Methods and devices for mobility between TN-NTN utilizing priority measurements in NTN

Abstract

The present disclosure provides for managing communications in an NTN environment. The disclosure provides for a method for wireless communications performed by a user equipment (UE). The method includes transmitting a random access preamble to an NTN (non-terrestrial network) cell, receiving a random access response from the NTN cell, searching for a TN (terrestrial network) cell with a periodicity T, wherein T is determined based on i) a distance between a location of the UE and a reference location of the TN, ii) a signal power from the TN cell, and iii) a serving time of the NTN cell.

Description

Technical Field

[0001] This disclosure relates to mobile communications. Background Technology

[0002] The 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) is a technology for achieving high-speed packet communication. Many proposals have been put forward for LTE objectives, including those aimed at reducing costs for users and providers, improving quality of service, and expanding and improving coverage and system capacity. 3GPP LTE requires lower cost per bit, increased service availability, flexible use of frequency bands, a simple architecture, open interfaces, and appropriate terminal power consumption as higher-level requirements.

[0003] The International Telecommunication Union (ITU) and 3GPP have begun work to develop requirements and specifications for New Radio (NR) systems. 3GPP must identify and develop the technical components needed to successfully standardize the new RATs that meet both urgent market demands and longer-term requirements outlined by the ITU Radiocommunication Sector (ITU-R) International Mobile Telecommunications (IMT)-2020 process. Furthermore, even in the more distant future, NR should be able to utilize any spectrum band available for wireless communication, at least up to 100 GHz.

[0004] NR aims for a single technology framework that addresses all use cases, requirements, and deployment scenarios, including enhanced mobile broadband (eMBB), massive machine-type communications (mMTC), and ultra-reliable low-latency communications (URLLC). NR should inherently be forward compatible.

[0005] Compared to existing mobile communication networks, NTN communication has a very large cell radius. This large cell radius can lead to significant path loss. Consequently, lower throughput and lower quality of service are expected compared to terrestrial networks. Therefore, applying existing terrestrial network technologies directly to NTN communication may result in inefficiencies.

[0006] In NTN communication, special search cycle settings and cell reselection settings are required. Summary of the Invention

[0007] For NTN cells, the UE sets the discovery period based on factors such as the distance to TN cells. Furthermore, a margin is adjusted to facilitate cell reselection to a TN cell.

[0008] According to embodiments of this disclosure, this specification provides a method for radio communication performed by a user equipment (UE). The method includes: sending a random access preamble to an NTN (non-terrestrial network) cell; receiving a random access response from the NTN cell; and searching for a TN (terrestrial network) cell over a period T, wherein T is determined based on i) the distance to the TN cell, ii) the signal power from the TN cell, and iii) the service time of the NTN cell.

[0009] This disclosure can have various beneficial effects.

[0010] For example, by adjusting the measurement cycle, it is possible to reduce the terminal's battery consumption, perform cell searches more efficiently, and predict effective mobility support.

[0011] For example, by making it easier for UEs to serve in TN cells, better communication quality can be provided to users.

[0012] The beneficial effects obtained through the specific examples in this specification are not limited to those listed above. For example, there may be various technical effects that can be understood or derived from this specification by one of ordinary skill in the art. Therefore, the specific effects of this disclosure are not limited to those explicitly described herein, but may include various effects that can be understood or derived from the technical features of this disclosure. Attached Figure Description

[0013] Figure 1 An example of a communication system applying embodiments of the present disclosure is shown.

[0014] Figure 2 Examples of wireless devices applying embodiments of the present disclosure are shown.

[0015] Figure 3 Examples of wireless devices applying embodiments of the present disclosure are shown.

[0016] Figure 4 An example of a UE applying an embodiment of this disclosure is shown.

[0017] Figure 5 This is an example of a wireless communication system.

[0018] Figure 6 The diagram illustrates the structure of a radio frame used in NR.

[0019] Figure 7 An example of subframe types in NR is shown.

[0020] Figure 8 Examples of measurements performed in E-UTRAN and NR(EN)DC cases are shown.

[0021] Figure 9An example of performing measurements in the case of NR carrier aggregation is shown.

[0022] Figure 10 This illustrates a typical scenario for a non-terrestrial network based on a transparent payload.

[0023] Figure 11 This illustrates a typical scenario for a non-terrestrial network based on regenerative payloads.

[0024] Figure 12 The states of the UE related to measurement are shown according to embodiments of this specification.

[0025] Figure 13 The procedure of the UE according to the first disclosure in this specification is shown.

[0026] Figure 14 The procedure of the UE according to the second disclosure of this specification is shown. Detailed Implementation

[0027] The following technologies, devices, and systems can be applied to a variety of wireless multiple access systems. Examples of multiple access systems include Code Division Multiple Access (CDMA) systems, Frequency Division Multiple Access (FDMA) systems, Time Division Multiple Access (TDMA) systems, Orthogonal Frequency Division Multiple Access (OFDMA) systems, Single-Carrier Frequency Division Multiple Access (SC-FDMA) systems, and Multi-Carrier Frequency Division Multiple Access (MC-FDMA) systems. CDMA can be implemented using radio technologies such as Universal Terrestrial Radio Access (UTRA) or CDMA2000. TDMA can be implemented using radio technologies such as Global System for Mobile Communications (GSM), Universal Packet Radio Service (GPRS), or Enhanced Data Rate GSM Evolution (EDGE). OFDMA can be implemented using radio technologies such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, or Evolved UTRA (E-UTRA). UTRA is part of the Universal Mobile Telecommunications System (UMTS). The 3GPP Long Term Evolution (LTE) is part of the Evolved UMTS (E-UMTS) using E-UTRA. 3GPP LTE employs OFDMA in DL and SC-FDMA in UL. The evolution of 3GPP LTE includes LTE-A (Advanced), LTE-A Pro, and / or 5G NR (New Radio).

[0028] For ease of description, embodiments of this disclosure are primarily described with respect to 3GPP-based wireless communication systems. However, the technical features of this disclosure are not limited thereto. For example, although the following detailed description is based on a mobile communication system corresponding to a 3GPP-based wireless communication system, the aspects of this disclosure that are not limited to 3GPP-based wireless communication systems are applicable to other mobile communication systems.

[0029] For any terms and techniques not specifically described in this invention, please refer to wireless communication standard documents published prior to this disclosure.

[0030] In this disclosure, "A or B" may mean "A only", "B only", or "both A and B". In other words, "A or B" in this disclosure may be interpreted as "A and / or B". For example, "A, B or C" in this disclosure may mean "A only", "B only", "C only", or "any combination of A, B and C".

[0031] In this disclosure, a forward slash ( / ) or a comma (,) can mean "and / or". For example, "A / B" can mean "A and / or B". Therefore, "A / B" can mean "A only", "B only", or "both A and B". For example, "A, B, C" can mean "A, B, or C".

[0032] In this disclosure, "at least one of A and B" may mean "only A", "only B" or "both A and B". Additionally, the expressions "at least one of A or B" or "at least one of A and / or B" in this disclosure may be interpreted as the same as "at least one of A and B".

[0033] Additionally, in this disclosure, "at least one of A, B, and C" may mean "A only", "B only", "C only" or "any combination of A, B, and C". Furthermore, "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".

[0034] Similarly, the brackets used in this disclosure may mean "for example". Specifically, when shown as "Control Message (PDCCH)", "PDCCH" can be proposed as an example of "Control Message". In other words, "Control Message" in this disclosure is not limited to "PDCCH", and "PDCCH" can be proposed as an example of "Control Message". Furthermore, even when shown as "Control Message (i.e., PDCCH)", "PDCCH" can be proposed as an example of "Control Message".

[0035] The technical features described individually in one of the accompanying drawings of this disclosure can be implemented individually or simultaneously.

[0036] Not limited thereto, the various descriptions, functions, processes, suggestions, methods and / or operation flowcharts disclosed herein can be applied to various fields requiring wireless communication and / or connectivity between devices (e.g., 5G).

[0037] The present disclosure will be described in more detail below with reference to the accompanying drawings. Unless otherwise stated, the same reference numerals in the following drawings and / or description may refer to the same and / or corresponding hardware blocks, software blocks and / or functional blocks.

[0038] Figure 1 An example of a communication system applying embodiments of the present disclosure is shown.

[0039] Figure 1 The 5G use cases shown are merely illustrative, and the technical features of this disclosure can be applied to... Figure 1 Other 5G use cases not shown.

[0040] The three main demand categories for 5G include (1) Enhanced Mobile Broadband (eMBB), (2) Massive Machine Type Communications (mMTC), and (3) Ultra Reliable Low Latency Communications (URLLC).

[0041] refer to Figure 1 The communication system 1 includes wireless devices 100a to 100f, a base station (BS) 200, and a network 300. Although Figure 1 The 5G network is illustrated as an example of a network for communication system 1, but the embodiments of this disclosure are not limited to 5G systems and can be applied to future communication systems beyond 5G systems.

[0042] The BS 200 and network 300 can be implemented as wireless devices, and a particular wireless device can operate as a BS / network node relative to other wireless devices.

[0043] Wireless devices 100a to 100f represent devices that use radio access technology (RAT) (e.g., 5G New RAT (NR) or LTE) to perform communication and may be referred to as communication / radio / 5G devices. Wireless devices 100a to 100f may include, but are not limited to, robots 100a, vehicles 100b-1 and 100b-2, extended reality (XR) devices 100c, handheld devices 100d, home appliances 100e, IoT devices 100f, and artificial intelligence (AI) devices / servers 400. For example, vehicles may include vehicles with wireless communication capabilities, autonomous vehicles, and vehicles capable of performing communication between vehicles. Vehicles may include unmanned aerial vehicles (UAVs) (e.g., drones). XR devices may include AR / VR / mixed reality (MR) devices and can be implemented in the form of head-mounted displays (HMDs), head-up displays (HUDs) installed in vehicles, televisions, smartphones, computers, wearable devices, home appliances, digital signage, vehicles, robots, etc. Handheld devices may include smartphones, smart tablets, wearable devices (e.g., smartwatches or smart glasses), and computers (e.g., laptops). Home appliances may include TVs, refrigerators, and washing machines. IoT devices may include sensors and smart meters.

[0044] In this disclosure, wireless devices 100a to 100f may be referred to as user equipment (UE). UE may include, for example, cellular phones, smartphones, laptop computers, digital broadcasting terminals, personal digital assistants (PDAs), portable multimedia players (PMPs), navigation systems, personal computers (PCs), tablet PCs, ultrabooks, vehicles, vehicles with autonomous driving capabilities, connected cars, UAVs, AI modules, robots, AR devices, VR devices, MR devices, hologram devices, public safety devices, MTC devices, IoT devices, medical devices, fintech devices (or financial devices), security devices, weather / environment devices, devices related to 5G services, or devices related to the Fourth Industrial Revolution.

[0045] Wireless devices 100a to 100f can be connected to network 300 via BS 200. AI technology can be applied to wireless devices 100a to 100f, and wireless devices 100a to 100f can be connected to AI server 400 via network 300. Network 300 can be configured using 3G networks, 4G (e.g., LTE) networks, 5G (e.g., NR) networks, and super 5G networks. Although wireless devices 100a to 100f can communicate with each other via BS 200 / network 300, wireless devices 100a to 100f can also perform direct communication with each other without going through BS 200 / network 300 (e.g., sidelink communication). For example, vehicles 100b-1 and 100b-2 can perform direct communication (e.g., vehicle-to-vehicle (V2V) / vehicle-to-everything (V2X) communication). IoT devices (e.g., sensors) can perform direct communication with other IoT devices (e.g., sensors) or other wireless devices 100a to 100f.

[0046] Wireless communication / connections 150a, 150b, and 150c can be established between wireless devices 100a to 100f and / or between wireless devices 100a to 100f and BS 200 and / or between BS 200. In this document, wireless communication / connections can be established via 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. Wireless devices 100a to 100f and BS 200 / wireless devices 100a to 100f can mutually send / receive radio signals via wireless communication / connections 150a, 150b, and 150c. For example, wireless communication / connections 150a, 150b, and 150c can send / receive signals via various physical channels. Therefore, at least a portion of various configuration information configuration processes, various signal processing processes (e.g., channel coding / decoding, modulation / demodulation, and resource mapping / demapping) and resource allocation processes for transmitting / receiving radio signals can be performed based on various proposals of this disclosure.

[0047] AI refers to the field of studying artificial intelligence or the methodologies that create it, while machine learning refers to the field that defines the various problems that AI addresses and the methodologies for solving these problems. Machine learning is also defined as an algorithm that improves task performance through stable experience with a task.

[0048] A robot is a machine that automatically processes or operates a given task through its own capabilities. Specifically, a robot capable of recognizing its environment and autonomously deciding to perform actions can be called an intelligent robot. Depending on its purpose or field of application, robots can be classified as industrial, medical, domestic, military, etc. Robots can perform various physical operations, such as moving robot joints using actuators or motors. Mobile robots also include wheels, brakes, propellers, etc., on their actuators, enabling them to travel on the ground or fly in the air.

[0049] Autonomous driving refers to a technology that drives itself, while autonomous vehicles refer to vehicles that drive with little or no user control. For example, autonomous driving can include lane keeping, automatic speed adjustment such as adaptive cruise control, automatic driving along a set route, and automatic route planning when a destination is set. Vehicles include vehicles equipped with internal combustion engines, hybrid vehicles equipped with both internal combustion engines and electric motors, electric vehicles equipped with electric motors, and may include trains, motorcycles, and automobiles. Autonomous vehicles can be viewed as robots with autonomous driving capabilities.

[0050] Extended reality is collectively referred to as VR, AR, and MR. VR technology provides real-world objects and backgrounds solely through computer graphics (CG) images. AR technology provides virtual CG images on top of real-world object images. MR technology is a CG technology that combines virtual objects with and integrates them into the real world. MR technology is similar to AR technology in that it presents both real and virtual objects together. However, the difference lies in the fact that in AR technology, virtual objects are used as a supplementary form to real-world objects, while in MR technology, virtual and real objects are treated as equal entities.

[0051] NR supports multiple parameter sets (and / or multiple subcarrier spacings (SCS)) to support a variety of 5G services. For example, a 15kHz SCS enables wide-area coverage in traditional cellular bands; and a 30kHz / 60kHz SCS enables dense urban areas, lower latency, and wider carrier bandwidth. A 60kHz or higher SCS enables bandwidths greater than 24.25GHz to overcome phase noise.

[0052] NR bands can be defined as two types of frequency ranges, namely FR1 and FR2. The numerical values ​​of the frequency ranges can be changed. For example, the frequency ranges of the two types (FR1 and FR2) can be shown in Table 1 below. For ease of explanation, in the frequency ranges used in NR systems, FR1 may mean "sub-6 GHz range", FR2 may mean "above 6 GHz range", and may be referred to as millimeter wave (mmW).

[0053] [Table 1]

[0054]

[0055] As mentioned above, the frequency range of the NR system can be varied. For example, FR1 can include a frequency band from 410MHz to 7125MHz, as shown in Table 2 below. That is, FR1 can include a frequency band of 6GHz (or 5850, 5900, 5925MHz, etc.) or more. For example, the 6GHz (or 5850, 5900, 5925MHz, etc.) or more frequency bands included in FR1 can include unlicensed bands. Unlicensed bands can be used for various purposes, such as for vehicle communications (e.g., autonomous driving).

[0056] [Table 2]

[0057]

[0058] Here, the radio communication technologies implemented in the wireless devices of this disclosure may include narrowband Internet of Things (NB-IoT) technologies 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, implemented in specifications such as LTE Cat NB1 and / or LTE Cat NB2, and may not be limited to the names mentioned above. Additionally and / or alternatively, the radio communication technologies implemented in the wireless devices of this disclosure may communicate based on LTE-M technology. For example, LTE-M technology may be an example of LPWAN technology and referred to by various names such as enhanced machine-type communication (eMTC). For example, LTE-M technology may be implemented in at least one of 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 names mentioned above. Additionally and / or alternatively, the radio communication technology implemented in the wireless devices of this disclosure may include at least one of ZigBee, Bluetooth, and / or LPWAN, which takes into account low-power communication, and may not be limited to the names mentioned above. For example, ZigBee technology may be based on various specifications such as IEEE 802.15.4 to generate personal area networks (PANs) associated with small / low-power digital communication, and may be referred to by various names.

[0059] Figure 2 Examples of wireless devices applying embodiments of the present disclosure are shown.

[0060] refer to Figure 2The first wireless device 100 and the second wireless device 200 can transmit radio signals to / receive radio signals from external devices via various RATs (e.g., LTE and NR).

[0061] exist Figure 2 In this context, {first wireless device 100 and second wireless device 200} can correspond to Figure 1 At least one of {wireless devices 100a to 100f and BS 200}, {wireless devices 100a to 100f and wireless devices 100a to 100f} and / or {BS 200 and BS200}.

[0062] The first wireless device 100 may include at least one transceiver, such as transceiver 106; at least one processing chip, such as processing chip 101; and / or one or more antennas 108.

[0063] The processing chip 101 may include at least one processor, such as processor 102, and at least one memory, such as memory 104. Figure 2 As exemplarily shown, memory 104 is included in processing chip 101. Alternatively and / or alternatively, memory 104 may be placed outside processing chip 101.

[0064] Processor 102 can control memory 104 and / or transceiver 106 and can be configured to implement the descriptions, functions, processes, suggestions, methods, and / or operation flowcharts described in this disclosure. For example, processor 102 can process information in memory 104 to generate first information / signal, and then transmit a radio signal including the first information / signal via transceiver 106. Processor 102 can receive radio signal 106 including second information / signal via transceiver and then store the information obtained by processing the second information / signal in memory 104.

[0065] Memory 104 may be operatively connected to processor 102. Memory 104 may store various types of information and / or instructions. Memory 104 may store software code 105 that implements the instructions, which, when executed by processor 102, execute the descriptions, functions, procedures, suggestions, methods, and / or operation flowcharts disclosed in this disclosure. For example, software code 105 may implement instructions that, when executed by processor 102, execute the descriptions, functions, procedures, suggestions, methods, and / or operation flowcharts disclosed in this disclosure. For example, software code 105 may control processor 102 to execute one or more protocols. For example, software code 105 may control processor 102 to execute one or more layers of a radio interface protocol.

[0066] In this document, processor 102 and memory 104 may be part of a communication modem / circuit / chip designed to implement RAT (e.g., LTE or NR). Transceiver 106 may be connected to processor 102 and transmit and / or receive radio signals via one or more antennas 108. Each of transceivers 106 may include a transmitter and / or a receiver. Transceivers 106 may be used interchangeably with radio frequency (RF) units. In this disclosure, first wireless device 100 may represent a communication modem / circuit / chip.

[0067] The second wireless device 200 may include at least one transceiver, such as transceiver 206; at least one processing chip, such as processing chip 201; and / or one or more antennas 208.

[0068] The processing chip 201 may include at least one processor, such as processor 202, and at least one memory, such as memory 204. Figure 2 As exemplarily shown, memory 204 is included in processing chip 201. Alternatively and / or alternatively, memory 204 may be placed outside processing chip 201.

[0069] Processor 202 can control memory 204 and / or transceiver 206 and can be configured to implement the descriptions, functions, processes, suggestions, methods, and / or operation flowcharts described in this disclosure. For example, processor 202 can process information in memory 204 to generate third information / signal, and then transmit a radio signal including the third information / signal via transceiver 206. Processor 202 can receive a radio signal including a fourth information / signal via transceiver 106, and then store the information obtained by processing the fourth information / signal in memory 204.

[0070] Memory 204 may be operatively connected to processor 202. Memory 204 may store various types of information and / or instructions. Memory 204 may store software code 205 that implements the instructions, which, when executed by processor 202, perform the descriptions, functions, procedures, suggestions, methods, and / or operation flowcharts disclosed in this disclosure. For example, software code 205 may implement instructions that, when executed by processor 202, perform the descriptions, functions, procedures, suggestions, methods, and / or operation flowcharts disclosed in this disclosure. For example, software code 205 may control processor 202 to execute one or more protocols. For example, software code 205 may control processor 202 to execute one or more layers of a radio interface protocol.

[0071] In this document, processor 202 and memory 204 may be part of a communication modem / circuit / chip designed to implement RAT (e.g., LTE or NR). Transceiver 206 may be connected to processor 202 and transmit and / or receive radio signals via one or more antennas 208. Each of transceivers 206 may include a transmitter and / or a receiver. Transceivers 206 may be used interchangeably with RF units. In this disclosure, second wireless device 200 may represent a communication modem / circuit / chip.

[0072] The hardware elements of wireless devices 100 and 200 will be described in more detail below. One or more protocol layers may be implemented by, but are not limited to, one or more processors 102 and 202. For example, one or more processors 102 and 202 may implement one or more layers (e.g., functional layers such as Physical (PHY), Layer 1, Media Access Control (MAC) layer, Radio Link Control (RLC) layer, Packet Data Convergence Protocol (PDCP) layer, Radio Resource Control (RRC) layer, and Service Data Adaptive Protocol (SDAP) layer). One or more processors 102 and 202 may generate one or more Protocol Data Units (PDUs) and / or one or more Service Data Units (SDUs) in accordance with the descriptions, functions, processes, suggestions, methods, and / or operation flowcharts disclosed in this disclosure. One or more processors 102 and 202 may generate messages, control information, data, or information in accordance with the descriptions, functions, processes, suggestions, methods, and / or operation flowcharts disclosed in this disclosure. One or more processors 102 and 202 may generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data, or information, in accordance with the descriptions, functions, processes, suggestions, methods, and / or operation flowcharts disclosed in this disclosure, and provide the generated signals to one or more transceivers 106 and 206. One or more processors 102 and 202 may receive signals (e.g., baseband signals) from one or more transceivers 106 and 206 and acquire PDUs, SDUs, messages, control information, data, or information, in accordance with the descriptions, functions, processes, suggestions, methods, and / or operation flowcharts disclosed in this disclosure.

[0073] One or more processors 102 and 202 may be referred to as controllers, microcontrollers, microprocessors, or microcomputers. One or more processors 102 and 202 may be implemented by hardware, firmware, software, or a combination thereof. For 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 one or more processors 102 and 202. The descriptions, functions, processes, suggestions, methods, and / or operation flowcharts disclosed in this disclosure may be implemented using firmware or software, and the firmware or software may be configured to include modules, processes, or functions. Firmware or software configured to execute the descriptions, functions, processes, suggestions, methods, and / or operation flowcharts disclosed in this disclosure may be included in one or more processors 102 and 202 or stored in one or more memories 104 and 204 for being driven by one or more processors 102 and 202. The descriptions, functions, processes, suggestions, methods, and / or operation flowcharts disclosed in this disclosure may be implemented using firmware or software in the form of code, commands, and / or command sets.

[0074] One or more memories 104 and 204 may be connected to one or more processors 102 and 202 and store various types of data, signals, messages, information, programs, code, instructions, and / or commands. One or more memories 104 and 204 may be configured with read-only memory (ROM), random access memory (RAM), electrically erasable programmable read-only memory (EPROM), flash memory, hard disk drive, registers, cache memory, computationally readable storage media, and / or combinations thereof. One or more memories 104 and 204 may be located internally and / or externally to one or more processors 102 and 202. One or more memories 104 and 204 may be connected to one or more processors 102 and 202 via various technologies such as wired or wireless connections.

[0075] One or more transceivers 106 and 206 can transmit user data, control information, and / or radio signals / channels mentioned in the descriptions, functions, processes, suggestions, methods, and / or operation flowcharts disclosed herein to one or more other devices. One or more transceivers 106 and 206 can receive user data, control information, and / or radio signals / channels mentioned in the descriptions, functions, processes, suggestions, methods, and / or operation flowcharts disclosed herein from one or more other devices. For example, one or more transceivers 106 and 206 can be connected to one or more processors 102 and 202 and transmit and receive radio signals. For example, one or more processors 102 and 202 can perform control such that one or more transceivers 106 and 206 can transmit user data, control information, or radio signals to one or more other devices. One or more processors 102 and 202 can perform control such that one or more transceivers 106 and 206 can receive user data, control information, or radio signals from one or more other devices.

[0076] One or more transceivers 106 and 206 may be connected to one or more antennas 108 and 208, and one or more transceivers 106 and 206 may be configured to transmit and receive user data, control information, and / or radio signals / channels mentioned in the descriptions, functions, processes, suggestions, methods, and / or operation flowcharts disclosed herein via one or more antennas 108 and 208. In this disclosure, one or more antennas 108 and 208 may be multiple physical antennas or multiple logical antennas (e.g., antenna ports).

[0077] One or more transceivers 106 and 206 can convert received user data, control information, radio signals / channels, etc., from RF band signals to baseband signals so that they can be processed by one or more processors 102 and 202. One or more transceivers 106 and 206 can also convert user data, control information, radio signals / channels, etc., processed by one or more processors 102 and 202 from baseband signals to RF band signals. For this purpose, one or more transceivers 106 and 206 may include (analog) oscillators and / or filters. For example, one or more transceivers 106 and 206, under the control of one or more processors 102 and 202, can upconvert OFDM baseband signals to OFDM signals using their (analog) oscillators and / or filters and transmit the upconverted OFDM signals at the carrier frequency. One or more transceivers 106 and 206 can receive OFDM signals at a carrier frequency and, under the control of one or more transceivers 102 and 202, down-convert the OFDM signals to OFDM baseband signals via their (analog) oscillators and / or filters.

[0078] In embodiments of this disclosure, the UE can operate as a transmitting device in the uplink (UL) and as a receiving device in the downlink (DL). In embodiments of this disclosure, the BS can operate as a receiving device in the UL and as a transmitting device in the DL. Hereinafter, for ease of description, it is primarily assumed that the first wireless device 100 is the UE and the second wireless device 200 is the BS. For example, a processor 102 connected to, mounted on, or started therein of the first wireless device 100 can be configured to perform UE behavior according to embodiments of this disclosure or to control the transceiver 106 to perform UE behavior according to embodiments of this disclosure. A processor 202 connected to, mounted on, or started therein of the second wireless device 200 can be configured to perform BS behavior according to embodiments of this disclosure or to control the transceiver 206 to perform BS behavior according to embodiments of this disclosure.

[0079] In this disclosure, BS is also referred to as node B (NB), e-node B (eNB), or gNB.

[0080] Figure 3 Examples of wireless devices applying embodiments of the present disclosure are shown.

[0081] Wireless devices can be implemented in various forms depending on the use case / service (see reference). Figure 1 ).

[0082] refer to Figure 3 Wireless devices 100 and 200 can correspond to Figure 2 The wireless devices 100 and 200 can be configured from various elements, components, units / parts, and / or modules. For example, each of the wireless devices 100 and 200 may include a communication unit 110, a control unit 120, a memory unit 130, and an additional component 140. The communication unit 110 may include a communication circuit 112 and a transceiver 114. For example, the communication circuit 112 may include... Figure 2 One or more processors 102 and 202 and / or Figure 2 One or more memories 104 and 204. For example, transceiver 114 may include Figure 2 One or more transceivers 106 and 206 and / or Figure 2One or more antennas 108 and 208. Control unit 120 is electrically connected to communication unit 110, storage unit 130, and add-on components 140 and controls the overall operation of each of wireless devices 100 and 200. For example, control unit 120 can control the electrical / mechanical operation of each of wireless devices 100 and 200 based on programs / code / commands / information stored in storage unit 130. Control unit 120 can transmit information stored in storage unit 130 to an external source (e.g., other communication devices) via communication unit 110 through a wireless / wired interface, or store in storage in storage unit 130 information received from an external source (e.g., other communication devices) via wireless / wired interface through communication unit 110.

[0083] The additional component 140 can be configured differently depending on the type of wireless devices 100 and 200. For example, the additional component 140 may include at least one of a power unit / battery, an input / output (I / O) unit (e.g., an audio I / O port, a video I / O port), a drive unit, and a computing unit. Wireless devices 100 and 200 can be implemented in the following forms (but are not limited to): robot ( Figure 1 100a), vehicles ( Figure 1 100b-1 and 100b-2), XR equipment ( Figure 1 100c), handheld devices ( Figure 1 100d), home appliances ( Figure 1 100e), IoT devices ( Figure 1 100f), digital broadcasting terminals, hologram devices, public safety equipment, MTC devices, medical devices, fintech devices (or financial devices), security devices, climate / environmental devices, AI servers / devices ( Figure 1 400 in the middle), BS ( Figure 1 The 200 devices, network nodes, etc., can be used in mobile or fixed locations, depending on the usage examples / services.

[0084] exist Figure 3In wireless devices 100 and 200, all of the various elements, components, units / parts, and / or modules can be connected to each other via wired interfaces, or at least a portion thereof can be wirelessly connected via communication unit 110. For example, in each of wireless devices 100 and 200, control unit 120 and communication unit 110 can be connected via a wire, and control unit 120 and first units (e.g., 130 and 140) can be wirelessly connected via communication unit 110. Each element, component, unit / part, and / or module within wireless devices 100 and 200 may also include one or more elements. For example, control unit 120 may be configured by a collection of one or more processors. As an example, control unit 120 may be configured by a collection of communication control processors, application processors (APs), electronic control units (ECUs), graphics processing units, and memory control processors. As another example, storage unit 130 may be configured by RAM, DRAM, ROM, flash memory, volatile memory, non-volatile memory, and / or combinations thereof.

[0085] Figure 4 An example of a UE applying an embodiment of this disclosure is shown.

[0086] refer to Figure 4 UE 100 can correspond to Figure 2 The first wireless device 100 and / or Figure 3 Wireless devices 100 or 200.

[0087] The UE 100 includes a processor 102, a memory 104, a transceiver 106, one or more antennas 108, a power management module 110, a battery 1112, a display 114, a keyboard 116, a subscriber identification module (SIM) card 118, a speaker 120, and a microphone 122.

[0088] Processor 102 can be configured to implement the descriptions, functions, processes, suggestions, methods, and / or operation flowcharts disclosed in this disclosure. Processor 102 can be configured to control one or more other components of UE 100 to implement the descriptions, functions, processes, suggestions, methods, and / or operation flowcharts disclosed in this disclosure. A layer of the radio interface protocol can be implemented in processor 102. Processor 102 may include an ASIC, other chipsets, logic circuits, and / or data processing devices. Processor 102 may be an application processor. Processor 102 may include at least one of a digital signal processor (DSP), a central processing unit (CPU), a graphics processing unit (GPU), and a modem (modulator and demodulator). Examples of processor 102 can be found in those manufactured by Qualcomm. ® Manufacturing SNAPDRAGON TM Series processors, by Samsung® EXYNOS manufactured TM Series processors, manufactured by Apple ® The A-series processors manufactured by MediaTek ® HELIO manufactured TM Series processors, manufactured by Intel ® Manufactured ATOM TM It can be found in the series of processors or the corresponding next-generation processors.

[0089] Memory 104 is operatively coupled to processor 102 and stores various information for operating processor 102. Memory 104 may include ROM, RAM, flash memory, memory card, storage medium, and / or other storage devices. When embodiments are implemented in software, the techniques described herein can be implemented using modules (e.g., processes, functions, etc.) that perform the descriptions, functions, processes, suggestions, methods, and / or operation flowcharts disclosed herein. Modules may be stored in memory 104 and executed by processor 102. Memory 104 may be implemented within or outside processor 102, in which case these modules may be communicatively coupled to processor 102 via various means as known in the art.

[0090] Transceiver 106 is operatively coupled to processor 102 and transmits and / or receives radio signals. Transceiver 106 includes a transmitter and a receiver. Transceiver 106 may include baseband circuitry for processing radio frequency signals. Transceiver 106 controls one or more antennas 108 to transmit and / or receive radio signals.

[0091] The power management module 110 manages the power supply to the processor 102 and / or transceiver 106. The battery 112 supplies power to the power management module 110.

[0092] Display 114 outputs the results processed by processor 102. Keypad 116 receives input used by processor 102. Keypad 116 can be displayed on display 114.

[0093] The SIM 118 is an integrated circuit designed to securely store International Mobile Subscriber Identity (IMSI) numbers and their associated keys, which are used to identify and verify subscribers on mobile devices such as mobile phones and computers. It can also store contact information on many SIM cards.

[0094] Speaker 120 outputs sound-related results processed by processor 102. Microphone 122 receives sound-related inputs used by processor 102.

[0095] Figure 5 This is an example of a wireless communication system.

[0096] For reference Figure 5 As can be seen, the wireless communication system includes at least one base station (BS). The BS is divided into gNodeB (or gNB) 20a and eNodeB (or eNB) 20b. gNB 20a supports 5G mobile communication. eNB 20b supports 4G mobile communication, namely, Long Term Evolution (LTE).

[0097] Each base station 20a and 20b provides communication services for a specific geographical area (usually called a cell) (20-1, 20-2, and 20-3). A cell can be further divided into multiple areas (called sectors).

[0098] A UE typically belongs to a cell, and the cell to which the UE belongs is called the serving cell. The base station that provides communication services to the serving cell is called the serving BS. Because wireless communication systems are cellular systems, there is another cell adjacent to the serving cell. This adjacent cell is called a neighboring cell. The base station that provides communication services to the neighboring cell is called the neighboring BS. The serving cell and neighboring cells are determined relatively based on the UE.

[0099] In the following text, downlink refers to communication from base station 20 to UE 10, and uplink refers to communication from UE 10 to base station 20. In the downlink, the transmitter may be part of base station 20, and the receiver may be part of UE 10. In the uplink, the transmitter may be part of UE 10, and the receiver may be part of base station 20.

[0100] Meanwhile, wireless communication systems can generally be classified into Frequency Division Duplex (FDD) and Time Division Duplex (TDD) types. In FDD, uplink and downlink transmissions are implemented while occupying different frequency bands. In TDD, uplink and downlink transmissions are implemented at different times while occupying the same frequency band. The channel response in TDD is essentially reciprocal. This means that the downlink and uplink channel responses are roughly the same in a given frequency region. Therefore, in a TDD-based wireless communication system, the downlink channel response can be obtained from the uplink channel response. In TDD, because the entire frequency band is time-divided in uplink and downlink transmissions, downlink transmissions performed by the base station and uplink transmissions performed by the terminal may not occur simultaneously. In a TDD system where uplink and downlink transmissions are divided into subframes, uplink and downlink transmissions are performed in different subframes.

[0101] Figure 6 The diagram illustrates the structure of a radio frame used in NR.

[0102] In NR, uplink and downlink transmissions consist of frames. A radio frame can be 10 milliseconds long and can be defined as two 5-millisecond half-frames (HF). Each half-frame can be defined as five 1-millisecond subframes (SF). Subframes can be divided into one or more time slots, and the number of time slots in a subframe can depend on the SCS (subcarrier spacing). Depending on the cyclic prefix (CP), each time slot can include 12 or 14 OFDM (A) symbols. In some implementations, if CP is used, each time slot contains 14 symbols. If extended CP is used, each time slot contains 12 symbols. Symbols can include, for example, OFDM symbols (or CP-OFDM symbols) and SC-FDMA symbols (or DFT-s-OFDM symbols).

[0103] Figure 7 An example of subframe types in NR is shown.

[0104] Figure 7 The transmission time interval (TTI) shown can be referred to as a subframe or time slot of NR (or new RAT). Figure 7 Subframes (or time slots) in NR (or new RAT) TDD systems can be used to minimize data transmission latency. For example... Figure 7 As shown, a subframe (or time slot) comprises 14 symbols, and the current subframe is no exception. The first symbol of a subframe (or time slot) can be used for the downlink control channel, and the last symbol can be used for the uplink control channel. Other channels can be used for downlink or uplink data transmission. Due to this structure of subframes (or time slots), downlink and uplink transmissions can be performed sequentially within a single subframe (or time slot). Therefore, downlink data can be received within a subframe (or time slot), and uplink acknowledgment responses (ACK / NACK) can be sent within the same subframe (or time slot).

[0105] The subframes (or time slots) in this structure can be called self-constrained subframes.

[0106] Specifically, the first N symbols in a time slot can be used to transmit the DL control channel (hereinafter referred to as the DL control area), and the last M symbols in a time slot can be used to transmit the UL control channel (hereinafter referred to as the UL control area). N and M are both integers greater than or equal to 0. The resource area between the DL control area and the UL control area (hereinafter referred to as the data area) can be used for either DL data transmission or UL data transmission. For example, a PDCCH can be transmitted in the DL control area, and a PDSCH can be transmitted in the DL data area. A PUCCH can be transmitted in the UL control area, and a PUSCH can be transmitted in the UL data area.

[0107] Using this subframe (or time slot) structure reduces the time required to retransmit data that has been received incorrectly, and thus minimizes the final data transmission latency. In this self-contained subframe (time slot) structure, transitions from transmit to receive mode may require time slots, and vice versa. Therefore, when transitioning from downlink to uplink in a subframe structure, some OFDM symbols can be set to a guard period (GP).

[0108] Support for various parameter sets

[0109] In the next system, multiple parameter sets can be provided to the terminal based on the development of wireless communication technology. For example, when the SCS is 15kHz, it supports wide-area coverage of traditional cellular bands, and when the SCS is 30kHz / 60kHz, it supports dense urban areas, lower latency, and wider carrier bandwidth, and when the SCS is 60kHz or higher, it supports bandwidths greater than 24.25 GHz to overcome phase noise.

[0110] The parameter set can be defined by the cyclic prefix (CP) length and the subcarrier spacing (SCS). A cell can provide multiple parameter sets to the terminal. When the index of the parameter set is expressed as μ, the spacing of each subcarrier and the corresponding CP length can be shown in the table below.

[0111] Table 3

[0112]

[0113] Under normal CP conditions, when the parameter set index is expressed as μ, the number of OFDM symbols (N) per time slot slot symb ), Number of time slots per frame (N) frame,μ slot ) and the number of time slots in each subframe (N) subframe,μ slot As shown in the table below.

[0114] Table 4

[0115]

[0116] In the case of extended CP, when the index of the parameter set is expressed as μ, the number of OFDM symbols per slot (N) slot symb ), Number of time slots per frame (N) frame,μ slot ()) and the number of time slots per subframe (N) subframe,μ slot As shown in the table below.

[0117] Table 5

[0118]

[0119] Figure 8 Examples of measurements performed in E-UTRAN and NR(EN)DC cases are shown.

[0120] refer to Figure 8 UE 100 is connected to an E-UTRAN (i.e., LTE / LTE-A) cell in the EN-DC. Here, the Pcell in the EN-DC can be an E-UTRAN (i.e., LTE / LTE-A) cell, and the PSCell in the EN-DC can be an NR cell.

[0121] UE 100 can receive measurement configuration (or “measconfig”) information elements (IEs) from E-UTRAN (i.e., LTE / LTE-A) cells. In addition to the fields shown in Table 6, the measurement configuration (or “measconfig”) IE received from E-UTRAN (i.e., LTE / LTE-A) cells may further include the fields shown in the following table.

[0122] Table 6

[0123]

[0124] The measurement configuration (or “measconfig”) IE may further include a measGapConfig field for setting the measurement gap (MG), as shown in Table 7.

[0125] In addition to the examples shown in Table 8, the gapoffset field within the measGapConfig field may further include gp4, gp5, ..., gp11 for EN-DC.

[0126] Meanwhile, UE 100 can receive the measurement configuration (“measconfig”) IE of the NR cell as a PSCell directly from the NR cell or through the E-UTRAN cell as a Pcell.

[0127] Additionally, the measurement configuration (“measconfig”) IE for NR cells can include fields as shown in the table below.

[0128] Table 7

[0129]

[0130] The measGapConfig above can further include the fields shown in the table below.

[0131] Table 8

[0132]

[0133] Simultaneously, UE 100 receives Radio Resource Configuration Information Elements (IEs) of the E-UTRAN (i.e., LTE / LTE-A) cell that serves as a Pcell. Furthermore, the UE can receive Radio Resource Configuration IEs of NR cells that serve as PSCells, either from an NR cell or through an E-UTRAN cell that serves as a Pcell. The Radio Resource Configuration IE includes subframe pattern information.

[0134] UE 100 performs measurements and reports the results. Specifically, during measurement intervals, UE 100 interrupts data transmission and reception with the E-UTRAN (i.e., LTE / LTE-A) cell, retunes its own RF chain, and performs measurements based on SS blocks received from the NR cell.

[0135] Figure 9 An example of performing measurements in the case of NR carrier aggregation is shown.

[0136] refer to Figure 9 UE 100 is configured for carrier aggregation with a first cell (e.g., Pcell) and a second cell (e.g., Scell). Here, Pcell can be an NR-based cell, and Scell ​​can also be an NR-based cell.

[0137] UE 100 can receive Measurement Configuration (or “measconfig”) Information Element (IE). The Measurement Configuration (or “measconfig”) IE may include the fields shown in the table above.

[0138] UE 100 receives Radio Resource Configuration Information (IE).

[0139] UE 100 performs measurements and reports the results.

[0140] <Neighborhood Re-selection>

[0141] The cell reselection process allows the UE to select a more suitable cell and camp on it.

[0142] When the UE is in Camped Normally or Camped on Any Cell, it will attempt to detect, synchronize, and monitor intra-frequency, inter-frequency, and inter-RAT cells indicated by the serving cell. For intra-frequency and inter-frequency cells, the serving cell may not provide an explicit neighbor list, but only carrier frequency and bandwidth information. UE measurement activities are also controlled by measurement rules, allowing the UE to restrict its measurement activities.

[0143] For idle mode cell reselection purposes, the UE should be able to monitor at least:

[0144] -Intra-frequency carrier, and

[0145] -Depending on the UE's capabilities, the seven NR frequency carriers, and

[0146] -Depending on UE capabilities, 7 FDD E-UTRA RAT inter-carriers, and

[0147] - Depending on the UE's capabilities, there are 7 TDD E-UTRA RAT inter-carriers.

[0148] In addition to the requirements defined above, a UE that supports E-UTRA measurements in the RRC_IDLE state should be able to monitor a total of at least 14 carrier frequency layers, including the service layer, which includes a combination of the E-UTRA FDD, E-UTRA TDD and NR layers defined above.

[0149] The UE will measure the SS-RSRP and SS-RSRQ levels of the serving cell, and every M1 The N1 DRX cycle evaluates the cell selection criterion S used for serving cells at least once.

[0150] The UE will use at least two measurements to filter the SS-RSRP and SS-RSRQ measurements of the serving cell. In the set of measurements used for filtering, at least two measurements should be spaced apart by at least DRX cycles / 2.

[0151] If UE is in N serv If, in a consecutive DRX cycle, the serving cell has been evaluated according to Table 9 and does not meet the cell selection criterion S, then the UE should initiate measurements of all neighboring cells indicated by the serving cell, regardless of the measurement rules currently restricting the UE's measurement activities.

[0152] If a UE in RRC_IDLE fails to find any new suitable cell within 10 seconds based on the search and measurement of intra-frequency, inter-frequency, and inter-RAT information indicated in the system information, the UE will initiate a cell selection process for the selected PLMN.

[0153] Table 9

[0154]

[0155] In the absence of an explicit in-frequency neighbor list containing physical layer cell identifiers, the UE should be able to identify new in-frequency cells and perform SS-RSRP and SS-RSRQ measurements on the identified in-frequency cells.

[0156] When Treselection=0, the UE should be able to assess whether the newly detected intra-frequency cell meets the T requirement. detect,NR_Intra Cell reselection criteria within the frequency band. Based on the conditions of the corresponding frequency band, cells within that frequency are considered detectable.

[0157] For in-frequency cells identified and measured according to measurement rules, the UE should at least in each T measure,NR_Intra (See Table 10) Measure SS-RSRP and SS-RSRQ.

[0158] The UE will use at least two measurements to filter the SS-RSRP and SS-RSRQ measurements of the cell within each frequency range. In the set of measurements used for filtering, the interval between at least two measurements should be at least T. measure,NR_Intra Use / 2 to separate them.

[0159] If the measurement and control system information of the serving cell indicates that it is not allowed, the UE should not consider NR neighbor cells in cell reselection.

[0160] For cells within a frequency range that have been detected but not yet reselected, filtering should enable the UE to assess the frequency range when Treselection = 0. evaluate,NR_Intra Cells within the same frequency have met the reselection criteria defined in [1], as specified in Table 10, provided that:

[0161] When rangeToBestCell is not configured:

[0162] - The community must rank at least 3dB better in FR1 or 4.5dB better in FR2.

[0163] When rangeToBestCell is configured:

[0164] - Among all detected cells whose cell ranking criterion R value[1] is within the rangeToBestCell of the cell ranking criterion R value of the highest-ranked cell, the cell has the highest number of beams above the threshold absThreshSS-BlocksConsolidation.

[0165] - If there are multiple such neighborhoods, the neighborhood has the highest ranking among them.

[0166] - If the current serving cell is among them, the cell is ranked at least 3 dB better in FR1, or better [4.5] dB in FR2.

[0167] When evaluating cells for reselection, SSB-side conditions are applied to cells in both serving and non-serving frequencies.

[0168] If the Treselection timer has a non-zero value and the cells within the frequency range meet the reselection criteria, the UE will evaluate the cells within that frequency range during the Treselection time. If the cells still meet the reselection criteria during this time, the UE should reselect the cell.

[0169] Table 10

[0170]

[0171] If the carrier frequency information is provided by the serving cell, the UE will be able to identify new inter-frequency cells and perform SS-RSRP or SS-RSRQ measurements for the identified inter-frequency cells, even if no explicit neighbor list with physical layer cell identifiers is provided.

[0172] If Srxlev > S nonIntraSearchP And Squal > S nonIntraSearchQ Then the UE should search for higher priority inter-frequency layers at least at each Thigher_priority_search.

[0173] If Srxlev ≤ SnonIntraSearchP or Squal ≤ S nonIntraSearchQ In this scenario, the UE should search for and measure higher, equal, or lower priority inter-frequency layers to prepare for a possible reselection. The minimum rate required for the UE to search for and measure higher priority layers in this scenario should be the same as defined below in this clause.

[0174] If in T reselection When K = 0, the serving cell provides at least carrier frequency information to its inter-frequency neighbor cells, then the UE will be able to assess whether the newly detected inter-frequency cell satisfies K. carrier T detect,NR_Inter The reselection criterion is met if there is a margin of at least 5 dB in FR1 or 6.5 dB in FR2 for ranking-based reselection, 6 dB in FR1 or 7.5 dB in FR2 for absolute priority-based SS-RSRP reselection, or 4 dB in FR1 and 4 dB in FR2 for absolute priority-based SS-RSRQ reselection. Parameter K carrier This refers to the number of inter-frequency carriers in the NR frequency range indicated by the serving cell. Based on the conditions of the corresponding frequency band, the inter-frequency cells are considered detectable.

[0175] When higher-priority cells are found through a higher-priority search, they should be at least in each T measure,NR_InterIf a cell is detected in a higher-priority search and it is determined that no cell reselection has occurred, the UE is not required to continue measuring the detected cell to assess the likelihood of an ongoing cell reselection. However, the UE must still meet the minimum measurement filtering requirements specified later in this clause before making any decision that might stop measuring the cell. If the UE detects a cell on an NR carrier whose physical identifier in the serving cell's measurement control system information indicates that the carrier is not allowed, the UE is not required to perform measurements on that cell.

[0176] The UE will provide at least one low- or equal-priority inter-frequency cell per K frequency. carrier T measure,NR_Inter (See Table 11) Measure SS-RSRP or SS-RSRQ. If the UE detects a cell on the NR carrier whose physical identifier is indicated as not allowing the carrier in the measurement and control system information of the serving cell, the UE does not need to perform a measurement on that cell.

[0177] The UE will use at least two measurements to filter the SS-RSRP or SS-RSRQ measurements of inter-frequency cells with higher, lower, and equal priorities for each measurement. In the set of measurements used for filtering, at least two measurements will pass through at least T... measure,NR_Inter Use / 2 to separate them.

[0178] If it is indicated as disallowed in the measurement and control system information of the serving cell, the UE should not consider NR neighbor cells in cell reselection.

[0179] For inter-frequency cells that have been detected but not yet reselected, filtering will enable the UE to assess whether the inter-frequency cell satisfies the Kcarrier requirement when Treselection = 0. T evaluate,NR_Inter The reselection criteria are provided that the following reselection criteria are met.

[0180] - The conditions for performing a reselection with equal priority, and

[0181] When rangeToBestCell is not configured:

[0182] - The community must be ranked at least 5 dB better in FR1 or 6.5 dB better in FR2.

[0183] When rangeToBestCell is configured:

[0184] - Among all detected cells in its cell ranking criterion R value[1], the cell has the highest number of beams above the threshold absThreshSS-BlocksConsolidation.

[0185] - If multiple such neighborhoods exist, the neighborhood with the highest ranking among them is the one that has the highest ranking.

[0186] - If the current serving cell is among them, then the cell is ranked at least 5 dB better in FR1 or [6.5] dB better in FR2. Or

[0187] - For SS-RSRP reselection based on absolute priority, 6dB in FR1 or 7.5dB in FR2 or

[0188] For SS-RSRQ reselection based on absolute priority, -4dB in FR1 or 4dB in FR2.

[0189] When evaluating cells for reselection, SSB-side conditions are applied to both the serving cell and inter-frequency cells.

[0190] If T reselection If the timer has a non-zero value and the inter-frequency cell reselection criteria are met, then the UE will be in T... reselection The inter-frequency cell is evaluated within a specified time period. If the cell still meets the reselection criteria within this time period, the UE should reselect the cell.

[0191] Under the following conditions, it is not expected that the UE will meet the measurement requirements for inter-frequency carriers at DRX cycle = 320ms:

[0192] - T SMTC_intra = T SMTC_inter = 160 ms; where T SMTC_intra and T SMTC_inter The periodicity of SMTC timing for intra-frequency carrier and inter-frequency carrier configurations, respectively.

[0193] - The SMTC timing configured for inter-frequency carriers occurs at most 1 ms before the start of the SMTC timing configured for intra-frequency carriers or at most 1 ms after the end of the SMTC timing configured for intra-frequency carriers.

[0194] - The SMTC timing configured for intra-frequency carriers and inter-frequency carriers occurs at most 1 ms before the paging timing [1] begins or at most 1 ms after the paging timing [1] ends.

[0195] Table 11

[0196]

[0197] Based on the signal quality of the serving cell, the UE can measure neighboring cells to perform cell selection or reselection.

[0198] If the serving cell satisfies S rxlev > S IntraSearchP and S qual > S IntraSearchQ If the UE can choose not to perform in-frequency measurements, then the UE can choose not to perform in-frequency measurements. Otherwise, the UE can perform in-frequency measurements.

[0199] S rxlev This refers to the RX level value (dB) selected for the cell. qual This is the selected quality value (dB) for the cell. IntraSearchP S measured within a specified frequency rxlev Threshold (in dB). S IntraSearchQ The Squal threshold (in dB) measured within the specified frequency range.

[0200] Non-terrestrial networks

[0201] Non-terrestrial networks refer to networks or network segments that use RF resources on satellites (or UAS platforms).

[0202] The following describes a typical scenario for a non-terrestrial network that provides access to user equipment.

[0203] Figure 10 This illustrates a typical scenario for a non-terrestrial network based on a transparent payload.

[0204] Figure 11 This illustrates a typical scenario for a non-terrestrial network based on regenerative payloads.

[0205] Non-terrestrial networks are typically characterized by the following elements:

[0206] - One or more satellite gateways that connect non-terrestrial networks to public data networks

[0207] - GEO satellites are fed by one or more satellite gateways deployed across the satellite target coverage area (e.g., regional or even continental coverage). We assume that a UE in a cell is served by only one satellite gateway.

[0208] - Non-GEO satellites are continuously served by one or more satellite gateways each time. The system ensures sufficient duration of continuous service between satellite gateways and feeder link continuity for mobility anchoring and handover.

[0209] - Feeder link or radio link between the satellite gateway and the satellite (or UAS platform)

[0210] - A service link or radio link between user equipment and a satellite (or UAS platform).

[0211] - Satellites (or UAS platforms) capable of delivering transparent or regenerated (with onboard processing) payloads. Satellites (or UAS platforms) typically generate multiple beams over a given service area within their field of view. The beam footprint is typically elliptical. The field of view of a satellite (or UAS platform) depends on the onboard antenna pattern and minimum elevation angle.

[0212] - Transparent payload: RF filtering, frequency conversion, and amplification. Therefore, the repeating waveform signal of the payload remains unchanged;

[0213] - Regenerated payload: RF filtering, frequency conversion and amplification, as well as demodulation / decoding, switching and / or routing, compilation / modulation. This is practically equivalent to having all or part of the base station functionality on a satellite (or UAS platform) (e.g., gNB).

[0214] - Optionally, inter-satellite links (ISL) in the case of a satellite constellation. This will require regenerative payloads on the satellites. ISLs can operate in RF frequencies or optical bands.

[0215] - User equipment is served by satellites (or UAS platforms) within the target service area.

[0216] The following are some of the different types of satellites (or UAS platforms):

[0217] Table 12 shows the types of NTN platforms.

[0218] Table 12

[0219]

[0220] GEO satellites and UAS are used to provide services to the continent, region, or local area.

[0221] LEO and MEO constellations are used to provide services in both the Northern and Southern Hemispheres. In some cases, constellations can even provide global coverage, including polar regions. For the latter, this requires appropriate orbital inclination, sufficient beam generation, and inter-satellite links.

[0222] <Problems to be solved in the disclosure of this specification>

[0223] NTN environments are expected to have very large cell radii and low service quality due to high path loss. In other words, a UE can receive higher quality service in a TN cell than in an NTN cell. Therefore, when NTN and TN cells compete for UE reselection, a method is needed that allows the UE to easily receive service from a TN cell.

[0224] When NTN and TN cells compete for re-election according to traditional standards, the following situations may occur.

[0225] - Based on the reselection result, the UE can be served by an NTN cell. However, if served by a TN cell, the UE can be provided with a better quality of service than if served by an NTN cell.

[0226] Furthermore, when configuring the search period for TN cells related to reselection, there is a problem that the distance to the TN cell, the signal strength from the TN cell, and the remaining service time with the currently serving satellite are not taken into account.

[0227] <Disclosure of this specification>

[0228] 5G NR NTN (Non-Terrestrial Network) has been introduced to enable UEs to receive communication services via satellite / aircraft within the coverage hall of existing terrestrial networks (TN). This specification describes methods for configuring high-priority serving cells based on the RRC status or location of NTN-supported terminals, methods for searching / measuring high-priority cells, and methods for selecting high-priority cells. For illustrative purposes, examples of NTN-TN mobility that can be used in mixed NTN and TN environments (areas where both satellite and terrestrial base station signals can be searched) and NTN-NTN mobility in an NTN environment (areas where only satellite signals can be searched) are presented. Each example is described separately, but each method in the examples can be similarly applied in different environments.

[0229] Even for UEs that support NTN, it is recommended to receive services from terrestrial network base stations to ensure high data rates or connection stability, as the distance between the satellite and the UE is much greater than the distance between the terrestrial network base station and the UE.

[0230] However, for UEs receiving services from satellite, periodically searching for / measuring ground base stations in areas where no signal is received (e.g., deserts, open seas, etc.) can be an inefficient operation. This can increase the UE's battery consumption.

[0231] In summary, since UEs whose serving cell is an NTN satellite ideally receive service from terrestrial base stations, it is necessary for the UE to periodically search for / measure terrestrial base stations. However, excessively frequent searches / measurements are inefficient operations that increase the UE's battery consumption.

[0232] Therefore, the priority of TN and NTN can be determined by considering the UE's location and status. The operation of a UE supporting both NTN and TN can be as follows:

[0233] a. If the UE is within the NR TN coverage area, it can also support NTN communication.

[0234] - If the UE is configured to perform NR communication instead of NR NTN communication, the UE can regard the frequency that provides NR TN communication configuration as the highest priority.

[0235] b. If the UE within the NTN coverage area is very far from the TN coverage area (e.g., at sea, in flight, etc.).

[0236] - If the UE is configured to perform NR NTN communication without performing NR communication, the UE can regard the frequency that provides NR NTN communication configuration as the highest priority.

[0237] c. If the UE is located at a specific distance from the NR NTN coverage edge and the TN coverage edge

[0238] - If the UE is configured to perform both NR communication and NR NTN communication, the UE may consider the frequency providing NR NTN communication configuration to have a higher priority than the frequency providing NR NTN communication.

[0239] d. etc.

[0240] - If the UE is configured to perform both NR communication and NR NTN communication, the UE can regard the frequency providing both NR communication configuration and NR NTN communication configuration as the highest priority.

[0241] In the above operations, if a specific system has a very high priority, it is possible to restrict the measurement of systems with low priority. For example, in case a, a UE located in the center of the TN coverage area is restricted from measuring NTN, so that the UE can only measure TN. In case b, the UE can be restricted from measuring TN, so that the UE can only measure NTN.

[0242] The conditions under which a TN cell has a higher priority can be as follows, and these conditions can be used individually or in combination.

[0243] Condition 1. When the UE receives a signal from the TN cell that is measured preferentially via system information.

[0244] Condition 2. When the UE measures the distance to the TN cell based on the location of the TN cell received through system information (in the case of receiving a separate signal through NTN track information), and determines that the distance is less than or equal to a specific distance (e.g., the service radius of the TN base station, or a multiple thereof).

[0245] Condition 3. When the UE receives the reference position of the NTN satellite through system information, but there are no satellites within a certain distance (i.e., there are not enough satellites to receive the service).

[0246] Condition 4. When the UE receives the remaining service time of the (service or service + neighbor) NTN satellite through system information, but there is no satellite with sufficient service time (i.e., there are not enough satellites to receive the service).

[0247] The conditions under which a TN cell has a lower priority are as follows.

[0248] Condition 5. When it is determined that there is no TN base station nearby because the terminal is located at a certain altitude (e.g., 1 km).

[0249] Condition 6. If the UE determines that its location is in the same place as the high seas, the terminal can determine that there are no TN base stations nearby and set the priority for TN cells to a lower level. In this case, the UE can determine that it is located in a coverage blind zone of a TN base station (e.g., the high seas) based on information received from the network. Alternatively, the UE can determine that it is located in a coverage blind zone of a TN base station based on the reference position or coverage information of the currently serving satellite. The UE may determine, due to interference, that there are no intra-frequency TN base stations near the reference position of an intra-frequency satellite received from the network. The UE can then set the priority of intra-frequency TN base stations to a lower level (or, based on equal distance). Similarly, the UE can determine that there are no inter-frequency TN base stations near the reference position of an inter-frequency satellite received from the network. The UE can then set the priority of intra-frequency TN base stations to a lower level (or, based on equal distance).

[0250] Condition 7. When the UE fails to find / measure a suitable cell, even if the UE searches for / measures a high-priority TN cell within a specific time period.

[0251] After configuring the TN cell priority as described above, the measurement operations based on the UE's state can be performed as follows. In the following description, for convenience, the UE operations are divided according to the UE's state; however, each operation is applicable even when the UE is in a state different from the described state.

[0252] 1. When the UE is in idle / inactive mode

[0253] A. A method for UE to search for TN cells

[0254] 1) In the existing TN network, if certain conditions are met, the UE may not perform in-frequency measurements.

[0255] If the serving cell satisfies Srxlev > S IntraSearchP And Squal > S IntraSearchQ If so, the UE can choose not to perform in-frequency measurements.

[0256] 1-1) However, NTN UE can be in each T higher_priority_search Periodically attempt TN cell measurements within a given time period to measure TN cells within a frequency set to higher priority. In this case, T higher_priority_search It can be defined as:

[0257] T higher_priority_search =(K (N layers) seconds

[0258] N layers are the total number of the highest priority NR and E-UTRA carrier frequencies broadcast in the system information.

[0259] Here, K can vary depending on the distance between the UE and the TN network, or the network can send K to the UE. Alternatively, the UE can adjust K by considering i) the signal strength from the TN network, ii) the distance to the TN network, and iii) the remaining time of the currently serving satellite. If K is not set, values ​​such as 60 and 120 can be set as default values ​​for K.

[0260] 1-2) A search within the cell can be triggered by satisfying another condition instead of a constant measurement. A search within the cell can be triggered when one or a combination of the following conditions are met.

[0261] i. Constant measurement without any conditions

[0262] ii. When the distance between the reference location of the cell to be searched and the UE is less than a certain value.

[0263] iii. When information is available in the searchable TN cells of the network system information.

[0264] iv. When the network specifies a TN cell for searching

[0265] v. When the remaining service time of the current cell becomes less than or equal to a specific value (if the measurement starts at a remaining service time of T, the discovery can be triggered at a time earlier than T).

[0266] 2) In the existing TN network, the UE can be configured in each T if the following conditions are met. higher_priority_search Internal measurement of higher priority frequency inter-layer / RAT inter-E-UTRAN.

[0267] If Srxlev > S nonIntraSearchP And Squal > S nonIntraSearchQ Then the UE can at least in each T higher_priority_search Search for higher priority frequency layers.

[0268] T higher_priority_search It can be defined as:

[0269] T higher_priority_search =(60 (N layers) seconds

[0270] N layers refer to the total number of higher-priority NR and E-UTRA carrier frequencies broadcast in system information.

[0271] However, since changing the measurement period based on factors such as distance from the base station is effective for NTN UEs, it is recommended to use a value of K for TN cell search instead of 60 in 1), where K is the same as in 1). The value of K may vary depending on factors such as distance to the TN network. The NW may consider the UE's location when sending the K value to the UE. By setting a threshold for signal strength from the TN, distance from the TN, or remaining time with the currently serving satellite, the UE can perform measurement relaxation. Unless otherwise specified, values ​​such as 60 and 120 can be set as default values ​​for K.

[0272] The methods described in 1) and 2) above are applicable not only to TN cells but also to NTN cells.

[0273] T in 1) and 2) higher_priority_search It can be used as a value in NTN.

[0274] Different K values ​​can be configured for NTN and TN cells. The K value of a TN (or NTN) cell may differ from that of another TN (or NTN) cell. In other words, different search times can be configured for different cells.

[0275] After the discovery process, the UE can measure the cell in each measurement cycle.

[0276] Method A can be described using a series of operational examples as follows. (High-priority search methods in NTN)

[0277] In step 1, the UE can receive frequency priority (e.g., via signaling such as cellReselectionPrioity) to prepare for discovery / measurement.

[0278] In step 2, the UE can perform the following operations based on the received measurement information and priority.

[0279] i. In-frequency measurement: In the existing operation, if Srxlev > S IntraSearchP And Squal > S IntraSearchQ Therefore, frequency in-cell measurements are not required. However, in this specification, for reselection to a TN-cell or reselection to an NTN-cell, the UE can use (K The discovery operation is performed periodically across N layers.

[0280] ii. Inter-frequency measurement: In existing operations, with (60 The UE searches for higher priority items at a frequency of (N layers) seconds. However, in this specification, the UE can search at a frequency of (K layers) seconds. (N layers) instead of (60) The discovery operation is performed in cycles of N layers.

[0281] iii. In this case, K may vary depending on the remaining service time of the serving cell and its distance from the reference location. For example, if the service time is sufficient or the distance to the reference location of the serving cell is close, a K greater than 60 can be used. Conversely, a K less than 60 can be used to search for cells more frequently.

[0282] In step 3, the UE can determine the signal strength of neighboring cells by discovering / measuring / evaluating.

[0283] B. UE Cell Selection / Ranking Settings

[0284] When a target cell meets a certain margin requirement, the UE can reselect the target cell. Adjusting this margin can make reselection between TN and NTN cells more or less difficult. For example, when a UE reselects from an NTN cell to a TN cell, lowering the margin requirement for the TN cell increases the likelihood of the UE reselecting to the TN cell. Conversely, if the margin requirement for the NTN cell is higher when the UE reselects from a TN cell to an NTN cell, the likelihood of the UE reselecting to the NTN cell decreases. In other words, by adjusting the margin, the UE can easily be served by a TN cell.

[0285] In NTN cells, cell reselection and ranking processes can be considered for TN cells with a smaller margin. This can be applied depending on the scenario, such as NTN to NTN, TN to NTN, or NTN to TN, as shown below. However, in the case of NTN to NTN or TN to NTN, the same margin can be applied because the target cell is an NTN cell.

[0286] -NTN to NTN

[0287] In NTN environments, the near-far effect (where signal strength is observed to decrease with distance from the cell center) is not clearly observed. That is, the decrease and increase in signal strength are not readily apparent, potentially leading to situations where the target cell's signal strength suddenly deteriorates or improves after a certain distance from the serving cell. Therefore, a margin that makes reselection more difficult can be considered.

[0288] -TN to NTN

[0289] As mentioned above, in the case of competition between TN and NTN, since receiving service from TN cells is better, a margin can be considered that makes reselection to NTN difficult.

[0290] -NTN to TN

[0291] Similarly, since receiving service from the TN is better, a margin can be considered to make reselection to the TN easier.

[0292] In the existing TN, consider the following rankings. When rangeToBestCell is not configured, the cell ranks at least 3 dB better in FR1 or 4.5 dB better in FR2.

[0293] In the reselection / ranking process, besides the scenarios mentioned above, there are several other scenarios, and different values ​​can be applied depending on the scenario. The examples above are only for explaining the principle. That is to say, other scenarios can also be applied.

[0294] In the above example, to force or make reselection of a TN cell easier, the same amount of reduction as the first value can be applied to the 3dB and 4.5dB described in the existing TN above.

[0295] To prioritize service from TN cells, a negative margin can be considered. This means that even if the signal strength of a TN cell is weaker than that of an NTN satellite, the UE can still be forced to access a TN cell.

[0296] In this process, i) the distance between the TN base station / NTN satellite (or the reference location of the satellite) and the UE, and ii) the cell service time of the surrounding NTN satellites, including the serving cell (etc.), can be considered to determine the margin.

[0297] In the examples above, to make reselection to an NTN cell more difficult, the same amount of increase as the second value can be applied to 3dB and 4.5dB. Furthermore, in the case of NTN-to-NTN reselection, the value of the third value can be increased. The value of the fourth value can be decreased in areas with well-defined boundaries.

[0298] The first, second, third, and fourth values ​​can be the same or different. The first, second, third, and fourth values ​​can be changed in real-time according to the NW configuration or changed to fixed values.

[0299] This specification does not recommend setting specific values, but rather describes the principles / methods that make reselecting a target cell easier / more difficult. However, values ​​similar to 3dB can generally be used for the first, second, third, and fourth values.

[0300] Furthermore, even if TN and NTN cells are in the same priority state, the reselection of TN cells can be prioritized when searching for TN cells.

[0301] The following guidelines can be applied.

[0302] -In the existing TN

[0303] Ranking criteria for service communities R s and neighboring communities R n By the following definition:

[0304] R s = Q meas,s +Q hyst - Qoffset temp

[0305] R n = Q meas,n -Qoffset - Qoffset temp

[0306] in:

[0307] Q meas RSRP is a measurement used in cell reselection.

[0308] Within the frequency range, Qoffset equals Qoffset. s,n If Qoffset s,n It's valid; otherwise, it's equivalent to zero.

[0309] For frequencies, Qoffset equals Qoffset. s,n Add Qoffset frequency If Qoffsets,n Valid, otherwise this is equivalent to Qoffset frequency .

[0310] Qoffset temp It is a temporary offset applied to the cell.

[0311] - Recommendations for NTN environments

[0312] Ranking criteria for service communities R s and neighboring communities R n It can be defined as follows:

[0313] R s = Q meas,s +Q hyst - Qoffset temp

[0314] R n_TN = Q meas,n -Qoffset_TN - Qoffset temp

[0315] R n_NTN = Q meas,n -Qoffset_NTN - Qoffset temp

[0316] By setting different offset values ​​for the TN cell and the NTN cell for the NTN UE, it is easier to perform TN cell reselection even if the signal to the TN cell is weaker than the existing criteria.

[0317] In the above operation, by setting the priority of the E-UTRA RAT inter-carrier to be higher than the priority of the NR NTN cell, the UE can prioritize searching for / measuring TN cells when it cannot find a suitable NR cell. This operation can be performed similarly to the one described above.

[0318] In addition, when a UE in idle / inactive mode changes its mode to a connection mode for QoS or data rate (or just before the change), the UE can perform priority measurement / discovery of TN cells.

[0319] Figure 12 The states of the UE related to measurement are shown according to embodiments of this specification.

[0320] In UE operation, because the satellite service area is very large, measurement relaxation can also be considered.

[0321] The UE can be in three states, and Figure 12 The measurement described herein can mean the measurement of TN.

[0322] A UE in state 1 may not measure the signals of the TN base stations at all. The UE may not measure the signals of any TN base stations until event 1 is triggered.

[0323] A UE in state 2 is able to measure the signals of the TN base stations with a long period. This state is maintained until event 2 is triggered. If the inverse condition of the trigger condition of event 1 holds, the state of the UE may change to state 1.

[0324] A UE in state 3 is able to measure the signals of the TN base stations with a normal measurement period. If the inverse condition of the trigger condition of event 2 holds, the state of the UE may change to state 2.

[0325] The distance between the UE served by the NTN satellite and the reference position of the NTN satellite is D. According to D, the states of the UE are as follows.

[0326] - If D is lower than the threshold D1, the UE can identify that it is near the center of the service area of the NTN satellite. The UE may not need to measure the signals of the TN cells. In this case, the UE may be in state 1.

[0327] - If D satisfies D1 < D < D2 with respect to a specific threshold D2 (D1 < D2), the UE may be in the middle between the edge and the center of the service area of the NTN satellite. The UE may need to measure other cells. The UE may be in state 2. In this case, the UE may preferentially search / measure the TN base stations.

[0328] - If D satisfies D > D3 with respect to a specific threshold D3 (D3 > D2), the UE may be at the edge of the service area and may be in state 3. A UE in state 3 is able to measure the neighboring cells with a certain period.

[0329] In the above example according to D, since the service area of the NTN satellite is very large, only two of the above states can be applied. For example, only D1 and D3 can be applied, and the states of the UE can be divided into two states, only state 1 and state 3. Alternatively, only D2 and D3 can also be applied, and the states of the UE can be divided into two states, only state 2 and state 3.

[0330] The method of B can be described by a series of operation examples as follows. (A method for setting the reselection margin in the NTN-TN environment)

[0331] Step 1 The UE can evaluate the signals of the neighbor cells through the steps of discovery / measurement / evaluation.

[0332] Step 2-1: If the signal strength of a neighboring cell is higher than the signal strength of the serving cell (NTN cell) by a threshold, the UE serving the NTN cell can perform a reselection to a neighboring cell (TN cell), where this threshold is less than 3dB (e.g., 2dB). (In the existing TN environment, under FR1, the UE performs a reselection to a neighboring cell with a signal strength 3dB higher than the serving cell.)

[0333] Step 2-2 In the opposite case, if the signal strength of the neighboring cell is higher than the signal strength of the serving cell (NTN cell) by a threshold, the TN-serving UE can perform a reselection to the neighboring cell (TNTN cell), where the threshold is higher than 3dB (e.g., 4dB).

[0334] After the above process, the serving cell for the UE can be changed by reselection.

[0335] 2. When the UE is in an RRC connection

[0336] The network can assess the UE's location by analyzing the location or latency information reported by the UE. Alternatively, the UE's location can be assessed using its PRS (etc.). If the network determines that the UE's location is sufficiently close to a TN base station, the network can assign the UE TN base station measurement information (frequency, etc.), measurement intervals, SMTC, etc., enabling the UE to prioritize measurements of the TN base station.

[0337] In this case, based on the base station power, the reference distance (the distance at which the network determines the UE's location is close enough to the TN base station) can be considered as the normal base station coverage area (5 km in the case of a 43dBm Tx power scale macro base station).

[0338] If the satellite signal is much weaker than the signal from a base station at the edge of the base station's coverage area, the reference distance can be "N". "Normal base station coverage area". N can be a natural number, such as 1, 2, or 3. In the case of completely open land, N can be a maximum of 120. N is usually 3 or less.

[0339] TN base station measurement information can be included in the measurement information. Alternatively, when the network sends surrounding satellite information (orbit information and remaining service time) to the UE, the network can include the actual location of the TN base station in the orbit information included in the surrounding satellite information. The UE may then be able to measure the TN base station. However, because the configured service time may be infinite, there may be a problem where the UE cannot distinguish between GEO and TN. In this case, the network can include the altitude information of the TN base station, as well as its velocity and acceleration set to 0, in the orbit information, enabling the UE to identify the TN base station.

[0340] Additionally, when multiple configurations for TN and NTN cells are configured in the UE, the priority of TN cells in the gaps of the shared factors can be configured as high to allow the UE to measure TN cells first.

[0341] 3. Other

[0342] In the case of NTN to NTN, in areas where only satellite signals can be searched, which satellite cell has high priority can vary based on the UE's RRC status or location.

[0343] (1) When the UE is in RRC connection state

[0344] - The UE can report to the network that it needs a high data rate. Alternatively, the network can determine for itself whether the UE needs a high data rate. When the network recognizes that the UE needs a high data rate, it can configure the priority of voice LEO (Low Earth Orbit) to high for the UE.

[0345] - If the UE determines that it needs a high data rate, the UE can search for / measure the LEO satellite with the highest priority based on the ephemeris information / remaining service time delivered from the network.

[0346] (2) When the UE is in the RRC idle / inactive state

[0347] The UE can search for / reselect the GEO satellite with the highest priority based on ephemeris information delivered from the network.

[0348] The following figures were created to illustrate specific embodiments of this disclosure. The names of specific devices or signals / messages / fields shown in the figures are provided as examples, and therefore the technical features of this disclosure are not limited to the specific names used in the following figures.

[0349] Figure 13 The procedure of the UE according to the first disclosure in this specification is shown.

[0350] 1. The UE can send a random access preamble to an NTN (non-terrestrial network) cell.

[0351] 2. The UE can receive a random access response from the NTN cell.

[0352] 3. The UE can search for TN (terrestrial network) cells in periods T.

[0353] T can be determined based on i) the distance from the TN cell, ii) the signal power from the TN cell, and iii) the service time of the NTN cell.

[0354] The steps of searching for a TN cell can be performed based on i) the distance between the UE's location and the reference location of the TN cell is less than a threshold D, ii) the TN cell is specified for searching, or iii) the service time of the TN cell is less than a threshold.

[0355] The threshold D can be based on the coverage area of ​​the base station in the TN cell or the signal strength of the NTN cell.

[0356] The UE can receive system information from the NTN cell.

[0357] The steps of searching for TN cells can be performed based on system information, including information about discoverable TN cells.

[0358] The UE can search for TN cells to measure the signal strength of TN cells.

[0359] The UE can determine the reselection to the TN cell based on the fact that the signal strength of the TN cell is higher than the signal strength of the NTN cell by a threshold K or more.

[0360] The UE can perform a cell reselection to a TN cell.

[0361] The threshold K can be less than 3 dB in FR1 (frequency range 1) and less than 4.5 dB in FR2.

[0362] Figure 14 The procedure of the UE according to the second disclosure of this specification is shown.

[0363] 1. The UE can send a random access preamble to the first cell.

[0364] 2. The UE can receive a random access response from the first cell.

[0365] 3. The UE can measure the signal strength of the second cell.

[0366] 4. The UE can determine to reselect the second cell based on the fact that the signal strength of the second cell is higher than the signal strength of the NTN cell by a threshold K or more.

[0367] Given that the first cell is an NTN (non-terrestrial network) cell and the second cell is a TN (terrestrial network) cell, the threshold K can be less than 3dB in FR1 (frequency range 1) and less than 4.5dB in FR2.

[0368] Given that the first cell is a TN cell and the second cell is an NTN cell, the threshold K can be higher than 3dB in FR1 and higher than 4.5dB in FR2;

[0369] 5. The UE can perform cell reselection to the second cell.

[0370] Based on the premise that the first cell is an NTN cell and the second cell is an NTN cell, the threshold K can be higher than 3dB in FR1 and higher than 4.5dB in FR2.

[0371] In the following, devices configured to operate in a wireless system according to some embodiments of the present disclosure will be described.

[0372] For example, a terminal may include a processor, a transceiver, and memory.

[0373] For example, the processor can be configured to be operatively coupled to the memory and the processor.

[0374] The processor can be configured to: send a random access preamble to an NTN (non-terrestrial network) cell; receive a random access response from an NTN cell; and search for a TN (terrestrial network) cell at a period T, wherein T is determined based on i) the distance between the UE's location and a reference location of the TN, ii) the signal power from the TN cell, and iii) the service time of the NTN cell.

[0375] In the following, apparatus in mobile communications according to some embodiments of the present disclosure will be described.

[0376] The processor can be configured to: send a random access preamble to an NTN (non-terrestrial network) cell; receive a random access response from an NTN cell; and search for a TN (terrestrial network) cell at a period T, wherein T is determined based on i) the distance between the UE's location and a reference location of the TN, ii) the signal power from the TN cell, and iii) the service time of the NTN cell.

[0377] In the following, a non-transitory computer-readable medium having a plurality of instructions stored thereon in a wireless communication system according to some embodiments of the present disclosure will be described.

[0378] According to some embodiments of this disclosure, the technical features of this disclosure may be embodied directly in hardware, in software executed by a processor, or in a combination of both. For example, a method executed by a wireless device in wireless communication may be implemented in hardware, software, firmware, or any combination thereof. For example, software may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, removable disk, CD-ROM, or any other storage medium.

[0379] Some examples of storage media are coupled to a processor, enabling the processor to read information from the storage media. Alternatively, the storage media can be integrated into the processor. The processor and storage media can reside in an ASIC. For example, the processor and storage media can reside as discrete components.

[0380] Computer-readable media can include tangible and non-transitory computer-readable storage media.

[0381] For example, non-transitory computer-readable media may include random access memory (RAM), such as synchronous dynamic random access memory (SDRAM), read-only memory (ROM), non-volatile random access memory (NVRAM), electrically erasable programmable read-only memory (EEPROM), flash memory, magnetic or optical data storage media, or any other medium that can be used to store instructions or data structures. Non-transitory computer-readable media may also include combinations of the above.

[0382] Furthermore, the methods described herein can be implemented at least in part through a computer-readable communication medium that carries or conveys code in the form of instructions or data structures and can be accessed, read, and / or executed by a computer.

[0383] According to some embodiments of this disclosure, a non-transitory computer-readable medium has stored a plurality of instructions thereon. The stored plurality of instructions can be executed by the processor of the UE.

[0384] The stored instructions enable the UE to send a random access preamble to an NTN (non-terrestrial network) cell; receive a random access response from an NTN cell; and search for a TN (terrestrial network) cell at a period T, where T is determined based on i) the distance between the UE's location and a reference location of the TN, ii) the signal power from the TN cell, and iii) the service time of the NTN cell.

[0385] This disclosure can have various beneficial effects.

[0386] For example, by adjusting the measurement cycle, it is possible to reduce the terminal's battery consumption, perform cell searches more efficiently, and predict effective mobility support.

[0387] For example, by making it easier for UEs to serve in TN cells, better communication quality can be provided to users.

[0388] The beneficial effects obtained through the specific examples in this specification are not limited to those listed above. For example, there may be various technical effects that can be understood or derived from this specification by one of ordinary skill in the art. Therefore, the specific effects of this disclosure are not limited to those explicitly described herein, but may include various effects that can be understood or derived from the technical features of this disclosure.

[0389] The claims in this disclosure can be combined in various ways. For example, the technical features in the method claims of this disclosure can be combined to implement or perform in an apparatus, and the technical features in the apparatus claims can be combined to implement or perform in a method. Furthermore, the technical features in the method claims and apparatus claims can be combined to implement or perform in a method. Other embodiments are within the scope of the following claims.

Claims

1. A method executed by a user equipment (UE), comprising: Identify inter-frequency cells and perform synchronization signal-reference signal received power (SS-RSRP) or SS-reference signal received quality (SS-RSRQ) measurements on the identified inter-frequency cells based on carrier frequency information provided by the serving cell. Wherein, the serving cell is a non-terrestrial network (NTN) cell, and The frequency-inter-cells correspond to TN cells in the terrestrial network. a) Based on cell selection reception level values ​​exceeding cell selection reception level thresholds and cell selection quality values ​​exceeding cell selection quality thresholds; i) Search for higher priority inter-frequency layers at least per cycle of value T, including: The integer value K is determined based on i) the distance between the UE and the TN cell and ii) the remaining service time of the NTN cell. The value T is defined by the following equation: T = (K N) seconds, Where N is the total number of higher-priority frequencies broadcast in the system information; and ii) Perform cell reselection on a higher priority frequency; b) Based on the cell selection reception level being less than or equal to the cell selection reception level threshold or the cell selection quality level being less than or equal to the cell selection quality threshold: i) Searching for and measuring frequency layers of equal priority; and ii) Based on the serving cell and the ranking of the cells at equal priority frequencies, perform cell reselection to a cell at the equal priority frequency. Wherein, the cell on the equal priority frequency is ranked at least 3 dB better than the serving cell in frequency range -1 FR1 with a negative offset, or ranked at least 4.5 dB better than the serving cell in frequency range -2 FR2 with a negative offset. The negative offset is applied to facilitate cell reselection to the TN cell.

2. The method according to claim 1, wherein, The value K is greater than 60 because the distance between the UE and the TN cell is greater than a first threshold.

3. The method according to claim 1, wherein, The value K is less than 60 because the distance between the UE and the TN cell is less than a first threshold.

4. The method according to claim 1, wherein, The remaining service time of the NTN cell is greater than the second threshold, where the value K is greater than 60.

5. The method according to claim 1, wherein, The remaining service time of the NTN cell is less than a second threshold, where the value K is less than 60.

6. A user equipment (UE), comprising: At least one transceiver, At least one processor, said at least one processor being operatively connected to said at least one memory, Wherein, the at least one memory stores instructions, the instructions causing the UE to perform an operation based on execution by the at least one processor, the operation including: Identify inter-frequency cells and perform synchronization signal-reference signal received power (SS-RSRP) or SS-reference signal received quality (SS-RSRQ) measurements on the identified inter-frequency cells based on carrier frequency information provided by the serving cell. Wherein, the serving cell is a non-terrestrial network (NTN) cell, and The frequency-inter-cells correspond to TN cells in the terrestrial network. a) Based on cell selection reception level values ​​exceeding cell selection reception level thresholds and cell selection quality values ​​exceeding cell selection quality thresholds: i) Search for higher priority inter-frequency layers at least per cycle of value T, including: The integer value K is determined based on i) the distance between the UE and the TN cell and ii) the remaining service time of the NTN cell. The value T is defined by the following equation: T = (K N) seconds, Where N is the total number of higher-priority frequencies broadcast in the system information; and ii) Perform cell reselection on a higher priority frequency; b) Based on the cell selection reception level being less than or equal to the cell selection reception level threshold or the cell selection quality level being less than or equal to the cell selection quality threshold: i) Searching for and measuring frequency layers of equal priority; and ii) Based on the serving cell and the ranking of the cells at equal priority frequencies, perform cell reselection to a cell at the equal priority frequency. Wherein, the cell on the equal priority frequency is ranked at least 3 dB better than the serving cell in frequency range -1 FR1 with a negative offset, or ranked at least 4.5 dB better than the serving cell in frequency range -2 FR2 with a negative offset. The negative offset is applied to facilitate cell reselection to the TN cell.

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