Apparatus and method for operating synchronization signal and physical broadcast channel block, and system information in on-demand manner in wireless communication system
Patent Information
- Application Number
- PCT/KR2024/011666
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2023-08-09
- Filing Date
- 2024-08-07
- Publication Date
- 2025-02-13
Smart Images

Figure KR2024011666_13022025_PF_FP_ABST
Abstract
Description
Device and method for operating synchronous signals and physical broadcast channel blocks and system information on-demand in a wireless communication system
[0001] The following description relates to a wireless communication system, and to a device and method for operating SSB (synchronization signal / physical broadcast channel block) and system information in an on-demand manner in a wireless communication system.
[0002] The 5G mobile communications system, the successor to LTE (long-term evolution), is a new, clean-slate mobile communications system characterized by high performance, low latency, and high availability. 5G NR can utilize all available spectrum resources, from low-frequency bands below 1 GHz, to mid-frequency bands between 1 GHz and 10 GHz, and to high-frequency bands (e.g., millimeter wave) above 24 GHz. 6G systems are being developed based on the underlying technologies of 5G mobile communications.
[0003] The 6G system aims to provide (i) very high data rates per device, (ii) a very large number of connected devices, (iii) global connectivity, (iv) very low latency, (v) low energy consumption for battery-free Internet of Things (IoT) devices, (vi) ultra-reliable connectivity, and (vii) connected intelligence with machine learning capabilities. The vision of the 6G system can be divided into four aspects: intelligent connectivity, deep connectivity, holographic connectivity, and ubiquitous connectivity.
[0004] The present disclosure relates to a device and method for effectively operating SSB (synchronization signal / physical broadcast channel block) and system information in an on-demand manner in a wireless communication system.
[0005] The present disclosure relates to a device and method for effectively supporting a network energy saving (NES) operation of a base station in a wireless communication system.
[0006] The present disclosure relates to a device and method for providing configuration information related to a signal for requesting transmission of SSB or system information in a wireless communication system.
[0007] The present disclosure relates to a device and method for providing configuration information related to a signal provided in response to a signal requesting transmission of SSB or system information in a wireless communication system.
[0008] The present disclosure relates to a device and method for selecting a frequency band for transmitting a signal for requesting transmission of SSB or system information in a wireless communication system.
[0009] The present disclosure relates to an apparatus and method for providing information on criteria for selecting a frequency band for transmitting a signal for requesting transmission of SSB or system information in a wireless communication system.
[0010] The present disclosure relates to a device and method for requesting transmission of SSB or system information in an SSB-less cell in a wireless communication system.
[0011] The present disclosure relates to a device and method for indicating a target of a request among SSB or system information in a wireless communication system.
[0012] The present disclosure relates to a device and method for requesting transmission of SSB or system information through step-wise signaling in a wireless communication system.
[0013] The present disclosure relates to a device and method for determining a time interval during which reception of SSB or system information transmitted in response to a request in a wireless communication system is expected.
[0014] The technical objectives to be achieved in the present disclosure are not limited to those mentioned above, and other technical tasks not mentioned can be considered by a person having ordinary skill in the technical field to which the technical configuration of the present disclosure is applied from the embodiments of the present disclosure described below.
[0015] As an example of the present disclosure, a method performed by a terminal in a wireless communication system includes the steps of receiving a first synchronization signal in a first frequency band, receiving second system information in the first frequency band, receiving configuration information related to a second frequency band based on the first synchronization signal and the first system information, transmitting a first signal requesting a second synchronization signal or second system information in the second frequency band, and receiving a second signal including the second synchronization signal or the second system information in the second frequency band, wherein the configuration information may include at least one of information related to a resource for transmitting the first signal or information related to the second signal.
[0016] As an example of the present disclosure, a method performed by a base station in a wireless communication system may include the steps of transmitting a first synchronization signal in a first frequency band, transmitting second system information in the first frequency band, transmitting configuration information related to a second frequency band based on the first synchronization signal and the first system information, receiving a first signal requesting a second synchronization signal or second system information in the second frequency band, and transmitting a second signal including the second synchronization signal or the second system information in the second frequency band. The configuration information may include at least one of information related to a resource for transmitting the first signal or information related to the second signal.
[0017] As an example of the present disclosure, in a wireless communication system, a terminal includes a transceiver and a processor connected to the transceiver, wherein the processor is configured to receive a first synchronization signal in a first frequency band, receive second system information in the first frequency band, receive configuration information related to a second frequency band based on the first synchronization signal and the first system information, transmit a first signal requesting the second synchronization signal or the second system information in the second frequency band, and receive a second signal including the second synchronization signal or the second system information in the second frequency band, wherein the configuration information may include at least one of information related to a resource for transmitting the first signal or information related to the second signal.
[0018] As an example of the present disclosure, in a wireless communication system, a base station includes a transceiver and a processor connected to the transceiver, wherein the processor is configured to transmit a first synchronization signal in a first frequency band, transmit second system information in the first frequency band, transmit configuration information related to the second frequency band based on the first synchronization signal and the first system information, receive a first signal requesting a second synchronization signal or second system information in the second frequency band, and transmit a second signal including the second synchronization signal or the second system information in the second frequency band. The configuration information may include at least one of information related to a resource for transmitting the first signal or information related to the second signal.
[0019] As an example of the present disclosure, a communication device includes at least one processor, and at least one computer memory coupled to the at least one processor and storing instructions that, when executed by the at least one processor, direct operations, the operations include: receiving a first synchronization signal in a first frequency band; receiving second system information in the first frequency band; receiving configuration information related to a second frequency band based on the first synchronization signal and the first system information; transmitting a first signal requesting the second synchronization signal or the second system information in the second frequency band; and receiving a second signal including the second synchronization signal or the second system information in the second frequency band, wherein the configuration information may include at least one of information related to a resource for transmitting the first signal or information related to the second signal.
[0020] As an example of the present disclosure, a non-transitory computer-readable medium storing at least one instruction includes at least one instruction executable by a processor, wherein the at least one instruction instructs a device to receive a first synchronization signal in a first frequency band, receive second system information in the first frequency band, receive configuration information related to a second frequency band based on the first synchronization signal and the first system information, transmit a first signal requesting the second synchronization signal or the second system information in the second frequency band, and receive a second signal including the second synchronization signal or the second system information in the second frequency band, wherein the configuration information may include at least one of information related to a resource for transmitting the first signal or information related to the second signal.
[0021] The above-described aspects of the present disclosure are only some of the preferred embodiments of the present disclosure, and various embodiments reflecting the technical features of the present disclosure can be derived and understood by a person having ordinary skill in the art based on the detailed description of the present disclosure to be described below.
[0022] The following effects may be achieved by embodiments based on the present disclosure.
[0023] According to the present disclosure, SSB (synchronization signal / physical broadcast channel block) and system information can be effectively operated.
[0024] The effects that can be obtained from the embodiments of the present disclosure are not limited to the effects mentioned above, and other effects not mentioned can be clearly derived and understood by those skilled in the art to which the technical configuration of the present disclosure is applied, from the description of the embodiments of the present disclosure below. In other words, unintended effects resulting from implementing the configuration described in the present disclosure can also be derived from the embodiments of the present disclosure by those skilled in the art.
[0025] Figure 1 illustrates an example of a flexible network topology applicable to the present disclosure.
[0026] FIG. 2 illustrates an example of the structure of a wireless communication system applicable to the present disclosure.
[0027] FIG. 3 illustrates an example of a wireless device applicable to the present disclosure.
[0028] FIG. 4 illustrates an example of a communication procedure between a first node and a second node applicable to the present disclosure.
[0029] Figure 5 illustrates an example of a general functional architecture related to both functionality-based life cycle management (LCM) and model-based LCM.
[0030] FIG. 6 illustrates an example of an operation procedure based on an artificial intelligence (AI) / machine learning (ML) model applicable to the present disclosure.
[0031] Figure 7 illustrates an example of an electromagnetic spectrum applicable to the present disclosure.
[0032] FIG. 8 illustrates an example of a procedure for transmitting system information for THz communication applicable to the present disclosure.
[0033] Figure 9 illustrates an example of a beam management procedure applicable to the present disclosure.
[0034] FIG. 10a illustrates an example of a general non-terrestrial network (NTN) scenario based on transparent payload applicable to the present disclosure.
[0035] Figure 10b illustrates an example of a general NTN scenario based on a replay payload applicable to the present disclosure.
[0036] Figure 11a illustrates an example of components of the orbital parameter ephemeris (OPE) format.
[0037] Figure 11b shows examples of offsets in links associated with satellites.
[0038] Figure 11c illustrates examples of TA (timing advanced) values in a link associated with a satellite.
[0039] Figures 12a and 12b illustrate examples of sensing operations applicable to the present disclosure.
[0040] FIG. 13 illustrates an example of time / frequency resources for sensing operations applicable to the present disclosure.
[0041] FIG. 14 illustrates an example of a procedure related to a sensing operation applicable to the present disclosure.
[0042] FIG. 15 illustrates an example of an operation procedure of a base station supporting network energy saving (NES) technology applicable to the present disclosure.
[0043] FIG. 16 illustrates an example of a procedure for a carrier aggregation (CA) operation using a synchronization signal / physical broadcast channel block (SSB)-less SCell (secondary cell) applicable to the present disclosure.
[0044] FIGS. 17A to 17C illustrate examples of on-demand system information transmission methods applicable to the present disclosure.
[0045] FIG. 18 illustrates examples of frequency bands operated by a base station according to one embodiment of the present disclosure.
[0046] FIG. 19 illustrates an example of a procedure for providing a communication service based on multiple frequency bands according to one embodiment of the present disclosure.
[0047] FIG. 20 illustrates an example of a procedure for performing communication based on multiple frequency bands according to one embodiment of the present disclosure.
[0048] FIG. 21 illustrates an example of a procedure for performing an on-demand SSB / SIB1 (system information block 1) procedure according to one embodiment of the present disclosure.
[0049] FIG. 22 illustrates an example of a procedure for receiving an SSB or SIB (system information block) based on an on-demand manner according to one embodiment of the present disclosure.
[0050] FIG. 23 illustrates an example of a procedure for transmitting an SSB or SIB based on an on-demand manner according to one embodiment of the present disclosure.
[0051] FIG. 24 illustrates an example of a procedure for performing an on-demand SSB / SIB1 procedure using multiple frequency bands according to one embodiment of the present disclosure.
[0052] In this disclosure, "A or B" can mean "only A," "only B," or "both A and B." In other words, "A or B" in this disclosure can be interpreted as "A and / or B." For example, "A, B or C" in this disclosure can mean "only A," "only B," "only C," or "any combination of A, B and C."
[0053] As used herein, a slash ( / ) or a comma may mean "and / or." For example, "A / B" may mean "A and / or B." Accordingly, "A / B" may mean "only A," "only B," or "both A and B." For example, "A, B, C" may mean "A, B, or C."
[0054] In the present disclosure, “at least one of A and B” may mean “only A,” “only B,” or “both A and B.” Additionally, in the present disclosure, the expressions “at least one of A or B” or “at least one of A and / or B” may be interpreted identically to “at least one of A and B.”
[0055] Additionally, in the present disclosure, “at least one of A, B and C” can mean “only A,” “only B,” “only C,” or “any combination of A, B and C.” Additionally, “at least one of A, B or C” or “at least one of A, B and / or C” can mean “at least one of A, B and C.”
[0056] Additionally, parentheses used in the present disclosure may mean "for example." Specifically, when "control information (ABC)" is indicated, "ABC" may be described as an example of "control information." For example, "control information" may include DEF as another example. In other words, the "control information" of the present disclosure is not limited to "ABC," and "ABC" may be described as an example of "control information." Furthermore, even when indicated as "control information (i.e., ABC)," "ABC" may be described as an example of "control information."
[0057] Additionally, in the present disclosure, terms such as “first,” “second,” etc. are used only for the purpose of distinguishing one component from another and are not used to limit the components, and do not limit the order or importance between the components unless specifically limited. Accordingly, a first component in one embodiment of the present disclosure may be referred to as a second component in another embodiment, and similarly, a second component in one embodiment may be referred to as a first component in another embodiment.
[0058] In the following explanation, ‘when, if, in case of’ can be replaced with ‘based on’.
[0059] Technical features individually described in one drawing in this disclosure may be implemented individually or simultaneously.
[0060] In the present disclosure, a terminal is a user equipment (UE) or a consumer-side device, and may also be referred to as a base station / second node / IAB (integrated access and backhaul) node / first node that receives / transmits signals from / to a Transmission-Reception Point (TRP). The terminal may correspond to a physical node or a logical node. The terminal may correspond to an endpoint on the user side, or may correspond to an intermediate point between other endpoints. In communication between two points that are not limited to endpoints (including one-to-one / many-to-one / one-to-many / many-to-many communication), the terminal may correspond to a served node. A terminal may be a node with a fixed location, or a node with an unfixed location (or mobile).
[0061] In the present disclosure, a base station (BS) is a device on the network side, and may also be called a second node / IAB node / x-NodeB (x-NodeB, x may be an abbreviation related to a radio access technology (RAT)) / Transmission-Reception Point (TRP). A base station may correspond to a physical node or a logical node. A base station may correspond to an endpoint on the network side, or may correspond to an intermediate point between other endpoints. In communication between two points that are not limited to endpoints (including one-to-one / many-to-one / one-to-many / many-to-many communication), a base station may correspond to a serving node. A base station may be a node with a fixed location, or a node with an unfixed location.
[0062] In the present disclosure, higher layer parameters may be set for the terminal, preset, or predefined. For example, the base station may transmit higher layer parameters to the terminal. For example, the terminal may transmit parameters such as capabilities to the base station as higher layer parameters. For example, the higher layer parameters may be transmitted via radio resource control (RRC) signaling or medium access control (MAC) signaling.
[0063] In the present disclosure, the information / state / parameter being “configured or pre-configured” can be interpreted as the information / state / parameter being provided / pre-provided to the terminal through pre-defined signaling (e.g., SIB, MAC, RRC) from the base station. In the present disclosure, the information / state / parameter being “defined or pre-defined” can be interpreted as the information / state / parameter being known in advance or pre-stored at the base station and the terminal without signaling between the base station and the terminal.
[0064] The technology described in the present disclosure can be used in various wireless communication systems such as code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), and single carrier frequency division multiple access (SC-FDMA). CDMA can be implemented with wireless technologies such as universal terrestrial radio access (UTRA) or CDMA2000. TDMA can be implemented with wireless technologies such as global system for mobile communications (GSM) / general packet radio service (GPRS) / enhanced data rates for GSM evolution (EDGE). OFDMA can be implemented with wireless technologies such as Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, evolved UTRA (E-UTRA), long term evolution (LTE), and 5G NR.
[0065] The technology described in the present disclosure can be implemented with 6G wireless technology and applied to various 6G systems. For example, the 6G system can have key factors such as enhanced mobile broadband (eMBB), ultra-reliable low latency communications (URLLC), massive machine-type communication (mMTC), artificial intelligence (AI) integrated communication, tactile internet, high throughput, high network capacity, high energy efficiency, low backhaul and access network congestion, and enhanced data security.
[0066] A. 6G network architecture
[0067] Figure 1 illustrates an example of a flexible network topology applicable to the present disclosure.
[0068] To compensate for incomplete network coverage areas, a network topology that allows for more flexible and resilient split radio access networks (RANs) may be considered. For this purpose, various nodes, such as IAB nodes, relays, and RF repeaters, as illustrated in the example in Figure 1, may be applied, or a non-terrestrial network (NTN) may be integrated. For example, an IAB node may correspond to a node that provides wireless backhaul. For example, a relay may refer to any intermediate point, or in the case of a sidelink relay where a terminal functions as a relay, it may collectively refer to a terminal-to-network (U2N) relay and a terminal-to-terminal (U2U) relay. For example, an RF repeater may correspond to a node that simply performs the function of signal amplification and forwarding, while a network-controlled repeater may not only amplify and forward signals but also adjust transmission and reception settings based on information provided by the network. For example, an NTN node may correspond to a satellite or aircraft that provides NTN coverage that terrestrial networks find difficult to provide. In addition to these examples, various intermediate points can be introduced to improve the network topology.
[0069] Referring to Figure 1, a split RAN can support the division of a base station into a centralized unit (CU) and one or more distributed units (DUs). The CU and DU can correspond to logical units. The CU can be further divided into a control plane (CP) portion and one or more user plane (UP) portions. Since a failure in the CU-CP affects not only the CU-UP but also the DUs, various intermediate points can be introduced to compensate for this.
[0070] An intermediate point may correspond to a terminal or a base station, depending on its relationship to other nodes. For example, an IAB node may include a mobile-termination (MT) portion and a unit (DU). The MT may connect the IAB node to a donor node. The unit (DU) of an IAB node may serve other terminals or connect to other IAB nodes to provide multi-hop wireless backhaul to the terminal. In other words, an IAB node may correspond to a base station in its relationship to a user-side node, and to a terminal in its relationship to a network-side node.
[0071] In some examples of the present disclosure, the description of a terminal may equally apply not only to a user-side endpoint, but also to an intermediate point corresponding to a terminal in a relative relationship with a network-side endpoint. Similarly, in some examples of the present disclosure, the description of a base station may equally apply not only to a network-side endpoint, but also to an intermediate point corresponding to a base station in a relative relationship with a user-side endpoint. However, in most cases where there is no additional description of the operations of three or more entities, the communicating entities in the present disclosure are briefly described as terminals and / or base stations (or first nodes and / or second nodes), and the terms terminal and / or base stations (or first nodes and / or second nodes) are interpreted to include / replace any endpoint or any intermediate point in relation to other nodes.
[0072] That is, in some examples of the present disclosure, for the sake of simplicity of explanation, the subjects of the operation may be referred to as a base station and / or a terminal (or a first node and / or a second node). In addition, the terms base station and / or terminal (or a first node and / or a second node) may also be interpreted / replaced as in the following examples: For example, the base station (or a first node) and the terminal (or a second node) may respectively correspond to a first endpoint and a second endpoint; may respectively correspond to an endpoint and an intermediate point; may respectively correspond to an intermediate point and an endpoint; or may respectively correspond to a first intermediate point and a second intermediate point.
[0073] In the present disclosure, there may be zero or more intermediate points between the base station and the terminal. If intermediate points exist, they may be IAB nodes / relays / RF repeaters / NTN (non-terrestrial network) nodes, or nodes supporting other functions. The intermediate points may be nodes with fixed locations or nodes with unfixed locations.
[0074] Systems applicable to this disclosure
[0075] FIG. 2 illustrates an example of a structure of a wireless communication system applicable to the present disclosure. The communication system (100) of FIG. 2 applicable to the present disclosure includes a wireless device (110), a network device (120), and a network (130). Here, the wireless device (110) refers to a device that performs communication using a wireless access technology (e.g., LTE, LTE-A, LTE-A pro, NR, 5G, 5G-A, 6G), and may be referred to as a communication / wireless / 5G / 6G device. Although not limited thereto, the wireless device (110) may include a robot (110a), a vehicle (110b-1, 110b-2), an XR (extended reality) device (110c), a hand-held device (110d), a home appliance (110e), an IoT (Internet of Things) device (110f), and an AI (artificial intelligence) device / server (110g). For example, the vehicle may include a vehicle equipped with a wireless communication function, an autonomous vehicle, a vehicle capable of performing vehicle-to-vehicle communication, etc. Here, the vehicle (110b-1, 110b-2) may include an unmanned aerial vehicle (UAV) (e.g., a drone). The XR device (110c) includes an augmented reality (AR) / virtual reality (VR) / mixed reality (MR) device, and may be implemented in the form of a head-mounted device (HMD), a head-up display (HUD) equipped in a vehicle, a television, a smartphone, a computer, a wearable device, a home appliance, a digital signage, a vehicle, a robot, etc. The portable device (110d) may include a smartphone, a smart pad, a wearable device (e.g., a smart watch, smart glasses), a computer (e.g., a laptop, etc.), etc. The home appliance (110e) may include a TV, a refrigerator, a washing machine, etc. The IoT device (110f) may include a sensor, a smart meter, etc.The wireless device (110) may correspond to a terminal (or first node) or an intermediate point. The network device (120) may correspond to a base station (or second node) or another intermediate point. For example, the network device (120) may also be implemented as a wireless device (110), and a specific wireless device (120a) may act as a network device (120) to another wireless device (110).
[0076] Wireless devices (110a to 110f) can be connected to a network (130) via a network device (120). AI technology can be applied to the wireless devices (110a to 110f), and the wireless devices (110a to 110f) can be connected to an AI server (110g) via a network (130). The network (130) can be configured using a 3G network, a 4G (e.g., LTE) network, a 5G (e.g., NR), or a 6G network. The wireless devices (110a to 110f) can communicate with each other via the network device (120) / network (130), but can also communicate directly (e.g., sidelink communication) without going through the network device (120) / network (130). For example, vehicles (110b-1, 110b-2) can communicate directly (e.g., V2V (vehicle to vehicle) / V2X (vehicle to everything) communication). Additionally, an IoT device (110f) (e.g., a sensor) can communicate directly with other IoT devices (e.g., sensors) or other wireless devices (110a to 110f).
[0077] Wireless communication / connection (150a, 150b, 150c) can be established between wireless devices (110a to 110f) / network devices (120), network devices (120) / network devices (120). Here, the wireless communication / connection can be established through various wireless access technologies such as uplink / downlink communication (150a), sidelink communication (150b) (or D2D communication), and communication between network devices (150c) (e.g., relay, IAB (integrated access backhaul)). Through the wireless communication / connection (150a, 150b, 150c), the wireless device and the network device / wireless device, and the network device and the network device can transmit / receive wireless signals to each other. For example, the wireless communication / connection (150a, 150b, 150c) can transmit / receive signals through various physical channels. To this end, based on various descriptions of the present disclosure, at least some of various configuration information setting processes for transmitting / receiving wireless signals, various signal processing processes (e.g., channel encoding / decoding, modulation / demodulation, resource mapping / demapping, etc.), resource allocation processes, etc. may be performed.
[0078] Devices applicable to the present disclosure
[0079] FIG. 3 illustrates an example of a wireless device applicable to the present disclosure.
[0080] Referring to FIG. 3, the wireless device (200) can transmit and receive wireless signals via various wireless access technologies (e.g., LTE, LTE-A, LTE-A pro, NR, 5G, 5G-A, 6G). The wireless device (200) includes at least one processor (202) and at least one memory (204), and may additionally include at least one transceiver (206) and / or at least one antenna (208).
[0081] The processor (202) controls the memory (204) and / or the transceiver (206), and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document. For example, the processor (202) may process information in the memory (204) to generate first information / signal, and then transmit a wireless signal including the first information / signal via the transceiver (206). In addition, the processor (202) may receive a wireless signal including second information / signal via the transceiver (206), and then store information obtained from signal processing of the second information / signal in the memory (204). The memory (204) may be connected to the processor (202) and may store various information related to the operation of the processor (202). For example, the memory (204) may store software code including instructions for performing some or all of the processes controlled by the processor (202), or for performing the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed herein. Here, the processor (202) and the memory (204) may be part of a communication modem / circuit / chip designed to implement wireless communication technology. The transceiver (206) may be connected to the processor (202) and may transmit and / or receive wireless signals via at least one antenna (208). The transceiver (206) may include a transmitter and / or a receiver. The transceiver (206) may be used interchangeably with an RF (radio frequency) unit. In the present disclosure, a wireless device may also mean a communication modem / circuit / chip.
[0082] Hereinafter, the hardware elements of the wireless device (200) will be described in more detail. Although not limited thereto, at least one protocol layer may be implemented by at least one processor (202). For example, at least one processor (202) may implement at least one layer (e.g., a functional layer such as physical (PHY), media access control (MAC), radio link control (RLC), packet data convergence protocol (PDCP), radio resource control (RRC), and service data adaptation protocol (SDAP)). At least one processor (202) may generate at least one Protocol Data Unit (PDU) and / or at least one Service Data Unit (SDU) according to the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. At least one processor (202) may generate a message, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. At least one processor (202) can generate a signal (e.g., a baseband signal) including a PDU, an SDU, a message, control information, data or information according to the functions, procedures, proposals and / or methods disclosed in this document, and provide the signal to at least one transceiver (206). At least one processor (202) can receive a signal (e.g., a baseband signal) from at least one transceiver (206) and obtain the PDU, SDU, message, control information, data or information according to the descriptions, functions, procedures, proposals, methods and / or operational flowcharts disclosed in this document.
[0083] At least one processor (202) may be referred to as a controller, a microcontroller, a microprocessor, or a microcomputer. The at least one processor (202) may be implemented by hardware, firmware, software, or a combination thereof. For example, at least one application specific integrated circuit (ASIC), at least one digital signal processor (DSP), at least one digital signal processing device (DSPD), at least one programmable logic device (PLD), or at least one field programmable gate array (FPGA) may be included in the at least one processor (202). The descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document may be implemented using firmware or software, and the firmware or software may be implemented to include modules, procedures, functions, etc. The descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document may be included in the at least one processor (202), or may be stored in at least one memory (204) and driven by the at least one processor (202). The descriptions, functions, procedures, suggestions, methods and / or flowcharts disclosed in this document may be implemented using firmware or software in the form of code, instructions and / or sets of instructions.
[0084] At least one memory (204) can be connected to at least one processor (202) and can store various forms of data, signals, messages, information, programs, codes, instructions and / or commands. The at least one memory (204) can be configured as a read only memory (ROM), a random access memory (RAM), an erasable programmable read only memory (EPROM), a flash memory, a hard drive, a register, a cache memory, a computer readable storage medium and / or a combination thereof. The at least one memory (204) can be located internally and / or externally to the at least one processor (202). In addition, the at least one memory (204) can be connected to the at least one processor (202) via various technologies such as a wired or wireless connection.
[0085] At least one transceiver (206) can transmit user data, control information, wireless signals / channels, etc., mentioned in the methods and / or flowcharts of this document to at least one other device. At least one transceiver (206) can receive user data, control information, wireless signals / channels, etc. mentioned in the descriptions, functions, procedures, proposals, methods and / or flowcharts disclosed in this document from at least one other device. For example, at least one transceiver (206) can be connected to at least one processor (202) and can transmit and receive wireless signals. For example, at least one processor (202) can control at least one transceiver (206) to transmit user data, control information, or wireless signals to at least one other device. Furthermore, at least one processor (202) can control at least one transceiver (206) to receive user data, control information, or wireless signals from at least one other device. In addition, at least one transceiver (206) may be connected to at least one antenna (208), and at least one transceiver (206) may be configured to transmit and receive user data, control information, wireless signals / channels, etc. mentioned in the descriptions, functions, procedures, proposals, methods and / or operation flowcharts disclosed in this document through at least one antenna (208). In this document, at least one antenna may be a plurality of physical antennas or a plurality of logical antennas (e.g., antenna ports). At least one transceiver (206) may convert the received wireless signals / channels, etc. from RF band signals to baseband signals in order to process the received user data, control information, wireless signals / channels, etc. using at least one processor (202). At least one transceiver (206) may convert the processed user data, control information, wireless signals / channels, etc. from baseband signals to RF band signals using at least one processor (202).For this purpose, at least one transceiver (206) may include an (analog) oscillator and / or filter.
[0086] The components of the wireless device described with reference to FIG. 3 may be referred to by different terms in terms of functionality. For example, the processor (202) may be referred to as a control unit, the transceiver (206) as a communication unit, and the memory (204) as a storage unit. In some cases, the communication unit may be used to mean at least a portion of the processor (202) and the transceiver (206).
[0087] The structure of the wireless device described with reference to FIG. 3 can be understood as the structure of at least a portion of various devices. For example, the structure of the wireless device illustrated in FIG. 3 can be at least a portion of various devices described with reference to FIG. 2 (e.g., a robot (110a), a vehicle (110b-1, 110b-2), an XR device (110c), a portable device (110d), a home appliance (110e), an IoT device (110f), an AI device / server (110g)). Furthermore, according to various embodiments, in addition to the components illustrated in FIG. 3, the device may further include other components.
[0088] For example, the device may be a portable device such as a smartphone, a smart pad, a wearable device (e.g., a smart watch, smart glasses), or a portable computer (e.g., a laptop, etc.). In this case, the device may further include at least one of a power supply unit that supplies power and includes a wired / wireless charging circuit, a battery, etc., an interface unit that includes at least one port for connection with another device (e.g., an audio input / output port, a video input / output port), and an input / output unit for inputting and outputting image information / signals, audio information / signals, data, and / or information input from a user.
[0089] For example, the device may be a mobile device such as a mobile robot, a vehicle, a train, an aerial vehicle (AV), a ship, etc. In this case, the device may further include at least one of a driving unit including at least one of an engine, a motor, a power train, wheels, brakes, and a steering unit of the device, a power supply unit including a wired / wireless charging circuit, a battery, etc. that supplies power, a sensor unit that senses status information, environmental information, and user information of the device or its surroundings, an autonomous driving unit that performs functions such as path maintenance, speed control, and destination setting, and a position measurement unit that obtains location information of the mobile device through a global positioning system (GPS) and various sensors.
[0090] For example, the device may be an XR device such as an HMD, a head-up display (HUD) installed in a vehicle, a television, a smartphone, a computer, a wearable device, a home appliance, a digital signage, a vehicle, a robot, etc. In this case, the device may further include at least one of a power supply unit that supplies power and includes a wired / wireless charging circuit, a battery, etc., an input / output unit that obtains control information, data, etc. from the outside and outputs the generated XR object, and a sensor unit that senses status information, environmental information, and user information of the device or the surroundings of the device.
[0091] For example, the device may be a robot that can be classified into industrial, medical, household, military, etc. types depending on the purpose or field of use. In this case, the device may further include at least one of a sensor unit that senses status information, environmental information, and user information of the device or its surroundings, and a driving unit that performs various physical actions, such as moving the robot joints.
[0092] For example, the device may be an AI device such as a TV, a projector, a smartphone, a PC, a laptop, a digital broadcasting terminal, a tablet PC, a wearable device, a set-top box (STB), a radio, a washing machine, a refrigerator, digital signage, a robot, a vehicle, etc. In this case, the device may further include at least one of an input unit that acquires various types of data from the outside, an output unit that generates output related to sight, hearing, or touch, a sensor unit that senses status information, environmental information, and user information of the device or its surroundings, and a training unit that trains a model composed of an artificial neural network using learning data.
[0093] The structure of the wireless device illustrated in FIG. 3 may be understood as a part of a terminal (or first node), or as a part of an intermediate point, or as a part of a base station (or second node). If the device illustrated in FIG. 3 is a base station (or second node), the device may further include a wired transceiver for front haul and / or back haul communications. However, if the front haul and / or back haul communications are based on wireless communications, at least one transceiver (206) illustrated in FIG. 3 may be used for front haul and / or back haul communications, and a wired transceiver may not be included.
[0094] B. Communication Procedures
[0095] FIG. 4 illustrates an example of a communication procedure between a first node (e.g., a terminal) and a second node (e.g., a base station) applicable to the present disclosure. The second node of FIG. 1 supports dynamic spectrum sharing (DSS) to provide connectivity to both nodes implementing 6G technology and nodes implementing pre-6G wireless communication technologies (e.g., 5G, 4G). That is, the first node of FIG. 1 may implement 6G technology or pre-6G wireless communication technologies (e.g., 5G, 4G). In addition, the first node and / or the second node may support a full duplex mode as well as a non-overlapping full duplex mode.
[0096] In Fig. 4, for the sake of simplicity of explanation, the first node and the second node are assumed to be a terminal and a base station, respectively, and operations of transmitting and / or receiving data by the terminal (440) and the base station (420) and operations performed prior thereto are illustrated. However, the operations of Fig. 1 are not limited to operations between the terminal and the base station, and may be interpreted as operations between the first node and the second node. In addition, although Fig. 1 illustrates direct wireless signal transmission and reception operations between the terminal (440) and the base station (420), one or more intermediate points may exist between the terminal (440) and the base station (420), and wireless signals may be transmitted and received via one or more intermediate points.
[0097] Referring to FIG. 4, in step 401, the terminal (440) and the base station (420) perform synchronization. For example, the terminal (440) performs an initial cell search operation. Specifically, the terminal (440) can detect a synchronization signal for connection to at least one base station transmitted from the base station (420) according to a predefined rule. Here, the synchronization signal can include a plurality of synchronization signals classified according to structure or purpose (e.g., a first synchronization signal (e.g., a primary synchronization signal), a second synchronization signal (e.g., a secondary synchronization signal), etc.). Through this, the terminal (440) can confirm the boundary of a unit (e.g., a frame, a subframe, a slot, and / or a symbol) constituting a wireless signal transmission of the base station (420) and obtain information (e.g., a cell identifier) about the base station (420).
[0098] In step 403, the terminal (440) obtains system information transmitted from the base station (420). The system information is information related to the properties, characteristics, and / or capabilities of the base station (420) required to access the base station (420) and use the service, and may be classified according to the content (e.g., whether it is essential for access), transmission structure (e.g., channel used, whether provided on-demand), etc., and may be classified into, for example, first system information (e.g., master information block (MIB), primary system information), second system information (e.g., system information block (SIB), secondary system information), etc. If necessary, the terminal (440) may transmit a signal requesting system information before receiving the system information. However, the request and provision of the system information may be performed after the random access procedure described below.
[0099] In step 405, the terminal (440) and the base station (420) perform a random access procedure. The terminal (440) may transmit and / or receive at least one message (e.g., a random access preamble, a random access response (RAR) message, etc.) for the random access procedure based on information related to a channel for the random access procedure of the base station (420) obtained through system information (e.g., a channel position, a channel structure, a structure of a supported preamble, etc.). For example, the terminal (440) may transmit a first message (e.g., a preamble, MSG1) through the channel for the random access procedure, receive a second message (e.g., an RAR message, MSG2), transmit a third message (e.g., MSG3) including information related to the terminal (440) (e.g., identification information) to the base station (420) using scheduling information included in the second message, and receive a fourth message (e.g., MSG4) for contention resolution and / or connection establishment. As another example, the first and third messages may be sent and received as one message, or the second and fourth messages may be sent and received as one message.
[0100] In step 407, the terminal (440) and the base station (420) perform signaling of control information. Here, the control information may be defined in various layers, such as a layer that controls a connection (e.g., a radio resource control (RRC) layer), a layer that handles mapping between logical channels and transport channels (e.g., a media access control (MAC) layer), and a layer that handles physical channels (e.g., a physical (PHY) layer). For example, the terminal (440) and the base station (420) may perform at least one of signaling for establishing a connection, signaling for determining settings related to communication, and signaling for indicating allocated resources.
[0101] In step 409, the terminal (440) and the base station (420) transmit and / or receive data. In other words, the terminal (440) and the base station (420) can process, transmit, and / or receive data based on the signaling of the control information. For example, when transmitting data, the terminal (440) or the base station (420) can perform at least one of channel encoding, rate matching, scrambling, constellation mapping, layer mapping, waveform modulation, antenna mapping, and resource mapping on the information bits. Conversely, when receiving data, the terminal (440) or the base station (420) can perform at least one of signal extraction from resources, waveform demodulation for each antenna, signal arrangement considering layer mapping, constellation demapping, descrambling, and channel decoding.
[0102] C. 6G System Core Technologies
[0103] As core implementation technologies of the 6G system, technologies such as artificial intelligence (AI), THz (terahertz) communication, optical wireless technology, FSO backhaul network, massive MIMO technology, blockchain, 3D networking, quantum communication, unmanned aerial vehicles, cell-free communication, wireless information and energy transfer (WIET), integration of sensing and communication, integration of access backhaul networks, holographic beamforming, big data analysis, and large intelligent surface (LIS) can be adopted.
[0104] C-1. Artificial intelligence
[0105] Incorporating AI into communications can streamline and improve real-time data transmission. AI can use numerous analytics to determine how complex target tasks should be performed. This means AI can increase efficiency and reduce processing delays. Time-consuming tasks such as handovers, network selection, and resource scheduling can be performed instantly using AI. AI can also play a crucial role in machine-to-machine (M2M), machine-to-human, and human-to-machine communications. Furthermore, AI can facilitate rapid communication in brain-computer interfaces (BCIs). AI-based communication systems can be supported by metamaterials, intelligent structures, intelligent networks, intelligent devices, intelligent cognitive radios, self-sustaining wireless networks, and machine learning.
[0106] [Functional Framework]
[0107] The following describes a functional framework for AI / ML operations.
[0108] Below, to explain AI (or AI / ML) more specifically, the terms can be defined as follows.
[0109] - Data collection: Data collected from network nodes, management entities, or terminals as a basis for AI model training, data analysis, and inference.
[0110] - AI Model: A data-driven algorithm that applies AI technology to generate a set of outputs containing predictive information and / or decision parameters based on a set of inputs.
[0111] - AI / ML Training: An online or offline process of training an AI model by learning features and patterns that best represent the data and obtain a trained AI / ML model for inference.
[0112] - AI / ML Inference: The process of making predictions or inducing decisions based on collected data and the AI model using a trained AI model.
[0113] Life Cycle Management (LCM) procedures for AI / ML models (i.e., model training, model deployment, model inference, model monitoring, model updates, etc.) can be divided into functionality-based LCM and model-based LCM. In functionality-based LCM, AI / ML models may not be identified by the network, and the network can direct the activation / deactivation / fallback / switching of AI / ML functionality. In model-ID (identifier)-based LCM, AI / ML models can be identified by the network, and the network / terminal can activate / deactivate / select / switch AI / ML models based on the model ID.
[0114] Figure 5 illustrates an example of a general functional architecture relevant to both Functionality-based LCM and Model-based LCM. Some of the functions or some of the data / information / command flows (i.e., arrows) illustrated in Figure 5 may be omitted.
[0115] Referring to FIG. 5, a general functional framework can be configured to include a data collection function (510), a model training function (520), a management function (530), an inference function (540), and a model storage function (550).
[0116] The Data Collection function (510) is a function that provides input data to the Model Training function (520), Management function (530), and Inference function (540). The Data Collection function (510) can perform data preparation based on raw data and provide input data processed through data preparation. Examples of raw data may include received data / measurement data from terminals or other network entities, inference / output of AI / ML models, etc. The Data Collection function (510) may be performed by a single entity (e.g., a terminal, a network node, etc.) or may be performed by multiple entities.
[0117] Here, training data (511) refers to data required as input for the AI / ML Model Training function (520). Monitoring data (512) refers to data required as input for the AI / ML model or AI / ML function Management (530). Inference data (513) refers to data required as input for the AI / ML Inference function (530).
[0118] The Model Training function (520) performs AI / ML model training, validation, and testing, which can generate model performance metrics that can be used as part of the AI / ML model testing process. If necessary, the Model Training function (520) can perform data preparation (e.g., data pre-processing and cleaning, forming, and transformation) based on the Training Data (511) transmitted from the Data Collection function (510).
[0119] Trained / Updated Model (521): If there is a Model Storage function (550), it is used to pass a trained, validated and tested AI / ML model to the Model Storage function (550) or to pass an updated version of the model to the Model Storage function (550).
[0120] The Management function (530) is a function that supervises the operation of the AI / ML model or AI / ML function. In addition, the Management function (530) may perform decisions to ensure appropriate inference operations based on data received from the Data Collection function (510) (i.e., Monitoring Data (512)) and / or data received from the Inference function (540) (i.e., Inference Output (541)).
[0121] Management Instruction (532) is information required as input to manage the Inference function (540). The relevant information may include selection / (de)activation / switching of an AI / ML model or AI / ML-based function, and may also include fallback to non-AI / ML operations (i.e., not relying on the inference process).
[0122] A Model Transfer / Delivery Request (533) can be used to request model(s) from Model Storage (550).
[0123] A Performance Feedback / Retraining Request (531) refers to information required as input to the Model Training function (520) (e.g., for the purpose of (re)training or updating the model).
[0124] The Inference function (540) is a function that provides output from the process of applying an AI / ML model or AI / ML function using data (i.e., Inference Data (513)) provided by the Data Collection (510) as input. Data preparation (e.g., data preprocessing and cleaning, formatting, and transformation) may also be performed based on the Inference Data (513) delivered by the Data Collection (510). If necessary, the Inference function (540) may also perform data preparation (e.g., data preprocessing and cleaning, forming, and transformation) based on the Inference Data (513) provided by the Data Collection function (510).
[0125] Inference Output (541) is data used by the Management function (530) to monitor the performance of an AI / ML model or AI / ML function. Inference Output (541) may also include the inference output of the AI / ML model generated by the Inference function (530), and the details of the inference output may vary depending on the use case.
[0126] The Model Storage function (550) stores a trained / updated model that can be used to perform the Inference function (540). The Model Storage function (550) illustrated in FIG. 5 can be used as a reference point (if any) when applicable to protocol termination, model transfer / delivery, and related processes. Furthermore, the Model Storage function (550) is merely an example and is not intended to limit the storage location of actual AI / ML models, and may be omitted.
[0127] Model Transfer / Delivery (551) is used to transfer AI / ML models to inference functions.
[0128] The level of cooperation can be defined as follows depending on the capability of AI / ML functions between multiple nodes, and variations due to combination of multiple levels or separation of any one level are also possible.
[0129] Cat 0a) No collaboration framework: AI / ML algorithms are purely implementation-based and do not require any changes to the wireless interface.
[0130] Cat 0b) This level corresponds to a framework with a modified wireless interface tailored to efficient implementation-based AI / ML algorithms, but without collaboration.
[0131] Category 1) involves inter-node support to improve the AI / ML algorithms of each node. For example, this applies when a specific node receives support from another node (for training, adaptation, etc.) and vice versa. At this level, model exchange between network nodes is not required.
[0132] Category 2) Joint AI / ML tasks can be performed across multiple nodes. This level requires the exchange of AI / ML model commands or network nodes.
[0133] FIG. 5 is a diagram illustrating an overall functional framework for an AI / ML model, and not all functions and / or all data / information / command signals illustrated in FIG. 5 may be performed within a specific node, but only some of them may be performed.
[0134] AI / ML models can be divided into one-side models and two-side models depending on whether training and / or inference are performed on a single node or jointly / sequentially on multiple nodes.
[0135] A one-side model can refer to an AI / ML model in which inference is performed entirely by a single node (e.g., a terminal or network). Here, AI / ML model training can also be performed entirely by a single node. AI / ML model training and inference can be performed by the same node, or they can be performed by separate nodes.
[0136] A two-side model can refer to an AI / ML model in which joint inference is performed across multiple nodes (e.g., terminals and networks). Joint inference refers to inference being performed jointly across multiple nodes. For example, the first part of the inference may be performed by a first node, and the remaining part by a second node. Two-side models can be categorized into several types depending on the training method of the AI / ML model, as follows:
[0137] - First type: AI / ML models can be trained on a single node. In this case, joint training can be performed. The trained model can then be distributed to other nodes / objects.
[0138] - Second type: Joint training of AI / ML models can be performed on multiple nodes / entities (e.g., networks and terminals). Joint training can mean that model generation (e.g., CSI generation part) and model reconstruction (CSI compression by sub-use case) are trained in the same loop for forward activation and backward gradient. In this type, joint training can include both simultaneous training (i.e., model generation training and model reconstruction training are performed simultaneously) and sequential training (i.e., model reconstruction training is performed after model generation training).
[0139] - Third type: Separate training of AI / ML models can be performed on multiple nodes (e.g., networks and terminals). Separate training may mean that training begins sequentially on one node and continues on other nodes. In this case, the first node first performs the AI / ML model and shares the training data with the second node. The second node can then use the shared training data to perform the AI / ML model. For example, training for the CSI generation part may be performed by the terminal, while CSI reconstruction may be performed by the network.
[0140] The operations described in the present invention described below can be described / interpreted based on the AI / ML model as shown in Fig. 6 below, even without separate mention (i.e., without explicit mention of being by / based on / for the AI / ML model). Fig. 6 illustrates an example of an operation procedure based on an AI / ML model applicable to the present disclosure.
[0141] Additionally, unless specifically limited in the description of the present invention, the AI / ML model may correspond to a one-side model in which inference is entirely performed by one node or a two-side model in which joint inference is performed by multiple nodes.
[0142] Step 1: In the description of the present invention described below, the signaling (e.g., information / data / channel / signal, etc.) or set of signaling between a specific node (e.g., terminal, network, etc.) and another node can be interpreted as the signaling or set of signaling of step 1 used to perform an operation based on an AI / ML model, even if there is no separate mention. For example, it can correspond to training data for training (i.e., generation and / or reconstruction) the AI / ML model of FIG. 2, or correspond to inference data used for inference of the AI / ML model, or correspond to feedback for the AI / ML model, etc. If signaling between nodes is not required prior to an operation based on an AI / ML model in the present invention, step 1 can be omitted. If a one-side model is used in the present invention, the unidirectional / bidirectional signaling (set) in the present invention can correspond to the signaling of step 1. In addition, when a two-side model is used in the present invention, unidirectional / bidirectional signaling in the present invention may correspond to one stage of signaling, and also repetitive signaling operations may correspond to one stage of signaling.
[0143] For example, in AI / ML model-based beam management (BM), if a base station predicts (i.e., infers) beam(s) with good quality based on an AI / ML model, the base station can receive quality / intensity information for multiple beams from a terminal. Furthermore, if a terminal predicts (i.e., infers) beam(s) with good quality based on an AI / ML model, the terminal can receive multiple beams from the base station.
[0144] Step 2: In the description of the present invention described below, an operation (e.g., calculation, selection, prediction, etc.) in a specific node (e.g., terminal, network, etc.) or a joint operation (e.g., calculation, selection, prediction, etc.) in multiple nodes (e.g., terminal, network, etc.) may correspond to a step 2 operation based on one or more functions in the functional framework of the AI / ML model, even if not mentioned separately. For example, it may correspond to training (i.e., generation and / or reconstruction) of the AI / ML model in FIG. 2 or inference of the AI / ML model, etc. When a one-side model is used, an operation performed by a single node in the present invention may correspond to a step 2 operation, and also when a two-side model is used, a joint operation performed by multiple nodes in the present invention may correspond to a step 2 operation.
[0145] For example, in an AI / ML model-based BM, the base station can use quality / intensity information for multiple beams received from the terminal as inference data to predict (i.e., infer) beam(s) with good quality based on the AI / ML model. Furthermore, the terminal can measure multiple beams received from the base station and use the measurement results as inference data to predict (i.e., infer) beam(s) with good quality based on the AI / ML model.
[0146] Step 3: In the description of the present invention described below, the signaling (e.g., information / data / channel / signal, etc.) or set of signaling between a specific node (e.g., terminal, network, etc.) and another node can be interpreted as a three-stage signaling or set of signaling generated due to (as a result of) an operation based on an AI / ML model, even if not otherwise mentioned. For example, it can correspond to an output due to inference of the AI / ML model in FIG. 2. If signaling between nodes is not required as a result of an operation based on an AI / ML model in the present invention, Step 3 can be omitted. If a one-side model is used in the present invention, the one-way / two-way signaling (set) in the present invention can correspond to the three-stage signaling. In addition, if a two-side model is used in the present invention, the one-way / two-way signaling in the present invention can correspond to the three-stage signaling, and furthermore, a repetitive signaling operation can correspond to the three-stage signaling.
[0147] For example, in an AI / ML model-based BM, the base station can transmit to the terminal the beam(s) predicted based on the AI / ML model as candidates so that the terminal can determine the optimal beam. Furthermore, the terminal can report to the base station the beam(s) predicted based on the AI / ML model to request the base station to transmit the candidate beams as candidates for determining the optimal beam.
[0148] C-2. THz communication
[0149] Data rates can be increased by increasing bandwidth. This can be achieved by utilizing sub-THz communications with wide bandwidths and applying advanced massive MIMO technology. THz waves, also known as sub-millimeter waves, typically refer to the frequency range between 0.1 THz and 10 THz, with corresponding wavelengths ranging from 0.03 mm to 3 mm. The 100 GHz to 300 GHz band (sub-THz band) is considered a key portion of the THz band for cellular communications. Adding the sub-THz band to the mmWave band will increase the capacity of 6G cellular communications. Among the defined THz bands, 300 GHz to 3 THz lies in the far infrared (IR) frequency band. While the 300 GHz to 3 THz band is part of the optical band, it lies at the boundary of the optical band, immediately following the RF band. Therefore, this 300 GHz to 3 THz band exhibits similarities to RF. Figure 7 illustrates an example of the electromagnetic spectrum applicable to the present disclosure. The embodiment of FIG. 7 can be combined with various other embodiments. Key characteristics of THz communications include (i) widely available bandwidth to support very high data rates, and (ii) high path loss at high frequencies (which necessitates highly directional antennas). The narrow beamwidth generated by highly directional antennas reduces interference. The small wavelength of THz signals allows for a significantly larger number of antenna elements to be integrated into devices and base stations operating in this band. This enables the use of advanced adaptive array technologies to overcome range limitations.
[0150] Transmitting system information (i.e., information related to the properties, characteristics, and / or capabilities of a BS required to use a service, such as MIB, SIB, etc.) in the THz frequency band may be inefficient because, as the beam width becomes narrower in high frequency bands, more beam sweeps must be performed to cover the entire area of the cell. In particular, transmitting system information in this manner is even more inefficient when there are not many users in the cell. Accordingly, a system information transmission procedure such as that illustrated in FIG. 8 may be used.
[0151] (How to receive system information)
[0152] Figure 8 illustrates an example procedure for transmitting system information for THz communication applicable to the present disclosure. While this example was developed with THz in mind, it is also applicable to 6G communication environments where THz is not applicable. Furthermore, the procedure illustrated in Figure 8 can be combined with various embodiments of the present disclosure described below. For example, the embodiments described below can be performed based on system information acquired through the procedure illustrated in Figure 8.
[0153] Referring to FIG. 8, in step 801, the base station (820) transmits system information of cell #1 through cell #2. That is, the base station (820) provides at least two cells, cell #1 uses a THz frequency band, and cell #2 uses a frequency band other than the THz frequency band. Here, the system information may include at least one information / state / parameter / setting generated in each of a higher layer and a physical layer. For example, the at least one information / state / parameter / setting generated in the higher layer may include at least one of SFN, control information setting for SIB1 (e.g., PDCCH configuration for SIB1, etc.), information related to cell selection / entry (e.g., cell barring, cell re-selection, etc.), and subcarrier spacing, and the at least one information / state / parameter / setting generated in the physical layer may include at least one of SFN, half frame indicator, and SSB index. However, this is merely an example, and system information may include information / status / parameters / settings related to Cell #1 / Cell #2 generated from various types of physical layers / upper layers. For this purpose, as an example, Cell #1 and Cell #2 may have a relationship as a secondary cell and a primary cell.
[0154] In step 803, UE (810) acquires synchronization for cell #1. Synchronization can be acquired by detecting a synchronization signal. Typically, synchronization is acquired before receiving system information. However, since system information for cell #1 is received from cell #2, synchronization acquisition for cell #1 can be performed after receiving the system information. For example, UE (810) can acquire synchronization based on system information. However, unlike FIG. 8, in another example, synchronization acquisition can be performed before step 801.
[0155] In step 805, the UE (810) transmits a signal for accessing cell #1. For example, the signal may include information for accessing cell #1 (e.g., a random access preamble, etc.). The structure of the signal and the resources for transmitting the signal (e.g., a channel) may be identified through system information. Thereafter, in step 807, the UE (810) and the base station (820) perform an access procedure for cell #1 and communicate. In this step, operations according to various embodiments described below may be performed.
[0156] The procedure described with reference to FIG. 8 may be performed when the UE (801) first connects to cell #1 of the base station (820). Alternatively, a similar procedure may be performed when the UE (801) hands over to cell #1 of the base station (820). However, in the case of handover, the system information of cell #1 may be received from a cell of a base station other than cell #2 of the base station (520).
[0157] Communications in the THz band are expected to experience extremely severe path loss, and to overcome this, terminals and base stations must use extremely sharp beams. The use of sharp beams means that terminals and base stations must perform beam control in addition to beamforming, and the number of beams used increases significantly. Consequently, it takes a very long time to align the transmit and receive beams between the base station and terminals. Furthermore, if the beam alignment between the base station and terminals is misaligned due to the movement or movement of the terminals, frequent re-alignment of the beams is required, which can lead to link instability. Accordingly, a beam management procedure, as illustrated in FIG. 9 below, may be used.
[0158] (Beam search procedure in THz communication environment)
[0159] FIG. 9 illustrates an example of a beam management procedure applicable to the present disclosure. FIG. 9 illustrates an example of a procedure for searching and / or selecting beams for THz communication, but is not limited to a THz environment, and the present disclosure is applicable to a 6G communication environment. In addition, the procedure illustrated in FIG. 9 can be combined with various embodiments of the present disclosure described below. Here, the beam can be interpreted as 'spatial (setting) information', 'spatial domain filter', 'spatial domain transmit filter', 'spatial domain receive filter', or / and a term having an equivalent technical meaning that can distinguish the beam (e.g., Reference signal, SSB (Synchronization Signal Block) Index, TRP (transmission reception point), panel, cell, TP (transmission point), base station, control resource related information (e.g., CORESET (control resource set) related information, etc.).
[0160] Referring to FIG. 9, in step 901, the base station (920) configures resources for beam management. Here, the resources may include at least one of time-frequency resources, channels, and spatial resources (e.g., antenna ports). For example, the base station (920) may utilize a beam search signal (BSS) that is transmitted spatially separated from an existing downlink signal / channel for beam search. Here, the BSS may be transmitted based on a dedicated port for beam search. The dedicated port may be a different port from a port for transmitting an existing downlink signal / channel (e.g., a synchronization signal (e.g., SSB, etc.), a data channel (e.g., PDSCH, etc.)). BSS is a term defined for convenience of explanation, and the technical concept according to the present embodiment is not limited to the term BSS itself. That is, a signal transmitted based on a dedicated port defined / configured for beam search may be included in the technical concept according to the present embodiment.
[0161] In step 903, the base station (920) transmits measurement signals using a plurality of transmission beams. For example, the measurement signals may include at least one of a reference signal and a synchronization signal. At this time, the measurement signals may be transmitted as many times as the number of beams that require measurement, and may be transmitted in a multi-beam transmission method that forms a plurality of beams simultaneously to reduce the sweeping time. Here, the multi-beam transmission may be performed based on at least one of a multi-panel, a sub-array, and a true time delay (TTD).
[0162] In step 905, the UE (910) transmits a feedback signal to the base station (920). The feedback signal indicates at least one beam selected by the UE (910). The UE (910) may select at least one preferred beam based on the measurement signals received in step 903. In step 907, the UE (910) and the base station (920) perform communication. At this time, the UE (910) and the base station (920) may perform communication using the beam selected in step 905. If channel reciprocity is established, the transmission beam of the UE (910) may also be determined through steps 903 and 905, and thus, the transmission operation of the UE (910) may also be performed using the beam selected in step 905. If channel reciprocity is not established, a procedure including transmitting measurement signals of the UE (910) and transmitting feedback signals of the base station (920) may be performed to determine the transmission beam of the UE (910). In step 907, operations according to various embodiments described below may be performed.
[0163] C-3. Non-terrestrial networks (NTN)
[0164] NTN can refer to a network or network segment that uses RF (radio frequency) resources mounted on a satellite (or unmanned aerial system (UAS) platform). The use of NTN services has been considered to secure wider coverage or to provide wireless communication services in locations where it is difficult to install wireless communication base stations. NTN services can collectively refer to a wireless communication system that provides terminals by installing base stations on satellites (e.g., geostationary-orbit, low-Earth orbit, medium-geometry satellites, etc.), airplanes, unmanned airships, drones, etc. rather than on the ground. The satellite described in the present disclosure can move at high speed from a specific location on the Earth, and the satellite beam directed toward the Earth can correspond to an area on the Earth where the satellite can provide services to users.
[0165] As an example of the present disclosure, NTN scenarios can be divided into Earth-fixed cell scenarios and Earth-moving cell scenarios depending on the type of cell supported by the satellite. The Earth-fixed cell scenario refers to a scenario in which a cell is maintained permanently or for a specific service period within a specific location on the Earth's surface based on the satellite's beam steering function. The Earth-moving cell scenario refers to a scenario in which a cell within the Earth's surface continuously moves as the satellite's beam steering function is not utilized and a fixed beam is used for service.
[0166] As another example of the present disclosure, the NTN scenario can be divided into a typical NTN scenario based on a transparent payload and a typical NTN scenario based on a regenerative payload, depending on the characteristics of the payload. Fig. 10a illustrates an example of a typical NTN scenario based on a transparent payload applicable to the present disclosure. Fig. 10b illustrates an example of a typical NTN scenario based on a regenerative payload applicable to the present disclosure. The embodiments of Fig. 10a or Fig. 10b can be combined with various embodiments of the present disclosure. Referring to Fig. 10a, a satellite (or UAS platform) can create a service link with a UE. The satellite (or UAS platform) can be connected to an (NTN) gateway via a feeder link. The satellite can be connected to a data network via the gateway. A beam footprint can refer to an area where a signal transmitted by a satellite can be received. Referring to Figure 10b, a satellite (or UAS platform) can establish a service link with a UE. A satellite (or UAS platform) connected to a UE can be connected to another satellite (or UAS platform) via an inter-satellite link (ISL). The other satellite (or UAS platform) can be connected to a gateway via a feeder link. Based on the replay payload, a satellite can be connected to a data network through another satellite and the gateway. If an ISL does not exist between a satellite and another satellite, a feeder link between the satellite and the gateway may be required. Figures 10a and (b) are merely examples of NTN scenarios, and NTN can be implemented based on various scenarios.For example, a satellite (or UAS platform) may implement a transparent or regenerative (with onboard processing) payload. For example, a satellite (or UAS platform) may generate multiple beams over a designated service area depending on the field of view of the satellite (or UAS platform). For example, the field of view of the satellite (or UAS platform) may vary depending on the onboard antenna diagram and minimum elevation angle. For example, a transparent payload may include radio frequency filtering, frequency conversion, and amplification. Therefore, the waveform signal repeated by the payload may not be altered. For example, a regenerative payload may include radio frequency filtering, frequency conversion and amplification, demodulation / decoding, switching and / or routing, and coding / modulation. For example, a regenerative payload may be substantially equivalent to equipping the satellite (or UAS platform) with all or part of the base station functionality.
[0167] Below, we describe procedures (e.g., initial cell selection, mobility management in idle mode, and mobility management in connected mode) for maintaining network service continuity and satellite coverage in a wireless communication system utilizing NTN elements.
[0168] - Initial cell selection procedure
[0169] Upon power-on, the terminal can search for the first satellite-based NTN cell (or the satellite broadcasting the cell). At this time, if the terminal has satellite orbit information (i.e., ephemeris data) and / or round-to-trip (RTT) information that can be used when performing a cell entry procedure (e.g., a random access procedure), the terminal can use such information to shorten the cell search procedure and the time required for cell search. To this end, the terminal may require (initial) system information including satellite ephemeris information to identify the exact location of the cell, and the (initial) system information may be set / determined / generated based on orbital plane information already possessed by the terminal. For example, satellite-level orbit parameters for all satellites capable of providing services to the terminal through the terminal uSIM, including satellite IDs or indices, may be provided in advance. Afterwards, the satellite ID of the service satellite is broadcast as part of the system information, allowing the terminal to derive ephemeris data and / or location coordinates of the service satellite stored in the uSIM. Additionally, to assist mobility handling, the terminal can obtain information about neighboring satellites through system information and / or dedicated RRC signaling.
[0170] Here, the satellite ephemeris information transmitted to the terminal via system information and / or RRC signaling can be implemented / supported in i) a position and velocity state vector orbit format and ii) an orbital parameter ephemeris format. For example, the position and velocity state vector orbit format can be configured with 17 bytes or less (e.g., 132 bits). The field size for position (x, y, z)(m) can be 78 bits, and the field size for velocity (vx, vy, vz)(m / s) can be 54 bits.
[0171] The orbital parameter ephemeris format can be composed of 21 bytes or less (e.g., 164 bits). Fig. 11a illustrates an example of the components of the orbital parameter ephemeris format. The components of the orbital parameter ephemeris format illustrated in Fig. 11a are as follows.
[0172] - Semi-major axis (half the major axis of an elliptical satellite orbit) "α" [m] (e.g. 33 bits)
[0173] - Eccentricity "e" (in an elliptical satellite orbit, 0 <e<1)(예: 20 비트)
[0174] - Argument of periapsis (the angle from the orbital periapsis, the point where an object is closest to the central body when orbiting, to the ascending node, which determines the direction of the ellipse in the orbital plane) "ω" (e.g. 28 bits) [rad]
[0175] - Longitude of ascending node (the angle measured counterclockwise from a reference point (e.g., the vernal equinox in the solar system) to the ascending node (the point where the orbit passes above the reference plane)) "Ω" (e.g., 28 bits) [rad]
[0176] - (orbital) inclination (the degree of tilt of the ellipse with respect to the reference plane, measured as the angle between the orbital plane and the reference plane at the ascending node) "i" (e.g. 27 bits) [rad]
[0177] - Mean anomaly (mathematically convenient angle that changes continuously over time, but does not correspond to a geometric angle) "M0" = M(t0) (e.g. 28 bits) [rad] at epoch t0 [JD]
[0178] - Mobility management in idle mode
[0179] During idle mode, the location of a terminal can be identified at the tracking area level / unit. Here, a tracking area is defined as a set of cells, and each cell can belong to a tracking area identified by a tracking area code (TAC). The TAC can be transmitted via system information on a broadcast channel. Multiple cells can belong to the same tracking area, and the same TAC corresponding to the same tracking area can be broadcast. The location of a terminal can be announced to the network when the terminal is first powered on (i.e., when performing a registration procedure). The registration request message transmitted by the terminal for the registration procedure can include the TAC of the cell in which the terminal is currently camping. When the terminal changes cells as it moves, the tracking area of the corresponding cell can be determined by decoding the system information of the changed cell. The terminal can move within the same tracking area without performing an update. When a terminal enters a new cell using a different TAC, the terminal can register in the new cell and transmit a new TAC to update the network about its location. Consequently, a larger tracking area can reduce signaling from the terminal to the network, minimizing terminal power consumption. When the network needs to reach a terminal in idle mode (e.g., during an incoming call), the network can page the terminal in all cells within the last tracking area in which the terminal registered. If the tracking area is very large and contains many cells, the network may page the terminal in all cells within the TAC, resulting in an increased number of pages. If the same model is used for a satellite system, with each satellite broadcasting a TAC, the tracking area can sweep the ground as the satellite orbits the Earth.In this case, even stationary terminals must frequently perform registration updates, which can impact terminal battery life and increase uplink signal throughput. To address this, the system can be designed so that the tracking area does not change its geographic location on Earth. Instead, the tracking area can change as the satellite moves, entering a new geographic area and updating the TAC broadcast by the satellite to reflect the new geographic area. Simultaneously, the terminal can perform a tracking area update procedure if it detects a new TAC on the broadcast channel. Accordingly, if the terminal's physical location on Earth does not change, the tracking area can remain fixed.
[0180] - Mobility management in connected mode
[0181] While the UE is in connected mode, mobility management procedures can be handled by handover. For terrestrial / NTN networks, handovers can be triggered by the network (i.e., measurement handover triggering) based on measurements reported by the UE regarding the current cell and neighboring cell signal quality. Within the handover procedure, service interruption time is defined as the time from when the UE ceases transmitting and receiving with the source base station to when it resumes transmitting and receiving with the target base station. The interruption time may vary for uplink and downlink. For downlink, the interruption time can be defined as the time from when the network transmits a synchronized RRC reconfiguration message to when the target base station receives an RRC reconfiguration complete message. After transmitting the RRC reconfiguration message, the base station cannot send any more data and can resume communication after receiving the RRC reconfiguration complete message. For uplink, the UE can potentially continue transmitting data to the source base station until a synchronized RRC reconfiguration message is received. And, the downtime can be defined as the time from the time the terminal receives a synchronized RRC reset message to the time the target base station receives an RRC reset complete message.
[0182] The propagation delay of satellite-based NTN is much larger than that of terrestrial systems, which may incur additional latency for mobility signals such as measurement reports, handover (HO) command reception, and HO requests / ACKs (if the target cell originates from a different satellite). The geostationary Earth orbit (GEO) scenario is characterized by much larger propagation delays than the low Earth orbiting (LEO) scenario, but the latter must take satellite movement into account. To avoid extended service interruptions, the latency associated with mobility signals must be addressed in both cases. In addition to the measurement-triggered handover described above, other handover triggering methods may be utilized, such as handover triggering based on the position of the UE and the satellite (or the distance between the UE and the satellite), handover triggering based on the timing advance (TA) of the target cell, handover triggering based on deterministic satellite movement / local time, and handover triggering based on the elevation angle of the source / target cells. Additionally or alternatively, the terminal may be provided with handover settings and triggering conditions (e.g., terminal / satellite location, signal strength transmitted by the terminal / satellite, etc.) in advance. For example, the terminal may receive handover settings and triggering conditions through information about a new cell that will be the handover target. Accordingly, the terminal can monitor handover conditions and, if the conditions are met, perform a handover to the target cell.
[0183] Meanwhile, as described above, wireless communication systems utilizing NTN elements have significantly larger RTT values compared to terrestrial communication systems. Therefore, various types of offsets and TA values can be set / defined / indicated / signaled for efficient time / frequency synchronization. Below, offsets (e.g., K_offset and k_mac), TA values, validity duration, and epoch time for time / frequency synchronization in NTN-based wireless communication systems are described.
[0184] - K_offset and k_mac
[0185] Figure 11b illustrates examples of offsets in a satellite-related link. K_offset illustrated in Figure 11b is an offset value indicating the RTT of an uplink time synchronization reference point (RP). Here, K_offset may correspond to the sum of the service link RTT and the common TA (if indicated). k_mac illustrated in Figure 11b is an offset value indicating the RTT between the RP and the base station. For example, K_offset may be applied to i) DCI and PUSCH transmission timing scheduled by the DCI, ii) random access response (RAR) and PUSCH transmission timing based on the RAR, iii) PUSCH transmission timing based on a configured grant, iv) PUCCH transmission timing according to MsgB, v) aperiodic SRS / CSI resource transmission timing, etc. For example, k_mac may be applied to terminal actions and assumptions regarding a downlink configuration indicated by a MAC-CE command in a PDSCH. In a beam failure recovery procedure, for PRACH transmission in uplink slot n, the terminal may monitor the corresponding PDCCH starting from downlink slot "n+k_mac+4" within the corresponding RAR window.
[0186] The cell-specific K_offset can be signaled via NTN-related system information (e.g., NTN-specific SIB). A range of cell-specific K_offset values (0 to 1023 ms) can be used to cover all scenarios. A differential UE-specific K_offset can be signaled via MAC CE, and the differential UE-specific value range is 0 to 63 ms. The total UE-specific K_offset value is equal to the cell-specific K_offset value minus the differential UE-specific K_offset value. k_mac can be provided by the network when the downlink and uplink frame timings are not aligned at the base station. k_mac updates are not supported, and the value range can be 1 to 512 ms. If the UE does not receive a k_mac value from the network, the UE can assume k_mac to be 0. The reference SCS value for the units of K_offset in FR1 can be 15 kHz.
[0187] - UE-specific TA and common TA
[0188] In an NTN-based communication system, a terminal can calculate TA based on the terminal's global navigation satellite system (GNSS) capability (e.g., terminal position) and upper layer parameters related to satellite orbit (ephemeris) transmitted from a base station, and this is called terminal-specific TA ( ) is named. If the upper layer parameters related to the satellite orbit are not received from the base station, the terminal-specific TA can be set to 0. Then, the TA calculated based on the common TA parameters (e.g., TACommon, TACommonDrift, and / or TACommonDriftVariation), which are upper layer parameters transmitted from the base station, is called the common TA ( ) is named. If the common TA parameter is not transmitted from the base station, the common TA can be set to 0. Accordingly, the total TA value (T_TA) in the NTN-based communication system is It can be calculated as follows. N_TA,offset means the TA offset value provided to the terminal for each serving cell, and N_TA means the value derived based on the timing advance command.
[0189] Figure 11c illustrates examples of timing advanced (TA) values for a satellite-related link. As illustrated in Figure 11c, a terminal-specific TA is calculated to compensate for transmission delay for the service link, and a common TA is calculated to compensate for transmission delay between the RP and the satellite.
[0190] - Valid interval and epoch time
[0191] The validity period refers to the (maximum) time period during which the terminal can apply the previously acquired assistance information (from the epoch time) without acquiring new assistance information (e.g., serving and / or neighboring satellite orbits (ephemeris) and common TA parameters, etc.). The configuration information related to the validity period can be broadcast from the base station via the NTN-related system information (e.g., SIB19) for each cell. For example, the validity period length range can be configured as, but is not limited to, {5s, 10s, 15s, 20s, 25s, 30s, 35s, 40s, 45s, 50s, 55s, 60s, 120s, 180s, 240s, 900s}. The validity timer with the set validity period value can be (re)started at the epoch time of the assistance information. If no new or additional support information is available within that validity period, the terminal may assume that uplink synchronization is lost.
[0192] The serving satellite ephemeris and common TA parameters are signaled in the same SIB message and may have the same epoch time. If the epoch time is explicitly provided via SIB, the epoch time of the assistance information (i.e., the satellite ephemeris and common TA parameters) is the start time of the DL subframe indicated by the SFN and the subframe number signaled together with the assistance information. If the epoch time is not explicitly indicated via SIB, the epoch time of the assistance information may be implicitly known as the end of the SI window in which NTN-specific system information (e.g., SIB19) is transmitted. If the epoch time is provided via dedicated signaling, the epoch time of the assistance information is the start time of the DL subframe and may be indicated by the SFN and the subframe number.
[0193] For a serving cell, if the epoch time is explicitly indicated by the SFN and subframe number, the UE may consider the frame as the current SFN or the next SFN after the frame in which the message indicating the epoch time was received. For a neighboring cell, if the epoch time is explicitly indicated by the SFN and subframe number, the UE may consider the frame as the frame closest to the frame in which the message indicating the epoch time was received.
[0194] C-4. Integrated Sensing and Communication (ISAC)
[0195] Wireless sensing is a technology that uses radio frequencies to determine the instantaneous linear velocity, angle, distance (range), etc. of an object, thereby obtaining information about the characteristics of the environment and / or objects within the environment. Because radio frequency sensing does not require a networked device to connect to the object, it can provide a service for object positioning without a device. The ability to obtain range, velocity, and angle information from radio frequency signals can enable a wide range of new capabilities, such as various object detection, object recognition (e.g., vehicles, humans, animals, UAVs), and high-precision localization, tracking, and activity recognition. Wireless sensing services can provide information to a variety of industries (e.g., drones, smart homes, V2X, factories, railways, public safety, etc.), enabling applications such as intruder detection, assisted vehicle steering and navigation, trajectory tracking, collision avoidance, traffic management, and health and traffic management. In some cases, wireless sensing can utilize non-3GPP type sensors (e.g., radar, cameras) to further support 3GPP-based sensing. For example, the operation of wireless sensing services, i.e., sensing operations, may depend on the transmission, reflection, and scattering of wireless sensing signals. Therefore, wireless sensing offers an opportunity to enhance existing communication systems from a communications network to a wireless communication and sensing network.
[0196] FIGS. 12A and 12B illustrate examples of sensing operations applicable to the present disclosure. The embodiments of FIGS. 12A and 12B can be combined with various embodiments of the present disclosure. Specifically, FIG. 12A illustrates an example of sensing using a sensing receiver and a sensing transmitter located at the same location (e.g., monostatic sensing), and FIG. 12B illustrates an example of sensing using separate sensing receivers and sensing transmitters (e.g., bistatic sensing).
[0197] For example, in a wireless communication system based on a 6G network of the present disclosure, referring to FIG. 12a, the sensing transmitter and the sensing receiver may be configured to be included in a single base station (i.e., the same base station) or a single terminal (i.e., the same terminal). Alternatively, referring to FIG. 12b, the sensing transmitter and the sensing receiver may be configured to be included in different base stations, different terminals, or each terminal and base station.
[0198] In this regard, the following six types of sensing modes can be defined based on whether the sensing transmitter and sensing receiver are included in the base station or the terminal, respectively.
[0199] - Mode 1: A mode in which the sensing transmitter and sensing receiver are contained in a single base station (e.g., base station-based sensing mode in monostatic mode).
[0200] - Second mode: A mode in which the sensing transmitter is included in a first base station and the sensing receiver is included in a second base station different from the first base station (e.g., base station-based sensing mode in bistatic mode).
[0201] - Mode 3: A mode in which the sensing transmitter is included in the base station and the sensing receiver is included in the terminal (e.g., base station-terminal sensing mode).
[0202] - Mode 4: A mode in which the sensing transmitter is included in the terminal and the sensing receiver is included in the base station (e.g., terminal-base station sensing mode).
[0203] - Mode 5: A mode in which the sensing transmitter and sensing receiver are contained in a single terminal (e.g., terminal-based sensing mode in monostatic mode).
[0204] - 6th mode: A mode in which the sensing transmitter is included in a first terminal and the sensing receiver is included in a second terminal different from the first terminal (e.g., terminal-based sensing mode in bistatic mode).
[0205] In a wireless communication system based on the 6G network of the present disclosure, one or more of the six types of sensing modes described above may be utilized independently / in combination.
[0206] With respect to the sensing operation in FIGS. 12A and 12B , the sensing transmitter may transmit a sensing signal for sensing one or more objects (and / or an environment around the objects). For example, the sensing signal may correspond to a radio (frequency) signal defined to be transmittable by a base station / terminal in a wireless communication system based on a 6G network of the present disclosure. The sensing receiver may receive a signal scattered / reflected by one or more objects (and / or an environment around the objects) from the sensing signal transmitted from the sensing transmitter. In the sensing receiver, sensing data may be derived from the scattered / reflected signals, and sensing results may be generated / obtained through processing of the sensing data. Here, the sensing results may include characteristic information (e.g., location, distance, speed, angle, etc.) about one or more objects (and / or the environment around the objects). The sensing results generated / obtained in this way may be utilized for wireless sensing services (e.g., detection, tracking, etc. of objects and / or environments) provided in a wireless communication system based on the 6G network of the present disclosure, or may be provided / disclosed to a trusted third party.
[0207] Additionally, the sensing operations in FIGS. 12A and 12B are described as a representative example of operations in a wireless communication system based on a 6G network, but can be extended and applied to cases where terminals / base stations / signals based on networks of previous generations (e.g., 4G, 5G, etc.) are utilized.
[0208] Additionally, with respect to the wireless sensing described in the present disclosure, in a wireless communication system based on a 6G network of the present disclosure, time / frequency resources for sensing operations and time / frequency resources for general communications (e.g., UL / DL / sidelink-based communications, etc.) may be scheduled / configured separately.
[0209] FIG. 13 illustrates an example of time / frequency resources for sensing operations applicable to the present disclosure. The embodiment of FIG. 13 may be combined with various embodiments of the present disclosure.
[0210] Referring to FIG. 13, time / frequency resources (hereinafter, sensing resources) for the aforementioned sensing operation (e.g., sensing operation based on FIG. 12a and FIG. 12b) can be set / allocated separately from time / frequency resources (hereinafter, communication resources) for general communication.
[0211] For example, as illustrated in FIG. 13, sensing resources can be set / allocated in units of symbols in the time domain and / or resource blocks in the frequency domain. Resources other than those for which the sensing resources are set / allocated can be utilized as resources for general communication. That is, sensing resources and communication resources can be set / allocated based on the time-division multiplexing (TDM) method and / or the frequency-division multiplexing (FDM) method in terms of the operation of the base station / terminal. Additionally or alternatively, unlike what is illustrated in FIG. 13, sensing resources can also be set / allocated based on other units in the time domain (e.g., slots, frames, absolute time (ms, us), etc.) and / or other units in the frequency domain (e.g., subcarriers, carriers, absolute frequencies (MHz, GHz), etc.).
[0212] Additionally or alternatively, in connection with the setting / allocation / scheduling of resources for general communication as described in the present disclosure, the relationship between the resources and the aforementioned sensing resources may need to be considered. For example, when setting / allocating resources for general communication according to the embodiment(s) of the present disclosure, the resources may be set / allocated to rate-match or puncture the resource region corresponding to the sensing resource. For example, when scheduling resources for general communication according to the embodiment(s) of the present disclosure, the resources may be scheduled so as not to overlap with the resource region corresponding to the sensing resource. If the resources for general communication according to the embodiment(s) of the present disclosure and the resource region corresponding to the sensing resource are set / allocated / scheduled to overlap, one or both operations may be dropped, skipped, or postponed based on priorities, predefined rules, etc. That is, in the embodiment(s) of the present disclosure, it may be desirable that resources related to general communication (e.g., resources for signals / channels related to UL / DL / Sidelink-based data / control, etc.) are set / allocated / scheduled so as not to overlap with the aforementioned sensing resources.
[0213] Additionally, various channel modeling methods may be applied to the wireless sensing described in the present disclosure. Channel modeling related to sensing may refer to configuring a path for transmitting and receiving sensing signals and / or scattered / reflected signals, taking into account the object being sensed and / or the environment in which the object resides. Channel modeling may be related to the performance / requirements of sensing in a wireless communication system, and thus may be an important factor in validating the sensing function.
[0214] Channels related to sensing can be divided into channels between objects (e.g., targets of interest) and sensing transmitters / receivers, and channels between the environment to which the object belongs and sensing transmitters / receivers. In this regard, channel modeling related to sensing can be divided based on sensing mode (e.g., the six types of modes described above), whether there is an object / environment, and / or sensing scenarios. For example, channel modeling for a target in a base station / terminal-based monostatic sensing mode, channel modeling for a target in a base station / terminal-based bistatic sensing mode, channel modeling for the environment in a base station / terminal-based monostatic sensing mode, and channel modeling for the environment in a base station / terminal-based bistatic sensing mode can be configured and optimized differently. For example, when various sensing scenarios are classified, channel modeling for detection, location, and tracking scenarios, channel modeling for motion recognition, and channel modeling for imaging / environment reconstruction scenarios can be divided, etc. Additionally, channel modeling related to sensing may be based on statistical channel modeling techniques and / or deterministic channel modeling techniques. For example, modeling for sensing in a wireless communication system based on a 6G network of the present disclosure may be based on stochastic geometric channel modeling techniques and / or a hybrid with ray tracing channel modeling technique. Here, the stochastic geometric channel model may be based on various statistical characteristics of the channel state. Furthermore, the hybrid channel model may be based on both ray tracing techniques and stochastic techniques.In a hybrid approach, channels for objects requiring high accuracy and consistency (e.g., targets of interest) can be modeled using ray tracing techniques, while channels for the environment can be modeled using probabilistic techniques.
[0215] FIG. 14 illustrates an example of a procedure related to a sensing operation applicable to the present disclosure. The embodiment of FIG. 14 may be combined with various embodiments of the present disclosure.
[0216] For example, in a wireless communication system based on a 6G network of the present disclosure, in the case of a sensing operation in which a terminal participates, the base station may need to verify the capability of the terminal for the sensing operation. In this regard, the terminal may be configured to report capability information regarding whether it supports the sensing operation to the base station. Additionally or alternatively, if the terminal is predefined in the standard to support the sensing operation, the procedure may be omitted. In addition, in the case of a sensing operation in which only the base station participates, the base station may be configured to report capability information regarding whether it supports the sensing operation to an entity that configures / controls its sensing operation (e.g., a network entity at a higher level / layer of the base station).
[0217] For example, the base station can perform signaling with the terminal to exchange configuration information related to the sensing operation. For example, the base station can configure / instruct the terminal information about the mode of the sensing operation (e.g., based on the six types of modes described above), the subject of the sensing operation (e.g., sensing transmitter, sensing receiver), the resource of the sensing operation (e.g., sensing resource as in FIG. 13), the target of utilizing the sensing result (e.g., type of wireless sensing service based on 6G network, trusted third party), channel modeling for sensing (e.g., channel between the base station / terminal and object / environment), etc. For example, the base station can also configure / instruct such information from a network entity at an upper level / layer of the base station.
[0218] For example, the base station and / or the terminal may perform a sensing operation based on the set / instructed information. For example, the base station and / or the terminal may, as a sensing transmitter and / or a sensing receiver, perform procedures such as transmitting a sensing signal, receiving a scattered / reflected signal, deriving sensing data, obtaining a sensing result through processing the sensing data, and providing the sensing result, as in FIGS. 12A and 12B described above. As an example, in the operation of the base station / terminal described in the present disclosure, a sensing result provided through a sensing operation may be utilized.
[0219] D. NES (network energy saving)
[0220] Energy conservation at base stations is a key consideration in wireless communication systems, including 3GPP, as it can contribute to building eco-friendly networks by reducing carbon emissions and reducing operational expenditures (OPEX) for telecommunications companies. In particular, the introduction of 5G communications will require higher transmission rates, necessitating base stations to be equipped with more antennas and provide services across wider bandwidths and frequency bands. Consequently, recent studies have shown that base station energy costs have reached as high as 20% of total OPEX. Accordingly, 5G systems are adopting various technologies to reduce energy consumption, known as network energy savings (NES), and the standardization of related technologies is expected to continue. Specifically, the following techniques were discussed in the recent Rel-18.
[0221] -----------------------------------------------------------------------
[0222] 1. If deemed feasible by RAN4 studies, specify SSB-less SCell operation for interband CA for FR1 and co-located cells, where the UE measures SSB transmitted on the PCell or another SCell for SCell time / frequency synchronization (including downlink AGC) and L1 / L3 measurements, including potential enhancements to the SCell activation procedure if required. [RAN4, RAN2]]
[0223] 2. Embody improvements to the cell DTX / DRX mechanism, including inter-node information exchange for cell DTX / DRX and alignment of cell DTX / DRX and UE DRX in RRC_CONNECTED mode. [RAN2, RAN1, RAN3]
[0224] ·Note: No changes to SSB transmission due to cell DTX / DRX.
[0225] ·Note: The above improvements should avoid any impact on IDLE / INACTIVE UEs.
[0226] 3. Implement the following technologies in the space and power domains:
[0227] · To enable efficient adaptation of spatial elements (e.g., antenna ports, active transceiver chains), specify necessary improvements to CSI and beam management-related procedures, including measurement and reporting, and signaling. [RAN1, RAN2]
[0228] · To enable efficient adaptation of power offset values between PDSCH and CSI-RS, necessary improvements to CSI-related procedures, including measurement, reporting, and signaling, are specified. [RAN1, RAN2]
[0229] · Note: The above goals are only applicable to UE specific channels / signals.
[0230] · Note: Given the total number and requirements of CSI reports, conventional UE CSI / CSI-RS capabilities apply.
[0231] 4. If necessary, specify a mechanism to prevent camping of legacy UEs in cells adopting Rel-18 NES technology. [RAN2]
[0232] 5. Implement improvements to the CHO procedure when the source / target cell is in NES mode. [RAN2]
[0233] 6. Improvements to limit paging in limited areas and specify inter-node beam activation [RAN3].
[0234] 7. If necessary, specify the RRM / RF core requirements for the above features. [RAN4]
[0235] -----------------------------------------------------------------------
[0236] According to the application of NES technology, the base station can perform operations such as controlling on / off for a certain duration in the time domain, controlling transmission / reception resources for UE-common or UE-specific signals / channels, changing the amount of frequency domain resources, controlling transmission power, or turning on / off antenna ports, transmission-reception points (TRPs), etc. in the spatial domain. Fig. 15 illustrates an example of an operation procedure of a base station supporting the NES technology applicable to the present disclosure. Referring to Fig. 15, the base station identifies NES solution(s) to be applied. The NES solution(s) may be related to control of signal transmission / reception (e.g., on / off), beam operation, handover procedure, channel measurement and reporting, etc. Which NES solution(s) to apply can be adaptively selected or predefined depending on the current situation (e.g., cell load level, characteristics of connected terminals, etc.). The base station, having identified the NES solution(s), performs signaling for the NES. The specific signaling procedure may vary depending on the identified NES solution(s). For example, the base station may transmit common information about the NES solution(s), transmit configuration information necessary for NES operation to at least one terminal, or transmit control information regarding the progress of the NES operation to at least one terminal. In addition, the base station may receive capability information related to the NES from at least one terminal. Thereafter, the base station performs operations for the NES. At this time, the base station may perform operations for the NES based on the previously performed signaling. That is, based on the system information, configuration information, and control information transmitted through the signaling, the base station may turn on / off the transmission / reception of a specific signal, turn on / off elements in the spatial domain, or adjust resources for the transmission / reception of a measurement signal.
[0237] Through a procedure similar to that in Fig. 12, NES technology can be implemented. Examples of NES solutions that can be implemented through a procedure similar to that in Fig. 12 are as follows.
[0238] · Intra-system energy saving solution: A RAN node can request a neighboring RAN node to switch at least one SSB beam into its inactive cell, or can perform paging using a limited set of beams to an inactive terminal (e.g., a stationary terminal).
[0239] · Inter-system energy saving solution: NG-RAN nodes that own capacity booster cells can autonomously transition those cells to an inactive state.
[0240] · SSB-less SCell solution: If SSB or SMTC (SSB-based RRM measurement timing configuration) configuration is not provided for the SCell, the UE can obtain the timing reference and AGC source from another serving cell. In FR1 or FR2, the base station can configure intra-band CA or inter-band CA including the SCell without SSB transmission, in which case the SSB / SIB transmission can be triggered by the WUS (wake-up signal) of the UE. Accordingly, since the period of common channels / signals such as SSB increases, the base station can stay in the sleep state for a longer time.
[0241] · Cell DTX / DRX (discontinuous transmission / discontinuous reception) solution: In order to reduce the downlink transmission / uplink reception activity time of a base station, a periodic cell DTX / DRX pattern (e.g., active and inactive periods) can be commonly set for terminals within a cell having the corresponding feature. Here, the cell DTX pattern and the cell DRX pattern can be separately set and activated, and up to two cell DTX / DRX patterns can be set per MAC entity. When cell DTX is set and activated, at least one of monitoring for SPS opportunities or monitoring PDCCH can be stopped during the cell DTX inactivity period. When cell DRX is set and activated, at least one of transmission on CG resources or SR transmission can be stopped during the cell DRX inactivity period. Cell DTX / DRX can be activated / deactivated via RRC signaling or L1 group common signaling.
[0242] · Parameters such as active duration and cycle may be configured for cell DTX / DRX. The active duration is the period during which the UE receives a PDCCH or SPS opportunity and waits to transmit SR or CG, and the cycle specifies the periodic repetition of the active duration and the inactive duration. When both cell DTX and cell DRX are configured, parameters such as active duration and cycle are common. If the base station recognizes an emergency call or a public safety-related service (e.g., MPS or MCS), the network may release or deactivate the cell DTX / DRX configuration so as not to affect the service. In addition, at least some overlap is required between the active duration of the connected mode DRX of the UE and the active duration of the cell DTX / DRX. For example, the connected mode DRX cycle of the UE may be a multiple of the cell DTX / DRX cycle, or vice versa.
[0243] · Conditional handover (CHO) solution: A CHO procedure is used when the UE determines whether to execute a handover while NES technology is applied (e.g., when the cell activates or deactivates cell DTX / DRX). In this case, the UE can use an NES-specific CHO event to initiate CHO to a candidate cell, and the reception of a DCI activating the CHO condition(s) set by the NES event indication can be applied as an additional triggering condition for this.
[0244] · Spatial and Power Domain Adaptation Solution: To support gNBs for transceiver muting and / or transmit power adaptation, a UE may be configured to report multiple CSI entries in a CSI report based on multiple sub-configurations. Each sub-configuration corresponds to a spatial domain adaptation pattern (e.g., a subset of available spatial elements) and / or a power offset between a data channel (e.g., PDSCH) and CSI-RS. Depending on the application of the spatial and power domain adaptation solution, the CSI configuration, measurement, and / or reporting behavior may be affected.
[0245] SCell without SSB
[0246] FIG. 16 illustrates an example of a procedure for a CA operation using an SSB-less SCell applicable to the present disclosure. Referring to FIG. 16, a base station transmits configuration information for an SCell to a terminal. That is, the base station transmits configuration information for CA to provide a service to the terminal through a CA operation. Here, the CA operation may be an intra-band CA or an inter-band CA. For example, the configuration information for an SCell may include information including information for adding an SCell (e.g., sCellToAddModList), and specifically, may include a cell index, a physical cell identifier, information related to DL-UL configuration, information related to BWP, information related to cell DTX / DRX, information related to downlink frequency (e.g., FrequencyInfoDL), etc. Then, the terminal can determine the configuration for the CA operation and perform communication using the PCell and SCell of the base station. At this time, the terminal can confirm that the SCell is an SSB-less SCell based on the information related to the downlink frequency included in the configuration information, and check the related parameters. For example, the UE can determine that the SCell is an SSB-less SCell by checking for the presence of a parameter indicating that the SCell is an SSB-less SCell (e.g., SSBlessSCell), and can determine the timing reference and AGC source for the SCell based on information about the reference cell (e.g., referenceCell). In the case of Figure D03, the reference cell may be the PCell. Therefore, the UE can use the PCell as a timing reference and AGC source for communications on the SCell.
[0247]
[0248] In 3GPP NR release 19, a work item titled “Enhancements of network energy savings for NR” was additionally approved. Specifically, the following enhancement techniques are being considered in 3GPP NR release 19:
[0249] -----------------------------------------------------------------------
[0250] Objectives of SI (study item) or core part WI (work item) or test part WI
[0251] The goals of WI are:
[0252] 1. Specify procedures and signaling methods to support on-demand SSB SCell operation for both in-band and inter-band CA for UEs in connection mode set to CA. [RAN1 / 2 / 3 / 4]
[0253] · Specify the triggering method(s). (Select from UE uplink wake-up signaling using existing signals / channels, cell on / off indication via backhaul, and Scell activation / deactivation signaling.)
[0254] · Note 1: On-demand SSB transmission can be used by the UE for minimum SCell time / frequency synchronization, L1 / L3 measurements, and SCell activation, and is supported for FR1 and FR2 in unshared spectrum.
[0255] 2. Study the procedures and signaling method(s) to support on-demand SIB1 for UEs in idle / inactive mode, as follows: [RAN1 / 2 / 3]
[0256] · Triggering method by uplink wake-up signal using existing signal / channel.
[0257] · Provide wake-up signal settings to the UE
[0258] - Note: Modification of SSB is not discussed in this goal.
[0259] · If necessary, exchange information between gNBs at least for setting up wake-up signals.
[0260] · Checkpoints for normative work in RAN#105
[0261] 3. Implement adaptation of common signal / channel transmission [RAN1 / 2 / 3 / 4]
[0262] · Adaptation of SSB in the time domain, e.g. periodic adaptation
[0263] · PRACH adaptation in the time domain
[0264] · Study adaptation of PRACH in the spatial domain, e.g., non-uniform PRACH resources per SSB, and implement if found to be beneficial.
[0265] - This study will be conducted only in the second quarter of 2024.
[0266] · Coordination of paging opportunities, including limiting paging opportunities in the time domain.
[0267] - Note: Paging delay time should not increase.
[0268] - Note: There should be no negative impact on existing UEs unless significant benefits are achieved.
[0269] 4. For the above features, specify the corresponding core requirements. [RAN4]
[0270] -----------------------------------------------------------------------
[0271] On-demand SSB
[0272] Through the aforementioned objective 1, a method can be discussed to reduce energy consumption by having the base station transmit SSB on a specific cell through the on-demand SSB process and not transmit SSB on the cell when the on-demand SSB process is not available. In the existing NR system, SSB must be transmitted periodically and constantly for purposes such as time / frequency synchronization or RRM measurement, making it difficult to reduce energy consumption even when the base station has no data to receive or send. Considering this, the base station can reduce base station energy consumption by not performing SSB transmission until the on-demand SSB process is involved and then performing SSB transmission. The on-demand SSB process can be triggered using one of the following methods:
[0273] 1) The terminal requests SSB transmission from the base station by transmitting an uplink signal / channel (e.g., PRACH, PUCCH, PUSCH, SRS in the NR system).
[0274] 2) Requesting SSB transmission from base station (or TRP) #1 to base station (or TRP) #2 through an interface between base stations (e.g., Xn interface in NR system) or backhaul signaling.
[0275] 3) Signaling whether SSB transmission is possible for the corresponding Scell through Scell activation / deactivation signaling.
[0276] Considering coexistence with existing NR terminals, Release 19 is limited to on-demand SSB operation for connected mode terminals and SCells. However, in future releases or next-generation communication systems, on-demand SSB operation (for SSB transmission on PCell) considering inactive or idle mode terminals or initially connected terminals may be defined. In addition, carrier aggregation (CA) including the SCell can be applied to both intra-band CA and inter-band CA, and the SSB on the SCell transmitted through the on-demand SSB process can be utilized for at least functionality such as time / frequency synchronization, L1 / L3 measurement, and SCell activation.
[0277] On-demand SIB1 transmission
[0278] Objective 2 in Table E-1 above can discuss a method of reducing energy consumption by having the base station transmit SIB1 for a specific cell through the on-demand SIB1 process and not transmit SIB1 for the cell when there is no on-demand SIB1 process. In the existing NR system, SIB1 containing system information, random access information, etc. for initial access or idle mode terminals to access a cell must always be periodically provided, making it difficult to reduce energy consumption even when the base station has no data to receive or send. Considering this, the base station can reduce base station energy consumption by not performing SIB1 transmission until the on-demand SIB1 process is accompanied and then performing SIB1 transmission. The on-demand SIB1 process can trigger SIB1 transmission of the base station when the terminal transmits an uplink signal / channel (e.g., PRACH in the NR system). Specifically, the following scenarios can be considered, but may not be limited to the following scenarios.
[0279] 1) Scenario 1: As shown in FIG. 17a, a terminal that receives an SSB (and / or other downlink signal / channel) from a cell#1 and recognizes that SIB1 is not transmitted on the cell#1 can trigger SIB1 transmission by transmitting a signal requesting SIB1 (for convenience, the signal is referred to as a WUS (wake-up signal) in the present invention) based on information provided in the SSB (and / or other downlink signal / channel) and / or predetermined information. The base station that receives the WUS can transmit a specific DL signal / channel on cell#1 in response thereto, and can transmit SIB1 on cell#1 (or without transmitting the DL signal / channel).
[0280] 2) Scenario 2: As in Fig. 17b, a terminal may attempt to camp on cell#2 when it receives an SSB (and / or other downlink signal / channel such as SIB1) from a cell#1 and recognizes that SIB1 is not transmitted on the corresponding cell#2. The terminal may trigger SIB1 transmission for cell#2 by transmitting a signal (i.e., WUS) requesting SIB1 on cell#1 based on information provided in the received SSB (and / or other downlink signal / channel such as SIB1) and / or predetermined information. The base station receiving the WUS may transmit a specific DL signal / channel (on cell#1 or cell#2) in response thereto, and may transmit SIB1 for cell#2 on cell#1 or cell#2 (or without transmitting the DL signal / channel).
[0281] 3) Scenario 3: As in Fig. 17c, a terminal may attempt to camp on cell#2 when it receives an SSB (and / or other downlink signal / channel such as SIB1) from a cell#1 and recognizes that SIB1 is not transmitted on the corresponding cell#2. The terminal may trigger SIB1 transmission for cell#2 by transmitting a signal (i.e., WUS) requesting SIB1 on cell#2 based on information provided in the received SSB (and / or other downlink signal / channel such as SIB1) and / or predetermined information. The base station receiving the WUS may transmit a specific DL signal / channel (on cell#1 or cell#2) in response thereto, and may transmit SIB1 for cell#2 on cell#1 or cell#2 (or without transmitting the DL signal / channel).
[0282]
[0283] Specific embodiments of the present disclosure
[0284] The present disclosure relates to a technology for operating SSB (synchronization signal / physical broadcast channel block) and system information on-demand in a wireless communication system. Specifically, the present disclosure proposes a technology for providing SSB (e.g., synchronization signal, MIB) and / or system information (e.g., MIB, SIB) on a request basis in a cell or frequency band where transmission of SSB is temporarily suspended for NES operation. Hereinafter, in the present disclosure, ' / ' means 'and', 'or', or 'and / or' depending on the context.
[0285]
[0286] The base station can operate technologies such as controlling the on / off of the UE for a certain period of time in the time axis for the purpose of NES, controlling the transmission / reception resources for UE-common or UE-specific signals / channels, changing the amount of frequency-axis resources, controlling the transmission power, or turning on / off the antenna port (AP), TRP, etc. in the spatial domain. In the present disclosure, the listed technologies are referred to as 'NES technologies' or 'NES_tech', and the state in which at least one of the NES_techs is applied is referred to as 'NES mode' or 'NES state'. The base station can inform the terminal of which NES_tech(s) is applied for each NES_tech or NES_tech group [Approach 1], or can preset the corresponding NES_tech or NES_tech group(s) for each code-point of a specific indicator [Approach 2]. Here, specific indicators may be indicated by DCI or MAC CE, etc., or may be set by higher layer signaling.
[0287] For Approach 1, if at least one NES_tech is applied to the terminal, the state can be defined as an NES mode or NES state, and further, can be treated as a different NES mode or different NES state depending on which NES_tech is applied. The NES mode or NES state can be used as a concept to indicate whether at least one NES technology is applied, or further to indicate which NES technology(s) are applied. If the NES mode or NES state further indicates which NES technology(s) are applied, different NES modes or different NES states can include different combinations of NES_tech. For Approach 2, for example, if a 1-bit indicator is used, '0' can indicate that the corresponding NES_tech is not applied, and '1' can indicate that at least one NES_tech is applied. In this case, if '1' is indicated through the indicator, the state can be defined as an NES mode or NES state. As another example, when a 2-bit indicator is used, '00' can indicate that there is no corresponding NES_tech, '01' can indicate that at least one NES_tech_A is applied, '10' can indicate that at least one NES_tech_B is applied, and '11' can indicate that at least one NES_tech_C is applied. In this case, if a code-point other than '00' is indicated through the indicator, the state can be defined as an NES mode or NES state. Furthermore, the terminal can determine NES state #1 when '01' is identified, NES state #2 when '10' is identified, and NES state #3 when '11' is identified. Accordingly, whether it is an NES state and / or which NES state it is can be distinguished for each code-point.
[0288] For NES purposes, the base station can turn on / off certain spatial elements (e.g., APs, active transmit / receive chains, panels or TRPs) or adjust the power value for the downlink signal / channel. To dynamically apply various NES techniques in the spatial and power domains, the base station can associate CSI-RS resources or resource sets with different APs for a single CSI report setting (e.g., CSI-ReportConfig) or associate multiple power offsets (e.g., powerControlOffset parameter, which is a power offset value between PDSCH and CSI-RS, powerControlOffsetSS parameter, which is a power offset value between SSS and CSI-RS, etc.).
[0289] Specifically, at least one of the following CSI frameworks may be introduced:
[0290] - Framework #1: Multiple CSI-RS resource sets are linked for one CMR (channel measurement resource) or one IMR (interference measurement resource) in CSI-ReportConfig. Here, the CMR can be set by the resourcesForChannelMeasurement parameter, and the IMR can be set by the csi-IM-ResourcesForInterference or nzp-CSI-RS-ResourcesForInterference parameter. For example, for CMR, CSI-RS resource set #1 and CSI-RS resource set #2 are linked, and the CSI-RS resources belonging to CSI-RS resource set #1 can be configured with 16 APs (antenna ports, APs), and the CSI-RS resources belonging to CSI-RS resource set #2 can be configured with 8 APs.
[0291] - Framework #2: When a CSI-RS resource set linked to a CMR or an IMR in CSI-ReportConfig is configured, at least one CSI-RS resource(s) with different properties such as the number of APs and / or power offsets within the CSI-RS resource set are configured. For example, for a CSI-RS resource set #1 configured as CMR, CSI-RS resource #1 belonging to the CSI-RS resource set #1 may be configured with 16 APs, and CSI-RS resource #2 belonging to the same set may be configured with 8 APs. For example, for a CSI-RS resource set #1 configured as CMR, CSI-RS resource #1 belonging to the CSI-RS resource set #1 may be configured with the power offset #1 value, and CSI-RS resource #2 belonging to the same set may be configured with the power offset #2 value.
[0292] - Framework #3: When a CSI-RS resource set linked to a CMR or an IMR is configured in CSI-ReportConfig, some or all CSI-RS resource(s) within the set can be configured with multiple AP numbers and / or power offset values. For example, for a CSI-RS resource set #1 configured with a CMR, CSI-RS resource #1 belonging to the CSI-RS resource set #1 can be configured with up to 16 APs, and CSI reporting utilizing at least one AP among them can be configured. Alternatively, CSI-RS resource #2 belonging to the same CSI-RS resource set #1 can be configured with multiple power offset values, and CSI reporting utilizing all or part of the power offsets can be configured.
[0293] For the CSI frameworks described above, the CSI reporting method can be defined through at least one of the following options.
[0294] - Option #1: CSIs that consider multiple AP count values and / or multiple power offset values set in a single CSI report may all be included in a single CSI report. Alternatively, CSIs that consider multiple AP count values and / or multiple power offset values determined through the configuration / instruction of the base station may be included in a single CSI report. In this case, the AP count values and / or power offset values set / instructed through the base station may be some of the AP count values and / or power offset values set in the corresponding CSI report.
[0295] - Option #2: Even if multiple AP count values and / or multiple power offset values are set in one CSI report, CSI(s) considering a single AP count value and / or a single power offset value can be included in one CSI report through the base station's configuration / instruction.
[0296] - Option #3: Even if multiple AP count values and / or multiple power offset values are set in one CSI report, CSI(s) that consider some AP count values and / or some power offset values may be included in one CSI report through judgment / decision / selection of the terminal based on criteria set in advance by the base station or defined in advance.
[0297] Within a configuration for CSI reporting (e.g., CSI-ReportConfig), one or more L sub-configurations can be configured, and each sub-configuration can correspond to either a spatial domain adaptation pattern or a power domain adaptation pattern.
[0298] Here, the spatial domain adaptation pattern may correspond to a specific number of APs or an AP on / off pattern, or may correspond to a specific CSI-RS power value (e.g., the CSI-RS power value determined by the powerControlOffsetSS parameter, which is a power offset value between SSS and CSI-RS, because the turning off of some antenna elements corresponding to one AP may affect the CSI-RS power value). For example, when applying framework #2, the number of APs A1 or the power value P1 may be set for the CSI-RS index #n1 belonging to the resource set, and the number of APs A2 or the power value P2 may be set for the CSI-RS index #n2 belonging to the same resource set. In this case, the sub-configuration index #s1 is set to be linked with the CSI-RS index #n1, and the sub-configuration index #s2 is set to be linked with the CSI-RS index #n2, so that the spatial domain adaptation pattern can be set differently for each sub-configuration. When applying the Framework #3 method, when the number of A1 APs (or P1 / P2 power values) is set for the CSI-RS index #n1 belonging to the resource set, the number of A1 APs (or P1 power values or delta values from the P1 power values) is linked to the sub-configuration index #s1, and the number of A2 APs (or P2 power values or delta values from the P1 power values) that is less than the number of A1 APs that constitute the CSI-RS index #n1 is linked to the sub-configuration index #s2, so that the spatial domain adaptation pattern can be set differently for each sub-configuration.
[0299] In addition, the power domain adaptation pattern may mean that the power offset value (e.g., the power offset value determined by the powerControlOffset parameter, which is the power offset value between PDSCH and CSI-RS, the powerControlOffsetSS parameter, which is the power offset value between SSS and CSI-RS, etc.) is changed. For example, when applying framework #2, the P1 power value may be set for the CSI-RS index #n1 belonging to the resource set, and the P2 power value may be set for the CSI-RS index #n2 belonging to the same resource set. In this case, the sub-configuration index #s1 may be linked to the CSI-RS index #n1, and the sub-configuration index #s2 may be linked to the CSI-RS index #n2, so that the power domain adaptation pattern may be set differently for each sub-configuration.
[0300] In addition, when applying framework #3, the P1 power value and the P2 power value can be set for the CSI-RS index #n1 belonging to the resource set. In this case, the sub-configuration index #s1 is set to be linked to the P1 power value, and the sub-configuration index #s2 is set to be linked to the P2 power value or the delta value from the P1 power value, so that the power domain adaptation pattern can be set differently for each sub-configuration.
[0301] By utilizing one of the aforementioned options #1 / 2 / 3, the terminal may feed back to the base station a CSI report including CSI(s) corresponding to N sub-configurations, which are 1 to L, among L sub-configurations.
[0302]
[0303] From the perspective of a base station operating multiple frequency bands, if the number of terminals served is small or the traffic load is relatively low, periodically transmitting SSB and / or system information may result in unnecessary energy consumption. In the present disclosure, the frequency band may be replaced with a band, a carrier, a serving cell, or a bandwidth part (BWP).
[0304] For example, three frequency bands may be operated as shown in FIG. 18. FIG. 18 illustrates examples of frequency bands operated by a base station according to an embodiment of the present disclosure. Referring to FIG. 18, when a base station operates three frequency bands, the base station may periodically transmit SSB (e.g., legacy SSB) in some frequency bands (e.g., F1), transmit simplified or modified S-SSB (simplified-SSB) in the remaining frequency bands (e.g., F2), or not transmit SSB and S-SSB in other frequency bands (e.g., F3). That is, F2 and F3 may be understood as SSB-free frequency bands. Through this, the base station can achieve energy conservation. In the present disclosure, S-SSB may have a structure in which some signals / channels are omitted, the structure of signals / channels is modified, or different information is transmitted through the PBCH payload compared to signals / channels included in the existing SSB (e.g., PSS, SSS, PBCH DM-RS, PBCH, etc.). In addition, in the present disclosure, S-SSB has a different structure from the existing SSB, and thus, it can be understood that the version / mode of SSB is different, and may be referred to by different terms.
[0305]
[0306] The present disclosure considers a scenario in which a terminal receives information about F2 and / or F3 via SSB and / or SIB1 transmitted on F1. According to one embodiment, the terminal, having received signaling for another frequency band, performs an on-demand SSB / SIB1 procedure on F2 or F3 to receive an SSB (e.g., one of an SSB and an S-SSB) and / or SIB1 on the F2 or F3 frequency band. Then, the terminal performs a RACH procedure (e.g., a random access procedure), enters a connected mode, and can receive and transmit downlink and / or uplink data via F2 or F3. Specifically, for a terminal operating according to this scenario, the present disclosure proposes various embodiments regarding information set to the terminal, a method for selecting F2 or F3, the on-demand SSB / SIB1 procedure, etc., but the technology proposed in the present disclosure is not limited to the scenario. For example, a terminal may first receive an S-SSB transmitted in the F2 frequency band from the initial access stage, and may confirm the existence of the F1 frequency band through information in the S-SSB of the F2 frequency band. In this case, the embodiments described below may be applied to the F1 frequency band.
[0307] In addition, for convenience of explanation, the present disclosure refers to a frequency band in which S-SSB can be transmitted, such as F2, and a frequency band in which SSB cannot be transmitted, such as F3, as the 'F2 frequency band'. However, it is obvious that the embodiments described below can also be applied to frequency bands with other names. For example, a frequency band in which SSB can be transmitted, such as F1, can be referred to as a 'first type frequency band' or a 'non-NES frequency band', a frequency band in which S-SSB can be transmitted, such as F2, can be referred to as a 'second type frequency band' or a 'first type NES frequency band', and a frequency band in which SSB and S-SSB cannot be transmitted, such as F3, can be referred to as a 'third type frequency band' or a 'second type NES frequency band'.
[0308]
[0309] FIG. 19 illustrates an example of a procedure for providing a communication service based on multiple frequency bands according to one embodiment of the present disclosure. FIG. 19 illustrates a method performed by a base station.
[0310] Referring to FIG. 19, in step S1901, the base station sets a first frequency band and a second frequency band. Here, the base station may set the first frequency band as a type 1 frequency band capable of providing SSB, and may set the second frequency band as a type 2 frequency band that provides S-SSB or a type 3 frequency band that does not provide SSB / S-SSB. In addition, the base station may set SSB and / or system information on the first frequency band so as to signal information related to the second frequency band in the first frequency band. Alternatively, the base station may set S-SSB and / or system information on the second frequency band so as to signal information related to the first frequency band in the second frequency band.
[0311] In step S1903, the base station transmits configuration information in the first frequency band or the second frequency band. The configuration information may include information necessary for a communication service using the first frequency band and the second frequency band. For example, the configuration information transmitted in the first frequency band may include information necessary for performing communication or proceeding with an on-demand SSB / SIB procedure in the second frequency band. Here, the configuration information may include at least one of information related to the correlation of channels between the first frequency band and the second frequency band, information related to a signal / channel for requesting an on-demand SSB / SIB procedure, information related to a signal / channel provided in response to the on-demand SSB / SIB procedure, information related to the structure of frequency bands, and information related to a RACH procedure or a paging procedure in the second frequency band.
[0312] In step S1905, the base station controls the state of the second frequency band based on the configuration information. Here, the state is related to whether or not to transmit SSB, S-SSB, and / or SIB. That is, the base station can operate the second frequency band in a first state in which SSB, S-SSB, and / or SIB are not transmitted in the second frequency band, or a second state in which SSB, S-SSB, and / or SIB are transmitted in the second frequency band. According to various embodiments, the state can be changed based on a signal received from the terminal. That is, the base station can receive a signal (e.g., UE WUS) transmitted from the terminal based on the configuration information transmitted in step S1903, and transmit the SSB, S-SSB, and / or SIB based on the reception of the signal. At this time, specific settings for transmission of the SSB, S-SSB, and / or SIB can be determined based on properties (e.g., resources, sequences, etc.) of the received signal.
[0313]
[0314] FIG. 20 illustrates an example of a procedure for performing communication based on multiple frequency bands according to one embodiment of the present disclosure. FIG. 20 illustrates a method performed by a terminal.
[0315] Referring to FIG. 20, in step S2001, the terminal receives a signal in a first frequency band or a second frequency band. Here, the signal is a broadcasted signal (e.g., SSB, S-SSB, synchronization signal, system information, etc.), and may include at least one signal that can be received even before establishing a connection with the base station. That is, the terminal may receive a synchronization signal, acquire synchronization based on the synchronization signal, and receive system information. Here, the first frequency band may include a first frequency band that can provide SSB, the second frequency band may include a second frequency band that provides S-SSB, or a third frequency band that does not provide SSB / S-SSB.
[0316] In step S2003, the terminal obtains configuration information for frequency bands based on the received signals. That is, the terminal may obtain the configuration information by decoding the received signal, or may obtain the configuration information by decoding another signal indicated by the received signal. At this time, the terminal may obtain information necessary for performing communication or proceeding with a procedure in the second frequency band based on a signal received in the first frequency band. Alternatively, the terminal may obtain information necessary for performing communication or proceeding with a procedure in the second frequency band based on a combination of a signal received in the first frequency band and a signal received in the second frequency band. Here, the configuration information may include at least one of information related to the correlation of channels between the first frequency band and the second frequency band, information related to a signal / channel for requesting an on-demand SSB / SIB procedure, information related to a signal / channel provided in response to the on-demand SSB / SIB procedure, information related to the structure of frequency bands, and information related to a RACH procedure or a paging procedure in the second frequency band.
[0317] In step S2005, the terminal receives an SSB / SIB in the second frequency band based on the configuration information. Here, the SSB / SIB includes an SSB, an S-SSB, and / or an SIB. Specifically, the terminal transmits a signal (e.g., UE WUS) requesting transmission of an SSB / SIB in the first frequency band or the second frequency band based on the configuration information transmitted in step S2003. At this time, according to the specific configuration for transmission of the SSB, S-SSB, and / or SIB to be requested, the terminal may determine the properties (e.g., resources, sequences, etc.) of the signal and transmit a signal having the determined properties to the base station. Furthermore, although not illustrated in FIG. 20, the terminal may perform a RACH procedure or a paging procedure in the second frequency band based on the SSB / SIB.
[0318]
[0319] According to various embodiments, a terminal may transmit a UE wake-up signal (WUS) to request transmission of SSB and / or SIB1 on an F2 frequency resource. Here, 'UE WUS' functionally means a signal that causes transmission of SSB / SIB1 on the corresponding frequency resource. Accordingly, the UE WUS may be implemented as another signal / message defined in the current specification document (e.g., measurement report, CSI report, PRACH preamble, reference signal (e.g., SRS), etc.) or may be implemented as a newly defined signal / message. In addition, the UE WUS may be referred to as a request signal, an initiation signal, a trigger signal, a state change signal, or other terms having an equivalent technical meaning thereto.
[0320]
[0321] As described with reference to FIGS. 19 and 20, the base station and the terminal can perform communication using frequency bands capable of providing SSB and frequency bands that do not provide SSB. Below, the present disclosure describes in more detail embodiments of various aspects necessary for performing communication using a plurality of different types of frequency bands.
[0322]
[0323] [Example #1] Information that can be set to a terminal through SSB and / or SIB transmitted in the F1 frequency band or S-SSB transmitted in the F2 frequency band, and operations of the terminal based on the information.
[0324] The terminal may receive at least some of the following information via SSB (e.g., synchronization signal, MIB) and / or system information (e.g., MIB, SIB) transmitted in the F1 frequency band. Alternatively, the terminal may receive at least some of the following information via S-SSB transmitted in the F2 frequency band.
[0325] Information Description List of frequency bands (e.g. F2 and / or F3) in association or QCL relationship with frequency band F1 The existence of an association or QCL relationship between two frequency bands (e.g. F1 and F2) means that frequency band F1 can be a timing and / or power control or path-loss estimation and / or synchronization reference for frequency band F2. That is, this can mean that frequency band F1 can be a timing reference for frequency band F2, or frequency band F1 can be a reference for power control or path-loss estimation for frequency band F2, or frequency band F1 can be a time / frequency synchronization reference for frequency band F2. Information related to time / frequency resources for transmitting UE WUS Time / frequency resource information on which UE WUS can be transmitted can be set. The corresponding UE WUS resource may be set within the F2 frequency band or the F1 frequency band. In particular, if it is a cell DRX inactive period of the base station, or if the F1 frequency band is not a synchronous reference of the F2 frequency band and S-SSB / SIB transmission is turned off in the F2 frequency band, the UE WUS resource may be set within the F1 frequency band. Frequency, time and / or sequence related information (e.g., PRACH preamble index, cyclic shift (CP), sequence index, root sequence index, phase offset, orthogonal cover code (OCC), etc.) of the UE WUS may vary depending on the frequency band (e.g., F2 or F3) in which the requested SSB and / or SIB1 will be transmitted.For example, even if a UE WUS is transmitted on a resource allocated to the F1 frequency band, information related to the frequency, time, and / or sequence of the UE WUS may be set differently depending on whether the UE requests an SSB transmitted on the F2 frequency band or an SSB transmitted on the F3 frequency band. Alternatively, information related to the frequency, time, and / or sequence of the UE WUS may vary depending on the requested SSB index and / or the requested signal (e.g., SSB or SIB1). For example, even if a SSB is to be transmitted on the F2 frequency resource, information related to the frequency, time, and / or sequence of the UE WUS may be set differently depending on the SSB index or SSB index group. Alternatively, information related to the frequency, time, and / or sequence of the UE WUS may be set differently depending on whether transmission for an SSB or an SSB group of a specific index or beam sweeping for all SSBs is requested. As another example, depending on whether the signal requesting transmission to the base station through the UE WUS is SSB or SIB1, information related to the frequency, time, and / or sequence of the UE WUS may be set differently. As another example, even for SIB1 requesting transmission to the base station through the UE WUS, information related to the frequency, time, and / or sequence of the UE WUS may be set differently depending on which SSB index corresponding to which SIB1 transmission is requested from a QCL perspective. Here, the fact that information related to the frequency, time, and / or sequence is set differently means that at least one of a plurality of candidates that are set to be selectable based on a given criterion (e.g., frequency band, requested signal, property of the requested signal, etc.) is included. Information related to a signal / channel corresponding to the UE WUS After the terminal makes a request for a specific signal / channel through the UE WUS transmission and receives the corresponding signal / channel, the terminal can determine whether the request has been properly transmitted.Therefore, it may be necessary for the base station to set information about the signal / channel corresponding to the UE WUS. For example, when the base station requests transmission of SSB and / or SIB1 through the UE WUS, information about the time point of first reception of SSB and / or SIB1 expected by the terminal may be set. The time point of first reception may be set to a relative time point from the UE WUS transmission time point (e.g., after X ms or Y slots from the UE WUS transmission time point, or after the nearest sub-frame boundary or half-frame boundary after X ms or Y slots from the UE WUS transmission time point, etc.), or may be determined according to a predefined rule. Alternatively, the initial reception time may be set to an absolute time (e.g., the first SFN#Z after the UE WUS transmission time), or may be determined according to a predefined rule. In the case of SIB1, by setting a type of information similar to the existing SI (system information)-window information, SIB1 may be transmitted periodically according to a specific cycle after the base station receives the UE WUS. Alternatively, SIB1 may be received periodically according to a specific cycle after the terminal transmits the UE WUS. For example, for SIB1 reception, a configuration for a CORESET transmitted on the F2 frequency band, separate from CORESET#0 on the F1 frequency band, may be provided, such as for reception of a SIB1 PDCCH (e.g., a PDCCH scheduling the SIB1 PDSCH) over the F2 frequency band. In addition, a configuration for a search space set for SIB1 reception associated with the corresponding CORESET may also be provided. Alternatively, information on PDSCH resources for PDCCH-less SIB1 PDSCH reception may be set.As another example, if the UE expects msg2 (e.g., random access response (RAR) for RACH procedure) or HARQ feedback as a response from the base station after the UE transmits a WUS, a configuration for a CORESET transmitted on the F2 frequency band, separate from CORESET#0 on the F1 frequency band, for the purpose of receiving msg2 and / or HARQ feedback may be provided, and further, a configuration for a search space set linked to the corresponding CORESET may be provided. Structure of the F1 and F2 frequency bands In configuring the F1 and F2 frequency bands to the UE, one of the following options may be applied. Opt1) The two frequency bands may be configured as a single BWP. The BWP may be configured to include a set of PRBs that are not contiguous in the frequency axis. Opt2) Each frequency band may be configured as separate BWPs. In this case, the F1 BWP and the F2 BWP can be set separately. Opt3) The F1 and F2 frequency bands can be set as different DL carriers belonging to a single serving cell. Opt4) The F1 and F2 frequency bands can be set as separate serving cells. Information related to RACH of F2 frequency band The mapping relationship between the SSB index and / or S-SSB index transmitted in the F1 and / or F2 frequency bands and the RO (RACH occasion) of the F2 frequency band, and the RACH configuration in the F2 frequency band can be provided through SIB1 transmitted in the F2 frequency band. Information related to CORESET for RACH procedure and / or paging procedure The terminal can perform a series of processes such as RACH procedure and paging reception in the F2 frequency band.Settings for a CORESET transmitted on the F2 frequency band for RACH procedures and paging reception, etc., can be provided through SIB1 transmitted on the F2 frequency band, and additionally, settings for a search space set linked to the CORESET can be provided through SIB1 transmitted on the F2 frequency band.
[0326] When information related to the interworking or QCL relationship between frequency bands is provided, the terminal can perform timing, power control, path-loss estimation, and synchronization for the F2 frequency band based on the F1 frequency band. That is, the terminal can use the F1 frequency band as a synchronization reference, timing reference, etc. when performing synchronization in the F2 frequency band.
[0327] When information related to time / frequency resources for transmitting UE WUS is provided, the terminal can check the resources (e.g., time, frequency, or sequence) for transmitting UE WUS and transmit UE WUS using the checked resources. At this time, based on the provided information, the terminal can select one of a plurality of resource candidates based on at least one of the target signal to be requested, the properties of the target signal, and the frequency band for transmitting UE WUS, and transmit UE WUS using the selected resource.
[0328] When information related to a signal / channel corresponding to a UE WUS is provided, the terminal can transmit a UE WUS and receive the signal / channel requested by the UE WUS based on the provided information. Specifically, the terminal can attempt to receive the requested signal / channel using a time point, resources, etc. determined based on the provided information.
[0329] When information related to the RACH of the F2 frequency band is provided, the terminal can perform a random access procedure in the F2 frequency band based on the SSB detected in the F1 frequency band or the S-SSB detected in the F2 frequency band. Specifically, the terminal can select an RO linked to the SSB detected in the F1 frequency band or the S-SSB detected in the F2 frequency band in the F2 frequency band, and transmit a RACH preamble through the selected RO.
[0330] When information regarding the structure of the F1 and F2 frequency bands is provided, the terminal can verify the structure of the F1 frequency band and / or the F2 frequency band. Accordingly, the terminal can verify the functional / hardware requirements for using the F1 frequency band and / or the F2 frequency band, and determine the operations required for switching between the F1 frequency band and / or the F2 frequency band. Through this, the terminal can determine whether the F2 frequency band is valid for the terminal.
[0331] When information related to a CORESET for a RACH procedure and / or a paging procedure in the F2 frequency band is provided, the terminal can determine a resource location set to monitor a PDCCH for the RACH procedure and / or a paging procedure in the F2 frequency band. That is, in order to receive a PDCCH in the F2 frequency band while performing a given procedure, the terminal can decode signals received through the indicated CORESET.
[0332]
[0333] [Example #2] Procedure for selecting the F2 frequency band as a frequency band for performing on-demand SSB / SIB1 procedures.
[0334] FIG. 21 illustrates an example of a procedure for performing an on-demand SSB / SIB1 procedure according to one embodiment of the present disclosure. FIG. 21 illustrates a method performed by a terminal.
[0335] Referring to FIG. 21, in step S2101, the terminal receives configuration information related to frequency band selection. The configuration information may include information related to conditions for selecting a frequency band for a RACH procedure or a paging procedure. The configuration information may be received via the first frequency band or the second frequency band. For example, the configuration information may include at least one of information indicating a condition and information indicating a parameter used to determine a condition. For example, the configuration information may be received according to embodiment #1.
[0336] In step S2103, the terminal acquires information for selecting a frequency band. The terminal acquires information for determining whether conditions indicated by the configuration information are satisfied. For example, the information may be acquired through measurement, by checking information stored in the terminal, or through computation. For example, the information may include at least one of the following: channel quality measured in the first frequency band, terminal capabilities, or weighted random variables for each frequency band.
[0337] In step S2105, the terminal selects a frequency band. The terminal can determine whether the conditions set by the configuration information are satisfied based on the acquired information. For example, the terminal can compare a value included in the acquired information with a threshold included in the configured conditions. Alternatively, the terminal can determine whether a value included in the acquired information matches a value included in the configured conditions. Alternatively, the terminal can process a value included in the acquired information based on information included in the configured conditions and confirm the processing result.
[0338] In step S2107, the terminal performs an on-demand SSB / SIB1 procedure. The terminal, having selected a frequency band depending on whether the conditions are satisfied, can perform the on-demand SSB / SIB1 procedure in the selected frequency band. That is, the terminal can transmit a signal requesting transmission of SSB / SIB1 in the selected frequency band and receive SSB / SIB1 in the second frequency band. At this time, the frequency band used to perform the on-demand SSB / SIB1 procedure may include either the first frequency band or the second frequency band, or may include both the first frequency band and the second frequency band.
[0339] As described with reference to FIG. 21, a frequency band for a RACH procedure or a paging procedure can be selected by evaluating established conditions. More specific examples of conditions for selecting a frequency band applicable to the procedure illustrated in FIG. 21 are as follows.
[0340] Based on the information / settings provided according to the aforementioned embodiment #1, the terminal may select the F2 frequency band, not the F1 frequency band, as a frequency band for performing the on-demand SSB / SIB1 procedure. At this time, the method for selecting the F2 frequency band may be based on one or a combination of the following embodiments. In this embodiment, selecting the F2 frequency band as a frequency band for performing the on-demand SSB / SIB1 procedure means performing a procedure for requesting SSB and / or SIB1 transmission of a base station in the corresponding frequency band. At this time, the UE WUS for requesting SSB and / or SIB1 transmission may be transmitted in the F1 frequency band or the F2 frequency band.
[0341] [Example #2-1] RSRP-based method measured by receiving SSB (e.g., PSS, SSS and / or PBCH DM-RS) transmitted in F1 frequency band: Based on a predefined RSRP threshold or an RSRP threshold set through SSB and / or SIB transmitted in F1 frequency band or S-SSB transmitted in F2 frequency band, the terminal may select one of the frequency bands F1 and F2. For example, the terminal may select F1 or F2 based on the RSRP measured using SSB (e.g., SSS and / or PBCH DM-RS) transmitted in F1 frequency band. Specifically, the terminal may select the F1 frequency band if the measured RSRP is equal to or greater than the threshold, and may select the F2 frequency band if the RSRP is less than the threshold. Alternatively, the terminal may select the F1 frequency band if the measured RSRP is less than the threshold, and may select the F2 frequency band if the RSRP is equal to or greater than the threshold.
[0342] [Example #2-2] UE capability-based method: Through base station signaling (e.g., information configured / provided via SSB and / or SIB transmitted in the F1 frequency band, or S-SSB transmitted in the F2 frequency band), a UE having a specific capability (e.g., a NES-capable UE or a UE WUS-capable UE) can be configured to use the F2 frequency band instead of the F1 frequency band. On the other hand, a UE not having the capability can remain in the F1 frequency band and perform RACH procedures, etc.
[0343] [Example #2-3] Random selection-based method: The terminal may randomly select either the F1 frequency band or the F2 frequency band. Alternatively, for a specific frequency band, a weighting factor may be configured through an SSB and / or SIB transmitted in the F1 frequency band or an S-SSB transmitted in the F2 frequency band. Based on the configured weighting factor (e.g., to increase the selection probability of a frequency band with a higher weight applied), the terminal may select one frequency band and, depending on the selected frequency band, perform a RACH procedure or an on-demand SSB / SIB1 procedure, etc., through the selected frequency band.
[0344] [Example #2-4] Combination between RSRP threshold-based and random selection-based methods: For example, if the RSRP measured through reception of SSB (e.g., SSS and / or PBCH DM-RS) transmitted in the F1 frequency band is above or below a threshold, a specific F1 or F2 frequency band can be selected. On the other hand, if the RSRP is below or above the threshold, a weighting factor can be set so that a specific F1 or F2 frequency band is given priority during random selection.
[0345]
[0346] [Example #3] A method for performing on-demand SSB / SIB1 procedures after changing the operating frequency to the F2 frequency band.
[0347] According to the above-described embodiments, the terminal can change its operating frequency to the F2 frequency band and then perform an on-demand SSB / SIB1 procedure in the F2 frequency band. Embodiments of the on-demand SSB / SIB1 procedure are as follows.
[0348]
[0349] FIG. 22 illustrates an example of a procedure for receiving an SSB or SIB based on an on-demand manner according to one embodiment of the present disclosure. FIG. 22 illustrates a method performed by a terminal.
[0350] Referring to FIG. 22, in step S2201, the terminal can check the structure of the request procedure. Here, the request procedure includes an on-demand SSB / SIB1 procedure that includes an operation of transmitting a request signal requesting transmission of SSB, S-SSB, and / or SIB1 in the second frequency band. The structure of the request procedure relates to whether the content of the request is transmitted through a single signaling or through staged signaling. In other words, the terminal can determine whether to perform a single signaling or multiple signaling to request transmission of SSB / SIB1. According to one embodiment, the terminal can determine the structure of the request signal based on configuration information provided from the base station or a predefined rule. When multiple signalings are used, the request signal can be understood as a set of a series of signals or as the first signal among the series of signals. However, if the structure of the request procedure is not configurable or selectable but is fixed in one method, this step can be understood as an operation of checking a predefined structure.
[0351] In step S2203, the terminal may determine a resource for the request signal. For example, the terminal may determine a resource (e.g., at least one of a time resource, a frequency resource, and a sequence) to be used for transmitting the request signal based on configuration information received from the base station in the first frequency band or the second frequency band. In this case, according to one embodiment, the resource may be selected from among a plurality of candidate resource regions, one corresponding to the type and / or transmission method of the signal to be requested.
[0352] In step S2205, the terminal transmits a request signal. That is, the terminal can transmit a request signal requesting transmission of SSB, S-SSB, and / or SIB1 in the second frequency band using the structure and resources confirmed in the previous steps. At this time, the terminal can transmit the request signal in the first frequency band or the second frequency band. If the structure of the request procedure in step S2201 is confirmed in a way that the contents of the request are transmitted through multiple signaling, the terminal can transmit at least one additional signal to the base station after transmitting the request signal. In this case, the request signal and the at least one additional signal can be transmitted in the same frequency band or in different frequency bands.
[0353] In step S2207, the terminal receives a signal corresponding to the request signal. That is, the terminal may receive an SSB, an S-SSB, and / or an SIB1 as a signal corresponding to the request signal. At this time, according to various embodiments, the terminal may determine a time window and receive an SSB, an S-SSB, and / or an SIB1 within the time window. According to one embodiment, the time window may start after a first time interval from the time at which the request signal is transmitted. The starting point and length of the time window may be determined based on configuration information received from the base station or based on a predefined rule.
[0354]
[0355] FIG. 23 illustrates an example of a procedure for transmitting an SSB or SIB based on an on-demand manner according to one embodiment of the present disclosure. FIG. 23 illustrates a method performed by a base station.
[0356] Referring to FIG. 23, in step S2301, the base station receives a request signal. The request signal is a signal requesting transmission of SSB, S-SSB, and / or SIB1 in the second frequency band, and includes a signal transmitted for an on-demand SSB / SIB1 procedure. The request signal may be received using a resource (e.g., at least one of a time resource, a frequency resource, and a sequence) determined based on configuration information provided by the base station. In this case, the request signal may be a signal for a request procedure based on a single signaling, or a signal for a request procedure based on step-by-step signaling. If the request signal is a signal for a request procedure based on step-by-step signaling, the base station may further receive at least one additional signal, although not illustrated in FIG. 23.
[0357] In step S2303, the base station can determine the requested target and transmission method. Depending on the resources used for the request signal, it can be indicated which type of signal (e.g., SSB, S-SSB, and / or SIB1) is requested, and what properties (e.g., beam direction, index, number of times, etc.) of the requested type of signal are requested. Accordingly, the base station can determine the type and properties of the requested signal based on the request signal. Furthermore, based on the resources used for the request signal, the capabilities of the terminal, the capabilities of the base station, or configuration information, the base station can determine when to transmit the requested signal, whether to transmit it in a single opportunity or repeatedly, etc.
[0358] In step S2305, the base station transmits the requested signal. For example, the base station may transmit at least one of SSB, S-SSB, or SIB1 in the second frequency band. At this time, the base station may transmit at least one of SSB, S-SSB, or SIB1 based on the target and transmission method determined in step S2303. That is, the base station may change the state of the second frequency band and transmit at least one of SSB, S-SSB, or SIB1.
[0359]
[0360] According to a defined procedure (e.g., a procedure using the configuration information according to the aforementioned embodiment #1), the terminal may transmit a UE WUS signal / channel on the F2 frequency band. At this time, when determining the timing and power control of the UE WUS transmission, it may be performed based on the SSB received through the F1 frequency band. For example, when transmitting the UE WUS on the F2 frequency band, if an association or QCL relationship between the F1 frequency band and the F2 frequency band is established, it is possible to determine the timing and power value of the UE WUS transmitted on the F2 frequency band based on a specific SSB index received on the F1 frequency band.
[0361] As with the configuration information proposed in the aforementioned embodiment #1, information related to the frequency and / or time and / or sequence of the UE WUS may be set differently depending on the frequency band in which the requested SSB / SIB1 is transmitted, the index of the requested SSB / SSB group, the type of the requested signal (e.g., SSB or SIB1), the SSB index corresponding to the requested SIB1, etc. Accordingly, the terminal may select an appropriate resource according to the requested SSB / SIB1 and attempt UE WUS transmission. If the appropriate UE WUS resource is set in a detailed state according to the requested SSB / SIB1, the terminal may receive only a response from the base station corresponding to the UE WUS (e.g., a response having a structure similar to RAR or msg2 in the RACH procedure) after transmitting the UE WUS, and may complete the corresponding SSB / SIB1 procedure.
[0362] Meanwhile, even after receiving the base station's response to the UE WUS transmission, the terminal may need to transmit additional request information (hereinafter referred to as 'msg3') including information that has not yet been transmitted via the UE WUS. For example, if a common UE WUS for SSB / SIB1 is defined, the terminal may receive the base station's response to the UE WUS transmission and indicate through msg3 whether the actually requested signal / channel is SSB or SIB1. As another example, if a common UE WUS for SSB or SIB1 is defined, the terminal may receive the base station's response to the UE WUS transmission and indicate through msg3 which SSB or SSB group index the actually requested signal / channel corresponds to, or which QCL relationship SIB1 it is. Here, information related to the resources allocated / configured for transmitting msg3 may be included in the base station's response.
[0363] After the terminal transmits the UE WUS, considering the processing time of the base station and / or the terminal, after a certain time interval has elapsed and / or during a certain time window, the terminal can expect the base station to transmit a signal corresponding to the UE WUS. At this time, the signal corresponding to the UE WUS may include a specific SSB and / or SIB1 requested through the UE WUS, or may include msg2 and / or HARQ feedback, as in the configuration information proposed in Embodiment #1. Here, the certain time interval may be expressed as X msec or Y slots, and the value of X or Y may be preset or predefined in a specification document. In addition, the terminal can expect to receive a signal corresponding to the UE WUS during a certain time window, that is, before the time window ends, and the duration value of the corresponding time window (e.g., 20 msec) may be preset or predefined in a specification document. For example, the value of the above time window may be received from the base station through a procedure similar to Example #1 or through separate signaling.
[0364] If the terminal expects to receive a signal corresponding to the UE WUS, but it is determined that there is no signal corresponding to the UE WUS, a penalty may be applied. Here, the case where it is determined that there is no signal corresponding to the UE WUS may mean, for example, that the signal is not detected during a certain timer or a duration of a time window, or that the reception sensitivity of the signal is determined to be below a given threshold (e.g., a threshold having a separately preset value or a predefined value). In addition, applying a penalty may mean ramping up the power value and / or count value in the on-demand procedure. If the power value and / or count value reaches a preset maximum value, the terminal may proceed with the RACH procedure in the F1 frequency band or select another frequency band (e.g., F3) and start a new on-demand SSB / SIB1 procedure.
[0365]
[0366] FIG. 24 illustrates an example of a procedure for performing an on-demand SSB / SIB1 procedure using multiple frequency bands according to one embodiment of the present disclosure. FIG. 24 illustrates signal exchange between a terminal (2410) and a base station (2420).
[0367] Referring to FIG. 24, in step S2401, the base station (2420) transmits an SSB in the F1 frequency band. Accordingly, the terminal (2410) can receive the SSB in the F1 frequency band. Here, the SSB includes information related to the F2 frequency band. That is, the base station (2420) can signal the existence of the F2 frequency band (e.g., signaling including the information proposed in Example #1) through the SSB transmitted in the F1 frequency band.
[0368] In step S2403, the terminal (2410) detects an SSB and changes its operating frequency from the F1 frequency band to the F2 frequency band to perform an on-demand SSB / SIB1 procedure. In step S2405, the terminal (2410) transmits a UE WUS to the base station (2420) in the F2 frequency band. That is, the terminal (2410) performs an on-demand SSB / SIB1 procedure. In step S2407, the base station (2420) transmits a downlink signal corresponding to the UE WUS to the terminal (2410). That is, the terminal (2410) that receives an SSB in the F1 frequency band can change its operating frequency to the F2 frequency band according to the criteria proposed in embodiment #2 and perform the on-demand SSB / SIB1 procedure as proposed in embodiment #3.
[0369]
[0370] When a base station operates across multiple frequency bands, the base station may periodically transmit SSB and / or system information only on certain frequency bands for the purpose of NES, while not periodically transmitting the corresponding signals / channels on other frequency bands. In this context, the present disclosure proposes a technique for a specific terminal to camp on a frequency band that periodically provides SSB and other frequency bands by successfully completing an initial connection.
[0371]
[0372] The proposed methods described above can be implemented independently, but they can also be implemented as a combination (or merge) of some of the proposed methods. Rules can be defined so that the base station notifies the terminal of the applicability of the proposed methods (or information about the rules of the proposed methods) through a predefined signal (e.g., a physical layer signal or a higher layer signal).
[0373] The present disclosure may be embodied in other specific forms without departing from the technical ideas and essential features described herein. Therefore, the above detailed description should not be construed as limiting in all respects but rather as illustrative. The scope of the present disclosure should be determined by a reasonable interpretation of the appended claims, and all modifications within the equivalent scope of the present disclosure are intended to be included within the scope of the present disclosure. Furthermore, claims that are not explicitly cited in the claims may be combined to form an embodiment or incorporated into a new claim through a post-filing amendment.
[0374] Embodiments of the present disclosure can be applied to various wireless access systems. Examples of various wireless access systems include the 3rd Generation Partnership Project (3GPP) or 3GPP2 systems.
[0375] The embodiments of the present disclosure can be applied not only to the various wireless access systems described above, but also to all technical fields that utilize these various wireless access systems. Furthermore, the proposed method can also be applied to mmWave and THz communication systems utilizing ultra-high frequency bands.
[0376] Additionally, embodiments of the present disclosure can be applied to various applications such as autonomous vehicles and drones.
Claims
1. In a method performed by a terminal in a wireless communication system, A step of receiving a first synchronization signal in a first frequency band; A step of receiving second system information in the first frequency band; A step of receiving setting information related to a second frequency band based on the first synchronization signal and the first system information; A step of transmitting a first signal requesting a second synchronization signal or second system information in the second frequency band; A step of receiving a second signal including the second synchronization signal or the second system information in the second frequency band, A method wherein the above setting information includes at least one of information related to a resource for transmitting the first signal or information related to the second signal.
2. In claim 1, Information related to a resource for transmitting the first signal includes information related to at least one of frequency, time, or sequence, A method wherein at least one of the frequency, the time or the sequence comprises at least one of a plurality of candidates selectable according to at least one of a frequency band for transmitting the first signal, a requested signal or a property of the requested signal.
3. In claim 1, A method in which information related to the second signal includes at least one of information related to a reception time of the second time point, information related to a window for receiving the second signal, or information related to a CORESET (control resource set) used to receive the second signal.
4. In claim 1, The step of transmitting the first signal comprises: A step of determining whether to transmit the first signal in the second frequency band based on the first synchronization signal and the first system information, A method in which the first signal is determined to be transmitted in the second frequency band based on the channel quality measured in the first frequency band, the capability of the terminal, and a weight for each frequency band.
5. In claim 1, Further comprising a step of transmitting a third signal indicating a target included in the second signal, A method in which the requested object comprises at least one of a type of signal or an attribute of a signal.
6. In claim 1, Further comprising a step of transmitting a third signal indicating a transmission method of the second signal, A method wherein the transmission method comprises at least one of a timing or repetitive transmission of the second signal.
7. In claim 6, A method in which the third signal is transmitted in response to the reception of a fourth signal received as a response to the first signal.
8. In claim 1, A method in which the second signal is received during a time window set for the second signal after the first time interval has elapsed after transmitting the first signal.
9. In claim 8, A method in which the above setting information includes information related to the duration of the time window.
10. In a method performed by a base station in a wireless communication system, A step of transmitting a first synchronization signal in a first frequency band; A step of transmitting second system information in the first frequency band; A step of transmitting setting information related to a second frequency band based on the first synchronization signal and the first system information; A step of receiving a first signal requesting a second synchronization signal or second system information in the second frequency band; A step of transmitting a second signal including the second synchronization signal or the second system information in the second frequency band, A method wherein the above setting information includes at least one of information related to a resource for transmitting the first signal or information related to the second signal.
11. In claim 10, Information related to a resource for transmitting the first signal includes information related to at least one of frequency, time, or sequence, A method wherein at least one of the frequency, the time or the sequence comprises at least one of a plurality of candidates selectable according to at least one of a frequency band for transmitting the first signal, a requested signal or a property of the requested signal.
12. In claim 10, A method in which information related to the second signal includes at least one of information related to a reception time of the second time point, information related to a window for receiving the second signal, or information related to a CORESET (control resource set) used to receive the second signal.
13. In claim 10, Further comprising a step of receiving a third signal indicating a target included in the second signal, A method in which the requested object comprises at least one of a type of signal or an attribute of a signal.
14. In claim 10, Further comprising a step of receiving a third signal indicating a transmission method of the second signal, A method wherein the transmission method comprises at least one of a timing or repetitive transmission of the second signal.
15. In claim 10, A method in which the second signal is transmitted during a time window set for the second signal after the first signal is received and a first time interval has elapsed.
16. In claim 15, A method in which the above setting information includes information related to the duration of the time window.
17. In a wireless communication system, at a terminal, Transmitter and receiver; and A processor connected to the above transmitter and receiver is included, The above processor, Receive a first synchronization signal in a first frequency band, Receive second system information in the first frequency band, Receive setting information related to a second frequency band based on the first synchronization signal and the first system information, Transmitting a first signal requesting a second synchronization signal or second system information in the second frequency band; configured to receive a second signal including the second synchronization signal or the second system information in the second frequency band; A terminal including at least one of information related to a resource for transmitting the first signal and information related to the second signal, wherein the above setting information is information related to a resource for transmitting the first signal.
18. In a base station in a wireless communication system, Transmitter and receiver; and A processor connected to the above transmitter and receiver is included, The above processor, Transmitting a first synchronization signal in the first frequency band, Transmitting second system information in the first frequency band, Transmitting setting information related to the second frequency band based on the first synchronization signal and the first system information, Receive a first signal requesting a second synchronization signal or second system information in the second frequency band; configured to transmit a second signal including the second synchronization signal or the second system information in the second frequency band; A method wherein the above setting information includes at least one of information related to a resource for transmitting the first signal or information related to the second signal.
19. In communication devices, At least one processor; At least one computer memory connected to said at least one processor and storing instructions that direct operations when executed by said at least one processor, The above actions are, A step of receiving a first synchronization signal in a first frequency band; A step of receiving second system information in the first frequency band; A step of receiving setting information related to a second frequency band based on the first synchronization signal and the first system information; A step of transmitting a first signal requesting a second synchronization signal or second system information in the second frequency band; A step of receiving a second signal including the second synchronization signal or the second system information in the second frequency band, A method wherein the above setting information includes at least one of information related to a resource for transmitting the first signal or information related to the second signal.
20. In a non-transitory computer-readable medium storing at least one instruction, comprising at least one instruction executable by the processor, At least one of the above commands causes the device to: Receive a first synchronization signal in a first frequency band, Receive second system information in the first frequency band, Receive setting information related to a second frequency band based on the first synchronization signal and the first system information, Transmitting a first signal requesting a second synchronization signal or second system information in the second frequency band; Instructs to receive a second signal including the second synchronization signal or the second system information in the second frequency band, A computer-readable medium including at least one of information related to a resource for transmitting the first signal and information related to the second signal, wherein the setting information is:
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