Method and apparatus for improved network search in wireless communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. According to various embodiments of the present disclosure, an operation method of a first terminal in a wireless communication system comprises the operations of: identifying a connection state of a second terminal; if the second terminal is connected to the first terminal through short-range communication and is not connected to a serving cell of the first terminal through a wireless network, receiving capability information from the second terminal; and transmitting, to the second terminal, a list of at least one candidate cell identified on the basis of the capability information.

Description

Method and device for enhanced network exploration in wireless communication systems

[0001] The present disclosure relates generally to wireless communication or mobile communication systems, and more particularly to methods and devices for enhanced network discovery of wearable devices in wireless communication or mobile communication systems.

[0002] To meet the growing demand for wireless data traffic following the commercialization of 4G (4th generation) communication systems, efforts are being made to develop improved 5G (5th generation) communication systems, or pre-5G communication systems. For this reason, 5G communication systems, or pre-5G communication systems, are also referred to as "Beyond 4G Network" communication systems or "Post-LTE" systems.

[0003] To achieve high data rates, 5G communication systems are being considered for implementation in ultra-high frequency (mmWave) bands (e.g., the 60 GHz band). To mitigate radio path loss and increase the transmission range of radio waves in ultra-high frequency bands, beamforming, massive MIMO (massive MIMO), full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and large-scale antenna technologies are being discussed in 5G communication systems.

[0004] Additionally, to improve the network of the system, technologies such as evolved small cells, advanced small cells, cloud radio access networks (cloud RAN), ultra-dense networks, device-to-device communication (D2D), wireless backhaul, moving networks, cooperative communication, CoMP (Coordinated Multi-Points), and interference cancellation are being developed in 5G communication systems.

[0005] In addition, 5G systems are developing advanced coding modulation (ACM) techniques such as Hybrid Frequency Shift Keying and Quadrature Amplitude Modulation (FQAM) and Sliding Window Superposition Coding (SWSC), as well as advanced access technologies such as Filter Bank Multi Carrier (FBMC), Non Orthogonal Multiple Access (NOMA), and Sparse Code Multiple Access (SCMA). As a result of the aforementioned advancements in wireless communication systems, a variety of services have become available, and methods for seamlessly delivering these services are becoming increasingly necessary.

[0006] To meet the demand for wireless data traffic, the 5G system, NR (new radio or next radio), has been commercialized. Like 4G, it is expected that 5G systems will provide users with high data transmission rates, and that various wireless communication services for specific purposes, such as the Internet of Things (IoT) and services requiring high reliability, will be provided. In the current mixed system of 4th generation and 5th generation communication systems, the O-RAN (Open Radio Access Network), established by operators and equipment providers, is defining new NE (network element) and interface specifications based on the existing 3GPP specifications and proposing the O-RAN architecture.

[0007] With the recent development of various wearable devices, wearable devices can connect to wireless networks without short-range communication with a host device. However, wearable devices may have various limitations, unlike host devices. Therefore, new network functions such as RedCap (reduced capability) may be provided to support low-spec devices like wearable devices. Discussions are ongoing regarding network search methods for wireless network connection when a wearable device supporting new network functions like RedCap loses connection with a host device.

[0008] The present disclosure provides a device and method for enhanced network exploration of a wearable device in a wireless communication system (or mobile communication system).

[0009] For example, the present disclosure can provide a list of neighboring cells for wireless network connection based on capability information previously received by a host device from a remote device (e.g., a wearable device) in a wireless communication system. Accordingly, the remote device can more quickly search for a network to which it wishes to connect based on the list of neighboring cells received from the host device.

[0010] The present disclosure provides a host device and a wearable device for performing enhanced network exploration in a wireless communication system.

[0011] According to various embodiments of the present disclosure, a method of operating a first terminal in a wireless communication system includes an operation of identifying a connection state of a second terminal, an operation of receiving capability information from the second terminal when the second terminal is connected to the first terminal via short-range communication and is not connected to a serving cell of the first terminal via a wireless network, and an operation of transmitting a list of at least one candidate cell identified based on the capability information to the second terminal, wherein the first terminal is a host device, the second terminal is a remote device capable of connecting to the at least one candidate cell via a wireless network, and the list may include information on the at least one candidate cell for wireless network connection of the second terminal when the short-range communication connection is released.

[0012] According to various embodiments of the present disclosure, in a method of operating a second terminal in a wireless communication system, when the second terminal is connected to a first terminal through short-range communication and is not connected to a serving cell of the first terminal through a wireless network, the method includes: transmitting capability information to the first terminal; receiving, from the first terminal, a list of at least one candidate cell identified based on the capability information; and searching for a serving cell of the second terminal based on the list of at least one candidate cell, wherein the first terminal is a host device, the second terminal is a remote device capable of connecting to the at least one candidate cell through a wireless network, and the list may include information on the at least one candidate cell for wireless network connection of the second terminal when the short-range communication connection is released.

[0013] According to various embodiments of the present disclosure, in a wireless communication system, a first terminal includes a transceiver, and at least one processor coupled to the transceiver, wherein the at least one processor identifies a connection state of a second terminal, receives capability information from the second terminal when the second terminal is connected to the first terminal via short-range communication and is not connected to a serving cell of the first terminal via a wireless network, and transmits a list of at least one candidate cell identified based on the capability information to the second terminal, wherein the first terminal is a host device, and the second terminal is a remote device capable of connecting to the at least one candidate cell via a wireless network, and the list may include information on the at least one candidate cell for wireless network connection of the second terminal when the short-range communication connection is released.

[0014] According to various embodiments of the present disclosure, in a wireless communication system, a second terminal includes a transceiver, and at least one processor coupled to the transceiver, wherein the at least one processor transmits capability information to the first terminal when the second terminal is connected to the first terminal through short-range communication and is not connected to a serving cell of the first terminal through a wireless network, receives a list of at least one candidate cell identified based on the capability information from the first terminal, and searches for a serving cell of the second terminal based on the list of at least one candidate cell, wherein the first terminal is a host device, and the second terminal is a remote device capable of connecting to the at least one candidate cell through a wireless network, and the list may include information on the at least one candidate cell for wireless network connection of the second terminal when the short-range communication connection is released.

[0015] Devices and methods according to various embodiments of the present disclosure enable a wearable device to independently establish a wireless network connection when a short-range communication connection with a host device is released.

[0016] Devices and methods according to various embodiments of the present disclosure enable a wearable device capable of connecting to a wireless network to perform faster network search and connection (camp-on) based on a list of neighboring cells received from a host device. In this case, the list of neighboring cells transmitted by the host device only includes information about cells that match the wearable device's capability information, thereby supporting enhanced network search by the wearable device.

[0017] The effects that can be obtained from the present disclosure are not limited to the effects mentioned above, and other effects that are not mentioned can be clearly understood from the technical field to which the present disclosure belongs from the description below.

[0018] The above and other aspects, features and advantages of specific embodiments of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings.

[0019] FIG. 1 illustrates a wireless communication system according to various embodiments of the present disclosure.

[0020] FIG. 2 illustrates a configuration of a base station in a wireless communication system according to various embodiments of the present disclosure.

[0021] FIG. 3 illustrates a configuration of a terminal in a wireless communication system according to various embodiments of the present disclosure.

[0022] FIG. 4 illustrates a network search method of a remote device in accordance with various embodiments of the present disclosure.

[0023] FIG. 5 illustrates a method for generating a neighbor cell list of a host device according to various embodiments of the present disclosure.

[0024] FIG. 6 illustrates a method for generating a neighbor cell list of a host device according to various embodiments of the present disclosure.

[0025] FIG. 7 illustrates information included in a neighboring cell list according to various embodiments of the present disclosure.

[0026] FIG. 8 illustrates a transmission procedure of a neighbor cell list of a host device according to various embodiments of the present disclosure.

[0027] FIG. 9 illustrates a concept of a transmission operation of a neighbor cell list of a host device according to various embodiments of the present disclosure.

[0028] FIG. 10 illustrates a network discovery procedure of a remote device according to various embodiments of the present disclosure.

[0029] FIG. 11 illustrates the operation sequence of a host device and a remote device according to various embodiments of the present disclosure.

[0030] FIG. 12 illustrates an improved network discovery method according to various embodiments of the present disclosure.

[0031] FIG. 13 illustrates the operation of a host device according to various embodiments of the present disclosure.

[0032] FIG. 14 illustrates the operation of a remote device according to various embodiments of the present disclosure.

[0033] FIG. 15 illustrates the operation of a host device according to various embodiments of the present disclosure.

[0034] FIG. 16 illustrates an improved network discovery method according to various embodiments of the present disclosure.

[0035] FIG. 17 illustrates the operation of a host device according to various embodiments of the present disclosure.

[0036] FIG. 18 illustrates an improved network discovery method according to various embodiments of the present disclosure.

[0037] FIG. 19 illustrates the operation of a host device according to various embodiments of the present disclosure.

[0038] FIG. 20 illustrates an improved network discovery method according to various embodiments of the present disclosure.

[0039] FIG. 21 illustrates a reduced network discovery procedure of a remote device according to various embodiments of the present disclosure.

[0040] FIG. 22 illustrates the operation of a host device according to various embodiments of the present disclosure.

[0041] The terms used in this disclosure are used only to describe specific embodiments and may not be intended to limit the scope of other embodiments. The singular expression may include plural expressions unless the context clearly indicates otherwise. Terms used herein, including technical or scientific terms, may have the same meaning as commonly understood by those of ordinary skill in the art described in this disclosure. Terms defined in general dictionaries among the terms used in this disclosure may be interpreted as having the same or similar meaning in the context of the relevant technology, and shall not be interpreted in an idealized or overly formal sense unless explicitly defined in this disclosure. In some cases, even if a term is defined in this disclosure, it cannot be interpreted to exclude embodiments of the present disclosure.

[0042] The various embodiments of the present disclosure described below illustrate a hardware-based approach as an example. However, since the various embodiments of the present disclosure include techniques utilizing both hardware and software, the various embodiments of the present disclosure do not exclude software-based approaches and / or combinations of hardware-based and software-based approaches.

[0043] The present disclosure relates to a method and device for a remote device disconnected from a host device in a wireless communication or mobile communication system to search for a wireless network. In this case, searching for a wireless network may refer to an operation of searching (searching, scanning) for an appropriate cell to receive a communication service. In addition, the host device may refer to a terminal or user equipment (UE) that can act as a host to the remote device. In addition, the remote device may refer to a wearable device (e.g., a smart watch, smart glasses, a smart ring, a tracking device, or a monitoring device) that can be connected to the host device via short-range communication (e.g., Bluetooth, Wi-Fi, or Ultra-wide band). The remote device may be a device that includes a modem (or SIM card (e.g., embedded-SIM, eSIM)) capable of supporting not only short-range communication with the host device but also wireless network connectivity (e.g., LTE, LTE-A, or 5G). Of course, the types of the host device and the remote device and the short-range communication method between the devices are not limited to the examples described above.

[0044] When the short-range communication connection between a remote device and a host device is lost, the remote device may perform cell search to connect to a wireless network. This cell search can result in connection delays and battery drain. To address the aforementioned issues, the present disclosure describes specific methods and devices for network search based on a list of neighboring cells (e.g., a white list) generated by the host device.

[0045] In the following description, terms referring to signals (e.g., message, information, preamble, signal, signaling, sequence, stream), terms referring to resources (e.g., symbol, slot, subframe, radio frame, subcarrier, resource element (RE), resource block (RB), bandwidth part (BWP), occasion), terms for operational states (e.g., step, operation, procedure), terms referring to data (e.g., information, bit, symbol, codeword), terms referring to channels, terms referring to control information (e.g., downlink control information (DCI), medium access control control element (MAC CE), radio resource control (RRC) signaling), terms referring to network entities, terms referring to components of devices, etc. are examples for convenience of explanation. Therefore, the present disclosure is not limited to the terms described below, and other terms having equivalent technical meanings may be used.

[0046] In the following description, the terms "physical channel" and "signal" may be used interchangeably with data or control signals. For example, while PDSCH (physical downlink shared channel) refers to a physical channel through which data is transmitted, PDSCH can also be used to refer to data. That is, in the present disclosure, the expression "transmitting a physical channel" can be interpreted equivalently to the expression "transmitting data or a signal through a physical channel."

[0047] Hereinafter, in the present disclosure, upper signaling refers to a signal transmission method in which a base station transmits a signal to a terminal using a downlink data channel of the physical layer, or a terminal transmits a signal to a base station using an uplink data channel of the physical layer. Upper signaling can be understood as RRC (radio resource control) signaling or a MAC control element (hereinafter referred to as 'CE').

[0048] Additionally, in the present disclosure, expressions such as "more than" and "less than" are used to determine whether a specific condition is satisfied or fulfilled. However, this is merely a description to express an example and does not exclude descriptions of more than or less than. Conditions described as "more than" may be replaced with "more than," conditions described as "less than" may be replaced with "less than," and conditions described as "more than and less than" may be replaced with "more than and less than."

[0049] Additionally, while this disclosure describes various embodiments using terminology used in certain communication standards (e.g., 3rd Generation Partnership Project (3GPP)), these are merely illustrative examples. The various embodiments of this disclosure can be easily modified and applied to other communication systems.

[0050] FIG. 1 illustrates a wireless communication system according to various embodiments of the present disclosure. FIG. 1 illustrates a base station (110), a terminal (120), and a terminal (130) as some of the nodes utilizing a wireless channel in the wireless communication system. While FIG. 1 illustrates only one base station, other base stations identical to or similar to the base station (110) may be included.

[0051] The base station (110) is a network infrastructure that provides wireless access to terminals (120, 130). The base station (110) has coverage defined as a certain geographical area based on the distance at which a signal can be transmitted. In addition to the base station, the base station (110) may be referred to as an 'access point (AP)', 'eNodeB (eNB)', '5th generation node', 'next generation nodeB (gNB)', 'wireless point', 'transmission / reception point (TRP)', or other terms having equivalent or similar technical meanings.

[0052] Each of the terminal (120) and the terminal (130) is a device used by a user and communicates with the base station (110) via a wireless channel. The link from the base station (110) to the terminal (120) or the terminal (130) is referred to as a downlink (DL), and the link from the terminal (120) or the terminal (130) to the base station (110) is referred to as an uplink (UL). In addition, although not shown in FIG. 1, according to one embodiment, the terminal (120) and the terminal (130) may communicate with each other via a wireless channel. In this case, the link (device-to-device link; D2D) between the terminals (120 and 130) is referred to as a sidelink, and the sidelink may be used interchangeably with the PC5 interface. In some cases, at least one of the terminals (120) and the terminals (130) may be operated without the intervention of the user. That is, at least one of the terminal (120) and the terminal (130) is a device that performs machine type communication (MTC) and may not be carried by the user. Each of the terminal (120) and the terminal (130) may be referred to as a 'user equipment (UE)', a 'mobile station', a 'subscriber station', a 'remote terminal', a 'wireless terminal', a 'user device', or other terms having equivalent or similar technical meanings thereto.

[0053] The base station (110), the terminal (120), and the terminal (130) can transmit and receive wireless signals in the millimeter wave (mmWave) band (e.g., 28 GHz, 30 GHz, 38 GHz, 60 GHz). At this time, in order to improve channel gain, the base station (110), the terminal (120), and the terminal (130) can perform beamforming. Here, the beamforming can include transmission beamforming and reception beamforming. That is, the base station (110), the terminal (120), and the terminal (130) can provide directionality to a transmission signal or a reception signal. To this end, the base station (110) and the terminals (120, 130) can select serving beams (121, 131) through a beam search or beam management procedure. After serving beams (121, 131) are selected, subsequent communication can be performed through resources that are in a QCL (quasi co-located) relationship with the resources that transmitted the serving beams (121, 131).

[0054] If large-scale characteristics of a channel carrying a symbol on a first antenna port can be inferred from a channel carrying a symbol on a second antenna port, the first antenna port and the second antenna port can be evaluated to have a QCL relationship. For example, the large-scale characteristics may include at least one of delay spread, Doppler spread, Doppler shift, average gain, average delay, and a spatial receiver parameter.

[0055] FIG. 2 illustrates the configuration of a base station in a wireless communication system according to various embodiments of the present disclosure. The configuration illustrated in FIG. 2 can be understood as the configuration of a base station (110). Terms such as "unit" and "unit" used hereinafter refer to a unit that processes at least one function or operation, and this can be implemented by hardware, software, or a combination of hardware and software. Referring to FIG. 2, the base station includes a wireless communication unit (210), a backhaul communication unit (220), a storage unit (230), and a control unit (240).

[0056] The wireless communication unit (210) performs functions for transmitting and receiving signals via a wireless channel. For example, the wireless communication unit (210) performs a conversion function between baseband signals and bit streams according to the physical layer specifications of the system. For example, when transmitting data, the wireless communication unit (210) encodes and modulates the transmitted bit stream to generate complex symbols. Additionally, when receiving data, the wireless communication unit (210) restores the received bit stream by demodulating and decoding the baseband signal.

[0057] In addition, the wireless communication unit (210) upconverts a baseband signal into an RF (radio frequency) band signal and transmits it through an antenna, and downconverts an RF band signal received through the antenna into a baseband signal. To this end, the wireless communication unit (210) may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a digital to analog convertor (DAC), an analog to digital convertor (ADC), etc. In addition, the wireless communication unit (210) may include a plurality of transmission and reception paths. Furthermore, the wireless communication unit (210) may include at least one antenna array composed of a plurality of antenna elements.

[0058] In terms of hardware, the wireless communication unit (210) may be composed of a digital unit and an analog unit, and the analog unit may be composed of a plurality of sub-units depending on operating power, operating frequency, etc. The digital unit may be implemented with at least one processor (e.g., a digital signal processor (DSP)) including a processing circuit.

[0059] The wireless communication unit (210) transmits and receives signals as described above. Accordingly, all or part of the wireless communication unit (210) may be referred to as a "transmitter," a "receiver," or a "transceiver." Furthermore, in the following description, transmission and reception performed via a wireless channel are used to mean that the wireless communication unit (210) performs the processing described above.

[0060] The backhaul communication unit (220) (e.g., including a backhaul communication circuit) provides an interface for performing communication with other nodes within the network. That is, the backhaul communication unit (220) converts a bit string transmitted from a base station to another node, such as another access node, another base station, an upper node, a core network, etc., into a physical signal, and converts a physical signal received from another node into a bit string.

[0061] The storage unit (230) stores data such as basic programs, application programs, and setting information for the operation of the base station. The storage unit (230) may be composed of volatile memory, non-volatile memory, or a combination of volatile and non-volatile memory. In addition, the storage unit (230) provides stored data upon request from the control unit (240).

[0062] The control unit (240) controls the overall operations of the base station. For example, the control unit (240) transmits and receives signals through the wireless communication unit (210) or the backhaul communication unit (220). In addition, the control unit (240) records and reads data in the storage unit (230). In addition, the control unit (240) can perform the functions of the protocol stack required by the communication standard. According to another implementation example, the protocol stack can be included in the wireless communication unit (210). For this purpose, the control unit (240) can include at least one processor. The processor can include various processing circuits and / or multiple processors. As used herein, including in the claims, the term "processor" can include various processing circuits including at least one processor, wherein at least one of the processors can be configured to perform various functions individually and / or in a distributed manner. As used herein, when "processor," "at least one processor," and "a processor" are described as being configured to perform a number of functions, these terms can encompass situations where, for example, one processor performs some of the rerouted functions and another processor(s) performs other of the rerouted functions, as well as situations where a single processor can perform all of the rerouted functions. Additionally, the at least one processor can comprise a combination of processors that perform various of the rerouted / publicized functions, for example, in a distributed manner. The at least one processor can execute program instructions to achieve or perform the various functions. According to various embodiments of the present disclosure, the control unit (240) can control the base station to perform operations according to various embodiments described below.

[0063] FIG. 3 illustrates the configuration of a terminal in a wireless communication system according to various embodiments of the present disclosure. The configuration illustrated in FIG. 3 can be understood as the configuration of a terminal (120). Terms such as "unit" and "unit" used hereinafter refer to a unit that processes at least one function or operation, and this can be implemented using hardware, software, or a combination of hardware and software. Referring to FIG. 3, the terminal includes a communication unit (310), a storage unit (320), and a control unit (330).

[0064] The communication unit (310) performs functions for transmitting and receiving signals via a wireless channel. For example, the communication unit (310) performs a conversion function between a baseband signal and a bit stream according to the physical layer specifications of the system. For example, when transmitting data, the communication unit (310) generates complex symbols by encoding and modulating a transmission bit stream. In addition, when receiving data, the communication unit (310) restores a reception bit stream by demodulating and decoding the baseband signal. In addition, the communication unit (310) upconverts a baseband signal to an RF band signal and transmits it through an antenna, and downconverts an RF band signal received through the antenna to a baseband signal. For example, the communication unit (310) may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, etc.

[0065] In addition, the communication unit (310) (e.g., including communication circuitry) may include a plurality of transmit / receive paths. Furthermore, the communication unit (310) may include at least one antenna array composed of a plurality of antenna elements. In terms of hardware, the communication unit (310) may be composed of digital circuits and analog circuits (e.g., radio frequency integrated circuits (RFIC)). Here, the digital circuits and analog circuits may be implemented in a single package. In addition, the communication unit (310) may include a plurality of RF chains. Furthermore, the communication unit (310) may perform beamforming.

[0066] The communication unit (310) transmits and receives signals as described above. Accordingly, all or part of the communication unit (310) may be referred to as a "transmitter," a "receiver," or a "transmitting and receiving unit." Furthermore, in the following description, transmission and reception performed via a wireless channel are used to mean processing performed by the communication unit (310) as described above.

[0067] The storage unit (320) stores data such as basic programs, application programs, and setting information for the operation of the terminal. The storage unit (320) may be composed of volatile memory, non-volatile memory, or a combination of volatile and non-volatile memory. In addition, the storage unit (320) provides stored data upon request from the control unit (330).

[0068] The control unit (330) controls the overall operations of the terminal. For example, the control unit (330) transmits and receives signals through the communication unit (310). In addition, the control unit (330) records and reads data in the storage unit (320). In addition, the control unit (330) can perform the functions of the protocol stack required by the communication standard. To this end, the control unit (330) may include at least one processor or microprocessor, or may be a part of a processor. The processor may include various processing circuits and / or multiple processors. As used herein, including in the claims, the term "processor" may include various processing circuits including at least one processor, wherein at least one of the processors may be configured to perform various functions individually and / or in a distributed manner. As used herein, when "processor," "at least one processor," and "a processor" are described as being configured to perform a number of functions, these terms can encompass situations where, for example, one processor performs some of the rerouted functions and another processor(s) performs other of the rerouted functions, as well as situations where a single processor can perform all of the rerouted functions. Additionally, the at least one processor may comprise a combination of processors that perform various of the rerouted / publicized functions, for example, in a distributed manner. The at least one processor may execute program instructions to achieve or perform the various functions. Additionally, a portion of the communication unit (310) and the control unit (330) may be referred to as a CP (communication processor). According to various embodiments, the control unit (330) may control the terminal to perform operations according to various embodiments described below.

[0069] FIG. 4 illustrates a network search method of a remote device in accordance with various embodiments of the present disclosure.

[0070] Referring to FIG. 4, a case in which a short-range communication connection between a remote device and a host device is disconnected, triggering a wireless network search operation of the remote device, may be described. For example, the host device may be camped on cell C2. At this time, the remote device may be connected to the host device via Bluetooth. The Bluetooth connection between the remote device and the host device may be in a state in which the quality of signals transmitted and / or received via Bluetooth is good (e.g., a state in which the quality of signals transmitted and / or received is above a certain threshold value). When the remote device is connected to the host device via Bluetooth, the remote device may receive services from a wireless network via the host device, and thus may operate in remote mode (or flight mode). For example, the remote device may not use a modem for a direct connection to a wireless network. The remote device may maintain remote mode while connected to the host device via Bluetooth. Therefore, the remote device may conserve battery power by not using a modem.

[0071] However, if the remote device releases its Bluetooth connection with the host device (or if the signal quality falls below or is below a certain threshold), the remote device may search for a wireless network to receive communication services. For example, the remote device may use a modem to search for a suitable LTE or 5G cell based on the frequency stored in the remote device. However, if the remote device moves to a new location different from before the Bluetooth connection was released, the frequency information and cell ID (identifier) ​​stored in the remote device may not match the frequency information and cell ID at the new location. Therefore, the remote device may have to search for cells in all frequency bands supported by the remote device at the new location. This may result in battery drain and connection delays.

[0072] To address the above-described issues, the host device may generate a neighboring cell list (e.g., a white list) that includes information about cells that match the remote device. In the embodiments of the present disclosure, the white list may refer to a neighboring cell list that includes information about cells that match the remote device. For example, the remote device may be a reduced capability (RedCap) (or new radio (NR)-Light) device. The RedCap device may be connected to a 5G communication system, but may differ from a typical 5G terminal in terms of network functionality. In this case, the RedCap device may be a device designed to satisfy somewhat reduced requirements of the high requirements of the 5G communication system (e.g., ultra-reliable, low-latency communication (URLLC) or enhanced URLLC (eURLLC)). More specifically, the RedCap device is designed for optimization and can support 150 Mbps (megabits per second) and 50 Mbps in the downlink (DL) and uplink (UL), respectively. For example, a RedCap device may support narrower bandwidth (e.g., 20 MHz in the sub-7 GHz band or 100 MHz in the millimeter wave (mmWave) frequency band), a single transmit antenna, a single receive antenna (e.g., two antennas are selectable), half-duplex frequency division duplex (FDD) selection, low-order modulation (e.g., 256-QAM selection), and low transmit power. In the present embodiments, if the remote device is a RedCap device, it may have at least one of the features set forth in Table 1 below.

[0073]

[0074] Referring to Table 1 above, the RedCap device can reduce device complexity and size, while also increasing device cost efficiency and battery efficiency. For example, the whitelist can include information about at least one cell capable of supporting RedCap. Therefore, when a remote device receives the whitelist from the host device, it can learn about cells that support RedCap, enabling it to perform wireless network discovery and connection operations more quickly.

[0075] For example, if a remote device is a redcap device, the host device can generate a whitelist containing information about cell C1, which supports redcap among neighboring cells C3 and C1, and a new redcap-supporting cell C4. If the Bluetooth signal quality between the remote device and the host device is poor or the Bluetooth connection is lost, the host device can transmit the whitelist to the remote device. Instead of performing a cell search across all frequency bands supported by the remote device, the remote device can perform a search only for cells C1 and C4 based on the whitelist received from the host device. Therefore, the remote device can save time required for cell search and reduce battery consumption.

[0076] FIG. 5 illustrates a method for generating a neighbor cell list of a host device according to various embodiments of the present disclosure.

[0077] Referring to FIG. 5, at step 510, the host device can identify whether it is connected to a remote device via short-range communication. For example, the host device can identify whether it can communicate with a remote device located within short range of the host device via a Bluetooth connection.

[0078] At step 520, if the host device is connected to the remote device via short-range communication, the host device can identify whether the remote device is connected to a wireless network. For example, the host device can identify whether the remote device is connected to a base station (e.g., an eNB or gNB) via a wireless network in addition to short-range communication with the host device. The host device can generate and transmit a white list only when the remote device is not connected to a wireless network (e.g., in flight mode). This is because, if the remote device is connected to the base station via a wireless network, the remote device may not perform cell scanning for a new wireless network connection even if the connection with the host device is lost or the connection with the host device is poor. Therefore, if the remote device is connected to the base station via a wireless network, the host device may not generate a white list or transmit the generated white list to the remote device.

[0079] In step 530, if the remote device is not connected to the base station and the wireless network, the host device may receive the wireless cellular capability (or capability information) of the remote device from the remote device. Hereinafter, in embodiments of the present disclosure, the wireless cellular capability of the remote device may be referred to as capability information of the remote device. At this time, the capability information may include information regarding whether at least one network function among supplementary uplink (SUL), redcap, multiple-input and multiple-output (MIMO), 5th generation (5G) standalone (SA), or 5G non-standalone (NSA) is supported. In addition, the capability information may further include information regarding whether at least one of a frequency (frequency band), a radio access technology (RAT), a bandwidth, a number of antennas, a modulation order, or a network function defined in 3GPP is supported. Of course, the capability information is not limited to the above examples.

[0080] The operations of the host device described above are merely examples, and some of the operations described above may be omitted or combined with more than one. Furthermore, at least one new operation, in addition to the operations described above, may be added and combined with existing operations.

[0081] FIG. 6 illustrates a method for generating a neighbor cell list of a host device according to various embodiments of the present disclosure.

[0082] Referring to FIG. 6, operations related to generating and storing a white list of a host device may be described. In step 610, the host device may receive information about at least one neighboring cell of the serving cell of the host device from a network (or a base station). At this time, the information about the at least one neighboring cell may be included in system information (e.g., a system information block (SIB)) or a terminal-specific message. Accordingly, the host device may obtain information about the at least one neighboring cell by decoding the system information or the terminal-specific message. The information about the at least one neighboring cell may include at least one of a network function supported by each neighboring cell, a supported frequency band, a signal strength, or a cell ID.

[0083] At step 620, the host device can identify whether it has moved to a new tracking area. If the host device has moved to a new tracking area, the host device needs to determine whether at least one neighboring cell is a new neighboring cell that is not included in the existing white list stored in the host device. However, if the host device has not moved to a new tracking area, the host device does not need to determine whether at least one neighboring cell is a new neighboring cell included in the existing white list stored in the host device, and thus step 640 can be performed.

[0084] In step 630, if the host device moves to a new tracking area, the host device can identify whether at least one neighboring cell is included in an existing white list stored in the host device based on the information about at least one neighboring cell received in step 610. At this time, if at least one neighboring cell is included in an existing white list stored in the host device, the host device may not need to generate a new white list. However, steps 620 to 630 described above may be performed if there is a white list stored in the host device. Accordingly, if there is no white list stored in the host device, the host device may not perform steps 620 to 630 described above.

[0085] In step 640, if at least one neighboring cell is not included in an existing white list stored in the host device, the host device can identify (or evaluate) whether the capabilities of the remote device (e.g., network capabilities supported by the remote device) match the cell information. For example, based on the capability information received in step 610, if the remote device is a redcap device, the host device can identify at least one neighboring cell that supports redcap. In this case, if there is no neighboring cell that supports redcap, the host device can terminate the white list generation procedure.

[0086] In step 650, if there is a neighboring cell that supports the function of the remote device, the host device can store information about at least one neighboring cell that supports the function of the remote device in a white list. For example, the host device can store information about at least one neighboring cell that supports redcap in a white list. That is, the host device can add information about at least one newly identified neighboring cell to the stored white list. However, if there is no white list stored in the host device, the host device can create a new white list that includes information about at least one neighboring cell that supports redcap.

[0087] The operations of the host device described above are merely examples, and some of the operations described above may be omitted or combined with more than one. Furthermore, at least one new operation, in addition to the operations described above, may be added and combined with existing operations.

[0088] FIG. 7 illustrates information included in a neighboring cell list according to various embodiments of the present disclosure.

[0089] Referring to FIG. 7, the configuration of the white list described in FIG. 6 (e.g., the white list generated or stored in step 650) may be described. For example, the white list may include at least one of a cell ID, frequency information, network function, or signal strength of at least one neighboring cell that supports the function of the remote device. The cell ID may refer to a physical cell ID (e.g., physical cell ID, PCI) of an LTE or 5G network. For example, the information on at least one neighboring cell that supports the function of the remote device included in the white list may include information required when the remote device searches for a cell to connect to a wireless network after the short-range communication connection with the host device is terminated. In other words, the white list may be a list of candidate cells for connecting to a wireless network when the short-range communication connection with the host device is terminated. Therefore, when the short-range communication connection with the host device is terminated, the remote device can connect to the wireless network more quickly based on the information included in the white list. Of course, the present invention is not limited to the above example, and the remote device may search for a new neighboring cell other than the neighboring cell included in the white list.

[0090] Meanwhile, the white list can be modified by the host device. For example, if the host device moves to a new tracking area, the host device can reset (or regenerate) the white list. Alternatively, the host device can add information about neighboring cells that support the remote device's functions to the white list based on capability information received from the remote device. Alternatively, the host device can remove information about neighboring cells that do not support the remote device's functions from the white list based on capability information received from the remote device. However, the above example may be an example of a case where the host device stores the white list, but is not limited thereto. Accordingly, the host device can also generate a new white list based on the above-described situation.

[0091] FIG. 8 illustrates a transmission procedure of a neighbor cell list of a host device according to various embodiments of the present disclosure.

[0092] Referring to FIG. 8, a procedure for transmitting a white list generated (or stored) through the procedure of FIG. 6 to a remote device can be described. At step 810, the host device can determine whether the signal quality with the remote device is below a certain threshold value (or below a certain threshold value). At this time, the certain threshold value for triggering transmission of the white list can be preset in the host device by the base station or can be instructed by the base station. Alternatively, the certain threshold value for triggering transmission of the white list can be determined from among values ​​preset (or stored) by the host device, taking into account the characteristics of the remote device.

[0093] At step 820, if the signal quality between the host device and the remote device is below a certain threshold (or below a certain threshold), the host device may transmit a whitelist to the remote device. Of course, the method of transmitting a whitelist based on the above-described certain threshold is merely an example, and the transmission of the whitelist may be triggered by other decision criteria. For example, if the host device is instructed to turn off Bluetooth power, the host device may transmit a whitelist to the remote device.

[0094] The operations of the host device described above are merely examples, and some of the operations described above may be omitted or combined with more than one. Furthermore, at least one new operation, in addition to the operations described above, may be added and combined with existing operations.

[0095] FIG. 9 illustrates a concept of a transmission operation of a neighbor cell list of a host device according to various embodiments of the present disclosure.

[0096] Referring to FIG. 9, an example of an operation for identifying whether the signal quality between the host device and the remote device is below a certain threshold value (or below a certain threshold value) in step 810 of FIG. 8 may be described. The signal quality threshold for triggering the host device to transmit a stored (or generated) white list to the remote device may be based on the strength of the received signal (e.g., the received signal strength indicator (RSSI)). For example, the host device may identify that the signal quality is good if the RSSI value of the signal received through the Bluetooth connection with the remote device is equal to or greater than -70 dBm. At this time, the host device may not transmit the stored (or generated) white list to the remote device. On the other hand, the host device may identify that the signal quality is poor if the RSSI value of the signal received through the Bluetooth connection with the remote device is less than -70 dBm. At this time, the host device may transmit the stored (or generated) white list to the remote device.

[0097] However, the threshold value that serves as the basis for triggering the transmission of the white list is not limited to the above example. Furthermore, while the above example described that the host device transmits the white list to the remote device when the RSSI value of the received signal is less than -70 dBm, this is not limited to cases where the value is less than an arbitrary threshold value. Accordingly, the transmission of the white list may also be triggered even when the RSSI value of the received signal is equal to an arbitrary threshold value.

[0098] FIG. 10 illustrates a network discovery procedure of a remote device according to various embodiments of the present disclosure.

[0099] Referring to FIG. 10, a network search method of a remote device may be described when the remote device receives a white list from the host device in step 820 of FIG. 8 described above. In step 1010, the remote device may search for a wireless network based on information included in the white list received from the host device. For example, the white list received from the host device may include at least one of a cell ID, frequency information, network function, or signal strength of at least one neighboring cell that supports a function of the remote device. At this time, the remote device, which is a redcap device, may receive an SS block (SSB) including a synchronization signal (e.g., a synchronization signal, SS) and a physical broadcast channel (PBCH) broadcast from a cell that supports redcap in the white list. The synchronization signal may be composed of a primary SS (PSS) and a secondary SS (SSS). In addition, the remote device may obtain information about time / frequency synchronization of a cell that supports redcap from the synchronization signal. At this time, the remote device may already know the cell ID (e.g., PCI) of the cell that transmitted the synchronization signal through the white list. However, if there are more cells supporting redcap than this number, the remote device may receive only the synchronization signal of the cell with the stronger reception signal based on the information about the reception signal strength of the cells supporting redcap among the information included in the white list. Therefore, the remote device may not need to search for all the synchronization signals broadcast by the candidate serving cells in all the frequency bands supported by the remote device. Therefore, the remote device can shorten the time required to receive the synchronization signal of the serving cell and also reduce the battery usage required for the network search by performing the network search based on the white list.

[0100] In step 1020, the remote device can perform a connection operation (e.g., camp-on) for the cell searched in step 1010. At this time, the procedure for the remote device to connect to the serving cell may be the same as or similar to the existing cell selection procedure. More specifically, the remote device can obtain information included in a master information block (MIB) by decoding the PBCH of the SSB received in the cell search procedure in step 1010. Based on the information included in the MIB, the remote device can identify whether the cell that transmitted the synchronization signal is a prohibited cell. In addition, the terminal can receive a physical downlink control channel (PDCCH) based on the information included in the MIB, and can decode the PDCCH to receive a system information block (SIB) (e.g., SIB 1) through the PDSCH. Based on the information included in the SIB, the remote device can identify the public land mobile network (PLMN) of the cell that transmitted the synchronization signal. If the PLMN ID of the cell that transmitted the synchronization signal matches the PLMN ID to which the remote device is subscribed, the remote device can select the cell that transmitted the synchronization signal as its serving cell. The remote device can then camp on the selected cell.

[0101] The above-described remote device operations are merely examples, and some of the above-described operations may be omitted or combined with more than one. Furthermore, at least one new operation, in addition to the above-described operations, may be added and combined with existing operations.

[0102] FIG. 11 illustrates the operation sequence of a host device and a remote device according to various embodiments of the present disclosure.

[0103] Referring to FIG. 11, the host device and the remote device may include both an application processor (AP) and a communication processor (CP), and a specific operation sequence of the AP and the CP for performing operations according to the above-described embodiments may be described. At step 1110, if the host device and the remote device are connected via Bluetooth (e.g., if the signal quality of the Bluetooth connection is good), the remote device may be maintained in flight mode, and thus the CP modem may be off. Accordingly, the remote device may not be connected to the base station via the CP modem via a wireless network.

[0104] At step 1120, the CP modem of the remote device can transmit capability information of the remote device to the AP of the remote device. The AP of the remote device can transmit the capability information received from the CP modem of the remote device to the AP of the host device via a Bluetooth connection. At this time, the capability information transmitted to the host device may refer to the capability information described in step 530. In addition, the AP of the host device can transmit the capability information received from the remote device to the CP modem of the host device. The CP modem of the host device can perform cell evaluation based on the capability information of the remote device received from the AP of the host device. At this time, the cell evaluation may refer to an operation (e.g., operation 640) of identifying whether neighboring cells support the function of the remote device based on the cell information and capability information received from the network.

[0105] At step 1130, the CP modem of the host device may add information about cells that satisfy the conditions (e.g., whether the cell supports redcap) to a white list through cell evaluation. Alternatively, if there is no stored white list, the host device may generate a white list containing information about cells that satisfy the conditions.

[0106] At step 1140, the AP of the host device may request the CP modem of the host device to transmit a white list when the signal quality with the remote device deteriorates or the Bluetooth connection is disconnected (for example, when the user of the host device disconnects the Bluetooth connection). The CP modem of the host device may transmit the stored (or generated) white list to the AP of the host device in response to the white list transmission request received from the AP of the host device. The AP of the host device may transmit the white list received from the CP modem of the host device to the AP of the remote device. In this case, when the user of the host device disconnects the Bluetooth connection, the white list may be transmitted before the Bluetooth connection is disconnected. In addition, the AP of the remote device may transmit the white list received from the AP of the host device to the CP modem of the remote device.

[0107] At step 1150, the remote device's AP may disconnect its Bluetooth connection with the host device. If the Bluetooth connection is disconnected, the remote device's CP modem may perform a wireless network connection based on the whitelist received from the host device. The wireless network connection procedure may include the cell search and camp-on procedures described in steps 1010 to 1020.

[0108] FIG. 12 illustrates an improved network discovery method according to various embodiments of the present disclosure.

[0109] Referring to FIG. 12, one embodiment of a process in which a remote device receives a white list from a host device based on capability information of the remote device, and searches for and connects to a wireless network based on information included in the white list, may be described.

[0110] In one embodiment, as a first step, if the host device is connected to a remote device, which is a redcap device, through short-range communication, the host device connected to cell C2 can identify whether the remote device is connected to a wireless network. For example, the remote device can identify whether it is connected to a base station (e.g., an eNB or gNB) through a wireless network in addition to short-range communication with the host device. The host device can receive information about at least one neighboring cell of the host device's serving cell from the network (or the base station). If the remote device is not connected to the base station through a wireless network and the signal quality of the Bluetooth connection is above a certain threshold, the host device can receive capability information about the remote device from the remote device. Of course, the case where the quality of the received signal is above a certain threshold is given as an example to determine the signal quality of the Bluetooth connection, but it is only one example and may include a case where the strength of the received signal is greater than a certain threshold. The capability information may include information about whether at least one network function among SUL, redcap, MIMO, 5G SA, or 5G NSA is supported. In addition, the capability information may further include information regarding frequency (frequency band), RAT, bandwidth, number of antennas, modulation order, or support for at least one of the network functions defined in 3GPP. Of course, the capability information is not limited to the above examples. Based on the capability information received from the remote device, the host device may add information on cell C1, which supports redcap among neighboring cells C3 and C1, to the white list. At this time, if there is no previously stored white list, the host device may create a white list including information on cell C1.

[0111] In the second step, the host device can discover a new neighboring cell C4 that supports redcap. The host device can then add information about cell C4 to its whitelist. Therefore, the whitelist stored in the host device can include information about cells C1 and C4 that support redcap.

[0112] In the third step, if the signal quality of the Bluetooth connection with the remote device is poor (e.g., if the received signal strength falls below a certain threshold), the host device can transmit the stored white list to the remote device. While the example of determining the signal quality of the Bluetooth connection when the received signal quality falls below a certain threshold is provided as an example, this is merely an example and may also include cases where the received signal strength is lower than a certain threshold. Furthermore, the arbitrary threshold value for triggering the transmission of the white list may be preset in the host device by the base station or may be instructed by the base station. Alternatively, the arbitrary threshold value for triggering the transmission of the white list may be determined by the host device from among preset (or stored) values, taking into account the characteristics of the remote device. Of course, the method of transmitting the white list based on the aforementioned arbitrary threshold value is merely an example, and the transmission of the white list may be triggered by other decision criteria. For example, if the host device is instructed to turn off the Bluetooth power, the host device may transmit the white list to the remote device.

[0113] In the fourth step, if the signal quality of the Bluetooth connection between the host device and the remote device is poor or the Bluetooth connection is disconnected, the remote device can search for a wireless network based on information included in a white list received from the host device. For example, the white list received from the host device may include at least one of a cell ID, frequency information, network function, or signal strength of at least one neighboring cell that supports the function of the remote device. At this time, the remote device, which is a redcap device, can receive an SSB including a synchronization signal and a PBCH broadcast from a cell that supports redcap in the white list. In addition, the remote device can obtain information about the time / frequency synchronization of the cell that supports redcap from the synchronization signal. At this time, the remote device may already know the cell ID (e.g., PCI) of the cell that transmitted the synchronization signal through the white list. However, if there are more cells supporting RedCap than this (for example, if both cells C1 and C4 support RedCap), the remote device may receive only the synchronization signal of a cell with a stronger reception signal strength (for example, a nearby cell C1) based on the information about the reception signal strength of cells C1 and C4 supporting RedCap among the information included in the whitelist. Therefore, the remote device may not need to search for all the synchronization signals broadcast by the candidate serving cells in all the frequency bands supported by the remote device. The remote device may perform a connection operation (for example, camp-on) for cell C1. The remote device may decode the PBCH of the SSB received from cell C1 to obtain the information included in the MIB. The remote device may identify whether cell C1 is a forbidden cell based on the information included in the MIB. In addition, the terminal may receive the PDCCH based on the information included in the MIB, and may decode the PDCCH to receive an SIB (for example, SIB 1) through the PDSCH.The remote device can identify the PLMN of cell C1 based on the information contained in the SIB. If the PLMN ID of cell C1 matches the PLMN ID to which the remote device subscribes, the remote device can select cell C1 as its serving cell. The remote device can then quickly camp on cell C1.

[0114] The operations of the host device and remote device described above are merely examples, and some of the operations described above may be omitted or combined with more than one. Furthermore, at least one new operation, in addition to the operations described above, may be added and combined with existing operations. Furthermore, the operations of the host device and remote device described above may further include or omit at least some of the operations described in FIGS. 5 to 12.

[0115] FIG. 13 illustrates the operation of a host device according to various embodiments of the present disclosure.

[0116] Referring to FIG. 13, an embodiment of a host device for an enhanced network discovery method based on a white list according to the embodiments described above is described.

[0117] At step 1310, the host device can identify whether it is connected to the remote device via short-range communication. For example, the host device can identify whether it can communicate with a remote device located within the vicinity of the host device via a Bluetooth connection. If the host device is connected to the remote device via short-range communication, the host device can identify whether the remote device is connected to a wireless network. For example, the host device can identify whether the remote device is connected to a base station (e.g., an eNB or gNB) via a wireless network in addition to short-range communication with the host device. The host device can generate and transmit a white list only when the remote device is not connected to a wireless network (e.g., in flight mode). If the remote device is connected to a base station via a wireless network, the host device may not generate a white list or may not transmit the generated white list to the remote device.

[0118] At step 1320, if the remote device is not connected to the base station via a wireless network, the host device may receive capability information about the remote device from the remote device. At this time, the capability information may include information regarding whether at least one network function among SUL, RedCap, MIMO, 5G SA, or 5G NSA is supported. In addition, the capability information may further include information regarding whether at least one of a frequency (frequency band), RAT, bandwidth, number of antennas, modulation order, or a network function defined in 3GPP is supported. Of course, the capability information is not limited to the above examples.

[0119] At step 1330, if at least one neighboring cell of the serving cell of the host device is not a cell included in the existing white list stored in the host device, the host device can identify (or evaluate) whether the capabilities of the remote device (e.g., network capabilities supported by the remote device) match the cell information. For example, based on the capability information received at step 1320, the host device can identify at least one neighboring cell that supports RedCap if the remote device is a RedCap device. At this time, the information about the at least one neighboring cell can be received from the network (or the base station), and the information about the at least one neighboring cell can be included in system information (e.g., SIB) or a terminal-specific message. Accordingly, the host device can obtain the information about the at least one neighboring cell by decoding the system information or the terminal-specific message. The information about the at least one neighboring cell can include at least one of a network capability supported by each neighboring cell, a supported frequency band, a signal strength, or a cell ID.

[0120] In step 1340, if there is a neighboring cell that supports the function of the remote device, the host device can store information about at least one neighboring cell that supports the function of the remote device in a white list. For example, the host device can store information about at least one neighboring cell that supports redcap in a white list. That is, the host device can add information about at least one newly identified neighboring cell to the stored white list. However, if there is no white list stored in the host device, the host device can create a new white list that includes information about at least one neighboring cell that supports redcap.

[0121] At step 1350, the host device can determine whether the signal quality with the remote device is below a certain threshold (or below a certain threshold). At this time, the certain threshold for triggering the transmission of the white list can be preset by the base station or instructed by the base station. Alternatively, the certain threshold for triggering the transmission of the white list can be determined by the host device from among preset (or stored) values, taking into account the characteristics of the remote device. If the signal quality between the host device and the remote device is below a certain threshold (or below a certain threshold), the host device can transmit the white list to the remote device. Of course, the method of transmitting the white list based on the above-described certain threshold is only one example, and the transmission of the white list can be triggered by other decision criteria. For example, if the host device is instructed to turn off the Bluetooth power, the host device can transmit the white list to the remote device.

[0122] The operations of the host device described above are merely examples, and some of the operations described above may be omitted, or more may be combined. Furthermore, at least one new operation, in addition to the operations described above, may be added and combined with existing operations. Furthermore, the operations of the host device described above may further include, or omit, at least some of the operations described in FIGS. 5 to 12.

[0123] FIG. 14 illustrates the operation of a remote device according to various embodiments of the present disclosure.

[0124] Referring to FIG. 14, in step 1410, if the remote device is connected to the host device via short-range communication and is not connected to the base station via a wireless network, the remote device may transmit capability information of the remote device to the host device. At this time, the capability information may include information regarding whether at least one network function among SUL, RedCap, MIMO, 5G SA, or 5G NSA is supported. In addition, the capability information may further include information regarding whether at least one of frequency (frequency band), RAT, bandwidth, number of antennas, modulation order, or network functions defined in 3GPP is supported. Of course, the capability information is not limited to the above examples.

[0125] At step 1420, if the signal quality between the host device and the remote device is below a certain threshold (or below a certain threshold), the remote device may receive a white list from the host device. Of course, the method of receiving a white list based on the above-described certain threshold is merely an example, and the white list may be received based on other decision criteria. For example, if the host device is instructed to turn off Bluetooth power, the remote device may receive a white list from the host device. In this case, the white list received from the host device may include information about at least one neighboring cell that supports the remote device's function.

[0126] At step 1430, the remote device can search for a wireless network based on information included in a white list received from the host device. For example, the white list received from the host device may include at least one of a cell ID, frequency information, network function, or signal strength of at least one neighboring cell that supports the function of the remote device. At this time, the remote device, which is a redcap device, can receive a synchronization signal and an SSB including a PBCH broadcast from a cell that supports redcap in the white list. In addition, the remote device can obtain information about the time / frequency synchronization of the cell that supports redcap from the synchronization signal. At this time, the remote device may already know the cell ID (e.g., PCI) of the cell that transmitted the synchronization signal through the white list. However, if there are more cells that support redcap than this, the remote device may receive only the synchronization signal of a cell with a stronger received signal strength based on the information about the received signal strength of the cells that support redcap among the information included in the white list. The remote device may perform a connection operation (e.g., camp-on) for the searched cell. At this time, the procedure for a remote device to connect to a serving cell may be identical or similar to the existing cell selection procedure. More specifically, the remote device can obtain information contained in the MIB by decoding the PBCH of the SSB received in the cell search procedure. Based on the information contained in the MIB, the remote device can identify whether the cell that transmitted the synchronization signal is a prohibited cell. In addition, the terminal can receive the PDCCH based on the information contained in the MIB, and can decode the PDCCH to receive an SIB (e.g., SIB 1) via the PDSCH. The remote device can identify the PLMN of the cell that transmitted the synchronization signal based on the information contained in the SIB.If the PLMN ID of the cell that transmitted the synchronization signal matches the PLMN ID to which the remote device is subscribed, the remote device can select the cell that transmitted the synchronization signal as its serving cell. The remote device can then camp on the selected cell.

[0127] The operations of the remote device described above are merely examples, and some of the operations described above may be omitted, or more may be combined. Furthermore, at least one new operation, in addition to the operations described above, may be added and combined with existing operations. Furthermore, the operations of the remote device described above may further include, or omit, at least some of the operations described in FIGS. 5 to 12.

[0128] FIG. 15 illustrates the operation of a host device according to various embodiments of the present disclosure.

[0129] Referring to FIG. 15, one embodiment of a host device for an improved network discovery method is described.

[0130] At step 1510, the host device can determine whether it is connected to the remote device via short-range communication. For example, the host device can determine whether it can communicate with the remote device via a Bluetooth connection located within the vicinity of the host device. If the host device is connected to the remote device via short-range communication, the host device can determine whether the remote device is connected to a wireless network. For example, the host device can determine whether the remote device is connected to a base station (e.g., an eNB or gNB) via a wireless network in addition to short-range communication with the host device. The host device can transmit information about neighboring cells to the remote device only when the remote device is not connected to a wireless network (e.g., in flight mode). If the remote device is connected to a base station via a wireless network, the host device may not transmit information about neighboring cells to the remote device.

[0131] At step 1520, if the remote device is not connected to the base station via a wireless network, the host device may receive capability information about the remote device from the remote device. At this time, the capability information may include information regarding whether at least one network function among SUL, RedCap, MIMO, 5G SA, or 5G NSA is supported. In addition, the capability information may further include information regarding whether at least one of a frequency (frequency band), RAT, bandwidth, number of antennas, modulation order, or a network function defined in 3GPP is supported. Of course, the capability information is not limited to the above examples.

[0132] At step 1530, the host device can identify (or evaluate) whether the capabilities of the remote device (e.g., network capabilities supported by the remote device) match the cell information. For example, based on the capability information received at step 1520, if the remote device is a redcap device, the host device can identify at least one neighboring cell that supports redcap. At this time, information about the at least one neighboring cell can be received from the network (or base station), and information about the at least one neighboring cell can be included in system information (e.g., SIB) or a terminal-specific message. Accordingly, the host device can obtain information about the at least one neighboring cell by decoding the system information or the terminal-specific message. Information about the at least one neighboring cell can include at least one of a network capability supported by each neighboring cell, a supported frequency band, a signal strength, or a cell ID.

[0133] At step 1540, if there are neighboring cells that support the remote device's functionality, the host device may transmit information about at least one neighboring cell that supports the remote device's functionality to the remote device. For example, the host device may transmit information about at least one neighboring cell that supports redcap directly to the remote device without storing it in a whitelist. Therefore, the host device may not need to create and manage a separate whitelist.

[0134] The operations of the host device described above are merely examples, and some of the operations described above may be omitted, or more may be combined. Furthermore, at least one new operation, in addition to the operations described above, may be added and combined with existing operations. Furthermore, the operations of the host device described above may further include, or omit, at least some of the operations described in FIGS. 5 to 12.

[0135] FIG. 16 illustrates an improved network discovery method according to various embodiments of the present disclosure.

[0136] Referring to FIG. 16, an embodiment of a process in which a remote device receives information about a neighboring cell evaluated based on capability information of the remote device from the host device and searches for and connects to a wireless network based on the information about the neighboring cell can be described according to the operation of the host device of FIG. 15 described above.

[0137] In one embodiment, as a first step, if the host device is connected to a remote device, which is a redcap device, through short-range communication, the host device connected to cell C2 can identify whether the remote device is connected to a wireless network. For example, the remote device can identify whether it is connected to a base station (e.g., an eNB or gNB) through a wireless network in addition to short-range communication with the host device. The host device can receive information about at least one neighboring cell of the host device's serving cell from the network (or the base station). If the remote device is not connected to the base station through a wireless network and the signal quality of the Bluetooth connection is above a certain threshold, the host device can receive capability information about the remote device from the remote device. Of course, the case where the quality of the received signal is above a certain threshold is given as an example to determine the signal quality of the Bluetooth connection, but it is only one example and may include a case where the strength of the received signal is greater than a certain threshold. The capability information may include information about whether at least one network function among SUL, redcap, MIMO, 5G SA, or 5G NSA is supported. In addition, the capability information may further include information regarding frequency (frequency band), RAT, bandwidth, number of antennas, modulation order, or support for at least one of the network functions defined in 3GPP. Of course, the capability information is not limited to the above examples.

[0138] In the second step, the host device can discover a new neighboring cell C4 that supports RedCap. The host device can then transmit information about cell C4 to the remote device.

[0139] In the third step, the host device can discover a new neighboring cell C1 that supports RedCap. The host device can then transmit information about cell C1 to the remote device.

[0140] In the fourth step, if the signal quality of the Bluetooth connection between the host device and the remote device is poor or the Bluetooth connection is disconnected, the remote device can search for a wireless network based on the information about neighboring cells C1 and C4 that support the redcap function received from the host device. For example, the information received from the host device may include at least one of the cell ID, frequency information, network function, or signal strength of cells C1 and C4 that support the redcap function. At this time, the remote device, which is a redcap device, can receive an SSB including a synchronization signal and a PBCH broadcast from cells C1 and C4 that support the redcap function in the white list. In addition, the remote device can obtain information about the time / frequency synchronization of cells C1 and C4 that support the redcap function from the synchronization signal. However, since there are more cells that support the redcap function, the remote device may receive only the synchronization signal of a cell (for example, a nearby cell C1) having a stronger reception signal strength based on the information about the reception signal strength of cells C1 and C4 that support the redcap function. Therefore, the remote device may not need to search for all synchronization signals broadcast by candidate serving cells in all frequency bands supported by the remote device. The remote device can perform a connection operation (e.g., camp-on) for cell C1. The remote device can decode the PBCH of the SSB received from cell C1 to obtain information contained in the MIB. Based on the information contained in the MIB, the remote device can identify whether cell C1 is a forbidden cell. In addition, the terminal can receive the PDCCH based on the information contained in the MIB, decode the PDCCH, and receive a SIB (e.g., SIB 1) through the PDSCH. The remote device can identify the PLMN of cell C1 based on the information contained in the SIB.If the PLMN ID of Cell C1 matches the PLMN ID to which the remote device is subscribed, the remote device can select Cell C1 as its serving cell. The remote device can then quickly camp on Cell C1.

[0141] The operations of the host device and remote device described above are merely examples, and some of the operations described above may be omitted or combined with more than one. Furthermore, at least one new operation, in addition to the operations described above, may be added and combined with existing operations. Furthermore, the operations of the host device and remote device described above may further include or omit at least some of the operations described in FIGS. 5 to 12.

[0142] FIG. 17 illustrates the operation of a host device according to various embodiments of the present disclosure.

[0143] Referring to FIG. 17, one embodiment of a host device for an improved network discovery method is described.

[0144] At step 1710, the host device can identify whether it is connected to the remote device via short-range communication. For example, the host device can identify whether it can communicate with the remote device via a Bluetooth connection located within the vicinity of the host device. If the host device is connected to the remote device via short-range communication, the host device can identify whether the remote device is connected to a wireless network. For example, the host device can identify whether the remote device is connected to a base station (e.g., an eNB or gNB) via a wireless network in addition to short-range communication with the host device. The host device can transmit information about neighboring cells to the remote device only when the remote device is not connected to a wireless network (e.g., in flight mode). If the remote device is connected to a base station via a wireless network, the host device may not transmit information about neighboring cells to the remote device.

[0145] At step 1720, if the remote device is not connected to the base station via a wireless network, the host device may receive capability information about the remote device from the remote device. At this time, the capability information may include information regarding whether at least one network function among SUL, RedCap, MIMO, 5G SA, or 5G NSA is supported. In addition, the capability information may further include information regarding whether at least one of a frequency (frequency band), RAT, bandwidth, number of antennas, modulation order, or a network function defined in 3GPP is supported. Of course, the capability information is not limited to the above examples.

[0146] At step 1730, if a user of the host device disconnects the Bluetooth connection between the host device and the remote device (e.g., turns off the Bluetooth power), the host device may search for at least one neighboring cell of the serving cell of the host device from the network (or the base station). For example, the host device may search for at least one neighboring cell in a frequency band supported by the remote device before the Bluetooth connection with the remote device is disconnected. Therefore, the host device may not need to receive information about at least one neighboring cell in advance from the network (or the base station). At this time, the information about the at least one neighboring cell may be included in system information (e.g., SIB) or a terminal-specific message. Therefore, the host device may obtain information about the at least one neighboring cell by decoding the system information or the terminal-specific message. The information about the at least one neighboring cell may include at least one of a network function supported by each neighboring cell, a supported frequency band, a signal strength, or a cell ID.

[0147] At step 1740, before the Bluetooth connection with the remote device is terminated, the host device may transmit information about at least one neighboring cell to the remote device. The information about the at least one neighboring cell may include information about a cell that supports RedCap.

[0148] The operations of the host device described above are merely examples, and some of the operations described above may be omitted, or more may be combined. Furthermore, at least one new operation, in addition to the operations described above, may be added and combined with existing operations. Furthermore, the operations of the host device described above may further include, or omit, at least some of the operations described in FIGS. 5 to 12.

[0149] FIG. 18 illustrates an improved network discovery method according to various embodiments of the present disclosure.

[0150] Referring to FIG. 18, an embodiment of a process in which a remote device receives information about a neighboring cell from a host device and searches for and connects to a wireless network based on the information about the neighboring cell can be described according to the operation of the host device of FIG. 17 described above.

[0151] In one embodiment, as a first step, if the host device is connected to a remote device, which is a redcap device, through short-range communication, the host device connected to cell C2 can identify whether the remote device is connected to a wireless network. For example, the remote device can identify whether it is connected to a base station (e.g., an eNB or a gNB) through a wireless network in addition to short-range communication with the host device. If the remote device is not connected to a base station through a wireless network, and the signal quality of the Bluetooth connection is above a certain threshold, the host device can receive capability information of the remote device from the remote device. Of course, the case where the quality of the received signal is above a certain threshold is given as an example to determine the signal quality of the Bluetooth connection, but it is only one example and may include a case where the strength of the received signal is greater than a certain threshold. In addition, the capability information may include information regarding whether at least one network function among SUL, redcap, MIMO, 5G SA, or 5G NSA is supported. In addition, the capability information may further include information regarding frequency (frequency band), RAT, bandwidth, number of antennas, modulation order, or support for at least one of the network functions defined in 3GPP. Of course, the capability information is not limited to the above examples.

[0152] In the second step, when a user of the host device disconnects the Bluetooth connection between the host device and the remote device (e.g., turns off the Bluetooth power), the host device can search for at least one neighboring cell of the serving cell of the host device from the network (or the base station). Therefore, the host device may not receive and store information about neighboring cells from the network in advance. The host device may receive information about at least one neighboring cell of the serving cell of the host device from the network (or the base station). At this time, the host device may evaluate at least one neighboring cell based on the capability information received from the remote device. In addition, the host device may transmit information about neighboring cells C1 and C4 that support RedCap to the remote device.

[0153] As a third step, the host device can send information about new neighboring cells C1 and C4 that support RedCap to the remote device, and then disconnect the Bluetooth connection with the remote device.

[0154] In the fourth step, if the signal quality of the Bluetooth connection between the host device and the remote device is poor or the Bluetooth connection is disconnected, the remote device can search for a wireless network based on the information about neighboring cells C1 and C4 that support the redcap function received from the host device. For example, the white list received from the host device may include at least one of the cell ID, frequency information, network function, or signal strength of cells C1 and C4 that support the redcap function. At this time, the remote device, which is a redcap device, can receive an SSB including a synchronization signal and a PBCH broadcast from cells C1 and C4 that support the redcap function in the white list. In addition, the remote device can obtain information about the time / frequency synchronization of cells C1 and C4 that support the redcap function from the synchronization signal. However, since there are more cells that support the redcap function, the remote device may receive only the synchronization signal of a cell (for example, a nearby cell C1) having a stronger reception signal strength based on the information about the reception signal strength of cells C1 and C4 that support the redcap function. Therefore, the remote device may not need to search for all synchronization signals broadcast by candidate serving cells in all frequency bands supported by the remote device. The remote device can perform a connection operation (e.g., camp-on) for cell C1. The remote device can decode the PBCH of the SSB received from cell C1 to obtain information contained in the MIB. Based on the information contained in the MIB, the remote device can identify whether cell C1 is a forbidden cell. In addition, the terminal can receive the PDCCH based on the information contained in the MIB, decode the PDCCH, and receive a SIB (e.g., SIB 1) through the PDSCH. The remote device can identify the PLMN of cell C1 based on the information contained in the SIB.If the PLMN ID of Cell C1 matches the PLMN ID to which the remote device is subscribed, the remote device can select Cell C1 as its serving cell. The remote device can then quickly camp on Cell C1.

[0155] The operations of the host device and remote device described above are merely examples, and some of the operations described above may be omitted or combined with more than one. Furthermore, at least one new operation, in addition to the operations described above, may be added and combined with existing operations. Furthermore, the operations of the host device and remote device described above may further include or omit at least some of the operations described in FIGS. 5 to 12.

[0156] FIG. 19 illustrates the operation of a host device according to various embodiments of the present disclosure.

[0157] Referring to FIG. 19, one embodiment of a host device for an improved network discovery method is described.

[0158] At step 1910, the host device can identify whether it is connected to the remote device via short-range communication. For example, the host device can identify whether it can communicate with the remote device via a Bluetooth connection located within the vicinity of the host device. If the host device is connected to the remote device via short-range communication, the host device can identify whether the remote device is connected to a wireless network. For example, the host device can identify whether the remote device is connected to a base station (e.g., an eNB or gNB) via a wireless network in addition to short-range communication with the host device. The host device can transmit information about neighboring cells to the remote device only when the remote device is not connected to a wireless network (e.g., in flight mode). If the remote device is connected to a base station via a wireless network, the host device may not transmit information about neighboring cells to the remote device.

[0159] At step 1920, if the remote device is not connected to the base station via a wireless network, the host device may receive capability information about the remote device from the remote device. At this time, the capability information may include information regarding whether at least one network function among SUL, RedCap, MIMO, 5G SA, or 5G NSA is supported. In addition, the capability information may further include information regarding whether at least one of a frequency (frequency band), RAT, bandwidth, number of antennas, modulation order, or a network function defined in 3GPP is supported. Of course, the capability information is not limited to the above examples.

[0160] In step 1930, the host device may receive information about at least one neighboring cell from the network (or base station). The host device may store the received information about at least one neighboring cell in a candidate list. At this time, the information about at least one neighboring cell may be included in system information (e.g., SIB) or a terminal-specific message. Accordingly, the host device may obtain information about at least one neighboring cell by decoding the system information or the terminal-specific message. The information about at least one neighboring cell may include at least one of a network function supported by each neighboring cell, a supported frequency band, a signal strength, or a cell ID. In addition, the host device may identify (or evaluate) whether a function of a remote device (e.g., a network function supported by the remote device) matches the cell information. For example, the host device may identify at least one neighboring cell that supports redcap based on the capability information received in step 1920 if the remote device is a redcap device. If there is a neighboring cell that supports the function of the remote device, the host device may store information about at least one neighboring cell that supports the function of the remote device in a white list. For example, the host device may store information about at least one neighboring cell that supports redcap in a whitelist. That is, the host device may add information about at least one newly identified neighboring cell to the stored whitelist. However, if the host device does not have a stored whitelist, the host device may create a new whitelist that includes information about at least one neighboring cell that supports redcap.

[0161] At step 1940, the host device can receive changed capability information from the remote device. If the host device receives changed capability information from the remote device, the host device can reevaluate at least one cell included in the candidate list based on the changed capability information. For example, if the user's subscription information or settings are changed, the capability information of the remote device may also be changed. Accordingly, if the changed capability information includes information about a remote device that supports both redcap and MIMO, the host device can identify whether at least one cell included in the candidate list supports both redcap and MIMO. If there is a cell in the candidate list that supports both redcap and MIMO, the host device can update the existing white list with a white list that includes information about cells that support both redcap and MIMO. For example, the host device can delete information about neighboring cells that only support redcap and maintain or add information about neighboring cells that support redcap and MIMO. The host device can then transmit the new white list to the remote device. Therefore, even if the capability information of the remote device changes, the host device can update the white list to reflect the changed capability information based on the stored candidate list.

[0162] The operations of the host device described above are merely examples, and some of the operations described above may be omitted, or more may be combined. Furthermore, at least one new operation, in addition to the operations described above, may be added and combined with existing operations. Furthermore, the operations of the host device described above may further include, or omit, at least some of the operations described in FIGS. 5 to 12.

[0163] FIG. 20 illustrates an improved network discovery method according to various embodiments of the present disclosure.

[0164] Referring to FIG. 20, an embodiment of a process in which a remote device receives a white list from a host device based on changed capability information of the remote device, and searches for and connects to a wireless network based on information included in the white list, according to the operation of the host device of FIG. 19 described above, can be described.

[0165] In one embodiment, as a first step, if the host device is connected to a remote device, which is a redcap device, through short-range communication, the host device connected to cell C2 can identify whether the remote device is connected to a wireless network. For example, the remote device can identify whether it is connected to a base station (e.g., an eNB or gNB) through a wireless network in addition to short-range communication with the host device. The host device can then receive information about at least one neighboring cell of the serving cell of the host device from the network (or the base station). The host device can store a candidate list including information about the serving cell, cell C2, and the neighboring cell C1 received from the network. If the remote device is not connected to the base station through a wireless network and the signal quality of the Bluetooth connection is above a predetermined threshold, the host device can receive capability information about the remote device from the remote device. Of course, the case where the quality of the received signal is above a predetermined threshold is given as an example to determine the signal quality of the Bluetooth connection, but this is only one example and may include a case where the strength of the received signal is greater than a predetermined threshold. And the capability information may include information on whether at least one network function among SUL, RedCap, MIMO, 5G SA, or 5G NSA is supported. In addition, the capability information may further include information on whether at least one of frequency (frequency band), RAT, bandwidth, number of antennas, modulation order, or network function defined in 3GPP is supported. Of course, the capability information is not limited to the above example. Based on the capability information received from the remote device, the host device may add information on cell C1 supporting RedCap to the white list. At this time, if there is no previously stored white list, the host device may create a white list including information on cell C1.

[0166] In the second step, the host device can search for cell C3, which supports MIMO, a redcap, and a new neighboring cell C4, which also supports MIMO. The host device can then add information about cell C3, which supports MIMO, a redcap, and a new neighboring cell C4, which also supports MIMO, to a candidate list. Furthermore, the host device can add information about cell C4, which supports redcap, to a whitelist based on capability information. Accordingly, the whitelist stored in the host device can include information about cell C1, which supports redcap, and cell C4, which supports redcap and MIMO. The host device can then transmit the whitelist, which includes information about cells C1 and C4, to a remote device.

[0167] In the third step, the host device can receive changed capability information from the remote device. When the host device receives changed capability information from the remote device, the host device can re-evaluate cells C1 to C4 included in the candidate list based on the changed capability information. Accordingly, when the changed capability information includes information about a remote device that supports both RedCap and MIMO, the host device can identify whether any of cells C1 to C4 included in the candidate list supports both RedCap and MIMO. In addition, the host device can update the existing white list to include information about cell C4 that supports both RedCap and MIMO in the candidate list. For example, the host device can delete information about cell C1, which only supports RedCap, from the existing stored white list, and maintain information about cell C4, which supports RedCap and MIMO.

[0168] In the fourth step, if the Bluetooth connection with the remote device is disconnected, the host device can transmit the updated white list to the remote device. If the Bluetooth connection between the host device and the remote device is disconnected, the remote device can search for a wireless network based on information contained in the white list received from the host device. For example, the white list received from the host device may include at least one of the cell ID, frequency information, network function, or signal strength of cell C4, which supports redcap and MIMO. At this time, the remote device, which is a redcap device, can receive an SSB including a synchronization signal and a PBCH broadcast from cell C4. The remote device can obtain information about the time / frequency synchronization of cell C4 from the synchronization signal. At this time, the remote device may already know the cell ID (e.g., PCI) of cell C4 through the white list. The remote device can perform a connection operation (e.g., camp-on) for cell C4. The remote device can decode the PBCH of the SSB received from cell C4 to obtain information contained in the MIB. The remote device can identify whether cell C4 is a prohibited cell based on the information contained in the MIB. The terminal can then receive a PDCCH based on the information contained in the MIB, decode the PDCCH, and receive a SIB (e.g., SIB 1) via the PDSCH. The remote device can identify the PLMN of cell C4 based on the information contained in the SIB. If the PLMN ID of cell C4 matches the PLMN ID to which the remote device subscribes, the remote device can select cell C4 as its serving cell. The remote device can then quickly camp on cell C4.

[0169] The operations of the host device and remote device described above are merely examples, and some of the operations described above may be omitted or combined with more than one. Furthermore, at least one new operation, in addition to the operations described above, may be added and combined with existing operations. Furthermore, the operations of the host device and remote device described above may further include or omit at least some of the operations described in FIGS. 5 to 12.

[0170] FIG. 21 illustrates a reduced network discovery procedure of a remote device according to various embodiments of the present disclosure.

[0171] Referring to FIG. 21, a reduced delay time during network search by a remote device according to embodiments of the present disclosure described above can be described. The remote device can omit searching for unnecessary cells / frequencies. Therefore, the time spent searching for a network by the remote device can be saved. In particular, for a redcap device that is smaller than the host device and has a very limited battery, the battery saving by the improved network search method of the present disclosure can be a great advantage. In addition, when the remote device operates in an energy-saving mode, the provision of other services can be maintained without interruption through the efficient implementation of the energy-saving mode by the improved network search method of the present disclosure. For example, when the remote device is not connected to a wireless network (e.g., when the remote device is operating in flight mode), when the remote device performs a network search, it previously had to sequentially search for a serving cell in all frequency bands supported by the remote device. However, according to the present disclosure, the search and decoding can be performed only for a frequency with an NR ARFCN (Absolute Radio Frequency Channel Number) of 5021110 in frequency band 41. Therefore, the time (e.g., 600 ms) and power required for searching and decoding other frequencies in frequency band 41 can be saved.

[0172] FIG. 22 illustrates the operation of a host device according to various embodiments of the present disclosure.

[0173] Referring to FIG. 22, in a network search method of a second terminal (e.g., a remote device), the flow of operations of a first terminal (e.g., a host device) can be described.

[0174] At step 2210, the first terminal can identify the connection status of the second terminal. For example, the first terminal can identify whether the second terminal, which is located in close proximity to the first terminal, can communicate via Bluetooth. If the first terminal is connected to the second terminal via close-range communication, the first terminal can identify whether the second terminal is connected to a wireless network. For example, the second terminal can identify whether it is connected to a base station (e.g., an eNB or gNB) via a wireless network in addition to close-range communication with the first terminal. The first terminal can generate and transmit a white list only when the second terminal is not connected to a wireless network (e.g., in flight mode). If the second terminal is connected to the base station via a wireless network, the first terminal may not generate a white list or may not transmit the generated white list to the second terminal.

[0175] At step 2220, if the second terminal is connected to the first terminal via short-range communication and is not connected to the serving cell of the first terminal via a wireless network, the first terminal may receive capability information from the second terminal. At this time, the capability information may include information regarding whether at least one network function among SUL, RedCap, MIMO, 5G SA, or 5G NSA is supported. In addition, the capability information may further include information regarding whether at least one of frequency (frequency band), RAT, bandwidth, number of antennas, modulation order, or network functions defined in 3GPP is supported. Of course, the capability information is not limited to the above examples.

[0176] In step 2230, the first terminal may transmit to the second terminal a list of at least one candidate cell (or neighboring cell) identified based on capability information. For example, the first terminal may identify at least one candidate cell supporting RedCap if the second terminal is a RedCap device based on the capability information received in step 2220. At this time, information about the at least one candidate cell may be received from a network (or a base station), and information about the at least one candidate cell may be included in system information (e.g., SIB) or a terminal-specific message. Accordingly, the first terminal may obtain information about the at least one candidate cell by decoding the system information or the terminal-specific message. Information about the at least one candidate cell may include at least one of a network function supported by each candidate cell, a supported frequency band, a signal strength, or a cell ID. Accordingly, if there is a candidate cell supporting the function of the second terminal, the first terminal may transmit to the second terminal a list of at least one candidate cell supporting the function of the second terminal.

[0177] The operations of the first terminal described above can be explained based on the operations of the first terminal according to the previously described embodiments. Furthermore, at least one of the operations of the first terminal described above may be omitted, or more operations may be combined. Furthermore, at least one of the operations of the first terminal described above may be added and combined with other operations.

[0178] According to various embodiments of the present disclosure, a method of operating a first terminal in a wireless communication system includes an operation of identifying a connection state of a second terminal, an operation of receiving capability information from the second terminal when the second terminal is connected to the first terminal via short-range communication and is not connected to a serving cell of the first terminal via a wireless network, and an operation of transmitting a list of at least one candidate cell identified based on the capability information to the second terminal, wherein the first terminal is a host device, the second terminal is a remote device capable of connecting to the at least one candidate cell via a wireless network, and the list may include information on the at least one candidate cell for wireless network connection of the second terminal when the short-range communication connection is released.

[0179] According to one embodiment, the capability information includes information about a network function supported by the second terminal, and the network function includes at least one of supplementary uplink (SUL), reduced capability (RedCap), multiple-input and multiple-output (MIMO), 5th generation (5G) standalone (SA), or 5G non-standalone (NSA), and the at least one candidate cell may be a cell supporting the network function.

[0180] According to one embodiment, the operation of transmitting the list of at least one candidate cell to the second terminal includes, when the quality of the short-range communication is below a certain threshold value, transmitting the list of at least one candidate cell to the second terminal, wherein the list of at least one candidate cell includes at least one of a cell identifier, frequency information, signal strength, modulation and coding scheme (MCS) level, bandwidth, number of antennas, or information about a function supported by a cell, and the information about the function supported by the cell may include information about whether the at least one candidate cell supports the network function.

[0181] In one embodiment, the at least one candidate cell is included in at least one neighboring cell excluding the serving cell of the first terminal, and the at least one neighboring cell can be discovered by the first terminal when the short-range communication connection is released.

[0182] In one embodiment, the operation of transmitting the list of at least one candidate cell to the second terminal may include the operation of identifying at least one first candidate cell based on the capability information, the operation of receiving changed capability information from the second terminal, and the operation of transmitting a list of at least one first candidate cell and at least one second candidate cell identified based on the changed capability information to the second terminal.

[0183] According to various embodiments of the present disclosure, in a method of operating a second terminal in a wireless communication system, when the second terminal is connected to a first terminal through short-range communication and is not connected to a serving cell of the first terminal through a wireless network, the method includes: transmitting capability information to the first terminal; receiving, from the first terminal, a list of at least one candidate cell identified based on the capability information; and searching for a serving cell of the second terminal based on the list of at least one candidate cell, wherein the first terminal is a host device, the second terminal is a remote device capable of connecting to the at least one candidate cell through a wireless network, and the list may include information on the at least one candidate cell for wireless network connection of the second terminal when the short-range communication connection is released.

[0184] According to one embodiment, the capability information includes information about a network function supported by the second terminal, and the network function includes at least one of supplementary uplink (SUL), reduced capability (RedCap), multiple-input and multiple-output (MIMO), 5th generation (5G) standalone (SA), or 5G non-standalone (NSA), and the at least one candidate cell may be a cell supporting the network function.

[0185] According to one embodiment, the operation of receiving the list of at least one candidate cell from the first terminal includes, when the quality of the short-range communication is below a certain threshold value, receiving the list of at least one candidate cell from the first terminal, wherein the list of at least one candidate cell includes at least one of a cell identifier, frequency information, signal strength, modulation and coding scheme (MCS) level, bandwidth, number of antennas, or information about a function supported by a cell, and the information about the function supported by the cell may include information about whether the at least one candidate cell supports the network function.

[0186] In one embodiment, the at least one candidate cell is included in at least one neighboring cell excluding the serving cell of the first terminal, and the at least one neighboring cell can be discovered by the first terminal when the short-range communication connection is released.

[0187] In one embodiment, the operation of receiving the list of at least one candidate cell from the first terminal includes the operation of transmitting changed capability information to the first terminal, and the operation of receiving, from the first terminal, a list of at least one first candidate cell and at least one second candidate cell identified based on the changed capability information, wherein the at least one first candidate cell can be identified based on the capability information.

[0188] According to various embodiments of the present disclosure, in a wireless communication system, a first terminal includes a transceiver, and at least one processor coupled to the transceiver, wherein the at least one processor identifies a connection state of a second terminal, receives capability information from the second terminal when the second terminal is connected to the first terminal via short-range communication and is not connected to a serving cell of the first terminal via a wireless network, and transmits a list of at least one candidate cell identified based on the capability information to the second terminal, wherein the first terminal is a host device, and the second terminal is a remote device capable of connecting to the at least one candidate cell via a wireless network, and the list may include information on the at least one candidate cell for wireless network connection of the second terminal when the short-range communication connection is released.

[0189] According to one embodiment, the capability information includes information about a network function supported by the second terminal, and the network function includes at least one of supplementary uplink (SUL), reduced capability (RedCap), multiple-input and multiple-output (MIMO), 5th generation (5G) standalone (SA), or 5G non-standalone (NSA), and the at least one candidate cell may be a cell supporting the network function.

[0190] According to one embodiment, the at least one processor transmits a list of the at least one candidate cell to the second terminal when the quality of the short-range communication is below a certain threshold value, wherein the list of the at least one candidate cell includes at least one of a cell identifier, frequency information, signal strength, modulation and coding scheme (MCS) level, bandwidth, number of antennas, or information about a function supported by a cell, and the information about the function supported by the cell may include information about whether the at least one candidate cell supports the network function.

[0191] In one embodiment, the at least one candidate cell is included in at least one neighboring cell excluding the serving cell of the first terminal, and the at least one neighboring cell can be discovered by the first terminal when the short-range communication connection is released.

[0192] According to one embodiment, the at least one processor may identify at least one first candidate cell based on the capability information, receive changed capability information from the second terminal, and transmit a list of the at least one first candidate cell and at least one second candidate cell identified based on the changed capability information to the second terminal.

[0193] According to various embodiments of the present disclosure, in a wireless communication system, a second terminal includes a transceiver, and at least one processor coupled to the transceiver, wherein the at least one processor transmits capability information to the first terminal when the second terminal is connected to the first terminal through short-range communication and is not connected to a serving cell of the first terminal through a wireless network, receives a list of at least one candidate cell identified based on the capability information from the first terminal, and searches for a serving cell of the second terminal based on the list of at least one candidate cell, wherein the first terminal is a host device, and the second terminal is a remote device capable of connecting to the at least one candidate cell through a wireless network, and the list may include information on the at least one candidate cell for wireless network connection of the second terminal when the short-range communication connection is released.

[0194] According to one embodiment, the capability information includes information about a network function supported by the second terminal, and the network function includes at least one of supplementary uplink (SUL), reduced capability (RedCap), multiple-input and multiple-output (MIMO), 5th generation (5G) standalone (SA), or 5G non-standalone (NSA), and the at least one candidate cell may be a cell supporting the network function.

[0195] According to one embodiment, the at least one processor receives a list of the at least one candidate cell from the first terminal when the quality of the short-range communication is below a certain threshold value, and the list of the at least one candidate cell includes at least one of a cell identifier, frequency information, signal strength, modulation and coding scheme (MCS) level, bandwidth, number of antennas, or information about a function supported by a cell, and the information about the function supported by the cell may include information about whether the at least one candidate cell supports the network function.

[0196] In one embodiment, the at least one candidate cell is included in at least one neighboring cell excluding the serving cell of the first terminal, and the at least one neighboring cell can be discovered by the first terminal when the short-range communication connection is released.

[0197] According to one embodiment, the at least one processor transmits changed capability information to the first terminal, and receives from the first terminal a list of the at least one first candidate cell and at least one second candidate cell identified based on the changed capability information, wherein the at least one first candidate cell can be identified based on the capability information.

[0198] It should be noted that the aforementioned configuration diagrams, examples of control / data signal transmission methods, examples of operational procedures, and configuration diagrams are not intended to limit the scope of the present disclosure. That is, not all components, entities, or operational steps described in the embodiments of the present disclosure should be construed as essential components for implementing the disclosure, and implementations may be made without detracting from the essence of the disclosure even if only some components are included. Furthermore, each embodiment may be combined and operated as needed. For example, parts of the methods proposed in the present disclosure may be combined to operate network entities and terminals.

[0199] The operations of the base station or terminal described above can be realized by providing a memory device storing the corresponding program code in any component within the base station or terminal device. That is, the control unit of the base station or terminal device can execute the operations described above by reading and executing the program code stored in the memory device using a processor or CPU (Central Processing Unit).

[0200] The various components and modules of the entity, base station or terminal device described in this specification may be operated using hardware circuits, such as logic circuits based on complementary metal oxide semiconductors, firmware, software and / or hardware and firmware and / or software embedded in a machine-readable medium. For example, various electrical structures and methods may be implemented using electrical circuits such as transistors, logic gates and application-specific semiconductors.

[0201] When implemented in software, a computer-readable storage medium storing one or more programs (software modules) may be provided. The one or more programs stored in the computer-readable storage medium are configured for execution by one or more processors within an electronic device. The one or more programs include instructions that cause the electronic device to execute methods according to embodiments described in the claims or specification of the present disclosure.

[0202] These programs (software modules, software) may be stored in a non-volatile memory including random access memory, flash memory, read only memory (ROM), electrically erasable programmable read only memory (EEPROM), magnetic disc storage devices, compact disc ROMs (CD-ROMs), digital versatile discs (DVDs) or other forms of optical storage devices, magnetic cassettes, or may be stored in a memory configured as a combination of some or all of these. In addition, each configuration memory may include multiple copies.

[0203] Additionally, the program may be stored in an attachable storage device that is accessible via a communication network such as the Internet, an intranet, a local area network (LAN), a wide local area network (WLAN), a storage area network (SAN), or a combination thereof. Such a storage device may be connected to a device performing an embodiment of the present disclosure via an external port. Additionally, a separate storage device on the communication network may be connected to a device performing an embodiment of the present disclosure.

[0204] In the specific embodiments of the present disclosure described above, components included in the disclosure are expressed singularly or plurally, depending on the specific embodiment presented. However, the singular or plural expressions are selected to suit the presented situation for convenience of explanation, and the present disclosure is not limited to singular or plural components. Components expressed in plural may be composed of singular elements, or components expressed in singular may be composed of plural elements.

[0205] While the detailed description of the present disclosure has described specific embodiments, it should be understood that various modifications are possible without departing from the scope of the present disclosure. Therefore, the scope of the present disclosure should not be limited to the described embodiments, but should be determined not only by the scope of the claims described below but also by equivalents thereof. In other words, it will be apparent to those skilled in the art that other modifications based on the technical idea of ​​the present disclosure are possible. In addition, the above-described embodiments can be combined and operated with each other as needed. For example, parts of the methods proposed in the present disclosure can be combined with each other to operate a base station and a terminal. In addition, although the above-described embodiments have been presented based on a 5G, NR system, other modifications based on the technical idea of ​​the above-described embodiments can be implemented with other systems such as LTE, LTE-A, and LTE-A-Pro systems.

[0206] While the detailed description of this disclosure has described specific embodiments, it should be understood that various modifications are possible without departing from the scope of this disclosure. Therefore, the scope of this disclosure should not be limited to the described embodiments, but should be defined not only by the scope of the claims described below, but also by equivalents thereof.

Claims

1. A method performed by a first terminal in a wireless communication system, An action to identify the connection status of a second terminal; An operation of receiving capability information from the second terminal when the second terminal is connected to the first terminal through short-range communication and is not connected to the serving cell of the first terminal through a wireless network; and An operation of transmitting a list of at least one candidate cell identified based on the above capability information to the second terminal, The first terminal is a host device, and the second terminal is a remote device capable of connecting to at least one candidate cell via a wireless network. A method wherein the above list includes information about at least one candidate cell for wireless network connection of the second terminal when the short-range communication connection is released.

2. In claim 1, The above capability information includes information about a network function supported by the second terminal, and the network function includes at least one of SUL (supplementary uplink), RedCap (reduced capability, RedCap), MIMO (multiple-input and multiple-output), 5G (5th generation) SA (standalone), or 5G NSA (non-standalone). A method wherein at least one of said candidate cells is a cell supporting said network function.

3. In claim 2, the operation of transmitting the list of at least one candidate cell to the second terminal comprises: If the quality of the short-range communication is below a certain threshold value, the operation of transmitting a list of at least one candidate cell to the second terminal is included. The list of at least one candidate cell includes at least one of a cell identifier, frequency information, signal strength, MCS (modulation and coding scheme) level, bandwidth, number of antennas, or information about a function supported by the cell. A method wherein information about the functions supported by the above cell includes information about whether the at least one candidate cell supports the above network function.

4. In claim 2, The at least one candidate cell is included in at least one neighboring cell excluding the serving cell of the first terminal, A method wherein at least one neighboring cell is searched by the first terminal when the short-range communication connection is released.

5. In a method performed by a second terminal in a wireless communication system, An operation of transmitting capability information to the first terminal when the second terminal is connected to the first terminal through short-range communication and is not connected to the serving cell of the first terminal through a wireless network; An operation of receiving a list of at least one candidate cell identified based on the above capability information from the first terminal; and An operation of searching for a serving cell of the second terminal based on a list of at least one candidate cell, The first terminal is a host device, and the second terminal is a remote device capable of connecting to at least one candidate cell via a wireless network. A method wherein the above list includes information about at least one candidate cell for wireless network connection of the second terminal when the short-range communication connection is released.

6. In claim 5, The above capability information includes information about a network function supported by the second terminal, and the network function includes at least one of SUL (supplementary uplink), RedCap (reduced capability, RedCap), MIMO (multiple-input and multiple-output), 5G (5th generation) SA (standalone), or 5G NSA (non-standalone). A method wherein at least one of said candidate cells is a cell supporting said network function.

7. In claim 6, the operation of receiving a list of at least one candidate cell from the first terminal comprises: If the quality of the short-range communication is below a certain threshold value, the operation of receiving a list of at least one candidate cell from the first terminal is included. The list of at least one candidate cell includes at least one of a cell identifier, frequency information, signal strength, MCS (modulation and coding scheme) level, bandwidth, number of antennas, or information about a function supported by the cell. A method wherein information about the functions supported by the above cell includes information about whether the at least one candidate cell supports the above network function.

8. In claim 6, The at least one candidate cell is included in at least one neighboring cell excluding the serving cell of the first terminal, A method wherein at least one neighboring cell is searched by the first terminal when the short-range communication connection is released.

9. In a wireless communication system, the first terminal, Transceiver; and comprising at least one processor coupled to the transceiver; At least one processor of the above, Identify the connection status of the second terminal, When the second terminal is connected to the first terminal through short-range communication and is not connected to the serving cell of the first terminal through a wireless network, capability information is received from the second terminal, and It is set to transmit a list of at least one candidate cell identified based on the above capability information to the second terminal, The first terminal is a host device, and the second terminal is a remote device capable of connecting to at least one candidate cell via a wireless network. A first terminal, wherein the above list includes information about at least one candidate cell for wireless network connection of the second terminal when the short-range communication connection is released.

10. In claim 9, The above capability information includes information about a network function supported by the second terminal, and the network function includes at least one of SUL (supplementary uplink), RedCap (reduced capability, RedCap), MIMO (multiple-input and multiple-output), 5G (5th generation) SA (standalone), or 5G NSA (non-standalone). A first terminal, wherein at least one of the above candidate cells is a cell supporting the above network function.

11. In claim 10, at least one processor, If the quality of the short-range communication is below a certain threshold value, the list of at least one candidate cell is set to be transmitted to the second terminal, The list of at least one candidate cell includes at least one of a cell identifier, frequency information, signal strength, MCS (modulation and coding scheme) level, bandwidth, number of antennas, or information about a function supported by the cell. A first terminal, wherein information about the functions supported by the above cell includes information about whether the at least one candidate cell supports the above network function.

12. In claim 10, The at least one candidate cell is included in at least one neighboring cell excluding the serving cell of the first terminal, A first terminal, wherein at least one neighboring cell is searched by the first terminal when the short-range communication connection is released.

13. In a wireless communication system, the second terminal, Transceiver; and comprising at least one processor coupled to the transceiver; At least one processor of the above, When the second terminal is connected to the first terminal through short-range communication and is not connected to the serving cell of the first terminal through a wireless network, capability information is transmitted to the first terminal, Receiving a list of at least one candidate cell identified based on the above capability information from the first terminal, and It is set to search for a serving cell of the second terminal based on the list of at least one candidate cell, The first terminal is a host device, and the second terminal is a remote device capable of connecting to at least one candidate cell via a wireless network. A second terminal, wherein the above list includes information about at least one candidate cell for wireless network connection of the second terminal when the short-range communication connection is released.

14. In claim 13, The above capability information includes information about a network function supported by the second terminal, and the network function includes at least one of SUL (supplementary uplink), RedCap (reduced capability, RedCap), MIMO (multiple-input and multiple-output), 5G (5th generation) SA (standalone), or 5G NSA (non-standalone). A second terminal, wherein at least one of the candidate cells is a cell supporting the network function.

15. In claim 14, the at least one processor, If the quality of the short-range communication is below a certain threshold value, the list of at least one candidate cell is set to be received from the first terminal, The list of at least one candidate cell includes at least one of a cell identifier, frequency information, signal strength, MCS (modulation and coding scheme) level, bandwidth, number of antennas, or information about a function supported by the cell. A second terminal, wherein the information about the functions supported by the above cell includes information about whether the at least one candidate cell supports the above network function.

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