a feature related to temporarilty available network slices) are used as a word having same meaning in the present disclosure. That is, non-supporting UE means UE not supporting the slice time validity criteria feature.

[0194] For example, the network may calculate the backoff timer for the UE. The non-supporting UE may transmit a request to use an unavailable network slice for a certain period of time. In this case, the network may inform the UE of the valid time to use the slice in the response message by including the backoff timer in the response message.

[0195] The following drawings are intended to illustrate specific embodiments of the present disclosure. The designations of specific devices or the designations of specific signals / messages / fields shown in the drawings are for illustrative purposes only, and the technical features of the present specification are not limited to the specific designations used in the drawings below.

[0196] FIG. 7 illustrates an example of a method according to an embodiment of the present disclosure.

[0197] FIG. 7 shows the example scenario that implements the proposed mechanism in the present disclosure.

[0198] For reference, the network of FIG. 7 may be an AMF or a SMF.

[0199] Operations according to implementations of the present disclosure may be as follows as presented in 7.

[0200] Step 1: The UE transmits a request message to use a slice to the network.

[0201] For examle, the UE may transmit request message to a network. For exmaple, the request message may include a requested NSSAI.

[0202] For example, the UE may include the requested slice information in the request message.

[0203] For example, the request message may be a Registration request message, UL NAS transport message, Service request message, PDU session establish request message, or PDU session modification request message.

[0204] For example, when the registration request message is transmitted, the network of FIG. 7 may be the AMF. For example, when the PDU session establish request message is transmitted, the network of FIG. 7 may be the SMF.

[0205] Step 2: The network checks the time validity criteria of the slice requested by the UE.

[0206] For example, the network may be an AMF or a SMF.

[0207] For example, if the requested slice from the UE is invalid for the UE, based on the time validity criteria, the network may calculate the remaining time to be available using the time validity criteria of the requested slice.

[0208] For example, if the slice is invalid based on the time validity criteria of the slice, the network may calculate the remaining time of the slice to be available, based on the time validity criteria of the slice. For example, the network may calculate the remaining time until the slice become valide, based on the time validity criteria of the slice.

[0209] For example, if the requested slice from the UE is invalid for the UE based on the time validity criteria, the network may not remove the slice in the configured network slice list.

[0210] For example, the network may check the time validity criteria of the requested slice. For example, the requested slice may be a slice related to the requested NSSAI.

[0211] Step 3: The network determines a value of the backoff timer related to the requested slice of the UE.

[0212] For example, if the slice is invalid based on the time validity criteria of the slice, the network may determine a value of backoff timer based on the remaining time and / or other network aspects(e.g., network overload).

[0213] For example, the network may determine the value of backoff timer of the requested slice, based on the remaining time for the slice to be available(or valid). The remaining time for the slice to be available(or valid) may be determined based on the time validity criteria of the requested slice. The remaining time would be (the start time point of the next slice valid period) - (the time point of the arrival time of the UE request).

[0214] For example, the network may determine the value of backoff timer of the requested slice, further based on the network situation. For example, the network situation may be network overload, or UE subscription information such as a charging rate plan.

[0215] Step 4: The network transmits the backoff timer related to the requested slice, to the UE.

[0216] For example, the network may transmit the response message including a backoff timer related to the requested slice to the UE.

[0217] For example, the response message may be a Registration accept, Registration reject message, DL NAS transport message, Service accept message, Service reject message, PDU session establish accept message, PDU session establish reject message, PDU session modification accept message, or PDU session modification reject message.

[0218] For example, the network may transmit response message to the UE. The response message may include the value for the backoff timer. When the UE receives the value for the backoff timer, the UE may start a timer based on the value for the backoff timer.

[0219] Step 5: Upon reception of the backoff time information (e.g., the value of backoff timer) related to the requested network slice, the UE starts the backoff timer for the slice.

[0220] For example, the UE may request the network slice if the backoff timer stops or expired.

[0221] For example, the UE may not request the network slice if the associated backoff timer is running.

[0222] For example, The UE may not request the network slice while the associated backoff timer is running. For example, the UE does not transmit requested message related to the requested slice that was included in the request message, until the backoff timer expires.

[0223] The following drawings are intended to illustrate specific embodiments of the present disclosure. The designations of specific devices or the designations of specific signals / messages / fields shown in the drawings are for illustrative purposes only, and the technical features of the present specification are not limited to the specific designations used in the drawings below.

[0224] FIG. 8 illustrates an example of a situation related to an embodiment of the present disclosure.

[0225] As presented in FIG. 8, the network may calculate the remaining time to be used to determine the value of a backoff timer.

[0226] For example, the network may calculate the remaining time based on (i) the time point upon the reception of the UE request message for the slice, and (ii) the start time point of the next slice valid period based on the time validity criteria of the slice.

[0227] For example, the network may calcuate the remaining time based on the following equation:

[0228] The remaining time = (the start time point of the next slice valid period) - (the time point of the arrival time of the UE request)

[0229] When a network slice is invalid based on the time validity criteria, the network maintains the network slice in the configured network slice list. For example, if the network slice is invalid based on the time validity criteria, the network performs operations shown in FIG. 7, which are perfored after the reception of the request message.

[0230] According to the present disclosure, alignment of non-supporting UE handling for temporary slice and cell level slice is explained. Herein, non-supporting UE may mean a UE does not support the slice time validity criteria feature.

[0231] According to clause 5.15.18 (Network based monitoring and enforcement of Network Slice Area of Service not matching deployed Tracking Areas) of TS 23.501 V18.2.0, there are two options to handle non-supporting UE. One is removing S-NSSAI when a UE moves out of Network Slice Area of Service (NS-AoS) and the other one is rejecting NAS Transport message with a back-off timer.

[0232] On the other hands, in clause 5.15.16 (Optimized handling of temporarily available network slices) of TS 23.501 V18.2.0, there is only one option to handle non-supporting UE. That is, removing a S-NSSAI from the Configured NSSAI when validity time indicates that the S-NSSAI is not available. Considering that validity time information can be periodic, it seems better to keep the S-NSSAI in the Configured NSSAI rather than removing it to avoid unnecessary signalling and provide back-off timer when UE requested PDU Session. Therefore, we propose to add another option, i.e., providing back-off timer to handle non-supporting UE for temporarily available network slices.

[0233] According to the present disclosure, option of providing back-off timer to handle non-supporting UE for temporarily available network slices is added.

[0234] According to the prior arts, inconsistent handling for location availability information and time validity information may occur. Also, the prior arts casue increased signalling to update Configured NSSAI for temporarily available network slices.

[0235] Examples of optimized handling of temporarily available network slices are explained.

[0236] A network slice may be available for all UEs or a limited number of UEs only for a limited time that is known at the network in advance e.g., by Operations, Administration, and Maintenance (OAM) or subscription. The limited time duration may be due to, for example, the fact that network slice is only temporarily active or periodically active in the deployment (e.g., for a limited time to serve an event or a UE may be only authorized to access the network slice for a limited time known in advance). Or, the limited time duration may be due to the network slice is being decommissioned at a known future time.

[0237] For example, this feature is enabled by S-NSSAI validity time that the network and the UE can handle to reduce the signalling load associated to the transitions in Registration Management (RM) and Session Management (SM) states for the network slice.

[0238] The UE may indicate its support for temporarily available network slices in the UE MM Core Network Capability in the Registration Request. For example, the UE may trasnmit a registration request message to an AMF. The registration request message may include the UE MM Core Network Capability including information related to the support for temporarily available network slices.

[0239] The AMF, based on OAM configuration or information received from the UDM or NSSF, may indicate to a supporting UE the validity time for one or more S-NSSAIs in the Configured NSSAI in the Registration Accept message or via the UE Configuration Update procedure. In roaming case, the AMF my include the validity time for an S-NSSAI in the Configured NSSAI either because of limited availability of the VPLMN S-NSSAI or the mapped S-NSSAI of the HPLMN.

[0240] If a supporting UE is configured with validity time for an S-NSSAI:

[0241] a) If the validity time indicates the S-NSSAI is available, the UE may request the S-NSSAI in a Requested NSSAI in a Registration request. If the S-NSSAI is included in the Allowed NSSAI or in the Partially Allowed NSSAI, the UE may establish PDU Sessions associated with the S-NSSAI.

[0242] b) If the validity time indicates the S-NSSAI is not available:

[0243] - The UE may not include the S-NSSAI in the Requested NSSAI;

[0244] - If the S-NSSAI is already part of the Allowed NSSAI or Partially Allowed NSSAI, the UE may remove the S-NSSAI from the locally stored Allowed NSSAI or Partially Allowed NSSAI and the UE shall also locally release any PDU Sessions associated with the S-NSSAI;

[0245] - If the validity time indicates the S-NSSAI will not be available again, the UE may remove the S-NSSAI from the locally stored Configured NSSAI.

[0246] For a supporting UE, if validity time applies to an S-NSSAI, an AMF supporting temporarily available network slices may perform the following operations:

[0247] - The S-NSSAI may be provided in a Requested NSSAI in a Registration Request by the UE and the validity time indicates the S-NSSAI is not available, but it is going to become available again (i.e., the UE is detected as not having up to date validity time). In this case, the AMF sends the Configured NSSAI to the UE including the validity time for the S-NSSAI in the Registration Accept message. If the validity time indicates the S-NSSAI is not available and will not become available again, then the AMF sends the Configured NSSAI to the UE, excluding the S-NSSAI from the Configured NSSAI;

[0248] - The S-NSSAI may be included in the Allowed NSSAI or the Partially Allowed NSSAI for the UE and the validity time may indicate that the S-NSSAI is not available. In this case, then the AMF locally removes (i.e. without sending any signalling to the UE) the S-NSSAI from the Allowed NSSAI or Partially Allowed NSSAI. If there is any PDU Session established for the S-NSSAI, the AMF requests the SMF to release the PDU Session:

[0249] - i) If the UE is in CM-CONNECTED state, the AMF releases the PDU Session for the S-NSSAI by sending to the SMF, a Nsmf_PDUSession_UpdateSMContext Request. The AMF transmits the Nsmf_PDUSession_UpdateSMContext Request with a release indication to request the release of the PDU Session and then the AMF forwards the N2 SM request to release the AN resources associated with the PDU Session

[0250] - ii) If the UE is in CM-IDLE state, the AMF locally releases the PDU session without paging the UE and causes the SMF to locally release the SM context for the UE by a Nsmf_PDUSession_ReleaseSMContext. The PDU Session status is synchronized at next time when the UE connects to the network.

[0251] For a non-supporting UE, if validity time applies to an S-NSSAI, an AMF supporting temporarily available network slices may peform the following operations:

[0252] - If the validity time indicates the S-NSSAI is available, the AMF may allow or partially allow the network slice when requested, establish PDU Sessions when requested.

[0253] - The S-NSSAI may be provided in a Requested NSSAI in a Registration Request by the UE and the validity time may indicate the S-NSSAI is not available. In this case, the AMF either rejects the registration and remove the S-NSSAI from the Configured NSSAI by providing an updated Configured NSSAI in the Registration Accept message. Or, the AMF accepts the registration and reject the PDU Session establishment with a back-off timer using S-NSSAI based congestion control when the UE requested PDU Session establishment using the S-NSSAI.

[0254] - The S-NSSAI may be included in the UE in the Allowed NSSAI or Partially Allowed NSSAI and the validity time may indicate the S-NSSAI is not available. In this case, the AMF requests the SMF to release the PDU Session if there is any PDU Session established for the S-NSSAI and either:

[0255] - i) the AMF may remove the S-NSSAI from the Configured NSSAI and the Allowed NSSAI or Partially Allowed NSSAI by a UE Configuration Update procedure.; or

[0256] - ii) reject the NAS Transport message with a back-off timer using S-NSSAI based congestion control when the UE requested PDU Session establishment using the S-NSSAI;

[0257] -iii) If the UE is in CM-CONNECTED state, the AMF releases the PDU Session for the S-NSSAI by sending a Nsmf_PDUSession_UpdateSMContext Request with a release indication, to the SMF, in order to request the release of the PDU Session and then the AMF forwards the N2 SM request to release the AN resources associated with the PDU Session.

[0258] - iv) If the UE is in CM-IDLE, the AMF locally releases the PDU Session without paging the UE and causes the SMF to locally release the SM context for the UE by a Nsmf_PDUSession_ReleaseSMContext. The PDU Session status is synchronized at next time when the UE connects to the network.

[0259] For reference, whether the AMF removes the S-NSSAI from Allowed NSSAI and Configured NSSAI or only releases the associated PDU Sessions when the AMF enforces validity time is up to AMF configuration.

[0260] If the network slice becomes unavailable, and a large number of UEs are impacted, the AMF can send the updates to the non-supporting UEs in a manner that avoids surge in signalling (e.g. next time the UE becomes connected).

[0261] - If the AMF detects from the validity time of a S-NSSAI that it is available again, then update the Configured NSSAI to include the S-NSSAI via a UE Configuration Update procedure.

[0262] For reference, for the case of UE not performing any actions despite the validity timing information provided by the network, the AMF can terminate PDU Session(s) associated with S-NSSAI subject to be terminated according to the validity time by explicitly releasing the PDU Sessions associated with the S-NSSAI.

[0263] The following drawings are intended to illustrate specific embodiments of the present disclosure. The designations of specific devices or the designations of specific signals / messages / fields shown in the drawings are for illustrative purposes only, and the technical features of the present specification are not limited to the specific designations used in the drawings below.

[0264] FIG. 9 illustrates an example of operations according to an embodiment of the present disclosure.

[0265] In addition, the operation of a UE and a network shown in the example of FIG. 9 is only an example. The operation of the UE is not limited by the example of FIG. 9, and the UE and the base station may perform the operations described in various examples of the present specification.

[0266] Note that the network in FIG. 7 and FIG. 9 may include an AMF, a SMF, a PCF, a UPF, a base station, a UDM, a DN.

[0267] In step S1201, the UE may transmit a request message to the network(e.g., the AMF or the SMF). For example, network may refer to a network entity.

[0268] For example, the network may receive a request message including requested Network Slice Selection Assistance Information (NSSAI) from the UE.

[0269] For example, the requested NSSAI is related to a network slice unavailable for a certain period of time.

[0270] For example, the network may determine the remaining time of the certain period, based on a time validity criteria of the network slice.

[0271] For example, the network may determine the remaining time of the rcertain period, based on a time point of the reception of the request message, and a start time point of a next slice valid period of the network slice based on the time validity criteria of the network slice.

[0272] For example, based on that the UE has not transmitted capability information for supporting temporarily available network slices, the network may determine a timer value for a bakckoff timer, based on a remaining time of the certain period.

[0273] For exmaple, the network may determine the timer value, based on the remaining time and network load.

[0274] For emxample, the remaining time of the certain period is a remaining time of the network slice to be valid.

[0275] In step S1202, the network(e.g., the network entity) may transmit a response message to the UE.

[0276] For emxample, the network may transmit a response message includes the timer value for the bakckoff timer to the UE.

[0277] For emxample, the timer value for the bakckoff timer enables the UE to start the backoff timer based on the timer value.

[0278] For emxample, the timer value for the bakckoff timer enables the UE not to transmit a request message related to the requested NSSAI, until the backoff timer expires.

[0279] For emxample, the request message may be a registration request request message. The response message may be a registration reject message, and the network is the AMF.

[0280] For exmaple, the request message may be a PDU session establishment request message. For exmaple, the response message may be a PDU sesison establishment reject message. For exmaple, the network may be the SMF.

[0281] The present specification may have various effects.

[0282] For example, according to the present disclosure, effective communication may be supported for devices that do not support time validity information. For example, the network may transmit backoff timer information to such terminals. In this case, the network may inform the terminal, based on the backoff timer, when the temporarily unavailable network slice will become available again. Accordingly, signalling overhead and signalling caused by the device unnecessarily re-requesting the use of the network slice and unnecessary reject responses to the device's request may be avoided. As a result, power loss of the device may be prevented.

[0283] The effects that may be obtained from the specific examples of this disclosure are not limited to those listed above. For example, there may be a variety of technical effects that a person having ordinary skill in the related art may understand or infer from this disclosure. Accordingly, the specific effects of the present disclosure are not limited to those expressly set forth herein, but may include a variety of effects that may be understood or inferred from the technical features of the present disclosure.

[0284] For reference, the operation of the terminal (e.g., UE) described in the present specification may be implemented by the apparatus of FIGS. 1 to 4 described above. For example, the terminal (e.g., UE) may be the first device 100 or the second device 200 of FIG. 2. For example, an operation of a terminal (e.g., UE) described herein may be processed by one or more processors 102 or 202 . The operation of the terminal described herein may be stored in one or more memories 104 or 204 in the form of an instruction / program (e.g., instruction, executable code) executable by one or more processors 102 or 202 . One or more processors 102 or 202 control one or more memories 104 or 204 and one or more transceivers 105 or 206, and may perform the operation of the terminal (e.g., UE) described herein by executing instructions / programs stored in one or more memories 104 or 204.

[0285] In addition, instructions for performing an operation of a terminal (e.g., UE) described in the present disclosure of the present specification may be stored in a non-volatile computer-readable storage medium in which it is recorded. The storage medium may be included in one or more memories 104 or 204 . And, the instructions recorded in the storage medium may be executed by one or more processors 102 or 202 to perform the operation of the terminal (e.g., UE) described in the present disclosure of the present specification.

[0286] For reference, the operation of a network node (e.g., AMF, SMF, UPF, PCF, UDM, etc.) or base station (e.g., NG-RAN, gNB, eNB, RAN, E-UTRAN etc.) described herein may be implemented by the apparatus of FIGS. 1 to 3 to be described below. For example, a network node or a base station may be the first device 100 of FIG.2 or the second device 200 of FIG.2. For example, the operation of a network node or base station described herein may be processed by one or more processors 102 or 202. The operation of the terminal described herein may be stored in one or more memories 104 or 204 in the form of an instruction / program (e.g., instruction, executable code) executable by one or more processors 102 or 202. One or more processors 102 or 202 may perform the operation of a network node or a base station described herein, by controlling one or more memories 104 or 204 and one or more transceivers 106 or 206 and executing instructions / programs stored in one or more memories 104 or 204.

[0287] In addition, instructions for performing the operation of the network node or base station described in the present disclosure of the present specification may be stored in a non-volatile (or non-transitory) computer-readable storage medium. The storage medium may be included in one or more memories 104 or 204. And, the instructions recorded in the storage medium are executed by one or more processors 102 or 202, so that the operations of a network node or base station are performed.

[0288] In the above, preferred embodiments have been exemplarily described, but the present disclosure of the present specification is not limited to such specific embodiments, and thus, modifications, changes, or may be improved.

[0289] In the exemplary system described above, the methods are described on the basis of a flowchart as a series of steps or blocks, but are not limited to the order of the steps described, some steps may occur in a different order or concurrent with other steps as described above. In addition, those skilled in the art will understand that the steps shown in the flowchart are not exclusive and that other steps may be included or that one or more steps of the flowchart may be deleted without affecting the scope of rights.

[0290] The claims described herein may be combined in various ways. For example, the technical features of the method claims of the present specification may be combined and implemented as an apparatus, and the technical features of the apparatus claims of the present specification may be combined and implemented as a method. In addition, the technical features of the method claim of the present specification and the technical features of the apparatus claim may be combined to be implemented as an apparatus, and the technical features of the method claim of the present specification and the technical features of the apparatus claim may be combined and implemented as a method.

Claims

1.A method, comprising:receiving a request message including requested Network Slice Selection Assistance Information (NSSAI) from a User Equipment (UE),wherein the requested NSSAI is related to a network slice unavailable for a certain period of time;based on that the UE has not transmitted capability information for supporting temporarily available network slices, determining a timer value for a bakckoff timer, based on a remaining time of the certain period; andtransmitting a response message includes the timer value for the bakckoff timer to the UE.2.The method of claim 1, wherein the method is performed by a network entity.3.The method of claim 1 or claim 2, further comprising:determining the remaining time of the certain period, based on a time validity criteria of the network slice.4.The method of any one of preceding claims,wherein the timer value is determined based on the remaining time and network load.5.The method of any one of preceding claims,wherein the timer value for the bakckoff timer enables the UE to start the backoff timer based on the timer value.6.The method of any one of preceding claims,wherein the timer value for the bakckoff timer enables the UE not to transmit a request message related to the requested NSSAI, until the backoff timer expires.7.The method of any one of preceding claims,wherein the remaining time of the certain period is a remaining time of the network slice to be valid.8.The method of any one of preceding claims,wherein the remaining time of the rcertain period is determined based on a time point of the reception of the request message, and a start time point of a next slice valid period of the network slice based on the time validity criteria of the network slice.9.The method of any one of preceding claims,wherein the request message is a registration request request message,wherein the response message is a registration reject message,wherein the method is performed by an Access and Mobility management function (AMF).10.The method of any one of preceding claims,wherein the request message is a Protocol Data Unit (PDU) session establishment request message,wherein the response message is a PDU sesison establishment reject message,wherein the method is performed by a Session Management function (SMF).11.An appratus, comprising:at least one transceiver;at least one processor; andat least one memory that stores instructions and is operably electrically connectable with the at least one processor,wherein operations performed based on the instructions being executed by the at least one processor include method of claims 1 to 10.12.A method, comprising:transmitting a request message including requested Network Slice Selection Assistance Information (NSSAI) to a network entity,wherein the requested NSSAI is related to a network slice unavailable for a certain period of time; andreceiving a response message includes a timer value for a bakckoff timer from the network entity,based on that capability information for supporting temporarily available network slices is not transmitted, wherein the timer value for the bakckoff timer based on a remaining time of the certain period is received.13.The method of claim 12, wherein the method is performed by a User Equipment (UE).14.The method of claim 12 or claim 13, further comprising:starting the backoff timer based on the timer value.15.The method of any one of claim 12 to claim 14,wherein a request message related to the requested NSSAI is not transmitted, until the backoff timer expires.16.The method of any one of claim 12 to claim 15,wherein the request message is a registration request request message,wherein the response message is a registration reject message,wherein the method is performed by an Access and Mobility management function (AMF).17.The method of any one of claim 12 to claim 16,wherein the request message is a Protocol Data Unit (PDU) session establishment request message,wherein the response message is a PDU sesison establishment reject message,wherein the method is performed by a Session Management function (SMF).18.A user equipment (UE), comprising:at least one transceiver;at least one processor; andat least one memory that stores instructions and is operably electrically connectable with the at least one processor,wherein operations performed based on the instructions being executed by the at least one processor include method of claims 12 to 17.19.An apparatus, comprising:at least one processor; andat least one memory storing instructions, operatively electrically coupled to the at least one processor, wherein the instructions are executed by the at least one processor to perform operations comprising method of claims 12 to 17.20.A non-transitory computer readable storage medium recording instructions,wherein the instructions, when executed by one or more processors, causing the one or more processors to perform operations compirsing method of claims 12 to 17.

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