Network selection

Abstract

The present disclosure provides a method performed by a UE. The method may include: transmitting a request message related to a connection between the UE and the network entity related to the mobility; receiving a response message related to the connection; receiving first information for a first network and second information for a second network; and performing a cell selection or a cell reselection, based on the first information and the second information.

Description

NETWORK SELECTION

[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] Control mechanisms related to access technology are being discussed. However, according to the prior art, when control information related to access technology is applied to both the current network and equivalent networks, there is a problem in that the service of the UE is degraded because control related to access technology is not effectively performed.

[0006] In one aspect, a method performed by a UE is provided. The method may comprise: transmitting a request message related to a connection between the UE and the network entity related to the mobility; receiving a response message related to the connection; receiving first information for a first network and second information for a second network; and performing a cell selection or a cell reselection, based on the first information and the second information,

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

[0008] In one aspect, a method performed by a network entity related to a mobility and comprising: receiving a request message related to a connection between the UE and the network entity related to the mobility; transmitting a response message related to the connection; and transmitting first information for a first network and second information for a second network,

[0009] In another aspect, an apparatus performing the above method is provided.

[0010] FIG. 1 shows an example of a communication system to which implementations of the present disclosure is applied.

[0011] FIG. 2 shows an example of wireless devices to which implementations of the present disclosure is applied.

[0012] FIG. 3 shows an example of UE to which implementations of the present disclosure is applied.

[0013] FIG. 4 shows an example of 5G system architecture to which implementations of the present disclosure is applied.

[0014] FIGS. 5 and 6 show an example of a registration procedure to which implementations of the present disclosure is applied.

[0015] FIG. 7 illustrates an example of operations of a terminal according to an embodiment of the present disclosure.

[0016] FIG. 8 illustrates an example of an operation 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] In the present disclosure, a terminal and a User Equipment (UE) may be used as terms having the same meaning. For example, descriptions related to a terminal in the present disclosure may also be applied to a UE, and descriptions related to a UE may also be applied to a terminal.

[0182] For reference, in the present disclosure, an Access and Mobility Management Function (AMF) is an example of a network entity related to mobility. Descriptions related to the AMF may be applied to a network entity related to mobility. In the present disclosure, descriptions related to the AMF are not applied only to the AMF, and may be applied to a network entity related to mobility regardless of its name.

[0183] The network operator may restrict subscriber's access to certain access technologies which are subject to access technology utilization based on subscription information as specified in 3GPP　TS　29.503 V18.7.0 or serving network local configuration if the subscription information is not available. For this purpose, the network (e.g., a network entity related to a mobility such as an AMF) may send the Access technology utilization control Information Element (IE) to a User Equipment (UE) to provide access technology utilization control information for the current network (e.g., Public Land Mobile Network (PLMN)) or for the current PLMN and its equivalent PLMN(s) via the REGISTRATION ACCEPT message, the CONFIGURATION UPDATE COMMAND message, the REGISTRATION REJECT message, the DEREGISTRATION REQUEST message and the SERVICE REJECT message. The network (e.g., a network entity related to a mobility such as AMF) may send the Access technology utilization control IE to the UE to indicate to the UE to remove the access technology utilization control information via the CONFIGURATION UPDATE COMMAND message.

[0184] For example, the network (e.g., the network entity related to the mobility such as the AMF) may transmit a message including the access technology utilization control information to the UE. For example, various messages such as REGISTRATION ACCEPT, REGISTRATION REJECT, SERVICE REJECT, DE-REGISTRATION REQUEST (UE terminated de-registration), and CONFIGURATION UPDATE COMMAND may be used. However, the names of messages for transmitting access technology utilization control information are merely examples, and the scope of the present disclosure is not limited by the names of the listed messages. For example, messages of different names or different types may be used, and the network may transmit only the access technology utilization control information to a UE without including the access technology utilization control information in a separate message.

[0185] In Rel-19, Radio Access Technology (RAT) utilization control mechanism is being discussed and Type of RAT utilization control is defined. Type of RAT utilization control includes two options to apply RAT utilization control information to the current network (e.g., PLMN) only or the current network (e.g., PLMN) and its equivalent network(s) (e.g., PLMN(s)).

[0186] The following presents the background related to RAT utilization control mechanism.

[0187] RAT restriction defines the 3GPP and non-3GPP Radio Access Technology(ies) that a UE is not allowed to access in a PLMN. In a restricted RAT a UE based on subscription is not permitted access to the network for this PLMN. For 3GPP access and Connection Management (CM)-CONNECTED state, when radio access network (e.g., a Next Generation NodeB (NG-RAN), a Next Generation NodeB (gNB), a base station, etc.) determines target RAT and target PLMN during Handover or redirection procedure, the radio access network should take per PLMN RAT restriction into consideration. The RAT restriction is enforced in the network, and not provided to the UE.

[0188] The UDM may provide NR or E-UTRA access restriction information of a subscriber to the AMF.

[0189] The UDM shall provide to the AMF the information defined in TS　23.008 V19.0.0　about the subscriber's NR or E-UTRA access restriction set by the operator determination e.g., based on a subscription scenario and a roaming scenario.

[0190] In order to enforce all primary RAT restrictions, the related RAT has to be deployed in different Tracking Area Codes and the subscriber shall not be allowed to access the network in Tracking Areas (TAs) using the particular RAT.

[0191] With all secondary RAT restrictions, the subscriber shall not be allowed to use this RAT as secondary RAT.

[0192] Network selection is described.

[0193] The order of automatic network selection procedure performs network search in the following order according to TS 23.122 V18.9.0.

[0194] For reference, descriptions related to a Mobile Station (MS) in the present specification may be applied to a UE. For example, the MS may be used as a term having the same meaning as the UE. Alternatively, the UE may include the MS.

[0195] The MS selects and attempts a registration on other PLMN / access technology combinations, if available and, for bullets i, ii, iii, iv, v, vi, vii, allowable, in the following order:

[0196] i) either the HPLMN (if the EHPLMN list is not present or is empty) or the highest priority EHPLMN that is available (if the EHPLMN list is present);

[0197] ii) each PLMN / access technology combination in the "User Controlled PLMN Selector with Access Technology" data file in the Subscriber Identity Module (SIM) (in priority order);

[0198] iii) each PLMN / access technology combination in the "Operator Controlled PLMN Selector with Access Technology" data file in the SIM (in priority order) or stored in the ME (in priority order);

[0199] iv) other PLMN / access technology combinations with received high quality signal in random order;

[0200] v) other PLMN / access technology combinations in order of decreasing signal quality;

[0201] vi) PLMN / NG-RAN combinations for any forbidden PLMNs broadcasting the PLMN ID of the UE determined PLMN with disaster condition or broadcasting the disaster related indication and matching the below conditions:

[0202] a) if the indication of 'applicability of "lists of PLMN(s) to be used in disaster condition" provided by a VPLMN' is set to true:

[0203] - each PLMN in the "list of PLMN(s) to be used in disaster condition" stored in the ME which is associated with the PLMN ID of the UE determined PLMN with disaster condition, if any, ordered based on this list; otherwise

[0204] - if the ME does not have a stored "list of PLMN(s) to be used in disaster condition" associated with the PLMN ID of the UE determined PLMN with disaster condition, each PLMN in the "list of PLMN(s) to be used in disaster condition" stored in the ME which is associated with the PLMN ID of the HPLMN, if any, ordered based on this list.

[0205] b) if the indication of 'applicability of "lists of PLMN(s) to be used in disaster condition" provided by a VPLMN' is set to false:

[0206] - each PLMN in the "list of PLMN(s) to be used in disaster condition" stored in the ME which is associated with the HPLMN, if any, ordered based on this list.

[0207] vii) PLMN / NG-RAN combinations for other forbidden PLMNs broadcasting the PLMN ID of the UE determined PLMN with disaster condition or broadcasting the disaster related indication, in random order.

[0208] For example, Control mechanisms related to access technology are being discussed. However, according to the prior art, when control information related to access technology is applied to both the current network and equivalent networks, there is a problem in that the service of the UE is degraded because control related to access technology is not effectively performed.

[0209] For example, according to the prior arts, in the following scenario, the UE service quality may be affected because the UE cannot find suitable cell after applying RAT utilization control mechanism:

[0210] - the network (e.g., the AMF) may transmit a list of "PLMNs with associated RAT restrictions" to the UE. The list of "PLMNs with associated RAT restrictions" may include:

[0211] - entry E1 of PLMN X with the type of RAT utilization control field = "current PLMN and its equivalent PLMN(s)" and E-UTRAN as restricted and GSM / EDGE Radio Access Network (GERAN) and NG-RAN as NOT restricted; and

[0212] - entry E2 of PLMN Y with the type of RAT utilization control field = "current PLMN" (or "current PLMN and its equivalent PLMN(s)") and E-UTRAN and GERAN as NOT restricted and NG-RAN as restricted.

[0213] - PLMN X is UE's RPLMN;

[0214] - PLMN Y is EPLMN; and

[0215] - the UE discovers E-UTRAN cell C1 of PLMN Y;

[0216] Then it is not clear whether the E-UTRAN cell C1 is suitable. The statement above restricts PLMN Y / E-UTRAN based on entry E1 but does not restrict PLMN Y / E-UTRAN based on entry E2.

[0217] In the present disclosure, a mechanism related to cell selection or cell reselection applying RAT utilization control information is proposed to resolve the above issue.

[0218] In addition, according to the prior art, degradation of service quality of the UE may also occur in the following scenario. For example, operator A may transmit RAT control information to users using a very cheap 5G data plan such that they use only NR and are not allowed to access other RATs such as E-UTRAN, UTRAN, and GERAN in PLMN A and equivalent PLMNs. For example, the UE may receive the following RAT control information in PLMN A of operator A. In the following examples, X means restricted and O means NOT restricted:

[0219] - RAT control information related to PLMN A: GERAN (X), E-UTRAN (X), Satellite E-UTRAN (X), NR (O), satellite NR (X)

[0220] - RAT control information related to PLMN B: GERAN (X), E-UTRAN (X), Satellite E-UTRAN (X), NR (O), satellite NR (X)

[0221] For reference, in the present disclosure, the types of RAT included in the RAT control information are merely examples. According to the scope of the present disclosure, the types of RAT are not limited only by GERAN, E-UTRA, Satellite E-UTRAN, NR, and satellite NR. The number of types of RAT may be less than five or more than five, and the types of RAT may include some or all of the listed five, or may include other RATs besides the listed five.

[0222] In addition, for users using this data plan, a specific equivalent PLMN B may allow the use of NR and E-UTRAN without performing RAT control. For example, the UE may receive the following RAT control information in equivalent PLMN B:

[0223] - RAT control information related to PLMN B: GERAN (O), E-UTRAN (O), Satellite E-UTRAN (X), NR (O), satellite NR (X)

[0224] In this case, a user (e.g., UE) may have previously received and stored RAT control information from PLMN A. Subsequently, when the UE performs cell (re)selection, E-UTRAN cells of PLMN B are not considered as candidate cells, and thus the E-UTRAN cells of PLMN B cannot become suitable cells. It is possible that only the E-UTRAN RAT of PLMN B has good signal quality. Even in such a case, there occurs a problem that the user (e.g., UE) cannot register with PLMN B. If the UE can only access E-UTRAN cells in PLMN A and PLMN B, there is a problem that the terminal has no way to access PLMN B. On the other hand, a UE that directly registered with PLMN B can receive services from PLMN B.

[0225] Only if the user (e.g., UE) can access the NR RAT of PLMN B, the UE may first register with PLMN B through the NR RAT and then move to the E-UTRAN.

[0226] Various examples of the disclosure of the present specification can solve the problems of the scenarios as described above. For example, according to an embodiment of the disclosure of the present specification, when the terminal performs a cell search based on RAT control information, if an equivalent PLMN is not a current registered PLMN or a last registered PLMN, the terminal may perform the cell search by considering a RAT for which RAT restriction is configured as a candidate cell. In this case, the above-described problem can be solved.

[0227] The present disclosure proposes examples of EPLMN (equivalent PLMN) selection enhancements. According to an embodiment of the present disclosure, a UE may perform a cell search based on RAT utilization control information. In this case, if an equivalent PLMN is not a registered PLMN or a last registered PLMN at a current cell search time point, the UE may perform the cell search by considering a RAT for which RAT restriction is configured in the corresponding EPLMN as a candidate cell.

[0228] An efficient EPLMN selection improvement scheme when applying RAT utilization control information according to an embodiment of the present disclosure consists of a combination of one or more of the following operations / configurations / steps.

[0229] In the present specification, RAT utilization control, RAT control, access technology utilization control, RAT utilization, RAT restriction, and restricted RAT may all be used as terms having the same meaning.

[0230] In the present specification, RAT (radio access technology), RAT type, access type, and access technology may be used as terms having the same meaning. The definition of RAT (radio access technology) is not limited to the definition of RAT used in a specific 3GPP standard document, and means a general access technology that can be distinguished between a terminal and a base station. In other words, the scope of the RAT described in the present specification may include a RAT and access technology associated with radio access capability mentioned in TS 38.304 V18.4.0, TS 36.304 V18.3.0, or TS 23.122 V18.8.0. The scope of the RAT described in the present specification may also include a RAT type classified as a RAT type value specified in TS 29.274 V18.8.0.

[0231] In the present specification, RAT information included in RAT utilization control information may include GERAN, UTRAN, E-UTRAN, NG-RAN, Satellite E-UTRAN, satellite NG-RAN, and the like.

[0232] For reference, in the present disclosure, the types of RAT included in the RAT control information are merely examples. According to the scope of the present disclosure, the types of RAT are not limited only by GERAN, UTRAN, E-UTRAN, NG-RAN, Satellite E-UTRAN, satellite NG-RAN. The number of types of RAT may be less than six or more than six, and the types of RAT may include some or all of the listed six, or may include other RATs besides the listed six.

[0233] RAT utilization control information of the present specification may mean restricted RAT list information, for which an operator has restricted use in a specific PLMN, and / or allowed RAT list information, for which use is allowed in a specific PLMN. For example, for efficient network management, an operator may allow a UE to access through E-UTRAN but restrict access through an NR satellite network when accessing PLMN-A through RAT utilization control. Additionally, RAT utilization control information may be applied by being limited to a specific area (e.g., PLMN, tracking area, registration area, service area, cell, geographical area, etc.), or applied by being limited to a specific time by a network operator.

[0234] In other words, RAT control information mentioned in the present specification may include all terms distinguished in relation to radio access, such as a RAT type or an access type used in a NAS layer or a Core network, as well as a RAT currently distinguished in an AS layer.

[0235] In some implementations, RAT control information may be a PLMN identifier and a RAT list allowed for use or restricted for use in a corresponding PLMN. RAT control information may be interpreted as control information for RAT utilization.

[0236] A network (e.g., AMF) may transmit RAT utilization control information to a terminal through a message such as REGISTRATION ACCEPT, REGISTRATION REJECT, SERVICE ACCEPT, SERVICE REJECT, DEREGISTRATION REQUEST, or CONFIGURATION UPDATE COMMAND.

[0237] A network (e.g., MME) may transmit RAT utilization control information to a terminal through a message such as ATTACH ACCEPT, ATTACH REJECT, TRACKING AREA UPDATE ACCEPT, TRACKING AREA UPDATE REJECT, SERVICE ACCEPT, SERVICE REJECT, DETACH REQUEST, or GUTI REALLOCATION COMMAND.

[0238] The present specification describes the proposed contents mainly. For operations and procedures related to cell (re)selection and PLMN selection, TS 38.304 V18.4.0 and TS 23.122 V18.8.0 will be basically referred to.

[0239] An operation in which a UE performs a cell search according to an embodiment of the present specification may include cell search scenarios before transitioning to an Any Cell selection state due to network loss after receiving RAT utilization control, or cell search scenarios after new PLMN selection.

[0240] 1. First example of the present disclosure

[0241] The UE may receive RAT utilization control information including the type of RAT utilization control is set to " the current PLMN and its equivalent PLMN(s)" from the network (e.g., AMF). In this case, the UE may perform cell selection and / or cell reselection as follows.

[0242] - The UE searches for a suitable cell based on the legacy mechanism (e.g., the two legacy cell selection procedures described below) applying the RAT utilization control information.

[0243] - If the UE cannot find a suitable cell in the selected PLMN or its equivalent PLMN(s), the UE ignores (or does not apply) the RAT utilization control information and searches for a suitable cell in the selected PLMN or its equivalent PLMN(s).

[0244] The legacy mechanism may be based on the two legacy cell selection procedures.

[0245] a) Initial cell selection (no prior knowledge of which Radio Frequency (RF) channels are NR frequencies):

[0246] 1. The UE shall scan all RF channels in the NR bands according to its capabilities to find a suitable cell.

[0247] 2. On each frequency, the UE need only search for the strongest cell, except for operation with shared spectrum channel access where the UE may search for the next strongest cell(s).

[0248] 3. Once a suitable cell is found, this cell shall be selected.

[0249] b) Cell selection by leveraging stored information (e.g., RAT utilization control information):

[0250] 1. This procedure requires stored information of frequencies and optionally also information on cell parameters from previously received measurement control information elements or from previously detected cells.

[0251] 2. Once the UE has found a suitable cell, the UE shall select it.

[0252] 3. If no suitable cell is found, the initial cell selection procedure in a) shall be started.

[0253] Priorities between different frequencies or different RATs provided to the UE by system information or dedicated signalling are not used in the cell selection process.

[0254] By applying RAT utilization control information, the UE will not find a suitable cell in the restricted RAT(s). But if the UE cannot find a suitable cell in the selected PLMN or its equivalent PLMN, the UE may perform cell selection procedure in the restricted RAT(s).

[0255] From which restricted RAT the UE starts finding a suitable cell could be up to UE implementation, the order of RAT search in the legacy cell selection procedure (not applying RAT utilization control), or a particular order could be applied.

[0256] The UE may determine a specific restricted RAT from which to start searching for a suitable cell. This determination may be performed based on UE implementation, a search order of RAT search used in a legacy cell selection procedure (by not applying RAT utilization control information), or a particular order.

[0257] The example of the particular order may be, based on the service type of the UE, and / or the RAT priority for cell search. For example, if the UE is configured for "voice centric", the UE may select RAT providing IMS services. For example, an example of the operation of the terminal is as follows. In the following, an example in which E-UTRAN is restricted is described, but this is merely an example. Even when a RAT other than E-UTRAN is restricted, the following example can be applied identically.

[0258] i) The terminal may receive RAT utilization control information from PLMN A. For example, the terminal may receive and store, through a message (e.g., a REGISTRATION ACCEPT message in a registration process), RAT utilization control information for restricting use of E-UTRAN for a selected PLMN A (e.g., current PLMN) and an EPLMN B (e.g., equivalent PLMN) from a network node (e.g., AMF) of PLMN A as follows:

[0259] A. Type of RAT utilization control may be configured as "current PLMN and its equivalent PLMN(s)". The RAT utilization control information may include the Type of RAT utilization control;

[0260] B. E-UTRAN may be configured as Restricted RAT information. The RAT utilization control information may include the Restricted RAT information.

[0261] ii) Before the terminal transitions to idle mode, the terminal fails to find a suitable cell for PLMN A in a cell selection process.

[0262] iii) The terminal may perform cell selection for EPLMN B based on stored information (e.g., RAT utilization control information). In this step, the terminal may also fail to find a suitable cell. In this case, the terminal may delete all of the RAT utilization control information received in step i), and perform cell selection by considering E-UTRAN cells, the use of which was restricted, as candidate cells as well. For example, the terminal may perform cell selection in PLMN A and / or PLMN B by considering the E-UTRAN cells, the use of which was restricted, as candidate cells.

[0263] iv) When the terminal finds a suitable cell, the terminal may inform an upper layer (e.g., NAS layer) of the terminal of that the suitable cell is found. When the upper layer of the terminal requests, the terminal transmits uplink signaling to this suitable cell. If the terminal does not find a suitable cell, the terminal may transition to an Any Cell selection state. In this case, in the Any Cell selection state, the terminal may perform a cell selection operation to find a suitable cell without applying the RAT utilization information.

[0264] FIG. 7 below illustrates an example of terminal operation to which the disclosure of the present specification is applied.

[0265] 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.

[0266] FIG. 7 illustrates an example of operations of a terminal according to an embodiment of the present disclosure.

[0267] In step S701, the UE may be registered to the PLMN A.

[0268] For example, the registration procedure in FIGS. 5 and 6 may be performed. For example, the UE may transmit a registration request message to a network entity related to a mobility (e.g., AMF) of the PLMN A. The UE may receive a registration accept message from the network entity related to the mobility.

[0269] In step S702, the UE may receive RAT utilization control information for the PLMN A from the network entity related to the mobility of PLMN A.

[0270] In step S703, the UE may receive RAT utilization control information for the PLMN B from the network entity related to the mobility of the PLMN B.

[0271] In some embodiments, step 703 may be optionally performed. For example, the RAT utilization control information for the PLMN A may also apply to the PLMN B. For example, the RAT utilization control information for the PLMN A may include a type of RAT utilization control. The type of RAT utilization control may be configured as "current PLMN and its equivalent PLMN(s)". In this case, the RAT utilization control information for the PLMN B may be interpreted as the RAT utilization control information for the PLMN A having the type of RAT utilization control configured as "current PLMN and its equivalent PLMN(s)".

[0272] In step S704, the UE may perform a cell selection or a cell reselection, based on the RAT utilization control information received from the PLMN A. For example, the RAT utilization control information received from the PLMN A may include the RAT utilization control information for the PLMN A and / or the RAT utilization control information for the PLMN B.

[0273] In some embodiments, step S705 to step S707 may be included in step S704. For example, the cell selection or the cell reselection may include at least one of step S705 to step S707.

[0274] In step S705, the UE may search for a suitable cell for PLMN A based on the RAT utilization control information for PLMN A. If no suitable cell is found, step S706 is performed. If a suitable cell is found, step S708 is performed.

[0275] In step S706, the UE may search for a suitable cell for PLMN B based on the RAT utilization control information for PLMN B. If no suitable cell is found, step S707 is performed. For example, E-UTRAN is restricted in PLMN B according to the RAT utilization control information, in step S706, if no suitable cell is found in PLMN B, the UE may search for a suitable cell in E-UTRAN for PLMN B in step S707. If a suitable cell is found, step S708 is performed.

[0276] In step S707, the UE may search for a suitable cell for PLMN B based not applying RAT utilization control information for PLMN B. Or, if a suitable cell is found, step S708 is performed. The UE may fail to search for the suitable cell for PLMN B. For example, if no suitable cell is found, the UE may search for an acceptable cell in any cell selection state.

[0277] In step S708, the UE may access to the selected cell. For example, the UE may perform a random access procedure for the selected cell. For example, the UE may transmit a random access preamble to the selected cell, the selected cell may transmit a response message to the UE.

[0278] In step S709, the UE may delete the RAT utilization control information received from PLMN A. For example, the UE may delete the RAT utilization control information for the PLMN A and / or the RAT utilization control information for the PLMN B.

[0279] For example, if the UE fails to find a suitable cell for both PLMN A and PLMN B, the UE may delete the RAT utilization control information for the PLMN A and the RAT utilization control information for the PLMN B.

[0280] For example, after the UE found a suitable cell for PLMN B, the UE may delete the RAT utilization control information for the PLMN A and the RAT utilization control information for the PLMN B. The UE may receive RAT utilization control information of the current PLMN (e.g., PLMN B) after the UE registers to PLMN B.

[0281] In some embodiments, step S709 may not be performed.

[0282] The UE NAS layer may receive available PLMN lists, signal quality, etc., from the AS layer. Thereafter, the UE NAS layer may forward assistance information for performing cell selection to the AS layer based on RAT utilization control information held in the NAS layer. For example, the NAS layer may forward selected PLMN and corresponding equivalent PLMN(s) information to the AS layer, and may forward RAT control information (e.g., associated restricted RAT or associated allowed RAT) to the AS layer. At this time, in some implementations, the UE NAS layer may deliver specific area information (e.g., one or multiple cells, tracking area, geographical area information) to which the RAT utilization control information (e.g., restricted RAT and / or allowed RAT) is applied and / or specific time information to which the RAT utilization control information is applied to the AS layer.

[0283] In some embodiments, he NAS (e.g., a NAS layer of the UE) may control the RAT(s) in which the cell (re)selection should be performed, for instance by indicating RAT(s) associated with the selected PLMN, and by maintaining a list of restricted registration area(s) and a list of equivalent PLMNs.

[0284] The UE NAS layer may forward RAT utilization control information received from a network or assistance information for RAT utilization control to the AS layer.

[0285] The UE AS layer may receive a specific PLMN (e.g., selected PLMN, registered PLMN), an equivalent PLMN list, and / or associated RAT(s) information for the corresponding PLMN from a UE NAS layer. The UE AS layer may perform cell (re)selection based on the specific PLMN (e.g., selected PLMN, registered PLMN), the equivalent PLMN list, and / or the associated RAT(s) information for the corresponding PLMN. Additionally, the UE AS layer receives forbidden TA information from the UE NAS layer, and the UE AS layer may use the forbidden TA information during cell (re)selection. If the terminal fails to find a suitable cell in all RATs, the terminal may transition to an Any Cell Selection state or a limited state.

[0286] In some implementations, an order in which a terminal scans allowed RATs for a PLMN to find a suitable cell may be as follows:

[0287] 1) An AS layer of the terminal may apply RAT utilization control information for PLMN(s) received from a NAS layer of the terminal (e.g., PLMN A and equivalent PLMN(s) of PLMN A) and / or a specific area (e.g., one or more cells, one or more tracking areas, or a geographical area). For example, the terminal may first scan allowed RATs, based on allowed RAT(s) according to the RAT utilization control information and excluding restricted RATs according to the RAT utilization control information, to find a suitable cell.

[0288] 2) If the terminal fails to find a suitable cell in the allowed RAT(s), the terminal may release (or ignore, or not apply) the RAT control information and find a suitable cell for the corresponding PLMN(s):

[0289] - The terminal may attempt to search for a suitable cell only in non-allowed RATs to which RAT control was applied, without retrying the allowed RATs for which scanning has already been completed;

[0290] - In some implementations, the order in which the terminal attempts the suitable cell search starting from a certain RAT may be in the order of NR -> E-UTRAN -> UTRAN -> GERAN. Alternatively, a RAT search priority may be determined according to a preferred service type of the UE;

[0291] - In some implementations, the terminal may first search for a suitable cell related to a non-allowed RAT in a selected PLMN. If the terminal fails to find a suitable cell related to a non-allowed RAT in the selected PLMN, the terminal may attempt to search for a suitable cell in a non-allowed RAT of equivalent PLMN(s); and / or

[0292] - In some implementations, the terminal may exclude a current PLMN and attempt to search for a suitable cell by releasing (or ignoring, or not applying) RAT control information only in equivalent PLMN(s).

[0293] 3) If a suitable cell is not found in a last registered PLMN and / or its equivalent PLMN(s) using the RAT control information held by the terminal, the terminal may delete the corresponding RAT control information.

[0294] Based on the RAT control information, the terminal may fail to find a suitable cell in allowed RAT(s) for a corresponding PLMN. In this case, the terminal may find a suitable cell in all RAT(s) detected for the corresponding PLMN.

[0295] In this case, when finding and camping on a suitable cell in a RAT other than the allowed RAT(s), the terminal may transition to an Any cell state or operate as if it is in the Any cell state. For example, the terminal may use only emergency services rather than normal services.

[0296] 2. Second example of the present disclosure

[0297] The UE may receive the UE has received RAT utilization control information including a type of RAT utilization control set to " the current PLMN and its equivalent PLMN(s)" and the equivalent PLMN is not the registered PLMN or the last registered PLMN, from the network. If the UE has received the RAT utilization control information including the type of RAT utilization control set to " the current PLMN and its equivalent PLMN(s)" and the equivalent PLMN is not the registered PLMN or the last registered PLMN, from the network, the UE may perform a cell selection or a cell reselection as follows.

[0298] - The UE may search for a suitable cell based on the legacy mechanism, based on not applying RAT utilization control information of equivalent PLMN(s) received from the last registered PLMN.

[0299] An example of the operation procedure of a terminal according to the second example of the present specification is as follows.

[0300] i) The terminal may receive RAT utilization control information from a network entity related to the mobility of PLMN A. For example, the terminal may receive and store RAT utilization control information that restricts the use of E-UTRAN for the selected PLMN A and EPLMN B through a message (e.g., a REGISTRATION ACCEPT message during the registration process of PLMN A) as follows:

[0301] A. Type of RAT utilization control may be set to "current PLMN and its equivalent PLMN(s)". The RAT utilization control information may include the Type of RAT utilization control.

[0302] B. Restricted RAT information may be set to E-UTRAN. The RAT utilization control information may include the Restricted RAT information.

[0303] ii) The terminal may perform deregistration from PLMN A and then select PLMN B as a selected PLMN through a PLMN selection procedure.

[0304] iii) Since PLMN B is not the last registered PLMN or the registered PLMN A that received the previous RAT utilization control information, the terminal may delete the RAT utilization control information for PLMN B and perform a cell selection operation for PLMN B. In other words, for the selected PLMN B, the terminal may perform cell selection by considering cells related to the restricted RAT (e.g., E-UTRAN cells in this example) as candidate cells.

[0305] iv) When the terminal (e.g., the AS layer of the terminal) finds a suitable cell, the terminal may inform the upper layer of that the suitable cell is found. If requested by the upper layer, the terminal may transmit uplink signaling to this suitable cell. If the terminal fails to find a suitable cell, the terminal may consider that the PLMN selection procedure for PLMN B has failed and perform PLMN selection to find a new PLMN.

[0306] In some implementations, the UE may delete the received RAT control information (e.g., RAT utilization control information) upon the occurrence of the following events (e.g., events related to i and / or ii). Depending on the event, the UE may delete the entire RAT control information or may delete only information related to some RATs among the RAT control information.

[0307] The UE may release an operation based on the RAT control information and re-enable the operation for the restricted RAT upon the occurrence of the following events(e.g., events related to i and / or ii). For example, if the terminal restricted cell selection / reselection, measurements, etc., to the restricted RAT, the terminal may allow the cell selection / reselection, measurements, etc., to the corresponding RAT again upon the occurrence of the following events:

[0308] i. Update of subscription information of the UE:

[0309] - The UE may receive an update indication (or information) related to the modification of the RAT control information from the network. This update indication (or information) may include updated RAT control information. In some embodiments, this update indication may be an indication (or information) related to deleting previously received RAT control information. For example, after receiving this indication (or information), the UE may delete all of the stored RAT control information; and / or

[0310] ii. In a case where the UE accesses a RAT that was restricted by network control:

[0311] - The UE may move to a restricted RAT based on network control through handover or redirection while the UE being in connected mode. In this case, the UE may release the restriction on the corresponding RAT.

[0312] 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.

[0313] FIG. 8 illustrates an example of an operation according to an embodiment of the present disclosure.

[0314] In addition, the operation of a UE and a network entity shown in the example of FIG. 8 is only an example. The operation of the UE is not limited by the example of FIG. 8, and the UE and the network entity may perform the operations described in various examples of the present specification.

[0315] In FIG. 8, the network entity may be a network entity related to a mobility. For example, the network entity related to the mobility may be an AMF.

[0316] In step S801, the UE may transmit a request message to the network entity.

[0317] For example, the UE may transmit a request message related to a connection between the UE and the network entity related to the mobility, to the network entity related to the mobility.

[0318] In step S802, the network entity may transmit a response message to the UE.

[0319] For example, the UE may receive a response message related to the connection from the network entity related to the mobility.

[0320] In step S803, the network entity may transmit information to the UE.

[0321] For example, the UE may receive first information for a first network and second information for a second network from the network entity related to the mobility.

[0322] For example, the first network includes the network entity related to the mobility.

[0323] For example, the first information is related to control information related to an access technology for the first network. The first information may be The second information is related to control information related to an access technology for the second network.

[0324] For example, the first information may be RAT utilization control information for the first network. For example, the second information may be RAT utilization control information for the second network.

[0325] In some embodiments, the first information and the second information may be included in one RAT utilization control information. For example, the RAT utilization control information may include Type of RAT utilization control. Type of RAT utilization control may be set to "current PLMN and its equivalent PLMN(s)". Herein, the second network may be included in the equivalent PLMN(s).

[0326] As a reference, step S803 may be omitted. For example, the information transmitted in step S803 may be included in the response message of step S802 and transmitted to the UE.

[0327] In step S804, the UE may perform a cell selection or a cell reselection.

[0328] For example, the UE may perform a cell selection or a cell reselection, based on the information received in step S803.

[0329] For example, the UE may perform the cell selection or the cell reselection, based on the first information and the second information,

[0330] For example, in step S804, the UE may further search for a suitable cell in the second network without (or without considering, or without applying) the second information, based on that no suitable cell is found in the first network based on the first information, and no suitable cell is found in the second network based on the second information.

[0331] In some embodiments, the UE may transmit information related to a connection between the UE and the suitable cell to the network entity related to the mobility. The UE may receive response information related to the connection between the UE and the suitable cell, from the network entity related to the mobility

[0332] In some embodiments, the UE may delete the first information and the second information, based on that the suitable cell has been searched.

[0333] In some embodiments, the UE may delete the first information and the second information, based on that no suitable cell is found in the second network without the second information.

[0334] In some embodiments, the UE may select a third network, based on that no suitable cell is found in the second network without the second information.

[0335] In some embodiments, the UE may receive information related to an update for at least one of the first information or the second information from the network entity related to the mobility. The UE may delete the at least one of the first information or the second information, based on that the information related to an update for at least one of the first information or the second information is received.

[0336] The present specification may have various effects.

[0337] For example, the control related to access technology is effectively performed.

[0338] For example, when control information related to access technology is applied to both the current network and equivalent networks, the service of the UE is not degraded based on that the control related to access technology is effectively performed according to the present disclosure.

[0339] For example, the situation in which a terminal is unable to be provided with a service due to RAT control information for the purpose of network resource management optimization can be effectively prevented.

[0340] 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.

[0341] 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.

[0342] 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.

[0343] For reference, the operation of a network node (e.g., a network related to a mobility, AMF, SMF, UPF, PCF, UDM, etc.) or base station (e.g., NG-RAN, gNB, eNB, RAN, E-UTRAN, a cell 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.

[0344] 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.

[0345] 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.

[0346] 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.

[0347] 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 performed by a User Equipment (UE) and comprising:transmitting, by the UE to a network entity related to a mobility, a request message related to a connection between the UE and the network entity related to the mobility;receiving, by the UE from the network entity related to the mobility, a response message related to the connection;receiving, by the UE from the network entity related to the mobility, first information for a first network and second information for a second network,wherein the first network includes the network entity related to the mobility,wherein the first information is related to control information related to an access technology for the first network, andwherein the second information is related to control information related to an access technology for the second network; andperforming, by the UE, a cell selection or a cell reselection, based on the first information and the second information,wherein the performing the cell selection or the cell reselection further comprising: searching, by the UE, for a suitable cell in the second network without the second information, based on that no suitable cell is found in the first network based on the first information, and no suitable cell is found in the second network based on the second information.2.The method of claim 1, further comprising:transmitting, by the UE to the network entity related to the mobility, information related to a connection between the UE and the suitable cell; andreceiving, by the UE from the network entity related to the mobility, response information related to the connection between the UE and the suitable cell.3.The method of claim 1 or 2, further comprising:deleting, by the UE, the first information and the second information, based on that the suitable cell has been searched.4.The method of any one of claims 1 to 3, further comprising:deleting, by the UE, the first information and the second information, based on that no suitable cell is found in the second network without the second information.5.The method of any one of claims 1 to 4, further comprising:selecting, by the UE, a third network, based on that no suitable cell is found in the second network without the second information.6.The method of any one of claims 1 to 5, further comprising:receiving, by the UE from the network entity related to the mobility, information related to an update for at least one of the first information or the second information; anddeleting, by the UE, the at least one of the first information or the second information, based on that the information related to an update for at least one of the first information or the second information is received.7.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 1 to 6.8.An apparatus performing communication, 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 1 to 6.9.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 comprising method of claims 1 to 6.10.A method performed by a network entity related to a mobility and comprising:receiving, by the network entity related to the mobility from a User Equipment (UE), a request message related to a connection between the UE and the network entity related to the mobility;transmitting, by the network entity related to the mobility to the UE, a response message related to the connection; andtransmitting, by the network entity related to the mobility to the UE, first information for a first network and second information for a second network,wherein the first network includes the network entity related to the mobility,wherein the first information is related to control information related to an access technology for the first network,wherein the second information is related to control information related to an access technology for the second network,wherein the first information and the second information is related to a cell selection or a cell reselection performed by the UE,wherein the cell selection or the cell reselection comprising: searching, by the UE, for a suitable cell in the second network without the second information, based on that no suitable cell is found in the first network based on the first information, and no suitable cell is found in the second network based on the second information.11.The method of claim 1, further comprising:transmitting, by the network entity related to the mobility to the UE, information related to an update for at least one of the first information or the second information,wherein the at least one of the first information or the second information is deleted by the UE, based on that the information related to an update for at least one of the first information or the second information is received.12.A network entity related to a mobility 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 claim 10 or claim 11.

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