Network node, method, and non-transitory computer-readable storage medium for interference control

Abstract

This network node may comprise: a communication circuit; a memory for storing instructions; and at least one processor including processing circuitry. The instructions, when executed individually or collectively by the at least one processor, may cause the network node to: acquire information on channel quality for each frequency unit allocated to a target terminal; transmit, to network nodes, information indicating a low-quality frequency unit; receive, from the network nodes through the communication circuit, information on terminals using the low-quality frequency unit; identify an interfering terminal from among the terminals on the basis of the information on the terminals; and transmit, to another network node connected to the interfering terminal, a request message for reducing transmission power of the interfering terminal.

Description

Network node, method, and non-transient computer-readable storage medium for interference control

[0001] The present disclosure relates to a network node for interference control, a method, and a non-transient computer-readable storage medium.

[0002] Various technologies are being researched to improve the transmission performance of the channel between a base station and a terminal in wireless communication systems. Various indicators can be used to measure the transmission performance of the channel between the base station and the terminal. For example, various indicators may include CQI (channel quality indicator), SINR (signal to interference plus noise ratio), and / or RSRP (reference signal received power).

[0003] The information described above may be provided as related art for the purpose of aiding understanding of the present disclosure. No claim or determination is made as to whether any of the foregoing may be applied as prior art related to the present disclosure.

[0004] A network node is provided. The network node may include a communication circuit. The network node may include a memory comprising one or more storage media for storing instructions. The network node may include at least one processor comprising a processing circuit. The instructions may cause the network node to obtain information regarding the channel quality for each of the frequency units assigned to a target terminal connected to the network node, when executed individually or collectively by the at least one processor. The instructions may cause the network node to transmit information indicating a low-quality frequency unit having the lowest channel quality among the frequency units to the network nodes via the communication circuit, when executed individually or collectively by the at least one processor. The instructions may cause the network node to receive information regarding terminals using the low-quality frequency unit from the network nodes via the communication circuit, when executed individually or collectively by the at least one processor. When the above instructions are executed individually or collectively by the at least one processor, they may cause the network node to identify an interfering terminal among the terminals based on the information regarding the terminals. When the above instructions are executed individually or collectively by the at least one processor, they may cause the network node to transmit a request message to reduce the transmission power of the interfering terminal to another network node connected to the interfering terminal via the communication circuit.

[0005] A method is provided. The method may be executed at a network node having a communication circuit. The method may include an operation of obtaining information regarding channel quality for each of the frequency units assigned to a target terminal connected to the network node. The method may include an operation of transmitting information indicating a low-quality frequency unit having the lowest channel quality among the frequency units to network nodes via the communication circuit. The method may include an operation of receiving information regarding terminals using the low-quality frequency unit from the network nodes via the communication circuit. The method may include an operation of identifying an interfering terminal among the terminals based on the information regarding the terminals. The method may include an operation of transmitting a request message to reduce the transmission power of the interfering terminal to another network node connected to the interfering terminal via the communication circuit.

[0006] A non-transient computer-readable storage medium is provided. The non-transient computer-readable storage medium may store one or more programs. The one or more programs may include instructions that cause the network node to obtain information regarding the channel quality for each of the frequency units assigned to a target terminal connected to the network node when executed by the network node having a communication circuit. The one or more programs may include instructions that cause the network node to transmit information indicating the low-quality frequency unit having the lowest channel quality among the frequency units to the network nodes via the communication circuit when executed by the network node. The one or more programs may include instructions that cause the network node to receive information regarding terminals using the low-quality frequency unit from the network nodes via the communication circuit when executed by the network node. The above one or more programs may include instructions that cause the network node to identify an interfering terminal among the terminals based on the information regarding the terminals when executed by the network node. The above one or more programs may include instructions that cause the network node to transmit a request message to reduce the transmission power of the interfering terminal to another network node connected to the interfering terminal via the communication circuit when executed by the network node.

[0007] Figure 1 illustrates an example of a wireless communication environment.

[0008] Figure 2 illustrates an example of an interface between an upper network node and a lower network node.

[0009] Figure 3 illustrates an example of the functional configuration of a network node.

[0010] Figure 4 illustrates an example of a resource structure in the time domain and the frequency domain.

[0011] FIG. 5 illustrates an example of a wireless communication environment including network nodes.

[0012] FIG. 6 illustrates examples of network node operations to reduce the transmission power of an interfering terminal.

[0013] FIG. 7 illustrates an example of frequency range information indicating the interference-used frequency range, the common-used frequency range, and the interference-non-used frequency range.

[0014] FIG. 8 illustrates examples of network node operations to reduce the transmission power of an interfering terminal.

[0015] FIG. 9 illustrates an example of the performance of network nodes' operations according to one embodiment.

[0016] FIG. 10 illustrates an example of the performance of the operations of network nodes according to one embodiment.

[0017] FIG. 11 illustrates an example of the performance of network nodes' operations according to one embodiment.

[0018] FIG. 12 illustrates an example of the performance of the operations of network nodes according to one embodiment.

[0019] FIG. 13 illustrates an example of the performance of the operations of network nodes according to one embodiment.

[0020] Throughout the drawings, the same reference numerals will be understood to refer to the same parts, components, and structures.

[0021] The terms used in this disclosure are used merely to describe specific embodiments and are not intended to limit the scope of other embodiments. A singular expression may include a plural expression unless the context clearly indicates otherwise. Terms used herein, including technical or scientific terms, may have the same meaning as generally understood by those skilled in the art described in this disclosure. Terms used in this disclosure that are defined in a general dictionary may be interpreted as having the same or similar meaning as they have in the context of the relevant technology, and are not to be interpreted in an ideal or overly formal sense unless explicitly defined in this disclosure. In some cases, even terms defined in this disclosure are not to be interpreted to exclude the embodiments of this disclosure.

[0022] In the various embodiments of the present disclosure described below, a hardware-based approach is described as an example. However, since the various embodiments of the present disclosure include techniques using both hardware and software, the various embodiments of the present disclosure do not exclude a software-based approach.

[0023] Terms used in the following description to refer to signals (e.g., signal, information, message, signaling), terms referring to resources (e.g., symbol, slot, subframe, radio frame, subcarrier, RE (resource element), RB (resource block), BWP (bandwidth part), occasion), terms for operation states (e.g., step, operation, procedure), terms referring to data (e.g., packet, user stream, information, bit, symbol, codeword), terms referring to channels, terms referring to network entities, terms referring to device components, etc., are examples provided for the convenience of explanation. Accordingly, the present disclosure is not limited to the terms described below, and other terms having equivalent technical meanings may be used. Additionally, terms such as '...part', '...device', '...object', '...body' used below may refer to at least one shape structure or a unit that processes a function.

[0024] Additionally, in this disclosure, expressions of "greater than" or "less than" may be used to determine whether a specific condition is satisfied or fulfilled; however, this is merely for the purpose of expressing an example and does not exclude descriptions of "greater than" or "less than." Conditions described as "greater than" may be replaced with "greater than," conditions described as "less than" may be replaced with "less than," and conditions described as "greater than and less than" may be replaced with "greater than and less than." Furthermore, "A" to "B" below refer to at least one of elements from A (including A) to B (including B). Below, "C" and / or "D" refers to including at least one of "C" or "D," i.e., {"C", "D", "C" and "D"}.

[0025] The present disclosure describes embodiments using terms used in some communication standards (e.g., 3GPP (3rd Generation Partnership Project)), but this is merely illustrative. The embodiments of the present disclosure may also be applied to other communication and broadcasting systems.

[0026] In the present disclosure, channel quality may be at least one of, for example, RSRP (reference signal received power), BRSRP (beam reference signal received power), RSRQ (reference signal received quality), RSSI (received signal strength indicator), SINR (signal to interference and noise ratio), CINR (carrier to interference and noise ratio), SNR (signal to noise ratio), EVM (error vector magnitude), BER (bit error rate), BLER (block error rate), and CQI (channel quality indicator). In addition to the examples described above, other terms having equivalent technical meanings or other metrics representing channel quality may be used. Hereinafter, in the present disclosure, high channel quality means a case where the channel quality value related to signal magnitude is large or the channel quality value related to the error rate is small. The higher the channel quality, the more likely it is that a smooth wireless communication environment is guaranteed.

[0027] FIG. 1 illustrates an example of a wireless communication environment. FIG. 1 illustrates a terminal and a base station as some of the nodes using a wireless channel in a wireless communication system.

[0028] Referring to FIG. 1, the wireless communication environment may include a terminal (110), a first base station (120), a second base station (121), a third base station (122), a fourth base station (123), a fifth base station (124), a sixth base station (125), and a seventh base station (126). The wireless communication environment may include a RAN (radio access network) controller (150) for controlling each base station (e.g., first base station (120), second base station (121), third base station (122), fourth base station (123), fifth base station (124), sixth base station (125), and seventh base station (126)).

[0029] A terminal (110) is a device used by a user and can communicate with base stations (e.g., a first base station (120), a second base station (121), a third base station (122), a fourth base station (123), a fifth base station (124), a sixth base station (125), and a seventh base station (126)) via a wireless channel. When the terminal (110) accesses a wireless network provided by the first base station (120), it can communicate with the first base station (120). When the terminal (110) accesses a wireless network provided by the second base station (121), it can communicate with the second base station (121). When the terminal (110) accesses a wireless network provided by the third base station (122), it can communicate with the third base station (122). When the terminal (110) accesses a wireless network provided by the fourth base station (123), it can communicate with the fourth base station (123). When the terminal (110) accesses a wireless network provided by the fifth base station (124), it can communicate with the fifth base station (124). When the terminal (110) accesses a wireless network provided by the sixth base station (125), it can communicate with the sixth base station (125). When the terminal (110) accesses a wireless network provided by the seventh base station (126), it can communicate with the seventh base station (126).

[0030] According to one embodiment, the terminal (110) may be operated without user involvement. The terminal (110) is a device that performs machine type communication (MTC) and may not be carried by a user. The terminal (110) may be referred to as 'user equipment (UE)', 'mobile station', 'subscriber station', customer-premises equipment (CPE) 'remote terminal', 'wireless terminal', or 'user device', 'electronic device', or other terms having an equivalent technical meaning.

[0031] Each of the first base station (120), the second base station (121), the third base station (122), the fourth base station (123), the fifth base station (124), the sixth base station (125), and the seventh base station (126) is a network infrastructure that provides wireless access. A base station has coverage defined as a specific geographical area based on the distance at which it can transmit signals. In addition to being a base station, a base station may be referred to as an 'access point (AP)', 'eNodeB (eNB)', '5G node (5th generation node)', 'next generation nodeB (gNB)', 'wireless point', 'transmission / reception point (TRP)', or other terms having an equivalent technical meaning.

[0032] A RAN controller (150) may be used to control base stations (e.g., a first base station (120), a second base station (121), a third base station (122), a fourth base station (123), a fifth base station (124), a sixth base station (125), and a seventh base station (126)). For example, the RAN controller (150) may be a device for controlling RAN elements and resources through data collection and operations. According to one embodiment, the RAN controller (150) may function as an O-RAN standard Near-RT RIC. According to another embodiment, the RAN controller (150) may function as an O-RAN standard Non-RT RIC. According to yet another embodiment, the RAN controller (150) may be a separate device for functioning as both an O-RAN standard Non-RT RIC and a Near-RT RIC. According to another embodiment, the RAN controller may be a device for receiving a report message from each base station that is defined separately from the O-RAN standard and transmitting a control message to each base station.

[0033] The RAN controller (150) can be connected to the first base station (120), the second base station (121), the third base station (122), the fourth base station (123), the fifth base station (124), the sixth base station (125), and the seventh base station (126). Hereinafter, the operation of the base station is described based on the first base station (120), but the description of the first base station (120) can be applied to other base stations (e.g., the second base station (121), the third base station (122), the fourth base station (123), the fifth base station (124), the sixth base station (125), the seventh base station (126)) in the same or similar manner.

[0034] The RAN controller (150) can receive network information of the first base station (120) from the first base station (120). The network information may refer to information related to a radio access network (RAN) provided by the first base station (120). According to one embodiment, the network information of the first base station (120) may include information about one or more cells provided by the first base station (120). Additionally, according to one embodiment, the network information of the first base station (120) may include information about one or more terminals served by the first base station (120). According to one embodiment, the RAN controller (150) may transmit cell identification information and frequency domain information to base stations connected to the RAN controller (150) (e.g., first base station (120), second base station (121), third base station (122), fourth base station (123), fifth base station (124), sixth base station (125), and seventh base station (126)). For example, the cell identification information may be used to identify a cell (e.g., physical cell identity (PCI)) provided by at least some of the base stations connected to the RAN controller (150). For example, the first base station (120) may use the received cell identification information to identify each of one or more cells provided by other base stations (e.g., second base station (121), third base station (122), fourth base station (123), fifth base station (124), sixth base station (125), seventh base station (126)). For example, cell identification information may include cell IDs of at least some of the base stations connected to the RAN controller (150) (e.g., neighboring base stations). Cell IDs may be generated by the RAN controller (150). Frequency domain information may indicate frequency ranges (e.g., frequency band, frequency index, frequency location) assigned to at least some of the base stations connected to the RAN controller (150).For example, the first base station (120) can identify the frequency range used by each of the other base stations (e.g., second base station (121), third base station (122), fourth base station (123), fifth base station (124), sixth base station (125), seventh base station (126)) by using the received frequency domain information. According to one embodiment, the first base station (120) can identify the frequency range used by each of the other base stations by applying a rule for frequency distribution to the frequency domain information.

[0035] In the present disclosure, a cell may refer to an area that can be covered by a single base station. A single base station may cover one cell or multiple cells. Here, multiple cells may be distinguished by the supported frequency and the area of ​​the sector covered. In the following description, the term "base station" may be used to include a cell, or the term "cell" may be used to refer to a base station.

[0036] A serving cell is a cell that provides upper-layer signaling (e.g., radio resource control (RRC) signaling) to a terminal, and may refer to a single cell or multiple cells. If the terminal is not configured to support carrier aggregation (CA) and dual connectivity (DC), the serving cell may be a single cell including a primary cell. If the terminal is configured to support CA or the terminal, the serving cell may be a set of one or more cells including a primary cell and at least one secondary cell.

[0037] Dual connectivity or multi-connectivity is a technology that increases frequency usage efficiency from the perspective of the terminal or base station by allowing a single terminal to be connected to multiple different base stations and simultaneously transmit and receive signals using carrier waves within each base station located in different frequency bands. The terminal can transmit and receive traffic by being simultaneously connected to a first base station (e.g., a base station providing services using LTE or 4th generation mobile communication technology) and a second base station (e.g., a base station providing services using NR (new radio) or 5G (5th generation) mobile communication technology). In this case, the frequency resources used by each base station may be located in different bands. A method operating based on the dual connectivity method of LTE and NR in this way can be referred to as 5G NSA (non-standalone).

[0038] Figure 2 illustrates an example of an interface between an upper network node and a lower network node.

[0039] FIG. 2 illustrates an interface between an upper network node and a lower network node. The interface between the upper network node and the lower network node may include a fronthaul interface. Fronthaul refers to the space between entities between a wireless LAN and a base station, unlike backhaul between a base station and a core network. FIG. 2 illustrates an example of a fronthaul structure between an upper network node (210) and one lower network node (220), but this is merely for convenience of explanation and the present disclosure is not limited thereto. In other words, an embodiment of the present disclosure may also be applied to a fronthaul structure between one upper network node and a plurality of lower network nodes. For example, an embodiment of the present disclosure may be applied to a fronthaul structure between one upper network node and two lower network nodes. Additionally, an embodiment of the present disclosure may also be applied to a fronthaul structure between one upper network node and three lower network nodes.

[0040] For example, an upper network node may include a DU (digital unit / distributed unit). An upper network node may be referred to as a DU. By example, but not limited to, an upper network node may include a CU (centralized unit). A lower network node may include a RU (radio unit) or a MMU (massive MIMO unit). A lower network node may be referred to as a RU or MMU.

[0041] Referring to FIG. 2, a base station (e.g., the first base station (120) of FIG. 1) may include an upper network node (210) and a lower network node (220). A fronthole (215) between the upper network node (210) and the lower network node (220) may be operated via an Fx interface. For the operation of the fronthole (215), an interface such as eCPRI (enhanced common public radio interface) or ROE (radio over ethernet) may be used.

[0042] As communication technology develops, mobile data traffic increases, and consequently, the bandwidth requirements for the fronthaul between the digital unit and the wireless unit have increased significantly. In a deployment such as a C-RAN (centralized / cloud radio access network), the upper network node (210) performs functions for PDCP (packet data convergence protocol), RLC (radio link control), MAC (media access control), and PHY (physical), and the lower network node (220) can be implemented to perform functions for the PHY layer in addition to RF (radio frequency) functions.

[0043] The upper network node (210) may be responsible for upper layer functions of the wireless network. For example, the upper network node (210) may perform functions of the MAC layer and parts of the PHY layer. Here, parts of the PHY layer are functions of the PHY layer that are performed at a higher level, and may include, for example, channel encoding (or channel decoding), scrambling (or descrambling), modulation (or demodulation), and layer mapping (or layer demapping). According to one embodiment, if the upper network node (210) conforms to the O-RAN standard, it may be referred to as an O-DU (O-RAN DU) (or DU). The upper network node (210) may be replaced and represented as a first network entity or DU for a base station (e.g., gNB) in the embodiments of the present disclosure as necessary.

[0044] The lower network node (220) can perform lower layer functions of the wireless network. For example, the lower network node (220) can perform RF functions, which are part of the PHY layer. Here, part of the PHY layer refers to functions of the PHY layer that are performed at a relatively lower level than the upper network node (210), and may include, for example, iFFT transformation (or FFT transformation), CP (cyclic prefix) insertion (CP removal), and digital beamforming. The lower network node (220) may be referred to as an 'access unit (AU)', 'access point (AP)', 'transmission / reception point (TRP)', 'remote radio head (RRH)', 'radio unit (RU)', or other terms having an equivalent technical meaning. According to one embodiment, if the sub-network node (220) conforms to the O-RAN standard, it may be referred to as an O-RU (O-RAN RU) (or RU). The sub-network node (220) may be replaced with a second network entity or RU for a base station (e.g., gNB) in the embodiments of the present disclosure as needed.

[0045] In the above example, it is described that the upper network node (210) includes a DU and the lower network node (220) includes an RU, but the embodiments of the present disclosure are not limited thereto. A base station according to the embodiments may be implemented in a distributed deployment according to a centralized unit (CU) configured to perform the functions of the upper layers of the access network (e.g., packet data convergence protocol (PDCP), radio resource control (RRC)) and a distributed unit (DU) configured to perform the functions of the lower layers. In this case, the distributed unit (DU) may include a digital unit (DU) and a radio unit (RU). Between a core network (e.g., 5G core or next generation core (NGC)) and a radio network (RAN), the base station may be implemented in a structure in which the CU, DU, and RU are arranged in that order. The interface between the CU and the distributed unit (DU) may be referred to as the F1 interface.

[0046] For example, a centralized unit (CU) can be connected to one or more DUs and perform functions at a higher layer than the DUs. For instance, the CU can perform functions at the radio resource control (RRC) and packet data convergence protocol (PDCP) layers, while the DU and RU can perform functions at lower layers. The DU can perform radio link control (RLC), media access control (MAC), and some functions of the physical (PHY) layer (high PHY), while the RU can perform the remaining functions of the PHY layer (low PHY). Additionally, as an example, a digital unit (DU) can be included in a distributed unit (DU) depending on the distributed deployment implementation of the base station. The following description describes the operations of DU and RU unless otherwise defined, but various embodiments of the present disclosure may be applied to both base station deployments including CU and deployments where DU is directly connected to the core network (i.e., implemented by integrating CU and DU into a single entity base station (e.g., NG-RAN node)).

[0047] Figure 3 illustrates an example of the functional configuration of a network node.

[0048] The configuration of the network node (300) exemplified in FIG. 3 can be understood as a configuration of a terminal (110), a base station (e.g., a first base station (120)), an upper network node (210), a lower network node (220), or a server. Terms such as '... unit' and '... unit' used below refer to a unit that processes at least one function or operation, and this can be implemented in hardware or software, or a combination of hardware and software.

[0049] Referring to FIG. 3, the network node (300) may include a transceiver (310), a memory (320), and a processor (330). However, the present disclosure is not limited thereto. For example, the network node (300) may not include at least some of the components shown in FIG. 3, or may further include components not shown in FIG. 3.

[0050] The transceiver (310) can perform functions for transmitting and receiving signals in a wired communication environment. The transceiver (310) may include a wired interface for controlling a direct connection between devices through a transmission medium (e.g., copper wire, optical fiber). For example, the transceiver (310) may transmit an electrical signal to another device through a copper wire or perform conversion between an electrical signal and an optical signal. According to one embodiment, a network node (300) may communicate with a radio unit (RU) through the transceiver (310). In this respect, the transceiver (310) may be referred to as a fronthole transceiver. In an example, but not limited to, the network node (300) may be connected to a core network or a distributed CU through the transceiver (310). In an example, but not limited to, the transceiver (310) may include a communication circuit for a wired communication interface.

[0051] The transceiver (310) may perform functions for transmitting and receiving signals in a wireless communication environment. For example, the transceiver (310) may perform a conversion function between a baseband signal and a bit sequence according to the physical layer specifications of the system. For example, when transmitting data, the transceiver (310) generates complex symbols by encoding and modulating the transmitted bit sequence. Also, when receiving data, the transceiver (310) restores the received bit sequence by demodulating and decoding the baseband signal. Additionally, the transceiver (310) may include a plurality of transmission and reception paths. As an example, but not limited to, the transceiver (310) may include a communication circuit for a wireless communication interface.

[0052] The transceiver (310) may include a first communication circuit for providing a wired communication interface and a second communication circuit for providing a wireless communication interface. The first communication circuit may be configured to transmit and receive signals in a wired communication environment. For example, a network node (300) may transmit a signal to another network node (e.g., a base station in FIG. 1) or receive a signal from another network node through the first communication circuit. The second communication circuit may be configured to transmit and receive signals in a wireless communication environment. The network node (300) may transmit a signal to a terminal (e.g., a terminal (110)) or receive a signal from a terminal through the second communication circuit.

[0053] The transceiver (310) can transmit and receive signals. The transceiver (310) can function as a fronthall transceiver. For example, a network node (300) can transmit or receive management plane (M-plane) messages through the transceiver (310). For example, the network node (300) can transmit or receive synchronization plane (S-plane) messages through the transceiver (310). For example, the network node (300) can transmit or receive control plane (C-plane) messages through the transceiver (310). For example, the network node (300) can transmit or receive user plane (U-plane) messages through the transceiver (310). Although only a transceiver (310) is shown in FIG. 3, according to other implementation examples, the network node (300) may include two or more transceivers.

[0054] The transceiver (310) transmits and receives signals as described above. Accordingly, all or part of the transceiver (310) may be referred to as a 'communication unit', 'transmitter unit', 'receiver unit', or 'transmitter / receiver unit'. Furthermore, in the following description, transmission and reception performed via a wireless channel are used to mean that processing as described above is performed by the transceiver (310).

[0055] Although not illustrated in FIG. 3, the transceiver (310) may further include a backhaul transceiver for connecting to a core network or another base station. The backhaul transceiver provides an interface for communicating with other nodes within the network. That is, the backhaul transceiver converts a sequence of bits transmitted from a base station to another node, e.g., another connection node, another base station, an upper node, a core network, etc., into a physical signal, and converts a physical signal received from another node into a sequence of bits.

[0056] The memory (320) stores data such as basic programs, applications, and configuration information for the operation of the network node (300). The memory (320) may be referred to as a storage unit. The memory (320) may store instructions for the operations of the upper network node (210). The memory (320) may be composed of volatile memory, non-volatile memory, or a combination of volatile and non-volatile memory. Additionally, the memory (320) provides the stored data upon the request of the processor (330).

[0057] The processor (330) controls the overall operations of the network node (300). The processor (330) may be referred to as a control unit. The processor (330) may include control circuits and / or processing circuits. For example, the processor (330) transmits and receives signals through the transceiver (310) (or through the backhaul communication unit). Additionally, the processor (330) writes and reads data to and from memory (320). Furthermore, the processor (330) may perform the functions of a protocol stack required by the communication standard. Although only the processor (330) is shown in FIG. 3, according to other implementation examples, the network node (300) may include two or more processors.

[0058] For example, the processor (330) may include various processing circuits and / or multiple processors. For example, the term “processor” as used herein, including in the claims, may include various processing circuits including at least one processor, and one or more of said at least one processor may be configured to perform the various functions described below in a distributed manner, individually and / or collectively. As used below, where “processor,” “at least one processor,” and “one or more processors” are described as being configured to perform various functions, these terms encompass situations where one processor performs some of the cited functions and another processor(s) perform other parts of the cited functions, and / or situations where one processor can perform all of the cited functions. Additionally, said at least one processor may include a combination of processors that perform the enumerated / disclosed various functions, for example, in a distributed manner. At least one processor may execute program instructions to achieve or perform the various functions.

[0059] The configuration of the network node (300) illustrated in FIG. 3 is merely an example, and the examples of network nodes (300) that perform the embodiments of the present disclosure are not limited to the configuration illustrated in FIG. 3. In some embodiments, some configurations may be added, deleted, or changed.

[0060] FIG. 4 illustrates examples of resource structures in the time domain and frequency domain. FIG. 4 illustrates the basic structure of the time-frequency domain, which is a wireless resource domain where data or control channels are transmitted in the downlink or uplink.

[0061] Referring to FIG. 4, the horizontal axis represents the time domain, and the vertical axis represents the frequency domain. The minimum transmission unit in the time domain is an OFDM (orthogonal frequency division multiplexing) symbol, and Nsymb OFDM symbols (402) are combined to form a subframe (406). The length of the subframe is defined as 1.0ms, and the length of the radio frame (414) is defined as 10ms. The minimum transmission unit in the frequency domain is a subcarrier, and the carrier bandwidth constituting the resource grid is composed of NDLRB (downlink) or NULRB (uplink) subcarriers (404).

[0062] In the time-frequency domain, the basic unit of a resource is a resource element (hereinafter 'RE') (412), which can be represented by an OFDM symbol index and a subcarrier index. A resource block may include multiple resource elements. In an LTE system, a resource block (RB) (or physical resource block (hereinafter 'PRB')) is defined as N symb consecutive OFDM symbols in the time domain and NSCRB consecutive subcarriers in the frequency domain. In an NR system, a resource block (RB) (408) may be defined as NSCRB consecutive subcarriers (410) in the frequency domain. One RB (408) includes NSCRB REs (412) in the frequency axis. Generally, the minimum transmission unit of data is an RB, and the number of subcarriers NSCRB = 12. The frequency domain may include common resource blocks (CRBs). Physical resource blocks (PRBs) can be defined in the bandwidth part (BWP) in the frequency domain. CRB and PRB numbers can be determined according to subcarrier spacing. The data rate can be increased in proportion to the number of RBs scheduled to the terminal.

[0063] In NR systems, for frequency division duplex (FDD) systems that operate downlink and uplink by separating frequencies, the downlink transmission bandwidth and uplink transmission bandwidth may differ. Channel bandwidth represents the radio frequency (RF) bandwidth corresponding to the system transmission bandwidth. [Table 1] shows part of the correspondence between the system transmission bandwidth, subcarrier spacing (SCS), and channel bandwidth defined in NR systems in frequency bands lower than x GHz (e.g., frequency range 1 (410 MHz ~ 7125 MHz)). And [Table 2] shows part of the correspondence between the transmission bandwidth, subcarrier spacing, and channel bandwidth defined in NR systems in frequency bands higher than y GHz (e.g., FR2 (24250 MHz - 52600 MHz) or FR2-2 (52600 MHz ~ 71000 MHz)). For example, an NR system with a 100 MHz channel bandwidth and a 30 kHz subcarrier spacing has a transmission bandwidth consisting of 273 RBs. In [Table 1] and [Table 2], N / A may be a bandwidth-subcarrier combination that is not supported by the NR system.

[0064] Channel Bandwidth [MHz] SCS5 10 20 50 80 100 Transmission Bandwidth Configuration N RB 15kHz2552106207N / AN / A30kHz11245113321727360kHzN / A112465107135

[0065] Channel Bandwidth [MHz] SCS50 100 200 400 Transmission Bandwidth Configuration N RB 60kHz66132264N / A120kHz3266132264

[0066] For example, resources from a network node (300) may be allocated to a terminal (110). For example, the resources may include resources for an uplink or resources for a downlink. However, the present disclosure is not limited thereto. For example, the resources may include resources for a sidelink between the terminal (110) and another terminal. For example, the network node (300) may perform resource allocation using a report message obtained from the terminal (110). For example, the report message may include at least one of terminal information, which is information about the terminal, configuration information set for the terminal, or measurement information measured by the terminal. For example, the report message may be included in channel state information (CSI). For example, the report message may include parameters related to a DC or CA to use concurrent connection technology (e.g., dual connectivity (DC)) or carrier aggregation (CA), or to secure priority for requesting as many resources as possible to be allocated from the DC or CA. Referring to the above, the report message may include parameters that can affect resource allocation (or PF scheduling, PF priority). For example, each piece of information included in the report message may be referenced as a parameter.

[0067] For example, a network node (300) can perform scheduling. For example, a scheduler of the media access control (MAC) layer of the network node (300) can perform resource allocation for multiple terminals through proportional fair (PF) scheduling. For example, the scheduler may be included in the network node (300), the upper network node (210) (or DU), or a base station (e.g., the first base station (120)). In the following examples, the resource is described as a frequency resource, but the present disclosure is not limited thereto.

[0068] FIG. 5 illustrates an example of a wireless communication environment including network nodes. The network node (300) of FIG. 5 may be an example of the network node (300) of FIG. 3. The network node (300) may be an example of the base station (e.g., the first base station (120)) of FIG. 1.

[0069] Referring to FIG. 5, network nodes (300) and network nodes (510) can be connected to a RAN controller (150). Network nodes (300) can transmit information about one or more cells provided by network nodes (300) to the RAN controller (150). Network nodes (510) can transmit information about one or more cells provided by network nodes (510) to the RAN controller (150). The RAN controller (150) can transmit cell identification information and frequency domain information to network nodes (300) and network nodes (510). For example, network nodes (300) can identify each of one or more cells provided by network nodes (510) using cell identification information. For example, cell identification information may include a cell ID. For example, network nodes (300) can identify the frequency range used by network nodes (510) using frequency domain information. For the RAN controller (150), the descriptions of the RAN controller (150) in FIG. 1 may be referenced.

[0070] A network node (300) may provide multiple cells. A network node (300) may be configured to provide a serving cell for a terminal (501). A network node (300) may be connected to a terminal (501). For the terminal (501), descriptions of the terminal (110) may be referenced. A network node (300) may allocate resources to the terminal (501). A network node (300) may transmit a wireless signal to the terminal (501) or receive a wireless signal from the terminal (501). A network node (300) may communicate with the terminal (501) via a wireless channel. The quality of the channel between the network node (300) and the terminal (501) may be an important factor in wireless communication. For example, the higher the quality of the channel between the network node (300) and the terminal (501), the higher the data transmission speed between the network node (300) and the terminal (501). For example, the higher the channel quality between the network node (300) and the terminal (501), the fewer the number of disconnections (or interruptions) in the connection between the network node (300) and the terminal (501). For example, the higher the channel quality between the network node (300) and the terminal (501), the fewer the number of errors in the data transmitted or received between the network node (300) and the terminal (501). The higher the channel quality between the network node (300) and the terminal (501), the more likely it is that a smooth wireless communication environment is guaranteed between the network node (300) and the terminal (501). Therefore, it is required that the channel quality between the network node (300) and the terminal (501) be higher than a certain level.

[0071] In the present disclosure, channel quality may be at least one of, for example, RSRP (reference signal received power), BRSRP (beam reference signal received power), RSRQ (reference signal received quality), RSSI (received signal strength indicator), SINR (signal to interference and noise ratio), CINR (carrier to interference and noise ratio), SNR (signal to noise ratio), EVM (error vector magnitude), BER (bit error rate), BLER (block error rate), and CQI (channel quality indicator). In addition to the examples described above, other terms having equivalent technical meanings or other metrics representing channel quality may be used. Hereinafter, in the present disclosure, high channel quality means a case where the channel quality value related to signal magnitude is large or the channel quality value related to the error rate is small. The higher the channel quality, the more likely it is that a smooth wireless communication environment is guaranteed.

[0072] Network nodes (510) may be located adjacent to network nodes (300). Each of the network nodes (510) may provide multiple cells. Each of the network nodes (510) may be configured to provide neighbor cells of the serving cell of the terminal (501) (e.g., a cell provided by the network node (300)). Network nodes (510) may include a first network node (510-1), a second network node (510-2), and / or a third network node (510-3). Network nodes (510) may cause interference in the channel between the network node (300) and the terminal (501) while performing wireless communication with the terminals (e.g., terminal (511), terminal (521), terminal (531)). For example, network nodes (510) may reduce the channel quality between network node (300) and terminal (501) while performing wireless communication with terminals (e.g., terminal (511), terminal (521), terminal (531)). For example, a signal transmitted by terminal (511) to the first network node (510-1) may cause interference in the channel between network node (300) and terminal (501). For example, a signal transmitted by the first network node (510-1) to terminal (511) may cause interference in the channel between network node (300) and terminal (501). The second network node (510-2) may perform communication with terminal (521) via a wireless channel. For example, a signal transmitted by terminal (521) to the second network node (510-2) may cause interference in the channel between network node (300) and terminal (501). For example, a signal transmitted by the second network node (510-2) to the terminal (521) may cause interference in the channel between the network node (300) and the terminal (501). The third network node (510-1) may communicate with the terminal (531) via a wireless channel.For example, a signal transmitted by the terminal (531) to the third network node (510-3) may cause interference in the channel between the network node (300) and the terminal (501). For example, a signal transmitted by the third network node (510-1) to the terminal (531) may cause interference in the channel between the network node (300) and the terminal (501). Due to interference from the network nodes (510) and interference from terminals connected to the network nodes (510) (e.g., terminal (511), terminal (521), terminal (531)), the quality of the channel between the network node (300) and the terminal (501) may be reduced.

[0073] In FIG. 5, the network nodes (510) are depicted as including three network nodes, but this is merely illustrative for convenience of explanation and the embodiments of the present disclosure are not limited thereto. The network nodes (510) may include three or more network nodes.

[0074] According to one embodiment, a network node (300) may increase the transmission power of a terminal (501) to improve the channel quality between the network node (300) and the terminal (501). For example, the network node (300) may send a message to the terminal (501) to increase the transmission power of the terminal (501) based on the channel quality between the network node (300) and the terminal (501) being lower than the reference channel quality. For example, the message may include a transmit power control (TPC) command. The terminal (501) may increase the transmission power based on the received message. Due to the increase in transmission power, the amount of interference from the terminal in neighboring cells may increase. When the transmission power of the terminal (501) increases, the channel quality between the corresponding terminal (e.g., terminal (511), terminal (521), terminal (531)) connected to each of the network nodes (510) caused by the transmission signal of the terminal (501) may decrease. Each of the network nodes (510) can increase the transmission power of a terminal (e.g., terminal (511), terminal (521), terminal (531)) to improve channel quality. The network node (300) and the network nodes (510) can competitively increase the transmission power of terminals (e.g., terminal (501), terminal (511), terminal (521), terminal (531)) within a cell provided by the network node. As the transmission power of terminals (e.g., terminal (511), terminal (521), terminal (531)) serviced by the network nodes (510) increases, the channel quality between the network node (300) and the terminal (501) may be lower than the reference channel quality, even if the terminal (501) utilizes maximum transmission power.

[0075] In the present disclosure, a technique for improving the channel quality between a network node (300) and a terminal (501) may be described so that a network node (300) can overcome interference caused by network nodes (510). According to embodiments of the present disclosure, the channel quality between the network node (300) and the terminal (501) can be improved by reducing the transmission power of one terminal (hereinafter referred to as the interference terminal) among the terminals (e.g., terminal (511), terminal (521), terminal (531)) serviced by the network nodes (510). The one terminal may be the terminal that contributed most significantly to degrading the channel quality between the network node (300) and the terminal (501) among the terminals serviced by the network nodes (510). Additionally, according to embodiments of the present disclosure, the network node (300) can improve the channel quality between the network node (300) and the terminal (501) by distinguishing the frequency range to be allocated to the terminal (501) from the frequency range to be allocated to the terminal serviced by at least some of the network nodes (510). This method will be described and illustrated in FIGS. 5, FIGS. 6, and / or FIGS. 7.

[0076] FIG. 6 illustrates examples of operations of a network node (300) to reduce the transmission power of an interfering terminal.

[0077] Referring to FIG. 6, in operation 601, the network node (300) can determine an interference non-use frequency range, an interference use frequency range, and a common use frequency range from the frequency resources.

[0078] The interference-free frequency range may be referred to as a frequency range that is unavailable for use by the network node (300). The interference-free frequency range may represent a frequency range that is not used by the network node (300) and where it is determined that interference of a certain level or higher will occur. The network node (300) may not perform resource allocation in the interference-free frequency range to terminals connected to the network node (300). If terminals serviced by at least some of the network nodes (510) use the interference-free frequency range, interference may be caused in the channel using the interference-free frequency range between the network node (300) and the terminal (e.g., terminal (501)).

[0079] The interference frequency range may be referred to as a frequency range that restricts the use of at least some of the network nodes (510). The interference frequency range may represent a frequency range used by the network node (300) where it is determined that interference of a certain level or higher will occur. If terminals serviced by at least some of the network nodes (510) use the interference frequency range, interference may be caused in the channel using the interference frequency range between the network node (300) and the terminal (e.g., terminal (501)). Because interference may be caused in the channel using the interference frequency range between the network node (300) and the terminal (e.g., terminal (501)), the use of the interference frequency range by at least some of the network nodes (510) may be restricted. The network node (300) may perform resource allocation in the interference frequency range to terminals connected to the network node (300).

[0080] The common frequency range may be referred to as a frequency range where interference is not or is not relatively caused by the network nodes (510). The common frequency range may represent a frequency range that is commonly available to the network nodes (510) regardless of interference. The network node (300) may perform resource allocation within the common frequency range to terminals connected to the network node (300).

[0081] Although not illustrated in FIG. 6, as an example but not limited to, a network node (300) may receive frequency domain information from a RAN controller (e.g., RAN controller (150)) connected to the network node (300) to determine the interference-free frequency domain, the interference-used frequency domain, and the common-used frequency domain of operation 601. The frequency domain information may include frequency ranges used by network nodes (e.g., network nodes (510)) connected to the RAN controller. The frequency domain information may include frequency ranges assigned to terminals connected to each of the network nodes (e.g., network nodes (510)). The network node (300) may use the frequency domain information to determine the interference-free frequency domain, the interference-used frequency domain, and the common-used frequency domain.

[0082] In operation 603, the network node (300) can perform resource allocation in the common frequency range in order, starting from the terminal with the highest channel quality between the terminal and the network node (300) among the terminals connected to the network node (300). The network node (300) can perform resource allocation in the common frequency range among the interference-free frequency range, the interference-used frequency range, and the common frequency range. For example, the network node (300) can perform resource allocation in the common frequency range preferentially to the terminal with the highest channel quality among the terminals connected to the network node (300). After performing resource allocation in the common frequency range to the first terminal among the terminals connected to the network node (300), the network node (300) can perform resource allocation in the common frequency range to the second terminal among the terminals connected to the network node (300) that has the next highest channel quality after the first terminal. A network node (300) can perform resource allocation sequentially, starting with terminals of high channel quality, until frequency resources within the common frequency range are allocated. According to various embodiments, resource allocation within the common frequency range of the network node (300) can be performed sequentially or in parallel.

[0083] In operation 605, the network node (300) may perform resource allocation in the interference-use frequency range for the remaining terminals among the terminals connected to the network node (300) for which resource allocation in the common-use frequency range has not been performed. The network node (300) may perform resource allocation in the interference-use frequency range among the interference-non-use frequency range, the interference-use frequency range, and the common-use frequency range. By executing operations 603 and 605, the network node (300) may perform resource allocation in the interference-use frequency range for the terminal with the lowest channel quality among the terminals connected to the network node (300). The terminal with the lowest channel quality among the terminals connected to the network node (300) may be an example of a target terminal to be described later.

[0084] A target terminal can be described as a terminal among the terminals connected to the network node (300) whose channel quality is below a reference channel quality. For example, the target terminal may include the terminal with the lowest channel quality among the terminals connected to the network node (300). For example, because the target terminal's channel quality is below the reference channel quality, a communication outage (or service interruption) may occur. For example, the target terminal may be located relatively out of the cell provided by the network node (300). Because the target terminal has the lowest channel quality among the terminals connected to the network node (300) or has a channel quality below the reference channel quality, a reduction in interference by adjacent base stations (e.g., network nodes (510)) may be required. The network node (300) can reduce interference by the network nodes (510) by performing resource allocation within the interference usage frequency range to the target terminal. While the target terminal communicates with the network node (300) using frequency resources within the allocated interference usage frequency range, at least some of the network nodes (510) may not use the interference usage frequency range.

[0085] In operation 607, the network node (300) can transmit frequency range information to the network nodes (510) via a first communication circuit (e.g., a wired communication interface of the transceiver (310)). The first communication circuit can perform the function of transmitting and receiving signals in a wired communication environment. The frequency range information may include an interference-free frequency range, an interference-used frequency range, and a common-use frequency range. A first portion of the network nodes (510) that receive the frequency range information may have resource allocation in the interference-used frequency range. A first portion of the network nodes (510) that receive the frequency range information may have resource allocation performed in the interference-free frequency range and the common-use frequency range. A second portion of the network nodes (510) that receive the frequency range information may have resource allocation restricted in the interference-free frequency range. A second portion of the network nodes (510) that receive the frequency range information may have resource allocation performed in the interference-used frequency range and the common-use frequency range. According to the cell ID of each network node (510), a first part of the network nodes (510) and a second part of the network nodes (520) may be determined. In various embodiments, the network nodes (510) may be composed of three or more parts of network nodes (510).

[0086] In operation 609, the network node (300) can obtain information about the channel quality for each of the frequency units assigned to the target terminal. Each of the frequency units may be composed of one or more resource blocks (RBs). For example, each of the frequency units may be a single RB. For another example, each of the frequency units may be a unit of multiple RBs. For yet another example, each of the frequency units may be a resource block group (RBG) unit. For yet another example, each of the frequency units may be a bandwidth part (BWP) unit. For yet another example, each of the frequency units may be a subband unit.

[0087] According to one embodiment, a network node (300) can determine the channel quality for each of the frequency units assigned to a target terminal. For example, the network node (300) can determine the channel quality for each of the frequency units using a signal received from the target terminal. For example, the network node (300) can calculate indicators representing channel quality (e.g., SINR, RSRP) using a signal received from the target terminal.

[0088] According to one embodiment, a network node (300) may receive information indicating channel quality for each of the frequency units from a target terminal via a second communication circuit (e.g., a wireless communication interface of a transceiver (310). The second communication circuit may perform the function of transmitting and receiving signals in a wireless communication environment. For example, the information indicating channel quality may include CQI, SINR, RSRP, and / or indicators indicating channel quality having equivalent technical meanings.

[0089] In operation 611, the network node (300) may transmit information indicating a low-quality frequency unit to the network nodes (510) via the first communication circuit. The low-quality frequency unit may be described as a frequency unit having the lowest channel quality among the frequency units. For example, the low-quality frequency unit may be an RB that measures the lowest channel quality among the RBs. Also, for example, the low-quality frequency unit may be a subband that measures the lowest channel quality among a plurality of subbands. Also, for example, the low-quality frequency unit may be a BWP that measures the lowest channel quality among a plurality of BWPs. For example, the network node (300) may determine the low-quality frequency unit among the frequency units using information regarding the channel quality for each of the frequency units.

[0090] According to one embodiment, network nodes (510) can determine or identify other terminals using a low-quality frequency unit among terminals connected to network nodes (510) in response to receiving information indicating a low-quality frequency unit.

[0091] In operation 613, network nodes (510) can transmit information about other terminals using a low-quality frequency unit to network node (300). For example, each of the network nodes (510) can transmit information about a terminal using a low-quality frequency unit to network node (300). Network node (300) can receive information about other terminals using a low-quality frequency unit from network nodes (510) through a first communication circuit (e.g., a wired interface of the transceiver (310) of FIG. 3).

[0092] In operation 615, the network node (300) can identify an interfering terminal based on information about other terminals using a low-quality frequency unit. An interfering terminal can be described as the terminal that has the greatest impact on the channel quality of the target terminal among other terminals using a low-quality frequency unit. For example, the interfering terminal may be the terminal with the highest transmission power among other terminals using a low-quality frequency unit. For example, the interfering terminal may be the terminal with the highest channel quality between the terminal and the network node (300) among other terminals using a low-quality frequency unit. For example, the interfering terminal may be a terminal connected to a neighbor cell that exhibits the greatest signal strength among the network nodes (510). The signal strengths of the cells of the network nodes (510) can be obtained from the measurement report of the terminal (501).

[0093] According to one embodiment, a network node (300) may receive a reference signal from each of the other terminals using a low-quality frequency unit through a second communication circuit (e.g., a wireless communication interface of a transceiver (310). The network node (300) may determine or identify the channel quality of each of the other terminals using the low-quality frequency unit by using the received reference signal. For example, the network node (300) may determine the channel quality of each of the other terminals using the low-quality frequency unit by determining the received signal strength indicator (RSSI) of the received reference signal. The network node (300) may determine the terminal with the highest channel quality among the other terminals using the low-quality frequency unit as the interference terminal.

[0094] According to one embodiment, information regarding other terminals using a low-quality frequency unit may include the channel quality between each of the other terminals and a network node connected to the terminal (e.g., included in network nodes (510)). The network node (300) may determine the terminal with the highest channel quality among the other terminals as the interfering terminal.

[0095] According to one embodiment, a target terminal can perform wireless communication with network nodes (510). The target terminal can determine the channel quality between the target terminal and each of the network nodes (510). The target terminal can transmit information regarding the channel quality between the target terminal and each of the network nodes (510) to the network node (300). For example, the target terminal can transmit a measurement report containing information regarding the channel quality between the target terminal and each of the network nodes (510) to the network node (300). For example, the network node (300) can use the received information to identify the interference network node among the network nodes (510) that has the highest channel quality between the target terminal and each of the network nodes (510). The network node (300) can determine a terminal using a low-quality frequency unit among the terminals connected to the interference network node as an interference terminal.

[0096] In operation 617, the network node (300) may transmit a request message to reduce the transmission power of the interfering terminal to the network node connected to the interfering terminal via the first communication circuit. The network node connected to the interfering terminal may be included in the network nodes (510). For example, the request message may be used by the network node connected to the interfering terminal to reduce the transmission power of the interfering terminal through a transmit power control (TPC) command. For example, the request message may be used by the network node connected to the interfering terminal to reduce the transmission power of the interfering terminal by causing the interfering terminal to allocate fewer resources than before.

[0097] According to one embodiment, a network node connected to an interference terminal may, in response to receiving the request message, transmit a signal to the interference terminal to reduce the transmission power of the interference terminal. For example, the signal may include a command to reduce the transmission power of the interference terminal by a predetermined amount (e.g., 1 dBm (decibel milliwatt)). After transmitting the signal to the interference terminal, the network node connected to the interference terminal may report the reduced transmission power of the interference terminal to the network node (300).

[0098] According to one embodiment, a network node (300) may repeatedly perform at least some of the operations illustrated in FIG. 6 until the transmission power of the trunk terminal decreases to reach a minimum transmission power or the channel quality of the target terminal increases to reach a reference channel quality.

[0099] In embodiments according to the present disclosure, the network node (300) is not limited to providing one cell. The network node (300) may provide one or more cells. At least some of the operations illustrated in FIG. 6 may also be applied between the cells provided by the network node (300).

[0100] FIG. 7 illustrates an example of frequency range information (700) representing an interference-use frequency range (701), a common-use frequency range (703), and an interference-non-use frequency range (705). The interference-use frequency range (701), the common-use frequency range (703), and the interference-non-use frequency range (705) exemplified in the frequency range information (700) may be determined by a network node (300). The network node (300) may transmit the frequency range information (700) to network nodes (e.g., network nodes (510)) via a first communication circuit (e.g., transceiver (310)). The frequency range information (700) may include a frequency range in which each network node (510) can perform resource allocation and a frequency range in which each network node (510) cannot perform resource allocation.

[0101] Referring to FIG. 7, a network node (300) may utilize the interference-use frequency range (701) and the common-use frequency range (703) among the interference-use frequency range (701), the common-use frequency range (703), and the interference-non-use frequency range (705). The network node (300) may perform resource allocation in the interference-use frequency range (701) and the common-use frequency range (703) to terminals connected to the network node (300). For example, the network node (300) may use proportional fair (PF) scheduling for resource allocation. For example, PF scheduling may be an example of a scheduling method. For example, the network node (300) may allocate resources to terminals based on the channel quality (or state) of each terminal according to PF scheduling. For example, the network node (300) may allocate resources to a terminal (or combination of terminals) having the maximum channel quality according to PF scheduling.

[0102] According to one embodiment, a network node (300) can determine the channel quality of each terminal connected to the network node (300). The network node (300) can perform resource allocation in the common frequency range (703) in order, starting from the terminal with the highest channel quality. For example, the network node (300) can perform resource allocation according to PF scheduling in the common frequency range (703).

[0103] According to one embodiment, a network node (300) may perform resource allocation in the interference usage frequency range (701) for the remaining terminals for which resource allocation in the common usage frequency range (703) has not been performed. For example, the network node (300) may perform resource allocation in the interference usage frequency range (701) according to PF scheduling. By the network node (300) performing resource allocation, a target terminal among the terminals that has a channel quality lower than the reference channel quality may be allocated frequency resources in the interference usage frequency range (701). While the target terminal is using the interference usage frequency range (701), the first network node (510-1) may not use the interference usage frequency range (701). While the target terminal is using the interference usage frequency range (701), the third network node (510-3) may not use the interference usage frequency range (701). While the target terminal is using the interference usage frequency range (701), interference caused by the network nodes (510) can be reduced because the first network node (510-1) and the third network node (510-3) are not using the interference usage frequency range (701). As the interference caused by the network nodes (510) is reduced, the channel quality of the target terminal can be increased.

[0104] FIG. 8 illustrates examples of operations of a network node (e.g., network node (300)) for reducing the transmission power of an interfering terminal. The operations exemplified in FIG. 8 may be related to operations 609, 611, 613, 615, and / or 617 of FIG. 6.

[0105] Referring to FIG. 8, in operation 801, the network node (300) can obtain the channel quality of each terminal connected to the network node (300). According to one embodiment, the network node (300) can calculate the channel quality of each terminal. According to one embodiment, the network node (300) can receive information about the channel quality of each terminal from the terminals through a second communication circuit (e.g., a wireless communication interface of a transceiver (310).

[0106] In operation 803, the network node (300) can identify a target terminal among the terminals that has a channel quality lower than the reference channel quality. For example, the target terminal may include the terminal with the lowest channel quality among the terminals connected to the network node (300). For example, a communication outage (or service interruption) may occur because the channel quality of the target terminal is below the reference channel quality. For the target terminal, the descriptions of the target terminal in FIG. 6 may be referenced.

[0107] In operation 805, the network node (300) can determine the low-quality frequency unit having the lowest channel quality among the frequency units assigned to the target terminal. The network node (300) can obtain information regarding the channel quality for each of the frequency units assigned to the target terminal. For example, the network node (300) can determine the channel quality for each of the frequency units using a signal received from the target terminal. For example, the network node (300) can receive information indicating the channel quality for each of the frequency units from the target terminal through a second communication circuit. For a method of the network node (300) obtaining information regarding the channel quality for each of the frequency units assigned to the target terminal, the descriptions of operation 609 of FIG. 6 may be referenced. The network node (300) can determine the low-quality frequency unit having the lowest channel quality among the frequency units assigned to the target terminal using the obtained information.

[0108] According to one embodiment, after determining a low-quality frequency unit, a network node (300) may transmit information indicating the low-quality frequency unit to network nodes (e.g., network nodes (510)) via a first communication circuit (e.g., a wired interface of a transceiver (310)). The network node (300) may perform operation 611 of FIG. 6. The network node (300) may receive information about terminals using the low-quality frequency unit from network nodes via the first communication circuit. Terminals using the low-quality frequency unit may be serviced by network nodes. For example, the network node (300) may receive information about terminals using the low-quality frequency unit from each of the network nodes via the first communication circuit. The network node (300) may perform operation 613 of FIG. 6.

[0109] In operation 807, the network node (300) can identify an interference terminal for a low-quality frequency unit. For example, the network node (300) can identify the interference terminal using information received from network nodes. For a method by which the network node (300) identifies the interference terminal, operation 615 of FIG. 6 may be referenced.

[0110] In operation 809, the network node (300) may send a request message to another network node connected to the interfering terminal to reduce the transmission power of the interfering terminal. Operation 809 of FIG. 8 may correspond to operation 619 of FIG. 6.

[0111] According to one embodiment, a network node (300) may repeatedly perform at least some of the operations illustrated in FIG. 8 until the transmission power of the trunk terminal decreases to reach a minimum transmission power or the channel quality of the target terminal increases to reach a reference channel quality.

[0112] FIG. 9 illustrates an example of the performance of operations of network nodes (e.g., network node (300)) according to one embodiment. FIG. 9 illustrates graphs (e.g., graph (910), graph (920)) representing the performance of network nodes performing the operations exemplified in FIG. 6 and the performance of network nodes performing the operations exemplified in FIG. 8. The graphs exemplified in FIG. 9 can be generated through simulation. The parameters for the simulation and the values ​​of the parameters can be set as shown in [Table 3] below.

[0113] Parameter Value Number of network nodes: 5 [units] Number of antennas for each network node: 64 [units] Number of terminals served by each network node: 20 [units] Number of strong-field terminals: 6 [units] Number of medium-field terminals: 8 [units] Number of weak-field terminals: 6 [units] Transmit power: 1 [dBm] or higher, 23 [dBm] or lower Total number of RBs: 100 [units] RB bandwidth: 15 [kHz] Minimum allocated RB: 2 [units] Carrier frequency: 2.4 [GHz] Noise density: -174 [dBm / Hz]

[0114] [Table 3] is merely an example for simulation purposes and is not limited thereto. Each network node is described as providing one cell, but this is for convenience of explanation and the example is not limited thereto. Each network node may provide one or more cells. The number of network nodes may be 5. The number of terminals serviced by each network node may be 20. Among the 20 terminals, the number of strong field terminals may be 6, the number of medium field terminals may be 8, and the number of weak field terminals may be 6. For example, the strong field terminals may have a path loss of about 70 dB or more and less than about 90 dB. For example, the medium field terminals may have a path loss of about 90 dB or more and less than about 100 dB. For example, the weak field terminals may have a path loss of about 100 dB or more and less than about 120 dB. In the simulation, each network node may be substantially identical to the network node (300) of FIG. 3. In the simulation, each network node may execute the operations exemplified in FIG. 6 or the operations exemplified in FIG. 8. For example, in the simulation, one network node may execute the operations of the network node (300) exemplified in FIG. 6 and the operations of the network nodes (e.g., network nodes (510)) exemplified in FIG. 6. The values ​​of the channel model settings for the simulation may be set as shown in [Table 4] below.

[0115] Channel Model Settings Path Loss Free-space path loss Channel Gain (Rx-gain) Beamforming with 5 degree main-lobe Small-scale fading Rayleigh model

[0116] Referring to FIG. 9, the graph (910) may represent power control probability according to path loss. In the graph (910), the horizontal axis may represent path loss. The unit of the horizontal axis of the graph (910) may be decibels (dB). The vertical axis of the graph (910) may represent transmission power control probability. The unit of the vertical axis of the graph (910) may be percentage (%). According to one embodiment, in the graph (910), because the simulation environment is a high congestion environment, terminals in the simulation may utilize maximum transmission power.

[0117] Line (901) of the graph (910) represents the probability of transmission power control due to path loss when network nodes perform the operations of FIG. 8. Line (901) of the graph (910) may represent the probability that the transmission power of terminals serviced by network nodes is controlled when network nodes perform the operations of FIG. 8. Line (901) of the graph (910) may correspond to the probability that terminals serviced by network nodes are determined to be interference terminals when network nodes perform the operations of FIG. 8. Line (903) of the graph (910) represents the probability of transmission power control due to path loss when network nodes perform the operations of FIG. 6. Line (903) of the graph (910) may represent the probability that the transmission power of terminals serviced by network nodes is controlled when network nodes perform the operations of FIG. 6. Line (903) of graph (910) may correspond to the probability that terminals serviced by network nodes are determined to be interference terminals when network nodes perform the operations of FIG. 6. Line (905) of graph (910) may represent the transmission power control probability when the transmission power of terminals is minimum transmission power (e.g., 1 dBm) as a result of network nodes performing the operations of FIG. 8. Line (907) of graph (910) may represent the transmission control probability when the transmission power of terminals is minimum transmission power (e.g., 1 dBm) as a result of network nodes performing the operations of FIG. 6.

[0118] In graph (910), the transmission power control probability of line (901) may be greater than the transmission power control probability of line (903) of graph (910) in the range where the path loss is about 104 dB or less. The transmission power control probability of line (905) of graph (910) may be greater than the transmission power control probability of line (907) of graph (910) in the range where the path loss is about 110 dB or less.

[0119] Graph (920) may represent average transmission power according to path loss. In graph (920), the horizontal axis may represent path loss. The unit of the horizontal axis of graph (920) may be decibels (dB). The vertical axis of graph (920) may represent average transmission power. The unit of the vertical axis of graph (920) may be decibel milliwatts (dBm). Line (901) of graph (920) represents average transmission power according to path loss when network nodes perform the operations of FIG. 8. Line (903) of graph (920) represents average transmission power according to path loss when network nodes perform the operations of FIG. 6. In graph (920), the average transmission power of line (901) may be smaller than the average transmission power of line (903) of graph (920) in the range where the path loss is about 105 dB or less.

[0120] FIG. 10 illustrates examples of the performance of operations of network nodes (e.g., network node (300)) according to one embodiment. FIG. 10 illustrates graphs (e.g., graph (1010), graph (1020)) representing the performance of network nodes performing the operations exemplified in FIG. 6, the performance of network nodes performing the operations exemplified in FIG. 7, and the performance of network nodes performing the operations exemplified in FIG. 8. The graphs exemplified in FIG. 10 may be generated through simulation. In the simulation, each network node may be substantially identical to the network node (300) of FIG. 3. In the simulation, each network node may perform the operations exemplified in FIG. 6, the operations exemplified in FIG. 7, or the operations exemplified in FIG. 8. For example, in the simulation, a network node may execute the operations of the network node (300) exemplified in FIG. 6 and the operations of the network nodes (e.g., network nodes (510)) exemplified in FIG. 6. The parameters and values ​​of the parameters for the simulation may be set as shown in [Table 3] and [Table 4] exemplified in the description of FIG. 9. In the simulation, resource allocation may be performed according to PF scheduling. In the simulation, the values ​​of the PF scheduling settings may be set as shown in [Table 5] below.

[0121] PF Scheduling Configuration Values Number of slots 1000 [units] Length of subframe (or TTI (transmission time interval)) 1 [ms (milliseconds)] Number of terminals allocated per slot 5 [units] Traffic of terminals Full-traffic model

[0122] Referring to FIG. 10, the graph (1010) may represent the number of allocated frequency units (e.g., RB) according to path loss. In the graph (1010), the horizontal axis may represent path loss. The unit of the horizontal axis of the graph (1010) may be decibels (dB). The vertical axis of the graph (1010) may represent the number of frequency units allocated to the terminal. The unit of the vertical axis of the graph (1010) may be count.

[0123] Line (1001) of the graph (1010) may indicate the number of allocated frequency units due to path loss when network nodes do not perform the operations exemplified in FIG. 6, the operations exemplified in FIG. 7, and the operations exemplified in FIG. 8. Line (1003) of the graph (1010) may indicate the number of allocated frequency units due to path loss when network nodes perform the operations exemplified in FIG. 8. Line (1005) of the graph (1010) may indicate the number of allocated frequency units due to path loss when network nodes perform the operations exemplified in FIG. 7. Line (1007) of the graph (1010) may indicate the number of allocated frequency units due to path loss when network nodes perform the operations exemplified in FIG. 6.

[0124] In graph (1010), the number of assigned frequency units of line (1001) may be greater than the number of assigned frequency units of line (1003), the number of assigned frequency units of line (1005) of graph (1010), or the number of assigned frequency units of line (1007) of graph (1010). The number of assigned frequency units of line (1007) may be relatively small because network nodes do not use the interference-free frequency range (e.g., interference-free frequency range (705)). The number of assigned frequency units of line (1005) of graph (1010) may be relatively small because network nodes do not use the interference-free frequency range (e.g., interference-free frequency range (705)).

[0125] The graph (1020) may represent the average channel quality according to path loss. In the graph (1020), the horizontal axis may represent path loss. The unit of the horizontal axis of the graph (1020) may be decibels (dB). The vertical axis of the graph (1020) may represent the average channel quality between the terminal and the network node. The unit of the vertical axis of the graph (1020) may be decibels (dB).

[0126] Line (1001) of the graph (1020) may represent the average channel quality according to path loss when network nodes do not perform the actions exemplified in FIG. 6, the actions exemplified in FIG. 7, and the actions exemplified in FIG. 8. Line (1003) of the graph (1020) may represent the average channel quality according to path loss when network nodes perform the actions exemplified in FIG. 8. Line (1005) of the graph (1020) may represent the average channel quality according to path loss when network nodes perform the actions exemplified in FIG. 7. Line (1007) of the graph (1020) may represent the average channel quality according to path loss when network nodes perform the actions exemplified in FIG. 6.

[0127] In graph (1020), the average channel quality of line (1003) may be greater than the average channel quality of line (1001) in the range where the path loss is about 90 dB or more. The average signal quality of line (1005) may be greater than the average channel quality of line (1001). The average channel quality of line (1007) may be greater than the average channel quality of line (1001) in the range where the path loss is about 75 dB or more. According to embodiments of the present disclosure, the average channel quality may be improved.

[0128] FIG. 11 illustrates examples of the performance of operations of network nodes (e.g., network node (300)) according to one embodiment. FIG. 11 illustrates graphs (e.g., graph (1110), graph (1120)) representing the performance of network nodes performing the operations exemplified in FIG. 6, the performance of network nodes performing the operations exemplified in FIG. 7, and the performance of network nodes performing the operations exemplified in FIG. 8. The graphs exemplified in FIG. 11 may be generated through simulation. In the simulation, each network node may be substantially identical to the network node (300) of FIG. 3. In the simulation, each network node may execute the operations exemplified in FIG. 6, the operations exemplified in FIG. 7, or the operations exemplified in FIG. 8. For example, in the simulation, a network node may execute the operations of the network node (300) exemplified in FIG. 6 and the operations of the network nodes (e.g., network nodes (510)) exemplified in FIG. 6. The values ​​of the parameters for the simulation, the values ​​of the channel model settings, and the values ​​of the PF scheduling settings may be set as described in [Table 3], [Table 4], and [Table 5].

[0129] Referring to FIG. 11, a graph (1110) may represent the probability of a communication connection failure due to path loss. In the graph (1110), the horizontal axis may represent path loss. The unit of the horizontal axis of the graph (1110) may be decibels (dB). The vertical axis of the graph (1110) may represent the probability of a communication connection failure occurring to a terminal. The unit of the vertical axis of the graph (1110) may be percentage (%).

[0130] Line (1001) of the graph (1110) may represent the probability of communication failure due to path loss when network nodes do not perform the actions exemplified in FIG. 6, the actions exemplified in FIG. 7, and the actions exemplified in FIG. 8. Line (1003) of the graph (1110) may represent the probability of communication failure due to path loss when network nodes perform the actions exemplified in FIG. 8. Line (1005) of the graph (1110) may represent the probability of communication failure due to path loss when network nodes perform the actions exemplified in FIG. 7. Line (1007) of the graph (1110) may represent the probability of communication failure due to path loss when network nodes perform the actions exemplified in FIG. 6.

[0131] In graph (1110), the probability of communication connection failure of line (1003) of graph (1110) may be smaller than the probability of communication connection failure of line (1001) of graph (1110) in the range where the path loss is about 96 dB or more. The probability of communication connection failure of line (1005) of graph (1110) may be smaller than the probability of communication connection failure of line (1001). The probability of communication connection failure of line (1007) of graph (1110) may be smaller than the probability of communication connection failure of line (1001) of graph (1110) in the range where the path loss is about 83 dB or more. It can be seen through graph (1110) that the probability of communication connection of terminals is reduced.

[0132] The graph (1120) may represent the correlation between path loss and the number of scheduling cycles of spectrum efficiency. In the graph (1120), the horizontal axis may represent path loss. The unit of the horizontal axis of the graph (1120) may be decibels (dB). The vertical axis of the graph (1120) may represent the number of scheduling cycles (e.g., PF scheduling) of spectrum efficiency. The unit of the vertical axis of the graph (1120) may be Mbps / Hz. Spectral efficiency can be described as an indicator of how efficiently a frequency domain (or bandwidth) is utilized in a communication system.

[0133] Line (1001) of the graph (1120) may represent the spectrum efficiency (i.e., spectrum efficiency obtained with respect to the number of scheduling operations) due to path loss when network nodes do not perform the operations exemplified in FIG. 6, the operations exemplified in FIG. 7, and the operations exemplified in FIG. 8. Line (1003) of the graph (1120) may represent the spectrum efficiency due to path loss when network nodes perform the operations exemplified in FIG. 8. Line (1005) of the graph (1120) may represent the spectrum efficiency due to path loss when network nodes perform the operations exemplified in FIG. 7. Line (1007) of the graph (1120) may represent the spectrum efficiency due to path loss when network nodes perform the operations exemplified in FIG. 6. In graph (1120), the spectral efficiency obtained for the number of scheduling cycles of line (1001) may converge to approximately 0 as the path loss increases. The spectral efficiency obtained for the number of scheduling cycles of line (1003) may converge to approximately 0 as the path loss increases. The spectral efficiency obtained for the number of scheduling cycles of line (1005) may converge to approximately 0 as the path loss increases. The spectral efficiency obtained for the number of scheduling cycles of line (1007) may converge to approximately 0 as the path loss increases. Graph (1120) may be related to graph (1210) of FIG. 12, which will be described later. Referring to the graph (1210) of FIG. 12 to be described later, the number of scheduling cycles of line (1001), line (1003), line (1005), and line (1007) can increase as the path loss increases, in the range where the path loss is about 115 dB or less.

[0134] FIG. 12 illustrates examples of the performance of operations of network nodes (e.g., network node (300)) according to one embodiment. FIG. 12 illustrates graphs (e.g., graph (1210), graph (1220)) representing the performance of network nodes performing the operations exemplified in FIG. 6, the performance of network nodes performing the operations exemplified in FIG. 7, and the performance of network nodes performing the operations exemplified in FIG. 8. The graphs exemplified in FIG. 12 may be generated through simulation. In the simulation, each network node may be substantially identical to the network node (300) of FIG. 3. In the simulation, each network node may execute the operations exemplified in FIG. 6, the operations exemplified in FIG. 7, or the operations exemplified in FIG. 8. For example, in the simulation, a network node may execute the operations of the network node (300) exemplified in FIG. 6 and the operations of the network nodes (e.g., network nodes (510)) exemplified in FIG. 6. The values ​​of the parameters for the simulation, the values ​​of the channel model settings, and the values ​​of the PF scheduling settings may be set as described in [Table 3], [Table 4], and [Table 5].

[0135] Referring to FIG. 12, the graph (1210) may represent the number of scheduling operations based on path loss. In the graph (1210), the horizontal axis may represent path loss. The unit of the horizontal axis of the graph (1210) may be decibels (dB). The vertical axis of the graph (1210) may represent the number of scheduling operations. The unit of the vertical axis of the graph (1210) may be the number of operations.

[0136] Line (1001) of the graph (1210) may indicate the number of scheduling operations due to path loss when network nodes do not execute the operations exemplified in FIG. 6, the operations exemplified in FIG. 7, and the operations exemplified in FIG. 8. Line (1003) of the graph (1210) may indicate the number of scheduling operations due to path loss when network nodes execute the operations exemplified in FIG. 8. Line (1005) of the graph (1210) may indicate the number of scheduling operations due to path loss when network nodes execute the operations exemplified in FIG. 7. Line (1007) of the graph (1210) may indicate the number of scheduling operations due to path loss when network nodes execute the operations exemplified in FIG. 6.

[0137] In the graph (1210), the number of scheduling cycles of line (1001) can increase as the path loss increases within a range where the path loss is approximately 115 dB or less. The number of scheduling cycles of line (1003) can increase as the path loss increases within a range where the path loss is approximately 115 dB or less. The number of scheduling cycles of line (1005) can increase as the path loss increases within a range where the path loss is approximately 115 dB or less. The number of scheduling cycles of line (1007) can increase as the path loss increases within a range where the path loss is approximately 115 dB or less.

[0138] Graph (1220) may represent the correlation between path loss and spectrum efficiency. In graph (1220), the horizontal axis may represent path loss. The unit of the horizontal axis of graph (1220) may be decibels (dB). The vertical axis of graph (1220) may represent spectrum efficiency. The unit of the vertical axis of graph (1220) may be Mbps / Hz. Spectral efficiency can be described as an indicator of how efficiently a frequency domain (or bandwidth) is utilized in a communication system. Line (1001) of graph (1220) may represent spectrum efficiency according to path loss when network nodes do not perform the operations exemplified in FIG. 6, the operations exemplified in FIG. 7, and the operations exemplified in FIG. 8. Line (1003) of graph (1220) may represent spectrum efficiency according to path loss when network nodes perform the operations exemplified in FIG. 8. Line (1005) of the graph (1220) may represent spectral efficiency according to path loss when network nodes perform the operations exemplified in FIG. 7. Line (1007) of the graph (1220) may represent spectral efficiency according to path loss when network nodes perform the operations exemplified in FIG. 6.

[0139] In graph (1220), the spectral efficiency obtained from line (1001) may decrease as path loss increases. The spectral efficiency of line (1003) of graph (1220) may decrease as path loss increases. The spectral efficiency of line (1005) may decrease as path loss increases. The spectral efficiency of line (1007) of graph (1220) may decrease as path loss increases. The spectral efficiency obtained from line (1001) of graph (1220), the spectral efficiency obtained from line (1003) of graph (1220), the spectral efficiency obtained from line (1005) of graph (1220), and the spectral efficiency obtained from line (1007) of graph (1220) may be similar. According to embodiments of the present disclosure, the amount of decrease in spectral efficiency may be relatively small.

[0140] FIG. 13 illustrates examples of the performance of operations of network nodes (e.g., network node (300)) according to one embodiment. FIG. 13 illustrates graphs (e.g., graph (1310), graph (1320)) representing the performance of network nodes performing the operations exemplified in FIG. 6, the performance of network nodes performing the operations exemplified in FIG. 7, and the performance of network nodes performing the operations exemplified in FIG. 8. The graphs exemplified in FIG. 13 may be generated through simulation. In the simulation, each network node may be substantially identical to the network node (300) of FIG. 3. In the simulation, each network node may execute the operations exemplified in FIG. 6, the operations exemplified in FIG. 7, or the operations exemplified in FIG. 8. For example, in the simulation, a network node may execute the operations of the network node (300) exemplified in FIG. 6 and the operations of the network nodes (e.g., network nodes (510)) exemplified in FIG. 6. The values ​​of the parameters for the simulation, the values ​​of the channel model settings, and the values ​​of the PF scheduling settings may be set as described in [Table 3], [Table 4], and [Table 5].

[0141] Referring to FIG. 13, the graph (1310) may represent the sum of spectral efficiencies. The vertical axis of the graph (1310) may represent the sum of spectral efficiencies. The unit of the vertical axis of the graph (1310) may be Mbps / Hz.

[0142] A bar (1001) of the graph (1310) may represent the sum of spectral efficiencies when network nodes do not perform the operations exemplified in FIG. 6, the operations exemplified in FIG. 7, and the operations exemplified in FIG. 8. A bar (1003) of the graph (1310) may represent the sum of spectral efficiencies when network nodes perform the operations exemplified in FIG. 8. A bar (1005) of the graph (1310) may represent the sum of spectral efficiencies when network nodes perform the operations exemplified in FIG. 7. A bar (1007) of the graph (1310) may represent the sum of spectral efficiencies when network nodes perform the operations exemplified in FIG. 6.

[0143] In graph (1310), the sum of the spectral efficiencies of the bars (1001) of graph (1310) may be approximately 1149.6895 Mbps / Hz. The sum of the spectral efficiencies of the bars (1003) of graph (1310) may be approximately 1170.0909 Mbps / Hz. The sum of the spectral efficiencies of the bars (1005) of graph (1310) may be approximately 1173.0578 Mbps / Hz. The sum of the spectral efficiencies of the bars (1007) of graph (1310) may be approximately 1154.6038 Mbps / Hz. According to embodiments of the present disclosure, the amount of change in the sum of the spectral efficiencies may be relatively small.

[0144] The graph (1320) may represent the probability of communication failure. The vertical axis of the graph (1320) may represent the probability of communication failure. The unit of the vertical axis of the graph (1320) may be a percentage (%). The bar (1001) of the graph (1320) may represent the probability of communication failure when network nodes do not perform the actions exemplified in FIG. 6, the actions exemplified in FIG. 7, and the actions exemplified in FIG. 8. The bar (1003) of the graph (1320) may represent the probability of communication failure when network nodes perform the actions exemplified in FIG. 8. The bar (1005) of the graph (1320) may represent the probability of communication failure when network nodes perform the actions exemplified in FIG. 7. The bar (1007) of the graph (1320) may represent the probability of communication failure when network nodes perform the actions exemplified in FIG. 6.

[0145] In graph (1320), the probability of communication failure of bar (1001) may be approximately 58.1177%. The probability of communication failure of bar (1003) in graph (1320) may be approximately 35.3671%. The probability of communication failure of bar (1005) in graph (1320) may be approximately 18.5594%. The probability of communication failure of bar (1007) in graph (1320) may be approximately 3.9253%. According to embodiments of the present disclosure, the probability of communication failure may be reduced. By reducing the probability of communication failure, it may be indicated that the performance of the wireless communication system is improved.

[0146] In an embodiment according to the present disclosure, a network node (e.g., network node (300)) can determine an interfering terminal among terminals serviced by network nodes (e.g., network nodes (510)). The network node (300) can send a request message to a network node connected to the interfering terminal to reduce the transmission power of the interfering terminal. As the transmission power of the interfering terminal is reduced, the channel quality of the terminals serviced by the network node (300) can be increased. For example, as the transmission power of the interfering terminal is reduced, the channel quality of the target terminal among the terminals can be increased. As the channel quality of the target terminal is increased, the performance of the target terminal can be guaranteed. As the channel quality of the target terminal is increased, the communication throughput of the network node (300) can be increased.

[0147] The effects obtainable from the present disclosure are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art to which the present disclosure belongs from the description below.

[0148] The technical problems to be solved in this disclosure are not limited to those mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art to which this disclosure pertains.

[0149] As described above, the network node may include a communication circuit. The network node may include a memory comprising one or more storage media for storing instructions. The network node may include at least one processor comprising a processing circuit. When the instructions are executed individually or collectively by the at least one processor, the network node may be caused to obtain information regarding the channel quality for each of the frequency units assigned to a target terminal connected to the network node. When the instructions are executed individually or collectively by the at least one processor, the network node may be caused to transmit information indicating a low-quality frequency unit having the lowest channel quality among the frequency units to the network nodes via the communication circuit. When the instructions are executed individually or collectively by the at least one processor, the network node may be caused to receive information regarding terminals using the low-quality frequency unit from the network nodes via the communication circuit. When the above instructions are executed individually or collectively by the at least one processor, they may cause the network node to identify an interfering terminal among the terminals based on the information regarding the terminals. When the above instructions are executed individually or collectively by the at least one processor, they may cause the network node to transmit a request message to reduce the transmission power of the interfering terminal to another network node connected to the interfering terminal via the communication circuit.

[0150] According to one embodiment, the target terminal may include the terminal with the lowest channel quality among other terminals connected to the network node.

[0151] According to one embodiment, the instructions may cause the network node to determine an interference non-use frequency range, an interference use frequency range, and a common use frequency range before obtaining information regarding the channel quality for each of the frequency units assigned to the target terminal when executed individually or collectively by the at least one processor. The instructions may cause the network node to perform resource allocation in the common use frequency range among the interference non-use frequency range, the interference use frequency range, and the common use frequency range, in order starting from the terminal with the highest channel quality between the terminal and the network node among other terminals connected to the network node when executed individually or collectively by the at least one processor, before obtaining information regarding the channel quality for each of the frequency units assigned to the target terminal. When the above instructions are executed individually or collectively by the at least one processor, the network node may be caused to perform resource allocation in the interference-used frequency range among the interference-non-used frequency range, the interference-used frequency range, and the common-used frequency range for the remaining terminals among the other terminals for which resource allocation in the common-used frequency range has not been performed, before obtaining information regarding the channel quality for each of the frequency units assigned to the target terminal. The target terminal may have the resource allocation in the interference-used frequency range performed.

[0152] According to one embodiment, the network node may correspond to a centralized unit (CU). The other network node may correspond to a distributed unit (DU) connected to the CU.

[0153] According to one embodiment, the request message may be used by the other network node to reduce the transmission power of the interfering terminal through a transmit power control (TPC) command.

[0154] According to one embodiment, the network node may further include a second communication circuit. When the instructions are executed individually or collectively by the at least one processor, the network node may be caused to receive information regarding the channel quality between the target terminal and each of the network nodes from the target terminal through the second communication circuit. When the instructions are executed individually or collectively by the at least one processor, the network node may be caused to identify the interference network node among the network nodes that has the highest channel quality between the target terminal and each of the network nodes by using the information regarding the channel quality between the target terminal and each of the network nodes. When the instructions are executed individually or collectively by the at least one processor, the network node may be caused to identify the interference terminal among the terminals using the low-quality frequency unit that is connected to the interference network node by using the information regarding the terminals using the low-quality frequency unit.

[0155] According to one embodiment, the information regarding the terminals using the low-quality frequency unit may include the channel quality between each of the terminals and the network node connected to the terminal. The interfering terminal may be determined as the terminal with the highest channel quality among the terminals.

[0156] A method performed at a network node having a communication circuit as described above may include an operation of obtaining information regarding channel quality for each of the frequency units assigned to a target terminal connected to the network node. The method may include an operation of transmitting information indicating a low-quality frequency unit having the lowest channel quality among the frequency units to network nodes via the communication circuit. The method may include an operation of receiving information regarding terminals using the low-quality frequency unit from the network nodes via the communication circuit. The method may include an operation of identifying an interfering terminal among the terminals based on the information regarding the terminals. The method may include an operation of transmitting a request message to reduce the transmission power of the interfering terminal to another network node connected to the interfering terminal via the communication circuit.

[0157] According to one embodiment, the target terminal may include the terminal with the lowest channel quality among other terminals connected to the network node.

[0158] According to one embodiment, the method may include an operation of determining an interference non-use frequency range, an interference use frequency range, and a common use frequency range before obtaining information regarding the channel quality for each of the frequency units assigned to the target terminal. The method may include an operation of performing resource allocation in the common use frequency range among the interference non-use frequency range, the interference use frequency range, and the common use frequency range, in order starting from the terminal with the highest channel quality between the terminal and the network node among other terminals connected to the network node before obtaining information regarding the channel quality for each of the frequency units assigned to the target terminal. The above method may include, before obtaining the information regarding the channel quality for each of the frequency units assigned to the target terminal, an operation of performing resource allocation in the interference-used frequency range among the interference-non-used frequency range, the interference-used frequency range, and the common-used frequency range for the remaining terminals among the other terminals for which resource allocation in the common-used frequency range has not been performed. The target terminal may have the resource allocation in the interference-used frequency range performed.

[0159] According to one embodiment, the network node may correspond to a centralized unit (CU). The other network node may correspond to a distributed unit (DU) connected to the CU.

[0160] According to one embodiment, the request message may be used by the other network node to reduce the transmission power of the interfering terminal through a transmit power control (TPC) command.

[0161] According to one embodiment, the network node may further include a second communication circuit. The method may include an operation of receiving information regarding the channel quality between the target terminal and each of the network nodes from the target terminal through the second communication circuit. The method may include an operation of identifying the interference network node among the network nodes that has the highest channel quality between the target terminal and each of the network nodes by using the information regarding the channel quality between the target terminal and each of the network nodes. The method may include an operation of identifying the interference terminal connected to the interference network node among the terminals using the low-quality frequency unit by using the information regarding the terminals using the low-quality frequency unit.

[0162] According to one embodiment, the information regarding the terminals using the low-quality frequency unit may include the channel quality between each of the terminals and the network node connected to the terminal. The interfering terminal may be determined as the terminal with the highest channel quality among the terminals.

[0163] In a computer-readable storage medium storing one or more programs as described above, the one or more programs may include instructions that cause the network node to obtain information regarding the channel quality for each of the frequency units assigned to a target terminal connected to the network node when executed by the network node having a communication circuit. The one or more programs may include instructions that cause the network node to transmit information indicating a low-quality frequency unit having the lowest channel quality among the frequency units to the network nodes via the communication circuit when executed by the network node. The one or more programs may include instructions that cause the network node to receive information regarding terminals using the low-quality frequency unit from the network nodes via the communication circuit when executed by the network node. The one or more programs may include instructions that cause the network node to identify an interfering terminal among the terminals based on the information regarding the terminals when executed by the network node. The above one or more programs may include instructions that cause the network node to transmit, through the communication circuit, a request message to reduce the transmission power of the interference terminal to another network node connected to the interference terminal when executed by the network node.

[0164] According to one embodiment, the target terminal may include the terminal with the lowest channel quality among other terminals connected to the network node.

[0165] According to one embodiment, the one or more programs may include instructions that cause the network node to determine an interference non-use frequency range, an interference use frequency range, and a common use frequency range before obtaining information regarding the channel quality for each of the frequency units assigned to the target terminal when executed by the network node. The one or more programs may include instructions that cause the network node to perform resource allocation in the common use frequency range among the interference non-use frequency range, the interference use frequency range, and the common use frequency range, in order starting from the terminal with the highest channel quality between the terminal and the network node among other terminals connected to the network node when the information regarding the channel quality for each of the frequency units assigned to the target terminal is obtained when executed by the network node. The above one or more programs may include instructions that cause the network node to perform resource allocation in the interference-used frequency range among the interference-non-used frequency range, the interference-used frequency range, and the common-used frequency range for the remaining terminals among the other terminals for which resource allocation in the common-used frequency range has not been performed, before obtaining information regarding the channel quality for each of the frequency units assigned to the target terminal when executed by the network node. The target terminal may have the resource allocation in the interference-used frequency range performed.

[0166] According to one embodiment, the network node may correspond to a centralized unit (CU). The other network node may correspond to a distributed unit (DU) connected to the CU.

[0167] According to one embodiment, the request message may be used by the other network node to reduce the transmission power of the interfering terminal through a transmit power control (TPC) command.

[0168] According to one embodiment, the network node may further include a second communication circuit. The one or more programs may include instructions that cause the network node to receive information regarding the channel quality between the target terminal and each of the network nodes from the target terminal through the second communication circuit when executed by the network node. The one or more programs may include instructions that cause the network node to identify the interference network node among the network nodes that has the highest channel quality between the target terminal and each of the network nodes, using the information regarding the channel quality between the target terminal and each of the network nodes when executed by the network node. The one or more programs may include instructions that cause the network node to identify the interference terminal connected to the interference network node among the terminals using the low-quality frequency unit, using the information regarding the terminals using the low-quality frequency unit when executed by the network node.

[0169] According to one embodiment, the information regarding the terminals using the low-quality frequency unit may include the channel quality between each of the terminals and the network node connected to the terminal. The interfering terminal may be determined as the terminal with the highest channel quality among the terminals.

[0170] The various embodiments of this document and the terms used therein are not intended to limit the technical features described in this document to specific embodiments, and should be understood to include various modifications, equivalents, or substitutions of said embodiments. In connection with the description of the drawings, similar reference numerals may be used for similar or related components. The singular form of a noun corresponding to an item may include one or more of said items unless the relevant context clearly indicates otherwise. In this document, phrases such as "A or B," "at least one of A and B," "at least one of A or B," "A, B or C," "at least one of A, B and C," and "at least one of A, B, or C" may each include any one of the items listed together in the corresponding phrase, or all possible combinations thereof. Terms such as "first," "second," or "first" or "second" may be used simply to distinguish said components from other said components and do not limit said components in any other aspect (e.g., importance or order). Where any (e.g., 1st) component is referred to as “coupled” or “connected” to another (e.g., 2nd) component, with or without the terms “functionally” or “communicationly,” it means that said any component may be connected to said other component directly (e.g., via a wire), wirelessly, or through a third component.

[0171] The term “module” as used in the various embodiments of this document may include a unit implemented in hardware, software, or firmware, and may be used interchangeably with terms such as logic, logic block, component, or circuit, for example. A module may be a component formed integrally, or a minimum unit of said component or a part thereof that performs one or more functions. For example, according to one embodiment, a module may be implemented in the form of an application-specific integrated circuit (ASIC).

[0172] Various embodiments of this document may be implemented as software comprising one or more instructions stored in a storage medium (e.g., memory (320)) readable by a machine (e.g., network node (300) of FIG. 3). For example, a processor (e.g., processor (330)) of the machine (e.g., network node (300)) may call at least one of the one or more instructions stored from the storage medium and execute it. This enables the machine to operate to perform at least one function according to the at least one called instruction. The one or more instructions may include code generated by a compiler or code that can be executed by an interpreter. The storage medium readable by the machine may be provided in the form of a non-transitory storage medium. Here, 'non-temporary' simply means that the storage medium is a tangible device and does not contain a signal (e.g., electromagnetic waves), and the term does not distinguish between cases where data is stored semi-permanently and cases where it is stored temporarily.

[0173] According to one embodiment, the method according to the various embodiments disclosed herein may be provided by being included in a computer program product. The computer program product may be traded between a seller and a buyer as a product. The computer program product may be distributed in the form of a device-readable storage medium (e.g., compact disc read-only memory (CD-ROM)), or distributed online (e.g., download or upload) through an application store (e.g., Play Store™) or directly between two user devices (e.g., smartphones). In the case of online distribution, at least a portion of the computer program product may be temporarily stored or temporarily created on a device-readable storage medium, such as the memory of a manufacturer's server, an application store's server, or a relay server.

[0174] According to various embodiments, each component (e.g., module or program) of the components described above may include a singular or multiple entities, and some of the multiple entities may be separated and placed in other components. According to various embodiments, one or more of the components or operations of the aforementioned components may be omitted, or one or more other components or operations may be added. Generally or additionally, multiple components (e.g., module or program) may be integrated into a single component. In this case, the integrated component may perform one or more functions of each of the multiple components in the same or similar manner as those performed by the corresponding component among the multiple components prior to integration. According to various embodiments, operations performed by the module, program, or other components may be executed sequentially, in parallel, iteratively, or heuristically, or one or more of the operations may be executed in a different order, omitted, or one or more other operations may be added.

Claims

1. Regarding network nodes, Communication circuit; Memory comprising one or more storage media for storing instructions; and It includes at least one processor comprising a processing circuit, and When the above instructions are executed individually or collectively by the at least one processor, the network node: Information on channel quality for each of the frequency units assigned to the target terminal connected to the above network node is obtained, and Information indicating a low-quality frequency unit having the lowest channel quality among the above frequency units is transmitted to network nodes through the communication circuit, and Information regarding terminals using the above low-quality frequency unit is received from the network nodes through the communication circuit, and Based on the information regarding the above terminals, an interfering terminal among the above terminals is identified, and Causing a request message to reduce the transmission power of the interference terminal to be transmitted to another network node connected to the interference terminal via the communication circuit, Network node.

2. In Claim 1, The above target terminal includes the terminal with the lowest channel quality among other terminals connected to the network node. Network node.

3. In Claim 1, When the above instructions are executed individually or collectively by the at least one processor, the network node: Before obtaining the information regarding the channel quality for each of the frequency units assigned to the above target terminal: Determine the interference non-use frequency range, the interference use frequency range, and the common use frequency range, Among other terminals connected to the network node, starting from the terminal with the highest channel quality between the terminal and the network node, resource allocation is performed in the common frequency range among the interference-free frequency range, the interference-used frequency range, and the common frequency range, and For the remaining terminals among the other terminals mentioned above for which resource allocation in the common usage frequency range has not been performed, cause to perform resource allocation in the interference usage frequency range among the interference non-use frequency range, the interference usage frequency range, and the common usage frequency range. The above target terminal is one in which the resource allocation in the interference usage frequency range is performed, Network node.

4. In Claim 1, The above network node corresponds to a CU (centralized unit), and The other network node mentioned above corresponds to a DU (distributed unit) connected to the CU, Network node.

5. In Claim 1, The above request message is used by the other network node to reduce the transmission power of the interfering terminal through a TPC (transmit power control) command, Network node.

6. In Claim 1, It further includes a second communication circuit, When the above instructions are executed individually or collectively by the at least one processor, the network node: Information regarding the channel quality between each of the above target terminal and the above network nodes is received from the above target terminal through the second communication circuit, and Using the information regarding the channel quality between each of the target terminal and each of the network nodes, identify the interference network node among the network nodes that has the highest channel quality between each of the target terminal and each of the network nodes, and Using the information regarding the terminals using the low-quality frequency unit, causing to identify the interference terminal connected to the interference network node among the terminals using the low-quality frequency unit, Network node.

7. In Claim 1, The information regarding the terminals using the low-quality frequency unit includes the channel quality between each of the terminals and the network node connected to the terminal, and The above interference terminal is determined to be the terminal with the highest channel quality among the above terminals, Network node.

8. A method performed at a network node having a communication circuit, The operation of obtaining information on channel quality for each of the frequency units assigned to the target terminal connected to the above network node, and The operation of transmitting information indicating a low-quality frequency unit having the lowest channel quality among the above frequency units to network nodes through the communication circuit, and The operation of receiving information about terminals using the above-mentioned low-quality frequency unit from the network nodes through the communication circuit, and Based on the information regarding the above terminals, an operation of identifying an interfering terminal among the above terminals, and The operation of transmitting a request message to reduce the transmission power of the interference terminal to another network node connected to the interference terminal via the communication circuit, method.

9. In Claim 8, The above target terminal includes the terminal with the lowest channel quality among other terminals connected to the network node. method.

10. In Claim 8, Before obtaining the information regarding the channel quality for each of the frequency units assigned to the above target terminal: Operation for determining the interference non-use frequency range, the interference use frequency range, and the common use frequency range, and The operation of performing resource allocation in the common frequency range among the interference-non-use frequency range, the interference-use frequency range, and the common frequency range, in order from the terminal with the highest channel quality between the terminal and the network node among other terminals connected to the network node, and For the remaining terminals among the other terminals for which resource allocation in the common usage frequency range has not been performed, the operation of performing resource allocation in the interference usage frequency range among the interference non-use frequency range, the interference usage frequency range, and the common usage frequency range is further included. The above target terminal is one in which the resource allocation in the interference usage frequency range is performed, method.

11. In Claim 8, The above network node includes an operation corresponding to a CU (centralized unit) and, and The other network node mentioned above corresponds to a DU (distributed unit) connected to the CU, method.

12. In claim 8, The above request message is used by the other network node to reduce the transmission power of the interfering terminal through a TPC (transmit power control) command, method.

13. In claim 8, The above network node further includes a second communication circuit, and The operation of receiving information regarding the channel quality between each of the above target terminal and the above network nodes from the above target terminal through the second communication circuit, and An operation of identifying the interference network node among the network nodes that has the highest channel quality between the target terminal and each of the network nodes using the information regarding the channel quality between the target terminal and each of the network nodes, and Using the information regarding the terminals using the low-quality frequency unit, the operation of identifying the interference terminal connected to the interference network node among the terminals using the low-quality frequency unit, method.

14. In Claim 8, The information regarding the terminals using the low-quality frequency unit includes the channel quality between each of the terminals and the network node connected to the terminal, and The above interference terminal is determined to be the terminal with the highest channel quality among the above terminals, method.

15. In a non-transient computer-readable storage medium storing one or more programs, When the above one or more programs are executed by a network node having a communication circuit, Information on channel quality for each of the frequency units assigned to the target terminal connected to the above network node is obtained, and Information indicating a low-quality frequency unit having the lowest channel quality among the above frequency units is transmitted to network nodes through the communication circuit, and Information regarding terminals using the above low-quality frequency unit is received from the network nodes through the communication circuit, and Based on the information regarding the above terminals, an interfering terminal among the above terminals is identified, and To transmit a request message for reducing the transmission power of the interference terminal to another network node connected to the interference terminal through the communication circuit, Including instructions that cause the above network node, Non-transient computer-readable storage media.

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